Research Koen Janssens

Abstract

This PhD delves deeper into understanding the creative process and techniques of Peter Paul Rubens(1577-1640). Rubens' extensive oeuvre is characterised by a complex and variable modus operandi, with continuous experimenting during all stages of the conception of his paintings. While art historians and conservators eagerly seek compositional changes in Rubens' work to uncover his creative process and understand the underlying structure for developing treatment strategies, systematic analysis of his materials and techniques remains limited. This study leverages MA-XRF imaging, a relatively recent technique in art analysis, to uncover Rubens' material composition, sketching and transfer methods. By visualizing elemental distribution, MA-XRF offers insights into sub-surface layers, revealing hidden compositions, sketches and position markers. Preliminary MA-XRF analysis of the monumental altarpiece "Enthroned Madonna adored by Saints" (1628, KMSKA) suggests Rubens employed a combination of copper or mercury based sketch lines to outline figures, offering new insights into his transfer and sketching methods. Moreover, this research aims to compile and expand knowledge on Rubens' materials and layer buildup, providing a comprehensive understanding of his artistic practices. This will provide researchers and conservators with valuable insights into Rubens' artistic techniques, material composition and layer buildup, allowing for a deeper understanding of his creative process.

Researcher(s)

• Promoter: Van der Snickt Geert
• Co-promoter: Janssens Koen
• Fellow: Vercruysse Lowie

Research team(s)

• Antwerp Cultural Heritage Sciences (ARCHES)

Project type(s)

• Research Project

Abstract

Over the last couple of decades, art historians have shown a growing interest in studies into women artists as well as into technical art history. Researchers of women studies have focused recently on the role of women in the production, trading and patronage of art, whereas recent developments in technical art history revealed new insights in the way artists produced their paintings (in terms of materials and techniques) and how these objects may have changed (both visually and chemically) over the years. However, during my PhD it became clear that there is a substantial knowledge gap regarding the artistic practice of women painters, as the two aforementioned approaches have not yet been combined. Therefore, the aim of this study is to understand (a) the studio practice of Dutch and Flemish women painters active between 1600 and 1750, (b) how this relates to the artistic practice of their male colleagues (with regard to painting techniques, iconography etc.) and (c) how this relates to the historical textual sources on artistic techniques of the period. This will be achieved by collecting and interpreting material-technical data from paintings by means of recently developed, non-invasive (chemical) imaging, supplemented by (limited) paint sample analysis, as well as by studying art technological sources. This way we will fully exploit advanced imaging techniques to make the invisible visible and write a more inclusive art history.

Researcher(s)

• Promoter: Van der Snickt Geert
• Co-promoter: Janssens Koen
• Fellow: Derks Kirsten

Research team(s)

• Antwerp Cultural Heritage Sciences (ARCHES)

Project type(s)

• Research Project

Abstract

Nanomaterials already have become indispensable in numerous modern technologies that impact our society. It recently became clear that their coupling with light holds significant promise for innovative developments that may open the route to novel light-driven applications in energy storage, photoelectrochemical sensing, photovoltaics, photocatalysis, drug delivery, and more. Incorporation in actual applications will, however, strongly depend on a deep understanding of the factors that influence the structure-property connection, an improved stability as well as on their technoeconomic and environmental performance. To tackle these crucial challenges, the Nano-Light consortium emerges as a unique and multidisciplinary platform. The consortium brings together extensive expertise in nanoscience covering the synthesis of photoactive nanostructures, advanced electron microscopy and X-ray characterisation, computational materials science, applied nanoengineering and techno-sustainability assessments. By combining cutting-edge (3D) transmission electron microscopy with advanced light sources and environmental holders, the consortium aims to optimize the interaction between nanomaterials and light under working conditions. Such experiments are extremely challenging, but if successful, they will yield unprecedented insights into the fundamental mechanisms governing light-matter interactions at the nanoscale. By exploiting a synergistic approach, one of the primary objectives of the consortium is to obtain comprehensive understanding on how nanomaterials absorb, scatter, emit, or manipulate light, thereby providing crucial knowledge for the design and optimization of next-generation technologies. Such understanding will be crucial for applications in which light plays a beneficial enabling role or, conversely, in scenarios where light accelerates the degradation of the behaviour of the nanomaterials. These areas include the plasmonic chiroptic nanoparticles for early disease detection, overcoming light degradation of pigments in art conservation or (perovskite) photovoltaic nanomaterials for solar cells or X-ray detectors, plasmon-enabled biosensing and light–driven drug delivery in nano-medicine applications, photo(-electro)catalytic hydrogen production or CO2 conversion. Furthermore, the consortium will develop techno-economic and environmental assessments at early technology readiness levels for the envisioned nanotechnological applications to promote safe and sustainable technological solutions. These goals of Nano-Light are in excellent agreement with the sustainable research and innovation goals put forward by the EU. As such, the research conducted under the Nano-Light consortium will strengthen the position of UAntwerp on the European map as an established nanoscience centre leading to further collaborations in the field of nanotechnology and related technologies.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: De Wael Karolien
• Co-promoter: Janssens Koen
• Co-promoter: Milosevic Milorad
• Co-promoter: Van Aert Sandra
• Co-promoter: Van Passel Steven
• Co-promoter: Verbruggen Sammy

Research team(s)

• Electron microscopy for materials research (EMAT)

Project website

Project type(s)

• Research Project

Abstract

Up to the early 20th century, carriages and sleighs have played a central role in society and thus are present in many museum collections today. Yet, the heritage of horse-drawn vehicles (Hippomobile heritage) remains a vastly understudied area in heritage scholarship. A first effort to shed light on this unique heritage has been made, since October 2022, with the Belcaire project, aiming at developing an informed conservation plan for the hippomobile heritage collection of the Royal Museums of Art and History (KMKG-MRAH) in Brussels. However, given the material complexity of these vehicles, focused analytical-technical research projects are also necessary to fully understand the chemistry of the different materials constituting a carriage. This is where the Imcotech project comes into play, aiming at gaining a deeper understanding of one of the most complex materials found in carriages: lacquer coatings. Because of their nature and use, horse-drawn vehicles were systematically exposed to environmental agents such as (UV) light, moisture, atmospheric pollution gases and dirt/dust. The water-sensitive materials that form part of these vehicles were protected against the adverse effect of the environment through the application of impermeable lacquer coatings. These coatings had also a fundamental decorative function, since they would ultimately determine the final appearance of the vehicles (conceived not only as a mean of transport, but also as a fashion statement and a symbol of social status). Today, the complete lack of research on the history, composition and chemistry of these complex multilayered coatings, makes it impossible to design a well-informed conservation plan for hippomobile heritage. Consequently, the lacquer on the exterior of historical horse-drawn vehicles, when original, is often found in a poor conservation state. Given the key twofold function of lacquer on carriages and sleighs, i.e., protective and decorative, its degradation can have dramatic consequences on the overall condition of the objects and cause a drastic loss of aesthetic, historical and thus (future) valorization value for the museums they are kept in. Imcotech aims at filling this critical knowledge gap by means of a multidisciplinary approach, combining (1) research of written and visual sources and (2) reproduction of historical lacquer recipes, with (3) material characterization of historical vehicles by means of advanced analytical methods. The fundamental information obtained in this project will allow to shed light on the composition and technology of these impermeable coatings. These results will complement previous research conducted on European lacquer for indoor applications (ELinC project, focus on furniture and other small objects), finally allowing to obtain a complete picture on lacquer materials and on the historical evolution of waterproofing and material technology as a whole. Moreover, the results of Imcotech will represent a key step towards completion of the ambitious goal of Belcaire, ultimately enabling a better preservation of hippomobile heritage for future generations.

Researcher(s)

• Promoter: Marchetti Andrea
• Co-promoter: Janssens Koen

Research team(s)

• Antwerp Cultural Heritage Sciences (ARCHES)

Project type(s)

• Research Project

Abstract

The aim of the project is to share scientific imaging data on works of art collected during the past few decades with several newly developed, such as macroscopic X-ray fluorescence and macroscopic X-ray diffraction, and more traditional methods.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

This PhD delves deeper into understanding the creative process and techniques of Peter Paul Rubens(1577-1640). Rubens' extensive oeuvre is characterised by a complex and variable modus operandi, with continuous experimenting during all stages of the conception of his paintings. While art historians and conservators eagerly seek compositional changes in Rubens' work to uncover his creative process and understand the underlying structure for developing treatment strategies, systematic analysis of his materials and techniques remains limited. This study leverages MA-XRF imaging, a relatively recent technique in art analysis, to uncover Rubens' material composition, sketching and transfer methods. By visualizing elemental distribution, MA-XRF offers insights into sub-surface layers, revealing hidden compositions, sketches and position markers. Preliminary MA-XRF analysis of the monumental altarpiece "Enthroned Madonna adored by Saints" (1628, KMSKA) suggests Rubens employed a combination of copper or mercury based sketch lines to outline figures, offering new insights into his transfer and sketching methods. Moreover, this research aims to compile and expand knowledge on Rubens' materials and layer buildup, providing a comprehensive understanding of his artistic practices. This will provide researchers and conservators with valuable insights into Rubens' artistic techniques, material composition and layer buildup, allowing for a deeper understanding of his creative process.

Researcher(s)

• Promoter: Van der Snickt Geert
• Co-promoter: Janssens Koen

Research team(s)

• Antwerp Cultural Heritage Sciences (ARCHES)

Project type(s)

• Research Project

Abstract

This project comprises the characterization of about 10 reliquary shrines, usually present in religious buildings, throughout Flanders. A combination of a number of non-destructive methods of analysis will be used to characterize these artefacts.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

This project concerns the exploitation and further development of the DUBBLE beamlines at ESRF for various forms of X-ray based materials characterization. Methods employed are X-ray absorption spectroscopy, small angle scattering, X-ray diffraction and X-ray fluorescence.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

It is commonly known that the stylistic revolution in the 19th c. was promoted by the introduction of innovative artists' materials. However, the emergence of styles like Pleinairism, Impressionism, post-Impressionism, etc. required a drastic shift in technique as well; from a traditional academic buildup to free, experimental brushwork. This turn in working methods is pivotal in the field of conservation science as today, many of these innovative materials and paint handling approaches appear unstable and prone to degradation. In order to gain insight in the multitude of problems, we propose research on the oeuvre of the influential Belgian painter James Ensor (1860-1949) as his frequent stylistic and technical changes offer ample opportunities to study the impact of Modernism on painting technique. In particular, an in-depth investigation aims to provide an insight in the evolution of Ensor's material use, paint layer build-up, methods of application, finishing preferences and the overall creative process throughout his career. By contrasting transitional works in his oeuvre, we assess how style breaks are translated into studio practice changes and vice versa. This is accomplished by a comparative visual and technical examination of pairs of key paintings, combined with literature and archival study. In this way, we anticipate to expand knowledge on the impact of new modus operandi on the long term stability of the paintings.

Researcher(s)

• Promoter: Van der Snickt Geert
• Co-promoter: Janssens Koen
• Fellow: Ríos-Casier Annelies

Research team(s)

• Antwerp Cultural Heritage Sciences (ARCHES)

Project type(s)

• Research Project

Abstract

Climate crisis and unsustainable development increasingly threaten Europe's tangible cultural heritage (CH), yet environmentally hazardous chemicals persist in CH conservation practice. The Sustainable Development Goals of the EU's Green Deal vision call for change in CH conservation, but cannot be implemented without effective and affordable green alternatives. Soiling and deposition of carbon-based contaminants (CBC) such as fine particulate pollution, smoke and vandalism all increasingly present formidable challenges to conservators, and are an emerging threat to CH because of the inherent vulnerability of CH surfaces created with unconventional materials and studio practices. Existing CH cleaning methods require toxic solvents, physical contact and water, which can damage many sensitive CH materials, and conservators, equipped with only conventional means, now encounter fragile and untreatable CH where soiling cannot be removed at all. MOXY aims to redefine the paradigm in cleaning methodology towards an eco-conscious approach by creating a transformative green, non-contact technology based on atomic oxygen (AO) to selectively remove CBCs from surfaces that are otherwise untreatable. AO cleaning methodology is a selective, non-mechanical and liquid-free cleaning action, without health or environmental risks, residues or waste. By leveraging a sophisticated yet simple technology, MOXY will enable practitioners to achieve unprecedented results that are green, safer and more effective. To achieve its goals, MOXY will bring together expertise from plasma physics, conservation science, sustainability science, and conservators to conduct a novel investigation of the physical and chemical aspects of AO generation and flux to develop a proof-of-concept AO system, test the viability of AO technology for diverse CH materials, and roadmap AO innovation, to propel AO technology to the bench practice in CH conservation and beyond, with its full potential yet to be realized.

Researcher(s)

• Promoter: Van der Snickt Geert
• Co-promoter: Janssens Koen

Research team(s)

• Antwerp Cultural Heritage Sciences (ARCHES)

Project type(s)

• Research Project

Abstract

The purpose of this project is to perform a systematic survey of the objects in the collection of the Africa Museum (Tervuren, Brussels) for the presence of inorganic and organic toxic substances. This information will be highly relevant for the museum with the aim of handling and preserving their collection in an optimal and sustainable manner.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Covaci Adrian
• Fellow: Alvarez Martin Alba

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

The purpose is to maintain the good functioning of the equipment of the research group and to cover incidental repair costs. xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

Recent developments in chemical imaging can force a breakthrough in one of the long-standing, key challenges for painting conservation: the treatment of hybrid artworks, presenting heritage professionals with a puzzling amalgam of original materials and non-original layers, accumulated during various interventions. In particular, the recent introduction of Macro X-Ray Powder Diffraction imaging (MA-XRPD) in the heritage field now allows to differentiate sub-types of pigments with unprecedented chemical specificity, without the need for sampling or moving the artwork. The aptitude to identify and quantify crystal phases in artists' materials allows for the first time to reliably discriminate pigments employed by Old Masters from their industrial-age equivalents, used by the (hyper-)restorers and forgers of the 19th-20th-C. Within the artist's palette, lead white holds the highest potential to serve as a marker for signaling 'pigment anachronism' due to its omnipresence, occurring in almost all pre-WWII paint layers. In addition, preliminary MA-XRPD experiments on historical paintings indicated a clear variation in the mass ratio of the constituting compounds of lead-white: cerussite (PbCO3), hydrocerussite (2PbCO2.Pb(OH)2) and plumbonacrite (PbO.3PbCO3.Pb(OH)2). These variations were tentatively linked to the gradual improvement of production methods over time. Although the drastic switch to large-scale industrial processes at the end of the 18th-C is expected to have a fundamental impact on the chemical composition of lead white, the production processes and crystallographic composition of industrial-age lead white were never studied. As a result, the proposed discrimination of original brushwork from younger paint strokes, based on the determination of the relative crystal phase composition of lead white, is currently prevented by the lack of reliable information on industrial-age lead white compositions (1750-1940). In the context of lead white, the discovery and production of CO2 in 1750 is considered as starting date for the industrial age, whereas WWII marked the gradual replacement of lead white by titanium white. Therefore, we propose defining the chemical signature of (modern) lead white by analyzing pigment powders, accurately reproduced in a chemical lab environment according to the production processes described in historical textual sources. In this way, the chemical fingerprint of the reproduced sub-types of lead white will serve as a ground truth for the anticipated variation in historical paintings. In the next step, the representativity of this fingerprint is benchmarked by analyzing a relevant group of late 18th to early 20th-C paintings in museum collections. Next, the ability of MA-XRPD to chemically contrast industrial-age lead white from traditional lead white on actual, complex paintings will be assessed by in situ experiments on well-studied 'hyper-restorations'. Examples of the latter are 15th-C paintings with well-documented areas of excessive overpaint. In a final step, the added value of this research will be valorized during the third and last phase of the conservation treatment of Van Eyck's Ghent Altarpiece, which confronts conservators with a particularly convoluted, hybrid and heterogenous paint system.

Researcher(s)

• Promoter: Van der Snickt Geert
• Co-promoter: Janssens Koen
• Fellow: Bijker Iryn

Research team(s)

• Antwerp Cultural Heritage Sciences (ARCHES)

Project type(s)

• Research Project

Abstract

The purpose of this project is to investigate the evolution of a number of Flemish Abstract modernist artists by contrasting their pigment and colourant usage in the period 1920-1930 (original period of interest for Belgian Modernism) to that of 1960-1970 (period of renewed interest for Belgian modernist art).

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

The purpose of this project is to investigate the relation between the manner of painting of James Ensor during his different stylistical periods and the material means (pigments, binding media, substrates) he employed for this purpose.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Van der Snickt Geert

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

Q-INSPEX aims at the development of novel imaging and image processing protocols to non-invasively and quantitatively inspect objects and subjects. Core imaging technologies herein are X-ray, (near)-infrared, and TeraHertz imaging. These technologies are largely complementary to each other and can be used in different set-ups as (i) an R&D tool to measure specific characteristics of materials (e.g. food structures or polymers), (ii) as a quality control procedure implemented within an industrial setting (i.e. compatible with processing speeds) or (iii) in-field inspections of crops and infrastructure (e.g. corrosion). Furthermore, they can be applied in a wide variety of domains: additive manufacturing, composites, art objects, textiles, archaeology, crops, food, etc.

Researcher(s)

• Promoter: Sijbers Jan
• Co-promoter: De Beenhouwer Jan
• Co-promoter: Janssens Koen
• Co-promoter: Scheunders Paul
• Co-promoter: Steenackers Gunther
• Co-promoter: Van der Snickt Geert
• Fellow: De Samber Björn
• Fellow: Levrau Elisabeth

Research team(s)

• Vision lab

Project type(s)

• Research Project

Abstract

The purpose of this project is the development and systematic application of non-invasive spectroscopic imaging tools for technical art history and conservation of painted artworks. As method of choice, macroscopic X-ray fluorescence will be employed, but also other methods. The imaging capabilities will be mostly used on works by Flemish artists present in the Kunsthistorisches Museum Vienna.

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Vanmeert Frederik

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

Nanomaterials play a key role in modern technology and society, because of their unique physical and chemical characteristics. The synthesis of nanomaterials is maturing but surprisingly little is known about the exact roles that different experimental parameters have in tuning their final properties. It is hereby of crucial importance to understand the connection between these properties and the (three-dimensional) structure or composition of nanomaterials. The proposed consortium will focus on the design and use of nanomaterials in fields as diverse as plasmonics, electrosensing, nanomagnetism and in applications such as art conservation, environment and sustainable energy. In all of these studies, the consortium will integrate (3D) quantitative transmission electron microscopy and X-ray spectroscopy with density functional calculations of the structural stability and optoelectronic properties as well as with accelerated molecular dynamics for chemical reactivity. The major challenge will be to link the different time and length scales of the complementary techniques in order to arrive at a complete understanding of the structure-functionality correlation. Through such knowledge, the design of nanostructures with desired functionalities and the incorporation of such structures in actual applications, such as e.g. highly selective sensing and air purification will become feasible. In addition, the techno-economic and environmental performance will be assessed to support the further development of those applications. Since the ultimate aim of this interdisciplinary consortium is to contribute to the societal impact of nanotechnology, the NanoLab will go beyond the study of simplified test materials and will focus on nanostructures for real-life, cost-effective and environmentally-friendly applications.

Researcher(s)

• Promoter: Bals Sara
• Co-promoter: De Wael Karolien
• Co-promoter: Janssens Koen
• Co-promoter: Lenaerts Silvia
• Co-promoter: Milosevic Milorad
• Co-promoter: Neyts Erik
• Co-promoter: Van Aert Sandra
• Co-promoter: Van Passel Steven
• Co-promoter: Verbruggen Sammy

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

The purpose of this project is to examine several 17th C. artworks with several non-destructive imaging methods. These include macroscopic X-ray fluorescence imaging and X-ray diffraction imaging as well as other forms of hyperspectral imaging.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

In many fields of science and technology, the Midwave Infrared range (MWIR) (4000-400 cm-1) is a highly relevant part of the electromagnetic spectrum, because in this region many compounds and materials feature a unique pattern of absorption bands, directly related to their molecular structure. Current MWIR spectroscopic techniques (like FT-IR) are often used, but these are relatively slow and can only be used in laboratory conditions (on small samples). In this project we will use a Quantum Cascade Laser (QCL) to enable in-situ remote spectroscopy. Reflection (solids) or transmission (liquids and gasses) spectra can be measured with a detector by (fast) scanning of the QCL wavelength (up to 10.000 cm-1 per seconds). We will use the QCL laser in combination with three detectors available at the UAntwerp-InViLab and AXIS research groups: 1) a deuterated triglycine sulfate, or DTGS detector, 2) a scanning laser Doppler vibrometer to perform remote scanning photoacoustic spectroscopy, 3) a thermal camera for mid-wave hyperspectral imaging. The three proposed QCL-based systems are complementary to each other: the DTGS enables a very high wavelength resolution, the LDV can be used for photoacoustic spectroscopy to perform measurements at large stand-off distances (up to 100m), and the thermal camera-based setup delivers a very high spatial resolution, but with a lower wavelength resolution. The QCL based system will be used for the research at InViLab and AXIS in different applications: artwork, corrosion, biomedical and textile inspection. Furthermore, we have identified several other potential applications that we will look into in the future together with other UAntwerp research teams: plasma chemistry, histopathology, road materials, metal oxide powders, meso-porous materials, drug detection, recycling of polymer materials, wastewater.

Researcher(s)

• Promoter: Steenackers Gunther
• Co-promoter: Janssens Koen
• Co-promoter: Vanlanduit Steve

Research team(s)

• Industrial Vision Lab (InViLab)

Project type(s)

• Research Project

Abstract

An important issue encountered in the historical artworks is the fading of the original colors because of their strong light sensitivity, infamously leading to the discoloration of masterworks even within an artist's lifetime. This phenomenon is clearly evidenced in many paintings of 19th century European impressionist artists, such as van Gogh, in particular when Organic Red Pigments (ORP) have been used. The identification of these ORP in historical paintings remains a main challenge because of (1) the generally low concentration of the original pigment remaining after an aging period of ca. 100 years, (2) the scarcity of the paint micro samples available for analysis and the difficulty of obtaining additional ones and (3) the complexity of degradation behavior in the presence of oxygen, inorganic semiconductor pigments, binding media or varnish. The objective of the RED-OPEN project is to develop a multi-analytical approach based on mass spectrometry and spectroscopic techniques (A) to understand their discoloration mechanism and (B) to identify their breakdown products, even if the original molecules are no longer present in the artworks. The successful completion of RED-OPEN will have a major impact in the understanding of the original artwork's appearance and will provide comprehensive and detailed knowledge of the progressive changes throughout the painting's history. RED-OPEN will generate knowledge that will help conservators and conservation scientists to understand the causes of discoloration and formulate mitigating actions, preserving invaluable art for future generations and further proposing a digital reconstruction of its originally intended appearance.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Covaci Adrian
• Fellow: Alvarez Martin Alba

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

During the term of the agreement, UAntwerp will carry out the following activities in the KMSKA. Materials engineering research using innovative analytical imaging techniques to support ongoing and planned restorations. Materials technical research through innovative analytical imaging techniques to support art historical research. The execution of the assignment will take place by invitation in function of the current needs of the KMSKA. The KMSKA will consult regularly to determine which recordings are useful for the KMSKA and/or UA and who will bear the costs for these recordings. However, the KMSKA will not draw up an annual planning, but will consult regularly so that the UA can can organize.

Researcher(s)

• Promoter: Van der Snickt Geert
• Co-promoter: Janssens Koen

Research team(s)

• Antwerp Cultural Heritage Sciences (ARCHES)

Project type(s)

• Research Project

Abstract

The beginning of the 16th century marked the start of a prosperous time for Flanders with the flourishing of culture, trade and science directly reflected into the works of art of the Antwerp School. However, the year 1500 does not only mark a period of stylistic revolution, the works of art also change from a technological point of view with Flemish painters experimenting with innovative materials and techniques, an aspect that has remained understudied hitherto. In this framework, recent analytical studies signaled the use of copper sulfates, an unknown green pigment type, that seems to witness the artist's pursuit to expand the limited range of pigments and enhance the realistic representation of nature. The aim of this research is to understand (a) the use (prevalence, technique, relation to other green pigments), (b) the provenance (where was it produced), the production method (historical technology) and (c) the trade (how and why did it come to Flanders) of these new materials. This will be done by combining the study of textual historical sources and the physical reproduction of the technology with a chemical screening of paintings and illuminated manuscripts. In this way, we propose exploiting the new vistas created by the recent introduction of chemical imaging techniques to enhance our understanding of the interplay of science, technology and trade with the bloom of Flemish Renaissance art and its stylistic innovations.

Researcher(s)

• Promoter: Van der Snickt Geert
• Co-promoter: Janssens Koen
• Fellow: Deleu Nina

Research team(s)

• Antwerp Cultural Heritage Sciences (ARCHES)

Project type(s)

• Research Project

Abstract

The purpose of this project is to construct an instrument, based on a Scanning Electron microscope, that allows to determine the structure of solid materials (in powder form). The powder needs to be available in the form of crystalline nanoparticles.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

High resolution Raman imaging is a versatile imaging technique that generates detailed maps of the chemical composition of technical as well as biological samples. The equipment with given specifications is not yet available at UAntwerp, and will crucially complement the high-end chemical imaging techniques (XRF, XRD, IR, SEM-EDX-WDX, LA-ICP-MS) that are already available at UAntwerp for material characterization. High resolution Raman imaging will expose, with high resolution, the final details (structural fingerprint) of the material of interest. In first instance, we aim to boost the following research lines: electrochemistry, photocatalysis, marine microbiology, environmental analysis and cultural heritage. The Raman microscope should be as versatile as possible, to support potential future technological enhancements.

Researcher(s)

• Promoter: De Wael Karolien
• Co-promoter: Caen Joost
• Co-promoter: Cool Pegie
• Co-promoter: Janssens Koen
• Co-promoter: Meysman Filip
• Co-promoter: Verbruggen Sammy

Research team(s)

Project type(s)

• Research Project

Abstract

The purpose of this chair is to provide education, do research and provide services in the area of Advanced imaging of painted works of art. This is done in collaboration with various partners such as the KULeuven, the Royal Institute of Cultural Heritage and the Museum of Fine Arts in Antwerp.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

Synchrotron X-rays are produced when charged particles circulate in a storage ring close to the speed of light and are much more intense compared to the X-rays used for example in hospitals. By studying the interaction of a synchrotron X-ray beam with matter, the matter structure is revealed down to the atomic and molecular scale. A synchrotron can be imagined as a giant microscope that can look at the inside of non-living and living matter down to the atomic level without damaging it. This project finances research at DUBBLE, the Dutch-Flemish research stations attached to the European Synchrotron Radiation Facility, ESRF, in Grenoble. Through experiments at the ESRF, Flemish scientists and engineers are able to explain the chemical and physical properties of matter. With this knowledge, they can design new materials, advanced electronic components or better solar cells. Such studies also allow revealing what our planet is made of, what the processes are that sustain life or what the secrets are hidden behind old paintings. Others use the outcome of synchrotron based research to develop more tasty and healthy food or to find new ways of conquering health threatening deceases.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

This project main aim is to apply data-fusion technology already successfully used in catalytic chemistry, to visualize in 3D the dynamic effects of degradation processes in paint multilayer structures, present in historical oil paintings. Such a hybrid 3D model will allow to better interpret the visual and chemical patterns that manifest themselves at the surface of degraded artworks in terms of the chemical alteration processes that have been going on in the (recent) past. 2D chemical maps on the macro (m range, on entire artworks) and microscale (μm-mm range, on paint cross sections) will be combined on the one hand with tomographic 3D density maps to link the formation, migration and superficial crystallization of secondary degradation products to visually observable clues on the condition of painted works of art. These observations will be combined with already available insights on chemical degradation mechanisms. Attention will be focused on two alteration mechanisms in 17th c. paintings, already familiar to the proposer: (a) the formation of lead soap protrusions and surface crusts of the ubiquitous pigment "lead white" (PbCO3) and its effects on the mechanical stability and appearance of paints in major works by Rubens, Jordaens and Rembrandt and (b) the oxidative color loss of arsenic sulfide pigments in paintings by J.D. De Heem et al. where the in situ formed arsenate species can be used as markers of transport processes occurring within paint systems.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

In the study of historical paintings and as a preparation for restoration activities of such artefacts, it is of great relevance to investigate which materials and degradation products are present and how these are distributed at or below the painting surface. Consequently, a large number of analytical techniques have been developed that can be used for the identification of artists' materials. However, most of the existing techniques are increasingly contested because they require destructive sampling while in situ analysis with mobile equipment provides compositional data from only a limited number of individual points. In response, mobile scanning instruments for chemical imaging were developed, such as macro X-ray fluorescence (MA-XRF), that supply highly specific chemical information, but entail long scanning times for recording full spectra. As an alternative, thermography inspection is used for material parameter identification but also for art inspection as it is particularly fast. Therefore the goal of this research proposal is to eliminate the drawbacks of current inspection techniques by preceding the chemical speciation of different materials in a painting or surface layer (with XRF) with a swift chemical screening with thermography in the nearinfrared range. The resulting multi-sensor inspection methodology combines fast inspection with a slow inspection to achieve more accurate results and faster inspection times, including IR pigment identification algorithm.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Steenackers Gunther

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

The purpose of this project is to examine three different paintings of the Flemish painter Peter Paul Rubens by non invasive XRF Scanning that are in the collection of the Kunsthistorische Museum Wien.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Van der Snickt Geert

Research team(s)

Project type(s)

• Research Project

Abstract

This Hercules proposal concerns screen printing facilities. Screen printing facilities enable UAntwerp to pioneer in the field of electronics, sensors and photocatalysis by (1) developing unique (photo)sensors/detectors (e.g. electrochemical sensors, photovoltaics, photocatalysis) by printing (semi)conducting materials on substrates, (2) designing parts of Internet of Things modules with more flexibility and more dynamically, meanwhile creating a unique valorization potential and IP position.

Researcher(s)

• Promoter: De Wael Karolien
• Co-promoter: Caen Joost
• Co-promoter: Cool Pegie
• Co-promoter: Janssens Koen
• Co-promoter: Meysman Filip
• Co-promoter: Samson Roeland
• Co-promoter: Steckel Jan
• Co-promoter: Verbruggen Sammy
• Co-promoter: Weyn Maarten

Research team(s)

Project type(s)

• Research Project

Abstract

PC-CT reveals complementary information to traditional attenuation based X-ray imaging (i.e. higher contrast in soft tissue). The FleXray system will allow us to acquire data to fully explore a far wider range of applications and opportunities for PC-CT that are currently not possible: ● Exploration of advanced CT acquisition models to enable reconstruction from (1) fewer projection images and (2) projection images acquired during continuous sample rotation. This will result in faster PC-CT imaging (currently up to 8 times longer than regular CT). ● Dark field tomography is only in its infancy but recently showed huge potential in material characterisation. The FleXray system will open new research lines on dark field tomography, in particular in accurate and precise estimation of localized scattering profiles. ● Development of Krylov solvers with much faster convergence for simultaneous multimodal reconstruction of full 3D images of attenuation, phase and dark field signals.

Researcher(s)

• Promoter: Sijbers Jan
• Co-promoter: De Beenhouwer Jan
• Co-promoter: Janssens Koen
• Co-promoter: Vanroose Wim

Research team(s)

• Vision lab

Project type(s)

• Research Project

Abstract

The purpose of Smart*Light is to develop a compact electron accelerator that is able to function as a source of highly brilliant inverse Compton source of X-rays, with the possibility to tune the energy of the radiation.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Sijbers Jan

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project website

Project type(s)

• Research Project

Abstract

Recently a number of fake 17th-century Netherlandish paintings has come on the market and rocked the world of art historians, curators, collectors and art dealers. One of the paintings that caused a great deal of controversy is a Portrait of a Man by Frans Hals that later has been revealed as false. Although some technological research had be done on the painting, the then used research methods were not enough to make the difference between an original painting and a present-day forgery. The aim of this project is twofold. First, to conduct a systematic investigation of a sample of works by two painters of the Brussels scene in the mid of the 17th century. A selection of paintings by Michael Sweerts will be analyzed in confrontation with some contemporary paintings by Michaelina Wautier. Second, the achieved results regarding the Brussels painterly characteristics will be measured in relation to the previously studied cases of Antwerp masters. For this purpose, we plan to make use of the recently developed method of scanning macro X-ray fluorescence (MAXRF) imaging. To guard against forgery technological strategies will be developed to reconstruct the stages of evolution of 17th-century painting in Brussels and Antwerp with special emphasis on the structure of underlying layers. To this end, in the starting phase of the project, the current MAXRF advanced imaging method will be improved.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

In this project a new methodology for product testing and quality control is developed based on infrared lock-in thermography. Infrared thermography permits to visualize the thermal/ warmup response of objects. In particular, lock-in thermography employs a sinusoidal light source to warm up the object being studied. Although pulsed thermography (PT) is commonly used as thermographic inspection technique, this method is not well suited for inspection of fragile structures (art and biological tissue inspection, blood circulation, …) due to the large instant energy emission which involves insufficient controllability and non-uniformity. On the other hand, with traditional lock-in thermography only one defect depth can be inspected at a time. In addition, at least one steady state period of the sine wave excitation is necessary to obtain quantitative results.

Researcher(s)

• Promoter: Steenackers Gunther
• Co-promoter: Janssens Koen
• Co-promoter: Louarroudi Ebrahim

Research team(s)

• Industrial Vision Lab (InViLab)

Project type(s)

• Research Project

Abstract

Many Southern Netherlandish 15th and 16th paintings by Jan and Hubert van Eyck, Robert Campin, Rogier van der Weyden, Hans Memling, Dirk Bouts, Bernard van Orley etc., in the federal collections of the Royal Museums of Fine Arts of Belgium, Brussels (RMFAB), are among to the most important masterpieces in their category. They are an inestimable source of information for scholars in art history, history and conservation science. It is essential, for the next generations, to keep the visual aspect of these artworks as close as possible to the original. It is well known that over time, the paint materials, pigments and binders are inevitably undergoing spontaneous chemical transformations; these unwanted reactions are influenced by multiple environmental factors such as light and humidity but also by repeated cleaning, varnishing and/or retouching. These transformations are sometimes very slow and insidious and during many years may remain not or hardly visible to the naked eye. Therefore, sensitive chemical analyses are needed to detect them at a very early stage in order to stop or at least slow down the on-going processes. This is one of the roles of material and conservation science. The project will focus on one class of alteration products: metal-oxalates - which environmental factors stimulate or inhibit their spontaneous formation. Metal-oxalates are formed either within the paint layers or precipitate on the surface as an optically disturbing crust that is very problematic to remove without damaging the original paint film. The presence of calcium oxalates in altered paint layers has been demonstrated in several previous studies directed by the project partners on Southern Netherlandish paintings such as van Eyck's the Adoration of the Mystic Lamb or Memling's Christ with singing and music-making Angels. Often, the oxalates were detected in the blue areas painted with natural ultramarine, the glazes and some varnishes; in many cases the layers were rich in (oil- and resin-based) organic binder. It is crucial to expand in a systematic manner our understanding of this phenomenon, its origin and its progress, in order to be able to control the chemical and physical oxalate formation process. The ability to stop or slow down the degradation process will be very useful for making conservation-restoration strategies more effective, and will thus contribute to the better preservation of 15th and 16th Southern Netherlandish oil paintings in the federal collections. The research project proposes to develop and apply an analytical methodology to provide the information that leads to a full understanding of the formation of metal-oxalates and their accumulation on (and below) the paint surface. The following issues will be addressed: (a) how degraded is the original layer, (b) which types of oxalate-related damage is present and (c) what are the causes of the chemical alteration ? In particular, the discoloration of transparent red and blue glaze layers caused by the formation of an opaque metal-oxalates surface coating will be studied. Our research will be carried out with advanced analytical techniques that operate at different length-scales: i.e., at macro-, micro- and nano-level.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

• Antwerp X-ray Imaging and Spectroscopy (AXIS)

Project type(s)

• Research Project

Abstract

In the study of historical paintings and more specifically as a preparation for restoration activities of such artefacts, it is of great relevance to investigate which materials and degradation products are present and how these are distributed at or below the painting surface. Commonly used non-destructive in situ methods such as X-ray fluorescence (XRF) and X-ray diffraction (XRD), are only used for spot analyses and require several minutes to record a spectrum from a single sample position, resulting in long scanning times required to record the data hypercubes. As an alternative, thermography inspection, as a non-contact and non-destructive technique is used for material parameter identification but also for art inspection as it is possible to differentiate chemical compounds. Therefore the goal of this research proposal is to improve non-invasive macroscopic material characterization of flat objects, both from an industrial and cultural heritage context, by augmenting existing elemental imaging technology with more species specific imaging of organic and inorganic compounds and this by combining the established X-ray based approaches with IR thermography and hyperspectral (HS) images. A combined X-ray, IR thermography and HS technique eliminates the disadvantages of these techniques and results in a faster measurement and material identification technique with respect to measurement time but also accuracy of the material parameter identification.

Researcher(s)

• Promoter: Steenackers Gunther
• Co-promoter: Janssens Koen
• Co-promoter: Ribbens Bart

Research team(s)

• Industrial Vision Lab (InViLab)

Project type(s)

• Research Project

Abstract

The purpose of this agreement is to provide the museum with various analytical services useful during the restoration of paintings; the purpose of these investigation will either be motivated from a conservation point of view or from an art historical interest.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The characterization of materials with light microscopy is usually limited by a limited depth of sharpness, resulting in partially sharp images of non flat surfaces. Therefore, the maximum magnification is limited to x100-200. The magnification of conventional microscopy can be enhanced using the z-stacking method, but it can never achieve the presentations of the new generation 3D-microscopes such as the DSX500 of Olympus.

Researcher(s)

• Promoter: Schalm Olivier
• Co-promoter: Janssens Koen

Research team(s)

• Antwerp Cultural Heritage Sciences (ARCHES)

Project type(s)

• Research Project

Abstract

Environmental toxicology (named ecotoxicology further on) is by name a multidisciplinary field involving a wide span of scientifical domains These domains cover areas as biology (and several sub-disciplines thereof), ecology, biochemistry, toxicology, molecular genetics, industrial and process chemistry etc On top of that it touches the sociological field in terms of human and environmental hazard and risk, and even economy by setting environmental standards, thereby directly influencing industrial processes Water treatment technology and risk assessment are both important answers and tools offered to problems put forward by ecotoxicology Both offer and raise questions and problems to be answered It is my believe that ecotoxicology, in its broadest sense, holds the mother key in the solution but has yet to fully gain it.

Researcher(s)

• Promoter: Blust Ronny
• Co-promoter: Bols Peter
• Co-promoter: Covaci Adrian
• Co-promoter: De Wael Karolien
• Co-promoter: Geuens Luc
• Co-promoter: Janssens Koen
• Co-promoter: Knapen Dries
• Co-promoter: Lenaerts Silvia
• Co-promoter: Meire Patrick
• Co-promoter: Samson Roeland
• Fellow: Dardenne Freddy

Research team(s)

Project type(s)

• Research Project

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university. The AGRECHEM consortium is an excellence centre of the University of Antwerp, focusing on green and sustainable chemistry. One of the biggest future challenges is the production of fine chemicals in a sustainable way. The quest for synthetic routes that are at the same time eco-friendly and economically feasible requires a concerted input of scientists with a variety of specializations. The progress in synthesis goes hand in hand with progress in materials characterization. Therefore, the consortium brings together two main research groups on synthetic chemistry and three research units specialized in material characterization techniques with emphasis on gaining mechanistic insight in chemical reactions. The consortium aims at consolidating and increasing the existing excellence in sustainable chemistry at the University of Antwerp.

Researcher(s)

• Promoter: Cool Pegie
• Co-promoter: Goovaerts Etienne
• Co-promoter: Janssens Koen
• Co-promoter: Maes Bert
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Laboratory of adsorption and catalysis (LADCA)

Project type(s)

• Research Project

Abstract

When light interacts with matter, it responds to this external stimulus in ways that depend on macroscopic properties but also on the microscopic details of the material. Pigments for instance, have a wavelength dependent reflection and absorption that causes the appearance of color in e.g. oil paintings. The absorption of light can also be used to capture the energy stored in solar light for use in photovoltaic solar cells. Perhaps surprisingly, the microscopic function of solar cells and pigments have a lot in common. Both absorb light and suffer from deterioration upon prolonged illumination and environmental conditions. This leads to chemical degradation (and altered colors) in historical paintings and to gradually reducing efficiencies in organic solar cells. In order to better understand their function and alteration behaviour, in this project, we propose to study in detail the microscopic origins of the capturing of light in heterogeneous materials found in oil paints and organic solar cells by combining state of the art experimental techniques based on synchrotron radiation and electron microscopy with advanced quantum mechanical models. This multidisciplinary approach will enable to improve the function and durability of future organic solar cells and will help to preserve and restore historical paintings from our cultural heritage.

Researcher(s)

• Promoter: Verbeeck Johan
• Co-promoter: Janssens Koen
• Co-promoter: Partoens Bart

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

This project focuses on improvement and adaptation of two immunochemical methods (CL and antibody-based SERS) to the routine laboratory practice in the field of cultural heritage. The expected results of this work are very challenging, because the successful employment of these methods will solve one the most actual question in the field of cultural heritage – the simultaneous localisation and identification of protein binders in paint layer systems of artworks.

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Hrdlickova Kuckova Stepanka

Research team(s)

Project type(s)

• Research Project

Abstract

Examination of instrumental parameters and current validation for the studied heavy metals in order to determine whether the sensitivity of the present apparatus can still be improved. Investigation into the cause of the large deviation between the ICP-MS and XRF results, in particular, for the element antimony (Sb). Investigation of different types of filters for sampling heavy metals. Optimization of XRF devices for elemental analysis, especially in terms of the projects on chemical characterization. This concerns the following elements: Al, As, Ba, Ca, Cd, Cr, Cu, Fe, K, Mn, Mo, Ni, Pb, Sb, Ti, V and Zn.

Researcher(s)

• Promoter: De Wael Karolien
• Co-promoter: Janssens Koen
• Co-promoter: Van Espen Piet
• Co-promoter: Van Grieken Rene

Research team(s)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand Fund InBev-Baillet Latour. UA provides Fund InBev-Baillet Latour research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The project comprises the use of synchrotronradiation for materials research of diverse nature. If concerns primarily experiments to be carried out at the European Synchrotron Radiation Facility ESRF, in Grenoble, France. Next to advanced types of material investigations using microscopic and nanoscopic X-ray fluorescence, X-ray diffraction and X-ray absorption microscopy and tomography, a number of less advanced experiments will take place at the DUBBLE CRG beamline. More specificially, attention is devoted to the natural wheathering of strogly pigmented inorganic compounds used by artists in different historical periods and to living material polluted by heavy metals and by radioactive materials.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the Province of Antwerp. UA provides the Province of Antwerp research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Pinxten Annie
• Co-promoter: Janssens Koen

Research team(s)

• Didactica
• Behavioural Ecology & Ecophysiology

Project type(s)

• Research Project

Abstract

The subject of this project is the study of the long-term evolution and degradation of metal-sulphides in painted works of art subjected to indoor atmospheric conditions. We will evaluate the effectiveness of air-quality amelioration systems in museums regarding the particular reactions of these pigments, and elaborate protocols for indoor preservation of works of art containing metal-sulphides.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the IAEA. UA provides the IAEA research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Within the area of conservation science, the performance of accelerated weathering tests is essential. The proposed collaboration project between the University of Antwerp and the Artesis University College of Antwerp aims to set up expertise within this research field. Based on two experiments which focus on different materials, experience on using a climatic chamber will be build up. The first experiment will study the interaction between particulate matter and paint layers. The second experiment aims to validate the contact-sponge method for use in situ.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of this project is the optimization of a scanning macro-XRF set-up for use with synchrotron and laboratory X-ray sources for the analysis of paintings from the 15th to 20th century. Next to the reduction of the total measurement time through the parallel use of multiple XRF-detectors, the possibilities of depth discrimination in mappings of large areas (hundreds of square centimeter) either by use of special detector geometry or by use of confocal optics will be included.

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Alfeld Matthias

Research team(s)

Project type(s)

• Research Project

Abstract

Historical oil painting are built up of many, fairly thin layers of paint. Each layer consists of an organic binder mixed with (in)organic pigment grains. Recently, several new methods have been developed to visualize this multilayer structure in a non-destructive manner. X-ray laminography is a variant of X-ray tomography that is more appropriate for the study of large, flat objects such as paintings. The project involves the optimization of the experimental parameters for X-ray laminography of (parts of) oil paintings with the aim of being able to reconstruct their internal structure and time-dependent process of creation.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Sijbers Jan

Research team(s)

Project type(s)

• Research Project

Abstract

The goal of the project is to verify a number of 15-17th C. recipes for synthesis of primary glass, as used for the production of stained glass windows and of utilitarian and decorative glass artefacts. The influence of unpurified starting materials (SiO2-rich sand and Na or K-rich flux) and of recycled glass on the required fusion temperature and fusion time will be investigated. Also we will verify experimentally the manner in which the fusion process influence the trace element pattern of the glass relative to that of the silica source.

Researcher(s)

• Promoter: Janssens Koen
• Co-principal investigator: Caen Joost

Research team(s)

Project type(s)

• Research Project

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university.

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Hellemans Kevin

Research team(s)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the Flemish Public Service. UA provides the Flemish Public Service research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Blust Ronny
• Co-promoter: Bogaerts Annemie
• Co-promoter: Caen Joost
• Co-promoter: D'Haese Patrick
• Co-promoter: Geuens Luc
• Co-promoter: Van Grieken Rene

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of this project is to fine-tune the timeline of pigment use in the late 19th and early 20th century painting. Through the study of existing historical painting palettes and paint tubes, using instrumental analytical techniques (XRF, light microscopy, electron microscopy), pigment analyses of paintings could be interpreted more correctly, enabling a better interpretation of the technological evolution of pigment use.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

UA will provide expertise and assistance towards characterization of model and original samples that are submitled to different treatments. These samples will be analysed, for instance at the SOLEIL Synchrotron, by X-ray absorption spectroscopy and X-ray diffraclion in order to document the side effects of the treatments and to get a beller insight in the involved chemical processes.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of this project is the optimization of a scanning macro-XRF set-up for use with synchrotron and laboratory X-ray sources for the analysis of paintings from the 15th to 20th century. Next to the reduction of the total measurement time through the parallel use of multiple XRF-detectors, the possibilities of depth discrimination in mappings of large areas (hundreds of square centimeter) either by use of special detector geometry or by use of confocal optics will be included.

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Alfeld Matthias

Research team(s)

Project type(s)

• Research Project

Abstract

The project aims to confront and compare the results of two related techniques for obtaining information on the structural environment of metals in solid materials: X-ray absorption near-edge spectroscopy (XANES) and electron loss near-edge spectroscopy (ELNES). Both probe the density of unoccupied electron states in atoms and the manner in which this distribution is influenced by the neighbours of these atoms. Both methods employ different primary projectiles (resp photons and electrons) and different ways modes of detection; as a result they operate on different length scales.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Lamoen Dirk
• Co-promoter: Verbeeck Johan

Research team(s)

Project type(s)

• Research Project

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

The unique collection of stained glass roundels of the Convent of the Grey Sisters (now University of Antwerp), dating from the 16th century, will be restaured during the next year. This, probable, coherent collection can be compared with other glassfragment of the 16th century out of the collections of J. Caen and C. Berserik. The execution of analytical investigation can give more information if the glasssubstrate for stained glass roundels is a subgroup in the well known high lime ¿ low alkali glassgroup. This for instance for the use of Mn. Also we would like to see if the glassroundels are made by the same workshop. Connecting to that, we suspect that, gattering the information of analytical spectroscopy, new characteristics of the glass will show up.

Researcher(s)

• Promoter: Janssens Koen
• Co-principal investigator: Caen Joost

Research team(s)

Project type(s)

• Research Project

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university.

Researcher(s)

• Promoter: Blust Ronny
• Co-promoter: D'Haese Patrick
• Co-promoter: Janssens Koen
• Co-promoter: Van Grieken Rene

Research team(s)

Project type(s)

• Research Project

Abstract

At synchrotrons µ-X-ray fluorescence spectroscopy (µ-XRF), confocal µ-X-ray fluorescence spectroscopy (confocal µ-XRF) and µ-X-ray diffraction (µ-XRD) are well established techniques that make use of an X-Ray microprobe for the analysis of samples in the micrometer range, but have till now only found partly use with X-ray tubes in the laboratory. In this project these techniques are applied with different X-ray tubes, optics and detectors to optimize their analytical capabilities and the results are compared to those from measurements at the synchrotron.

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Alfeld Matthias

Research team(s)

Project type(s)

• Research Project

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of this project is to obtain a better understanding of the physico-chemical phenomena that take place during the corriosion of glass, in particular the processes giving rise to MnO2-inclusions, which give the glass a dark, opaque outlook. Microscopic investigations by means of optical microscopy, electron microscopy and X-ray microtomography are envisaged; untreated and treated corroded fragments of glass will be examined.

Researcher(s)

• Promoter: Janssens Koen
• Co-principal investigator: Caen Joost

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of this project is to understand why yellowish films are formed during plasma cleaning of tarnished silver-copper alloys. The intensity of these films for alloys containing less than 97 w% of silver increases with the amount of copper in the alloy. In order to understand this phenomenon both sulphide layers and yellowish films will be analysed in detail.

Researcher(s)

• Promoter: Schryvers Nick
• Co-principal investigator: Storme Patrick
• Co-promoter: Janssens Koen

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

As binding media in of artist paints, usually mixtures of natural products such as different proteins, vegetable oils, sugars and/or resins have been employed in the last 500 years. The project aims to develop procedures for the type-identification and quantitative analysis of the binding media employed in oil paintings by means of a combination of spectroscopic and chromatographic techniques, while causing minimal damage to the paintings involved.

Researcher(s)

• Promoter: Janssens Koen
• Co-principal investigator: Tavernier Serge

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the Federal Public Service. UA provides the Federal Public Service research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of the project is to define the optimal circumstances within which a recently developed plasma cleaning device can be used for the cleaning of the silver surfaces in works of art of different kind (daguerrotypes, silver mirrors, antique textiles, silver decorations on wooden furniture, silverleaf in polychromated statues, ¿). Additionally, we will investigate whether or not an accelerated resulphidisation of the plasma-cleaned surfaces takes place.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of this project is to study the relation between the artistic changes in de art of painting in Belgium at the end of the 19th century and the new pigments that were introduced during that period. For this, approximately 100 paintings will be studied by means of instrumental analytical techniques (XRF, light microscopy and electron microscopy). The patterns in pigment usage and stratigraphy present in paintings will be studies as well.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

This project aims to determine if Jan Van Eyck considered the panel painting 'H. Barbara' as a finished masterpiece or not. If this painting is an unfinished work of art, then it provides unique information about the first phase of the creation process that he has used. Therefore, this painting is an excellent case-study for a reconstruction investigation.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The project aim is to study the relation between the recipes, the chemical composition and the damage inflicted on historical documents by ferro-gallic inks. A series of documents from Antwerp archives will be selected and characterized in various manners. The information contained in historical ink recipes will be used to facilitate the interpretation of the analysis results. Also a course will be prepared on the basis of the research results.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Vincze Laszlo

Research team(s)

Project type(s)

• Research Project

Abstract

The main goal of the project is the development/improvement of advanced forms of tomography and its application in practice. On the one hand attention will be paid to the development of tomography at the nanoscopic level by means of EFTEM while on the other hand element-specific X-ray fluorescence tomography with micrometer resolution will be optimised and quantitatively calibrated. An important area of application is the quantitative three-dimensional measurement of various phases in (human and animal) bone.

Researcher(s)

• Promoter: Van Dyck Dirk
• Co-promoter: D'Haese Patrick
• Co-promoter: Janssens Koen

Research team(s)

• Vision lab

Project type(s)

• Research Project

Abstract

Het project will focus on a series of documents, written with ferro-gallic inks, to be seleced from various Antwerp archives (among which that of the Hogeschool Antwerpen), to document the state of conservation of these documents and to determine the composition of the inks in various manners. Other metals that are present in the ink next to Fe will be determined while also the location of Fe2+/Fe3+ redox equilibrium will be determined on a selected set of samples. Then the correlation between the data will be studied.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

By means of a scientific exhibition in the Museum of the city of Lier for highschool pupils, their teachers and the public at large, the materials that are used to construct paintings and the deterioration phenomena that are associated with these materials are investigated. In an introductory part of the exhibition, the necessary knowledge will be refreshed by means of interactive displays. In the second part the visitor can apply this knowledge.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Vincze Laszlo

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Adams Freddy
• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The project aims to develop a method for the quantitative determination of the different molecular/crystalline forms in which transition metals (such as Ni) are present in microscopically small particles. By means of irradiation with an X-ray microbeam, a combination of three analysis methods in the same equipment can be used to reach this goal: H-XRF (elemental composition), p-XANES (oxidation states) en p-XRD (crystal phases).

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Vincze Laszlo

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The X-ray camera will be of use for two kinds of experiments at the HASYLAB synchrotron facility: (a) micro-tomography, where series of transmission X-ray micrograph are collected while the object being analyzed is rotated in front of the camera under divergent X-ray beam irradiation (b) micro-XRD (X-ray diffraction), where material is analyzed with a 20-30 keV monochromatic microbeam and the resulting Laue pattern is collected in transmission while the direct beam is blocked-out.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Proost Kristof

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The aim ofthis project proposal is to characterize U and Pu particles released frorn nuclear sources (e.g., Chemobyl) by means of different synchrotron X-ray microbearn techniques. By means of appropriate models, the rate can be calculated with which radioactive fission products will be released frorn these particles when exposed to ambient environmental conditions.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

In view of the evolution on the instrumental level of u-XRF both at synchrotron beamlines and by means of laboratory equipment, the activities will predominantly be of methodological nature. Attention will be devoted to applied research in a number of domains as these activities alow to refine the applied methodologies and to set up interdisciplinary collaborations.

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Vincze Laszlo

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Proost Kristof

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

In view of the evolution on the instrumental level of u-XRF both at synchrotron beamlines and by means of laboratory equipment, the activities will predominantly be of methodological nature. Attention will be devoted to applied research in a number of domains as these activities alow to refine the applied methodologies and to set up interdisciplinary collaborations.

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of the project is to construct two prototypes of a compact X-ray microanalyser, consisting of an air-cooled X-ray tube, a polycapillaire X-ray tube and a 'drift-chamber' detector. Once the prototypes are ready, they will be used for developing standard operating procedures for the local characterisation of silver and gold art-objects and of forensic glass fragments.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The project aims to construct a portable XRF-analyser to allow in-situ and non-destructive analysis of pigments in painings in musea. The apparatus will be tested on a number of works which are present in various Antwerp musea.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The project aims to improve the transmission characteristics of polycapillary X-ray lenses, as produced by Bejing Normal University and to reduce the spot size of the focussed microbeam. In a next stage, the lenses will be employed for micro-XRF and micro-XRD measurements.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Monte Carlo calculations allow a precise description of the interaction of X-ray beams with capillary optical components and heterogeneous samples.

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Vincze Laszlo

Research team(s)

Project type(s)

• Research Project

Abstract

The project aims to improve the micro-XRF infrastructure of two laboratories (one in Budapest, one in Krakow) and the use of the equipment for the determination of heavy metals in environmental particles (fly-ash collected at Hungarian power plants) and in a poly ethylene reference material.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

Microscopical X-ray beams allow X-ray fluorescence analysis with high sensitivity and accuracy. Other methdos complement the analysis : microscopical X-ray diffraction, tomography and X-ray absorption analysis. Applications are situated in fundamental analytical chemistry, environmental science, materials science and archaeology.

Researcher(s)

• Promoter: Adams Freddy
• Co-promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The project is involved with getting experience in the use of synchrotron radiation induced X-ray fluoresce by means of the facilities in Daresbury, Hamburg and Paris. Emphasis will be placed on the microscopical imaging capabilities of this technique. Also, the construction of instrumentation for use in Hamburg is part of the project

Researcher(s)

• Promoter: Adams Freddy
• Co-promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

European Synchrotron Radiation facility (ESRF, Grenoble) will be used for microscopical analysis and characterization using methods such as X-ray fluorescence analysis, fluorescence EXAFS and X-ray microtomography.

Researcher(s)

• Promoter: Adams Freddy
• Co-promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

In order to improve GDMS (glowdischarge mass spectrometry) as an analytical technique, the ion source i.e. the glow discharge, is modelled by stimulating the collisions between ions, electrons and neutral particles and their transport in the applied electical field. Stimulating the interaction between X-ray photon in solids is simulated for the optimization of microscopic X-ray fluorescence analysis.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Gijbels Renaat

Research team(s)

Project type(s)

• Research Project

Abstract

Development and optimization of microscopic X-ray fluorescence spectrometry using capillary optics and a rotating anode X-ray generator.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

It concerns panel B: outlines and other preparatory stages in Rubens' work: contribution to the economy of picture realisation in the 17th century art. Th objective is to systematically apply infra-red reflectography to the work of Rubens, in order to see the outlines, where possible. But also to analyse his complex construction technique in greater detail than has been done before. In order to do this, we will also make use of other types of technology, such as X-ray photos and studies with a stereomicroscope.

Researcher(s)

• Promoter: Balis Arnout
• Co-promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The project deals with the optimisation of x-ray fluorescence spectrometer with respect to excitation and detection geometry and excitation conditions for microscopic x-ray fluorescence. Both the cases of conventional XRF as synchrotron radiation induced XRF are treated.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

The project is involved with getting experience in the use of synchrotron radiation induced X-ray fluorescence by means of the facilities in Daresbury, Hamburg and Paris. Emphasis will be placed on the microscopical imaging capabilities of this technique. Also, the construction of instrumentation for use in Hamburg is part of the project.

Researcher(s)

• Promoter: Adams Freddy
• Co-promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

The software package AXIL, which permits the evaluation of energy dispersive X-ray spectra and their quantification will be adapted to the needs of the total reflection X-ray fluorescence spectrometer in the laboratory of Prof. Knöchel, Univ. of Hamburg, Germany. The project entails software development and spectrometry interfacing.

Researcher(s)

• Promoter: Janssens Koen

Research team(s)

Project type(s)

• Research Project

Abstract

The project is involved with getting experience in the use of synchrotron radiation induced X-ray fluoresce by means of the facilities in Daresbury, Hamburg and Paris. Emphasis will be placed on the microscopical imaging capabilities of this technique. Also, the construction of instrumentation for use in Hamburg is part of the project

Researcher(s)

• Promoter: Adams Freddy
• Co-promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Janssens Koen
• Fellow: Janssens Koen

Research team(s)

Project type(s)

• Research Project