TY - CONF A1 - Gojani, Ardian A1 - Gornushkin, Igor B. T1 - Combined Raman and LIBS using Spatial Heterodyne Spectrometer with High Repetition Rate Laser N2 - Spatial heterodyne spectroscopy is used for Raman and laser-induced breakdown spectroscopy of six rocks with various mineral content, using high repetition rate diode-pumped solid state lasers. While LIBS data are obtained for all samples, Raman signal was determined only for half of those. This work shows that it is possible to combine LIBS and Raman spectrometry into a single instrument consisting of a DPSS laser for excitation and SHS for spectral recording. For better results and gain from complementary spectrochemical information that the system provides, it is necessary to optimize light collection. T2 - 2020 Winter Conference on Plasma Spectrochemistry CY - Tucson, Arizona, USA DA - 13.01.2020 KW - Laser-Induced Background Spectroscopy KW - Spatial heterodyne spectroscopy KW - Raman spectroscopy PY - 2020 AN - OPUS4-50265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steger, Simon A1 - Stege, H A1 - Bretz, S. A1 - Hahn, Oliver T1 - A complementary spectroscopic approach for the non invasive in situ identification of synthetic organic pigments in modern reverse paintings on glass N2 - This work addresses the identification of synthetic organic pigments (SOP) in ten modern reverse paintings on glass (1912-1946) by means of an in-situ multi-analytical approach. The combination of the complimentary properties of mobile Raman spectroscopy and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) enabled the detection of sixteen SOP even in complex mixtures with inorganic compounds and binders. For the β-naphthol pigments, both Raman and DRIFTS yield appropriate results. DRIFTS was the preferred method for the detection of synthetic alizarin (PR83). Its diagnostic band pattern even allows its detection in complex mixtures with mineral pigments, binders and fillers. Raman spectroscopy yielded distinctive spectra for the triaryl carbonium pigments (PG1, PV2, PR81) and the two-yellow azo SOP (PY3, PY12), whereas DRIFT spectra were affected by extensive band overlapping. This may also occur in Raman spectra, but in less problematic amounts. Fluorescence is the major problem with Raman and it significantly hampers the SOP spectra even with the 785 nm laser. On the one hand the big spot size of DRIFTS (10 mm) limits the technique to rather large sampling areas, whereas the use of a 50× objective for in-situ Raman measurements permits a focus on small spots and aggregated SOP flakes. Moreover, “environmental” factors like temperature changes, artificial light, limited space and vibrations when people pass by need to be considered for in-situ measurements in museums. Finally, the results show the experimental use of SOP in modern reverse glass paintings. Among several rare SOP (e.g. PB52, PR81), two of them (PG1, PV2) have never been reported before in any artwork. T2 - Technart2019 CY - Bruges, Belgium DA - 07.05.2019 KW - Synthetic organic pigments KW - Reverse glass painting KW - DRIFTS KW - Raman spectroscopy PY - 2019 AN - OPUS4-48009 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steger, Simon A1 - Oesterle, D. A1 - Mayer, R. A1 - Hahn, Oliver A1 - Bretz, S. A1 - Geiger, G. T1 - First insights into Chinese reverse glass paintings gained by non invasive spectroscopic analysis N2 - A non-invasive methodological approach (X-ray fluorescence (XRF), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), Raman spectroscopy) has been carried out to identify the pigments and classify the binding media in two Chinese reverse glass paintings (The Archer, Yingying and Hongniang) from the late 19th and early 20th centuries. The results reveal a combined use of traditional Chinese and imported European materials. Several pigments like cinnabar, lead white, orpiment, carbon black and copper-arsenic green (probably emerald green) were found in both paintings; red lead, artificial ultramarine blue, Prussian blue and ochre appear in at least one of the paintings. The presence of portlandite (Ca(OH)2) along calcite (CaCO3) in the fine-grained, white backing layer of Yingying and Hongniang indicates the presence of limewash. In Chinese tradition, limewash was produced from clamshells, and was then sold as clamshell white. In contrast to the Japanese pigment, Chinese clamshell white was made of finely grounded shells, which were heated over a low fire. The residue (CaO) forms portlandite (Ca(OH)2) when water is continuously added. This water-rich mixture is applied on the painting. Portlandite reacts with atmospheric CO2 during drying and forms fine-grained calcite (CaCO3) [1,2]. The identification of emerald green (The Archer) suggests an earliest manufacturing date in the 1830s [3] and promotes the sinological dating of the painting. Drying oil was classified as a binding media in most areas of both paintings. However, the orange background of The Archer yielded prominent bands of both proteinaceous and fatty binder. T2 - Technart2019 CY - Bruges, Belgium DA - 07.05.2019 KW - Reverse glass painting KW - Raman spectroscopy KW - Non-invasive analysis PY - 2019 AN - OPUS4-48010 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gojani, Ardian A1 - Gornushkin, Igor B. A1 - Palásti, David J. A1 - Galbacs, G. T1 - Quantitative and qualitative analysis of liquid samples N2 - Spatial heterodyne spectroscopy (SHS) is an optical setup that combines both dispersive and interference based methods to obtain spectroscopic information. It has the high light throughput characteristic for interference based methods, but at the same time it has the high resolution typical of grated spectrometers. The basic SHS optical setup is similar to that of the Michelson interferometer, with the mirrors replaced by diffraction gratings positioned at fixed, equal distances from the beamsplitter and are slightly tilted. The resulting interference pattern is recorded by a digital camera and the spectrum is recovered by using Fourier Transformation. Although initially SHS was developed for astronomical and satellite-based atmospheric measurements, where spectroscopy of faint but large light sources are investigated, but in recent years the application of SHS spectroscopy is gaining popularity. Our research group is active both in Raman-SHS and LIBS-SHS, due to the fact that there are many overlapping challenges for the two spectroscopies in terms of optical and optoelectronic optimization. In the present study, we investigated the possibility of using SH detection for the qualitative and quantitative Raman spectroscopy of liquid samples. We constructed our own compact spatial heterodyne spectrometer using 300 mm-1 gratings (Newport), a 50:50 cube beamsplitter (Thorlabs), dischroic mirrors, bandpass and notch filters (Semrock), a Tamron telelens and a Retiga R1 CCD camera. A DPSS laser (532 nm, 20 ns) with variable energy and repetition rate (up to 100 µJ and 80 kHz) was used for excitation, with its beam driven through a 10x microscope objective (Thorlabs) to focus the laser light inside the liquid samples. The evaluation of the recorded interference patterns was carried out by self-developed software written in Octave. In the qualitative experiments, we investigated several oils and additives and employed principal component analysis (PCA) for their classification. It was found that the recorded spectra could be separated well in the subspace of just two principal components. The quantitative experiments were conducted with two sets of binary solvent mixtures (isopropanol-cyclohexane, glycerol-water). The simple univariate method based on the net intensity of one spectral peak did not give good results, but principal component regression (PCR) gave rise to fairly good and robust calibrations. Our results therefore show that a relatively simple and robust SHS setup can be advantageously used for both quantitative and qualitative Raman spectroscopy. T2 - European Winter Conference on Plasma Spectrochemistry (EWSPS-2019) CY - Pau, France DA - 03.02.2019 KW - SHS KW - Raman spectroscopy KW - Spatial Heterodyne Spectrometer PY - 2019 AN - OPUS4-47542 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steger, Simon A1 - Hahn, Oliver T1 - Development of a methodical approach for in-situ analysis of modern reverse paintings on glass N2 - The technique of painting on the reverse side of glass was rediscovered by artists in the early 20th century and gained great popularity, especially in Germany. In contrast to other paint techniques (e.g. panel and mural painting), the paint layers are applied in reverse succession starting with the foremost paint layer and ending with the primer (backmost layer). The paintings are viewed in reflected light, thus revealing an impressive gloss, luminosity and depth of colour. Scientific investigation of the material provides important information for appropriate conservation concepts. Transport of the precious and fragile objects to the lab is often not feasible. Therefore, in-situ, non-invasive analysis is necessary to analyse colorants and binders. However, some analytical problems need to be considered: due to the reverse paint stratigraphy in reverse paintings on glass, the measured layer is always the backmost one. The analytical possibilities are extremely reduced, when the back is covered by a metal foil (or by paper, carton etc.). However, measurements through the glass (using Raman and VIS) can still yield information on the colourants of the front layer. When the paint layer is accessible, we start our procedure using X-ray fluorescence (Tracer III-SD, Bruker AXS Microanalysis GmbH, 40 kV, 15 μA) and VIS reflectance spectroscopy (SPM 100, Gretag-Imaging AG). Both techniques provide first information on the inorganic colourants. Raman measurements (i-Raman®Plus, Bwtek inc., 785 nm, 50× objective, resolution 4 cm-1) are then carried out to clarify uncertain XRF measurements and to identify synthetic organic pigments (SOP). Diffuse Reflection-Infrared-Fourier-Transform Spectroscopy (DRIFTS; ExoScan, Agilent GmbH, 4000–650 cm-1, 500 scans, spectral resolution 4 cm-1) is used for the classification of the binders. Moreover, it may help to identify SOP, when fluorescence dominates the Raman signal. This analytical sequence yields the best results, when time is the limiting factor. We present two in-situ studies of the paintings “Kreuzabnahme” (1914-15) by Carlo Mense and “Stadt am Morgen” (1921) by Walter Dexel. The painting “Kreuzabnahme” is an outstanding piece in Mense’s ɶuvre, because the glass plate was painted on both sides (Fig. 1). The results of the back-side show mainly inorganic pigments: basic lead white, talc, red and brown ochre, cinnabar, chrome yellow, viridian, ultramarine blue, Prussian blue and bone black. The classification of binding media using DRIFTS yields positive results for drying oil. Acrylic resin could be identified in two areas, resulting from a previous restauration treatment. For the front side painting, Mense used basic lead white, cinnabar, chrome yellow and umbra as pigments and oil as binder. Measurements of the abstract painting “Stadt am Morgen” by Walter Dexel show zinc white, basic lead white, chalk, cinnabar, red lead, strontium yellow, cadmium yellow, cobalt blue, Prussian blue, ultramarine blue, brown ochre and bone black as pigments. Moreover, synthetic alizarin (PR83) was identified as dark red colorant. The results of DRIFTS classify oil as binding media. We conclude that, the use of complementary spectroscopic methods yields the best results for in-situ analysis of reverse paintings on glass. T2 - 3rd International Conference on Innovation in Art Research and Technology CY - Parma, Italy DA - 26.03.2018 KW - Modern painting KW - Non invasive analysis KW - Raman spectroscopy PY - 2018 AN - OPUS4-44780 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steger, Simon A1 - Hahn, Oliver T1 - In-situ Raman spectroscopic study of pigments used in modern reverse paintings on glass N2 - The technique of painting on the reverse side of glass was rediscovered by artists in the early 20th century. The artist group “Der Blaue Reiter” around Wassily Kandinsky and Franz Marc got in touch with this technique in 1908 and 1909. In the following years it gained great popularity, especially in Germany. Nevertheless, the technique has not received its due appreciation in art history. It was considered as stained glass. However, the paint layers are applied cold, hence this artistic technique doesn’t involve a firing step. Our multidisciplinary project investigates the art historic backgrounds, the painting techniques and materials of modern reverse paintings on glass. More than 1000 paintings from ~100 artists were discovered in the framework of our project. A selection of 60 paintings could be analyzed using non-invasive, in-situ methods such as Raman and VIS spectroscopy, Diffuse Reflectance Fourier Transform Infrared Spectroscopy (DRIFTS) and X-ray fluorescence (XRF). In this paper we want to point out the key role of Raman spectroscopy for our research. It offers the unique opportunity to measure paint layers from both sides. (front = through the glass; reverse = directly on the paint layer). T2 - XIII International GeoRaman Conference CY - Catania, Italy DA - 10.06.2018 KW - Raman spectroscopy KW - Reverse painting on glass KW - Non-invasive analysis PY - 2018 AN - OPUS4-45400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Donskyi, Ievgen A1 - Guday, G. A1 - Lippitz, Andreas A1 - Adeli, M. A1 - Haag, R. A1 - Unger, Wolfgang T1 - Gram-scale production of high quality nanographene under mild conditions and doping via non-destructive covalent functionalization N2 - We report a new method for top-down one-pot, gram-scale production of high-quality nanographene from graphite under mild conditions. The nanographene sheets had a very low oxygen content, comparable to that of nanographene grown by chemical vapor deposition. This method is easily scalable and comparatively mild, opening the door to an environmentally friendly process to produce high-quality nanographenes. Nanographene sheets were further covalently functionalized using a non-destructive [2+1] cycloaddition reaction that left the π-conjugated system intact. T2 - 10th Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 05.12.2018 KW - Nano graphene KW - X-ray Photoelectron Spectroscopy (XPS) KW - NEXAFS KW - Raman spectroscopy PY - 2018 AN - OPUS4-47086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Paul, Andrea A1 - Neddermeyer, F. A1 - Krämer, D. A1 - Eckhardt, H. S. A1 - Lange, C. A1 - Maiwald, Michael A1 - King, R. T1 - Online Raman spectroscopy for the quantitative evaluation of a Ralstonia cultivation N2 - Spectroscopic methods possess important advantages for the observation of bioprocesses: they are robust, gain many data within a short time scale, and allow for the measurement of multiple relevant information at the same time. Next to Near-infrared spectroscopy, Raman spectroscopy is increasingly applied as a powerful online tool to monitor bioprocesses. However, Raman spectra may be obscured by straylight, cosmic rays and fluorescence. To achieve the best performance, optimal conditions for spectral quality and stability should be pursued. This comprises not only the choice of highly-sensitive equipment, but also the way of implementation into the process. Here we compared the potential of introducing a sterilized fiber optical Raman probe, and a flow-through cell into the bypass of a stirred tank reactor to monitor an autotrophic cultivation of Ralstonia eutropha where gasses are the energy and carbon sources. Raman spectra were continuously recorded over seven days and 22 samples were taken for the reference analytics of biomass, optical density, and protein. In addition, data for of phosphate and ammonium were available. The quantitative Evaluation of Raman spectra by Partial Least Squares Regression (PLSR) yielded comparable results for both approaches, however, there was a general trend of lower prediction errors with the immersion probe. The better performance of the non-contact optic may be either related to a more representative interaction of the measurement optics with the probe or simply to the absence of probe-fouling, which was observed with the immersion optic in the interstice between window and metal frame. T2 - 5th BioProScale Symposium CY - Berlin, Germany DA - 20.03.2018 KW - Raman spectroscopy KW - Bioprocess KW - Chemometrics PY - 2018 UR - www.bioproscale-conference.org AN - OPUS4-44580 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steger, Simon A1 - Hahn, Oliver T1 - Study of modern reverse paintings on glass with Raman Spectroscopy N2 - The technique of painting on the reverse side of glass was rediscovered by artists in the 20th and gained especially in Germany strong popularity. Compared to other techniques (e.g. canvas, mural paintings), the paint layers are applied in reverse succession. The paintings are viewed in reflected light, thus revealing an impressive gloss, luminosity, and depth of color. Reverse glass paintings comprise a non-porous glass substrate and multi-layered paint system, hence delamination of the paint layer is the most common disfigurement. Scientific investigation of the material provides important information for appropriate conservation concepts. Transport of the precious and fragile objects to the lab is often not feasible. Therefore, in-situ, non-invasive analysis is necessary to analyze colorants and binders. Based on modern reverse glass paintings, we clarify advantages and limitations of mobile Raman spectroscopy for the identification of colorants. We compare the use of mobile Raman spectroscopy with other methods of our mobile lab (i.e. X-ray fluorescence (XRF), Diffuse Reflectance Fourier Transform Infrared Spectroscopy (DRIFTS). T2 - 9th International Congress on the Application of Raman Spectroscopy in Art and Archaeology (RAA2017) CY - Évora, Portugal DA - 24.10.2017 KW - Reverse glass painting KW - Raman spectroscopy KW - Synthetic organic pigments PY - 2017 AN - OPUS4-42825 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Akhmetova, Irina A1 - Wilke, Manuel A1 - Emmerling, Franziska A1 - Rademann, K. T1 - In situ investigation of mechanochemical syntheses of metal phosphonates N2 - We report on the in situ investigation of mechanochemical syntheses of metal phosphonates. The metal phosphonates are formed in milling reactions starting from a metal acetate and a phosphonic acid. The conversions are observed by synchrotron PXRD and Raman spectroscopy to shed light on the reaction mechanisms including possible intermediates. T2 - 8th HZB User Meeting CY - Berlin, Germany DA - 07.12.2016 KW - Mechanochemistry KW - In situ KW - Metal phosphonates KW - XRD KW - Raman spectroscopy PY - 2016 AN - OPUS4-38780 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -