Sara Zaccaron- PhD in Chemistry
- PostDoc Position at BOKU University
Sara Zaccaron
- PhD in Chemistry
- PostDoc Position at BOKU University
About
25
Publications
6,561
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225
Citations
Introduction
Current institution
Additional affiliations
February 2016 - February 2016
Position
- Lecturer
Description
- Conservation of Books and Paper, Conservation of Material Culture: Art, Artefacts, and Heritage Sites
August 2013 - September 2013
Museo Ca´ Rezzonico
Position
- Conservation Scientist
Description
- Non-invasive analyses for characterization, dating and attribution of artworks
June 2016 - present
Position
- PostDoc Position
Description
- Chromophore und Cellulosealterung (Chromophore II): mechanisms of chromophoric substances generation in cellulosic matrices and optimization of industrial bleaching processes
Education
September 2015 - September 2015
Analytical Techniques in Lignocellulosic Chemistry
Field of study
- University of Natural Resources and Life Science BOKU
June 2013
CHARISMA Meeting
Field of study
- New techniques for the non-invasive investigation of the surface and subsurface structure of heritage objects & Training on application of Optical Coherence Tomography (OCT) to structural analysis
June 2013
6th introductive Course on Photochemistry
Field of study
- University of Bologna
Publications
Publications (25)
During peroxide bleaching of pulp (“P-stage”), the heavy metal ions must be removed from the pulp and inactivated by chelation before the bleaching to prevent undesired degradation of cellulose by reactive oxygen species. Ethylenediaminetetraacetic acid (EDTA) is mostly used as a chelating agent; however, it may soon be banned because of environmen...
Correctness and reliability of molar mass data by viscometry in organometallic solvents (cuen, cuoxam, cadoxen) are compromised by the alkalinity of these solvents which causes immediate depolymerization especially in the case of pulps with higher carbonyl content (oxidative damage). The viscosity values thus correspond to the molar mass after the...
Cellulosic material is capable of permanently retaining nitrogen compounds (mostly having amino functions), which is reflected in a residual nitrogen content (in the low per mille range to the low percent range) of some pulps and certain lab samples. Merely adsorptively bound compounds can be removed by mild acidic washing, but part of the nitrogen...
2,5-Dihydroxy-[1,4]-benzoquinone (DHBQ, 1) is the most prominent representative of cellulosic key chromophores, which occur almost ubiquitously in all types of aged cellulosics. The degradation of DHBQ by chlorine dioxide under conditions of industrial pulp bleaching (“D stage”) was studied, i.e. in moderately acidic medium (pH 3) at temperatures b...
The effect of the degradation induced by the solvents for cellulose cuoxam and cadoxen and its dependency on the nature of the carbonyls in oxidatively-damaged cellulosics was investigated by combining a novel approach of sample regeneration and gel permeation chromatography coupled with carbonyl-selective labelling for reliable molecular character...
Biomass conversion processes have become increasingly important to mitigate fossil fuel consumption and to increase the contribution of renewable fuels into the world energy matrix. In this study, Eucalyptus urograndis wood chips were pretreated by autocatalytic steam explosion to produce cellulosic ethanol after enzymatic hydrolysis and fermentati...
Although efficient and inexpensive, conventional viscometry to determine cellulose’s average degree of polymerization (DP) may mislead the final DP because cellulose degradation occurs in the used solvents, which consist of alkaline amino complexes of transition metals, such as cupri-ethylenediamine (CED). For oxidatively damaged pulps or cellulose...
The quantity of adhesives that are currently used within conservation is both a blessing and curse to conservators. The immense number of adhesives available provide the potential for tailoring adhesives to a particular application, however this same variety can present a paralyzing wealth of choice to conservators. We are developing a user-driven...
Literature is strongly contradictory about the molecular reasons for yellowing and brightness reversion of pure (lignin- and hemicellulose-free) celluloses, such as in highly bleached pulps, bacterial cellulose, or cotton linters. While oxidized groups—carbonyls (CO) and carboxyls (COOH)—have been recognized as the initiators of yellowing, they are...
Iron gall inks are known to be detrimental to the permanence of historic documents. Among the transition metals present, copper is the greatest threat and an open challenge due to the lack of Cu-specific treatments. In this study, we address the inhibition of copper by comparing extraction (a newly proposed glucose-based treatment) vs. chelation (p...
Historic documents are frequently protected by placing them in a sealed polyethylene-terephthalate (PET) envelope. Although the paper is mechanically stabilized, the PET film may limit transmission of moisture or acidic degradation by-products of the paper. This creates a microenvironment for the encapsulated document. The permeation of water and a...
The study investigates the stability of polymer-coated papers by means of spectroscopic kinetics on thermally aged samples. Multivariate cellulosic samples were prepared (using different substrates and polymeric coatings) and artificially aged according to standard protocol in order to understand the influence of each component on the final product...
Oxidizing properties of transition metal ions towards cellulose are well know and widely studied in respect to an induced discoloration as well as the formation of oxidized groups on the substrate. Iron gall inks represent the most well-know and highly degrading iron complexes in paper conservation. In order to investigate its influence on the oxid...
This kinetic study aims to shed some light on degrading processes occurring to papers in closed environments. An in-depth investigation has been carried out with a novel insight into cellulosic materials. Unlike the majority of previous researches, this project has based on two main key points: (1) the paper is a complex system constituted by syner...
The electronic structures of iron coordination compounds having formulae [FeL4H12]-, [FeL4H12]2-, [Fe3L8H22]- and [Fe3L8H22]2- (H4L = gallic acid, 3,4,5-trihydroxybenzoic acid) have been studied by means of DFT calculations, together with that of the 1D periodic complex [Fe3L6H15]∞. Data regarding the ground-state spin multiplicities of these model...
![Figure 4. 3D structure of [(Fe 3 L 3 ) 3- ] ∞ , view along a vector.](profile/Sara-Zaccaron/publication/258152505/figure/fig4/AS:297656137076749@1447978161495/D-structure-of-Fe-3-L-3-3-view-along-a-vector_Q320.jpg)
![Figure 5. 3D structure of [(Fe 3 L 3 ) 3- ] ∞ , view along b vector.](profile/Sara-Zaccaron/publication/258152505/figure/fig5/AS:297656137076750@1447978161527/D-structure-of-Fe-3-L-3-3-view-along-b-vector_Q320.jpg)
The electronic structure of a 3D iron-based coordination polymer having formula [(Fe3L3)3-]∞ (H4L = gallic acid, 3,4,5-trihydroxybenzoic acid) has been studied by applying DFT-based computational methods
in combination with periodic boundary conditions and plane-waves or numerical basis sets. The model compound has been built on the basis of report...
The present paper exposes a characterization study carried out on a copy of La sepoltura di Cristo by Federico Barocci painted on a copper plate support probably around the 17th century. In order to identify the
pictorial technique of the artist and dating the artwork, both historical and scientific researches were carried
on. Non-invasive and micr...
Questions
Questions (3)
I am trying and study the Fehling's test in solution using the UV-Vis spectroscopy. The test involves the precipitation of red solid particles of Cu2O owing to the redox reaction of a reducing sugar and Cu(II) ions in an alkaline medium. I want to determine the spectroscopic characteristics/differences between free Cu(II) ions and Cu(I) oxide. I have performed some (cuvette) measurements using a NanoDrop 2000/2000c Spectrophotometer but all my spectra are very noisy especially in the UV range (190-380 nm) despite the high absorbance (Amax=2.5) of all my samples. As an example, I cannot even ascertain how many peaks are present due to the noise.
Does anyone know if the problem could be due to the instrument (high scan speed, just 3 seconds per analysis) or if there is any mistake in my operating procedure?
The Raspail test is commonly used to identify rosin in paper: a drop of nearly saturated solution of sugar is applied on paper; after about 5 seconds the excess solution is blotted off the sample and a drop of concentrated H2SO4 is added to the sugar on the paper; a raspberry-red colouration indicates the presence of rosin.
Which reactions take place during the different steps? Why should sucrose be used as a saturated solution? Which molecule is responsible for the raspberry-red colouration?
Does anybody know some good references about thermal degradation of cellulose paper? We have used DSC and TGA but have not found enough information about data interpretation. We lack especially references about air\nitrogen analysis conditions. Any suggestions?
