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Author Al-Emam, E.; Beltran, V.; De Meyer, S.; Nuyts, G.; Wetemans, V.; De Wael, K.; Caen, J.; Janssens, K.
Title Removal of a past varnish treatment from a 19th-century Belgian wall painting by means of a solvent-loaded double network hydrogel Type A1 Journal article
Year (down) 2021 Publication Polymers Abbreviated Journal Polymers-Basel
Volume 13 Issue 16 Pages 2651-20
Keywords A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab); Antwerp X-ray Imaging and Spectroscopy (AXIS)
Abstract Polymeric materials have been used by painting conservator-restorers as consolidants and/or varnishes for wall paintings. The application of these materials is carried out when confronting loose paint layers or as a protective coating. However, these materials deteriorate and cause physiochemical alterations to the treated surface. In the past, the monumental neo-gothic wall painting 'The Last Judgment' in the chapel of Sint-Jan Berchmanscollege in Antwerp, Belgium was treated with a synthetic polymeric material. This varnish deteriorated significantly and turned brown, obscuring the paint layers. Given also that the varnish was applied to some parts of the wall painting and did not cover the entire surface, it was necessary to remove it in order to restore the original appearance of the wall painting. Previous attempts carried out by conservator-restorers made use of traditional cleaning methods, which led to damage of the fragile paint layers. Therefore, gel cleaning was proposed as a less invasive and more controllable method for gently softening and removing the varnish. The work started by identifying the paint stratigraphy and the deteriorated varnish via optical microscopy (OM), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy. A polyvinyl alcohol-borax/agarose (PVA-B/AG) hydrogel loaded with a number of solvents/solvent mixtures was employed in a series of tests to select the most suitable hydrogel composite. By means of the hydrogel composite loaded with 10% propylene carbonate, it was possible to safely remove the brown varnish layer. The results were verified by visual examinations (under visible light 'VIS' and ultraviolet light 'UV') as well as OM and FTIR spectroscopy.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000690248000001 Publication Date 2021-08-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2073-4360 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.364 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 3.364
Call Number UA @ admin @ c:irua:181567 Serial 8470
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Author Das, P.P.; Guzzinati, G.; Coll, C.; Gomez Perez, A.; Nicolopoulos, S.; Estrade, S.; Peiro, F.; Verbeeck, J.; Zompra, A.A.; Galanis, A.S.
Title Reliable Characterization of Organic & Pharmaceutical Compounds with High Resolution Monochromated EEL Spectroscopy Type A1 Journal article
Year (down) 2020 Publication Polymers Abbreviated Journal Polymers-Basel
Volume 12 Issue 7 Pages 1434
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Organic and biological compounds (especially those related to the pharmaceutical industry) have always been of great interest for researchers due to their importance for the development of new drugs to diagnose, cure, treat or prevent disease. As many new API (active pharmaceutical ingredients) and their polymorphs are in nanocrystalline or in amorphous form blended with amorphous polymeric matrix (known as amorphous solid dispersion—ASD), their structural identification and characterization at nm scale with conventional X-Ray/Raman/IR techniques becomes difficult. During any API synthesis/production or in the formulated drug product, impurities must be identified and characterized. Electron energy loss spectroscopy (EELS) at high energy resolution by transmission electron microscope (TEM) is expected to be a promising technique to screen and identify the different (organic) compounds used in a typical pharmaceutical or biological system and to detect any impurities present, if any, during the synthesis or formulation process. In this work, we propose the use of monochromated TEM-EELS, to analyze selected peptides and organic compounds and their polymorphs. In order to validate EELS for fingerprinting (in low loss/optical region) and by further correlation with advanced DFT, simulations were utilized.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000556786700001 Publication Date 2020-06-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2073-4360 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.364 Times cited 6 Open Access OpenAccess
Notes C.C., F.P., S.E. acknowledges the Spanish government for projects MAT2016-79455-P, Research Network RED2018-102609-T and the FPI (BES-2017-080045) grant of Ministerio de Ciència, Innovación y Universidades. G.G. acknowledges support from a postdoctoral fellowship grant from the Fonds Wetenschappelijk Onderzoek—Vlaanderen (FWO). P.P.D., A.G.P., S.N. gratefully acknowledge much helpful discussion on EELS study for organic compounds with Dr. Andrey Chuvilin (CIC NANOGUNE, Donostia—San Sebastian, Spain). The authors also acknowledge Raúl Arenal (University de Zaragoza, Spain) for useful discussion on EELS. The authors acknowledge also Ulises Julio Amador Elizondo (Universidad CEU San Pablo, Spain) for kindly provide the aripiprazole and piroxicam samples for EELS study.; EUSMI_TA; Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:170603 Serial 6400
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