Paper Ageing: The Effect of Paper Chemical Composition on Hydrolysis and Oxidation

The degradation of cellulose is an important factor influencing its mechanical, optical, physical, and chemical properties and, hence, the lifetime of paper in libraries and archival collections. Regardless of the complexity of the paper material, the main chemical pathways for its degradation are hydrolysis and oxidation. This study presents an overview of the analytical techniques employed in the evaluation of the hydrolysis and oxidation processes; these techniques include size-exclusion chromatography, Fourier-transform infrared and ultraviolet–visible spectroscopy, and X-ray diffraction. This paper aims to determine the extent to which these instrumental methods are useful for studying the aforementioned processes and for which lignin contents. It also highlights how atmospheric humidity could affect the cellulose structure in paper containing lignin. It was found that humidity causes significant changes in the cellulose chain lengths and that a high lignin content in paper could suppress some cellulose degradation pathways. This knowledge can be applied to developing strategies and selective chemical treatments preventing the consequences of paper ageing.

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Chemical and physical interactions of regenerated cellulose yarns and isocyanate-based matrix systems

Scientific Reports ◽

10.1038/s41598-021-91115-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Bernhard Ungerer ◽

Ulrich Müller ◽

Antje Potthast ◽

Enrique Herrero Acero ◽

Stefan Veigel

Keyword(s):

Mechanical Performance ◽

Tensile Force ◽

Tensile Modulus ◽

Tensile Tests ◽

Size Exclusion ◽

Regenerated Cellulose ◽

Hydrolytic Cleavage ◽

Yarn Twist ◽

Exclusion Chromatography ◽

Physical And Chemical

AbstractIn the development of structural composites based on regenerated cellulose filaments, the physical and chemical interactions at the fibre-matrix interphase need to be fully understood. In the present study, continuous yarns and filaments of viscose (rayon) were treated with either polymeric diphenylmethane diisocyanate (pMDI) or a pMDI-based hardener for polyurethane resins. The effect of isocyanate treatment on mechanical yarn properties was evaluated in tensile tests. A significant decrease in tensile modulus, tensile force and elongation at break was found for treated samples. As revealed by size exclusion chromatography, isocyanate treatment resulted in a significantly reduced molecular weight of cellulose, presumably owing to hydrolytic cleavage caused by hydrochloric acid occurring as an impurity in pMDI. Yarn twist, fibre moisture content and, most significantly, the chemical composition of the isocyanate matrix were identified as critical process parameters strongly affecting the extent of reduction in mechanical performance. To cope with the problem of degradative reactions an additional step using calcium carbonate to trap hydrogen ions is proposed.

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Synthesis of L-DOPA Based Melanins with Reproducible Physic-Chemical Properties

10.26434/chemrxiv.7471388.v1 ◽

2018 ◽

Author(s):

Koen Vercruysse ◽

Jayla Moore

Keyword(s):

Ir Spectroscopy ◽

Enzymatic Synthesis ◽

Chemical Properties ◽

Size Exclusion ◽

Synthesis Methods ◽

Ongoing Research ◽

Vis Spectroscopy ◽

Exclusion Chromatography ◽

Ft Ir ◽

Ft Ir Spectroscopy

This report expands our ongoing research efforts into the non-enzymatic synthesis of melanins. We have explored four different methods for the synthesis of L-DOPA based melanins and evaluated the reproducibility of some of their physic-chemical properties. The melanins were synthesized through the addition of NaOH, tyrosinate or Fe2+/H2O2. Two different approaches for the reactions involving Fe2+ and H2O2 were tested: a) addition of H2O2 spread out over multiple days or b) addition of H2O2 in one fraction at the start of the reaction. The physic-chemical properties of the melanins explored involved: 1) retention on size exclusion chromatography column, 2) FT-IR spectroscopy, 3) UV-Vis spectroscopy and 4) the capacity to reduce a redox dye, dichlorophenolindophenol. Overall the results obtained indicated that 1) the various synthesis methods lead to melanins with reproducible physic-chemical properties, 2) that the melanins synthesized in the presence of Fe2+/H2O2 are distinctly different from the melanins synthesized in the presence of NaOH or tyrosinate and 3) that no distinctly different melanins were generated when comparing the two different synthesis approaches involving Fe2+/H2O2. Only the melanins synthesized in the presence of Fe2+/H2O2 appeared to possess the capacity to reduce dichlorophenolindophenol.

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Differentiation of wastewater effluent organic matter (EfOM) from natural organic matter (NOM) using multiple analytical techniques

Water Science & Technology ◽

10.2166/wst.2008.165 ◽

2008 ◽

Vol 57 (7) ◽

pp. 1009-1015 ◽

Cited By ~ 54

Author(s):

Seong-Nam Nam ◽

Gary Amy

Keyword(s):

Organic Matter ◽

Natural Organic Matter ◽

Dissolved Organic Nitrogen ◽

Organic Nitrogen ◽

Analytical Techniques ◽

Size Exclusion ◽

Effluent Organic Matter ◽

Fluorescence Excitation ◽

Wide Range ◽

Exclusion Chromatography

Using three analytical techniques of size exclusion chromatography (SEC), fluorescence excitation-emission matrix (EEM), and dissolved organic nitrogen (DON) measurement, differentiating characteristics of effluent organic matter (EfOM) from natural organic matter (NOM) have been investigated. SEC reveals a wide range of molecular weight (MW) for EfOM and high amount of high MW polysaccharides, and low MW organic acids compared to NOM. Clear protein-like peaks using fluorescence EEM were a major feature of EfOM distinguishing it from NOM. Fluorescence index (FI), an indicator to distinguish autochthonous origin from allochthonous origin, differentiated EfOM from NOM by exhibiting higher values, indicating a microbial origin. In EfOM samples, DON present in higher amounts than NOM.

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In situ physical and chemical characterisation of the Eyjafjallajökull aerosol plume in the free troposphere over Italy

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-1075-2014 ◽

2014 ◽

Vol 14 (2) ◽

pp. 1075-1092 ◽

Cited By ~ 8

Author(s):

S. Sandrini ◽

L. Giulianelli ◽

S. Decesari ◽

S. Fuzzi ◽

P. Cristofanelli ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Gamma Ray ◽

Fine Fraction ◽

Chemical Properties ◽

Analytical Techniques ◽

Ground Level ◽

Coarse Fraction ◽

Volcanic Plume ◽

Physical And Chemical ◽

Aerosol Plume

Abstract. Continuous measurements of physical and chemical properties at the Mt. Cimone (Italy) GAW-WMO (Global Atmosphere Watch, World Meteorological Organization) Global Station (2165 m a.s.l.) have allowed the detection of the volcanic aerosol plume resulting from the Eyjafjallajökull (Iceland) eruption of spring 2010. The event affected the Mt. Cimone site after a transport over a distance of more than 3000 km. Two main transport episodes were detected during the eruption period, showing a volcanic fingerprint discernible against the free tropospheric background conditions typical of the site, the first from April 19 to 21 and the second from 18 to 20 May 2010. This paper reports the modification of aerosol characteristics observed during the two episodes, both characterised by an abrupt increase in fine and, especially, coarse mode particle number. Analysis of major, minor and trace elements by different analytical techniques (ionic chromatography, particle induced X-ray emission–particle induced gamma-ray emission (PIXE–PIGE) and inductively coupled plasma mass spectrometry (ICP-MS)) were performed on aerosols collected by ground-level discrete sampling. The resulting database allows the characterisation of aerosol chemical composition during the volcanic plume transport and in background conditions. During the passage of the volcanic plume, the fine fraction was dominated by sulphates, denoting the secondary origin of this mode, mainly resulting from in-plume oxidation of volcanic SO2. By contrast, the coarse fraction was characterised by increased concentration of numerous elements of crustal origin, such as Fe, Ti, Mn, Ca, Na, and Mg, which enter the composition of silicate minerals. Data analysis of selected elements (Ti, Al, Fe, Mn) allowed the estimation of the volcanic plume's contribution to total PM10, resulting in a local enhancement of up to 9.5 μg m−3, i.e. 40% of total PM10 on 18 May, which was the most intense of the two episodes. These results appear significant, especially in light of the huge distance of Mt. Cimone from the source, confirming the widespread diffusion of the Eyjafjallajökull ashes over Europe.

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What Was Released? Assessing the Physical Properties and Chemical Composition of Petroleum and Products of Burned Oil

Oceanography ◽

10.5670/oceanog.2021.116 ◽

2021 ◽

Vol 34 (1) ◽

pp. 44-57

Author(s):

Jürgen Rullkötter ◽

John Farrington

Keyword(s):

Oil Spills ◽

Complex Mixture ◽

Chemical Properties ◽

Analytical Techniques ◽

Ion Cyclotron Resonance ◽

Model Calculations ◽

Research Questions ◽

Physical And Chemical ◽

And Chemical Properties

The severity of oil spills depends on the quantity of material released and its physical and chemical properties. The total amount of petroleum spilled during the Deepwater Horizon incident and the relative fractions of the chemical compound classes of the Macondo oil were obtained by measurements, observations, and model calculations, with a significant amount of uncertainty. Because petroleum is an extremely complex mixture of many thousands or more of gaseous, liquid, and solid constituents, full elucidation of their compositions at the molecular level is impossible with presently available analytical techniques. This paper reviews published work on widely used analytical techniques and points out that scientists’ varying approaches to research questions and preferences for methods of analysis constitute a source of uncertainty. In addition, the focus is on two technical advancements developed over the last two decades, namely two-dimensional gas chromatography and Fourier transform ion cyclotron resonance mass spectrometry. Both were particularly valuable in the analysis of the spilled Macondo oil and its weathering products. Among the different processes of alteration of the original oil, only in situ oil burning is dealt with in this paper. This review reveals the paucity of data on this mitigation process and shows the need for more systematic coordination of methods in burned oil research studies.

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A Comprehensive Characterization of Different Fractions of Corn Stover and Their Relationships to Multipollutant Sorption Characteristics

Adsorption Science & Technology ◽

10.1155/2021/9988938 ◽

2021 ◽

Vol 2021 ◽

pp. 1-19

Author(s):

Dan Peng ◽

Fan Ouyang ◽

Min Deng ◽

Lei Nie ◽

Sifang Kong

Keyword(s):

Adsorption Capacity ◽

Corn Stover ◽

Organic Pollutants ◽

Lignin Content ◽

Chemical Properties ◽

Cellulose Content ◽

Adsorption Effect ◽

Adsorption Processes ◽

Pseudo Second Order ◽

Physical And Chemical

Corn stover (CS) is mainly composed of three parts: pith (CSP), rind (CSR), and leaf (CSL). These parts have different lignocellulosic constituents and structural properties. Herein, biosorbents derived from individual corn stover constituents were prepared in an effort to determine the significance of each constituent for multipollutant removal. In this study, SEM, BET, XRD, FTIR, XPS, fibre composition, and contact angle measurements were used to characterize and analyse the physical and chemical properties of the three components of CS and to study their adsorption effects, adsorption isotherms, and kinetics. The lignocellulosic compositions of CSP and CSR were similar, the cellulose content in CSP and CSR was significantly higher than that in CSL, and the hemicellulose content of CSL was much higher than those of CSP and CSR. The minimum lignin content was found in CSP, and the maximum lignin content was found in CSR. The results show that each component had a certain adsorption effect on typical organic pollutants (antibiotics, oils, and dyes). CSP had the strongest oil adsorption capacity, CSR was more suitable for adsorbing antibiotics, and CSL had outstanding adsorption capacity for dye. The pseudo-second-order model and the Langmuir adsorption isotherm model could describe the adsorption processes well, and they consisted of monolayer adsorption accompanied by chemical adsorption reactions. The focus of this study was to provide references for selecting effective adsorbent precursors to remove organic pollutants from wastewater.

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Soil Organic Matter Quality From Soils Cropped by Traditional Peasants

Sustainable Agriculture Research ◽

10.5539/sar.v3n4p63 ◽

2014 ◽

Vol 3 (4) ◽

pp. 63

Author(s):

Luciano Pasqualoto Canellas ◽

Riccardo Spaccini ◽

Natalia De Oliveira Aguiar ◽

Fabio Lopes Olivares

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Root Growth ◽

High Performance ◽

Chemical Properties ◽

Size Exclusion ◽

Native Forest ◽

Organic Matter Quality ◽

African Descendants ◽

Exclusion Chromatography

In this work we have analyzed soil samples from Oxisols collected from two traditional communities, one formed by Guarany Indians at South of Brazil and other by African descendants on North of Rio de Janeiro State, Brazil. The content and fractional composition of humus was investigated and the isolated humic acids (HAs) were characterized by elemental composition, 13C solid-state nuclear magnetic resonance, and high-performance size exclusion chromatography. The bioactivity of HAs was evaluated considering the effects on root growth of maize seedlings. Chemical properties from adjacent soils under native forest were used as control samples. The local field sites matching the traditional cropping requirements, were characterized by higher soil chemical fertility and soil organic matter hydrophobicity, as compared to the land plots considered as inadequate by rural peasants. The HAs from cropped soils revealed significant differences in respect to content, hydrophobicity, biostimulation and molecular dimension. Although all humic extracts promoted, both, root growth and the stimulation of lateral root emergence over control, the HAs from preferential local sites, revealed a larger bioactivity response on root stimulation even at lower concentration. The assessment of soil quality issued by local farmers, showed a valuable fitting with bio-chemical fertility indicators and SOM hydrophobicity.

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A size exclusion chromatography study of cellulose degradation

Polymer ◽

10.1016/s0032-3861(00)00243-3 ◽

2000 ◽

Vol 41 (24) ◽

pp. 8513-8521 ◽

Cited By ~ 29

Author(s):

A.M. Emsley ◽

M. Ali ◽

R.J. Heywood

Keyword(s):

Size Exclusion Chromatography ◽

Cellulose Degradation ◽

Size Exclusion ◽

Exclusion Chromatography

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Inhomogeneities in the Chemical Structure of Hardwood Lignins

Holzforschung ◽

10.1515/hf.2003.039 ◽

2003 ◽

Vol 57 (3) ◽

pp. 255-265 ◽

Cited By ~ 32

Author(s):

H. Önnerud ◽

G. Gellerstedt

Keyword(s):

Secondary Wall ◽

Lignin Content ◽

Middle Lamella ◽

Size Exclusion ◽

Wall Material ◽

Thermomechanical Pulp ◽

Aryl Ether ◽

Spruce Wood ◽

Exclusion Chromatography ◽

The Difference

Summary Bauer-McNett fractions of an aspen chemi-thermomechanical pulp showed a significant variation with respect to lignin content and sugar composition, and two of the fractions were found to be particularly rich in middle lamella and secondary wall material, respectively. The secondary wall lignin of aspen was found to contain larger amounts of non-condensed β-O-4 aryl ether structures than the middle lamella lignin and the difference was attributed to a larger amount of syringyl structures as revealed by thioacidolysis. Size exclusion chromatography of the thioacidolysis products from birch and spruce wood showed a larger part of lignin oligomers being present in the degraded spruce lignin. Moreover, birch lignin had a lower phenolic content than both aspen and spruce lignin. Thioacidolysis followed by Raney-nickel desulphuration was used for the analysis of hardwood lignin trimers.

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Extraction products from var. ‘Soranovskii’

Chemical Papers ◽

10.1515/chempap-2015-0158 ◽

2015 ◽

Vol 69 (11) ◽

Author(s):

Sergey G. Il’yasov ◽

Viktor A. Cherkashin ◽

Gennady V. Sakovich ◽

Dmitri A. Parkhomenko

Keyword(s):

Analytical Techniques ◽

2D Nmr ◽

Size Exclusion ◽

Gas Chromatography Mass Spectrometry ◽

Polar Solvents ◽

Chemical Structures ◽

Organosolv Lignin ◽

Lignocellulosic Feedstock ◽

Exclusion Chromatography ◽

Thermobaric Conditions

AbstractThe chemical structures of Miscanthus var. ‘Soranovskii’ lignin fractions released via extraction of lignin from the lignocellulosic feedstock using moderately heated acetone under atmospheric pressure, without acidic and alkaline catalysts, were studied. A blend of Miscanthus stems and leaves was pretreated with water under thermobaric conditions. The acetone organosolv process subsequently afforded a substance related to a lignin-like matter-acetone organosolv Miscanthus lignin (AOML). Non-destructive analytical techniques such as FTIR spectroscopy, gas chromatography-mass spectrometry, size-exclusion chromatography, and 2D NMR were used. The IR and NMR spectroscopies revealed the AOML structure to comprise all the three major types of phenylpropane units: guaiacyl (G), syringyl (S), and p-hydroxyphenyl (H). The resultant acetone-organosolv lignin exhibits good solubility in polar solvents, moderate solubility in aromatic chemicals, and is insoluble in non-polar solvents, exhibiting the physicochemical properties of a thermoplastic polymer with a softening point of 67.0°C (onset 33.0°C, endset 81.5°C).

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