scholarly journals Surface Chemical Changes of Sugar Maple Wood Induced by Thermo-Hygromechanical (THM) Treatment

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1946 ◽  
Author(s):  
Qilan Fu ◽  
Alain Cloutier ◽  
Aziz Laghdir ◽  
Tatjana Stevanovic
Keyword(s):  
Wood Surface ◽  
Sugar Maple ◽  
Chemical Properties ◽  
Attenuated Total Reflection ◽  
Gas Chromatography Mass Spectrometry ◽  
Surface Chemical ◽  
Densification Process ◽  
Pyrolysis Process ◽  
Pyrolysis Gas ◽  
Chemical Changes

The aim of this study was to investigate the effects of heat and steam on the chemical properties of thermo-hygromechanical (THM)-densified sugar maple wood. The THM densification process was performed at two different temperatures (180 °C and 200 °C) with and without steam. The functional groups, surface chemical composition and internal structure and components of the control and densified samples were investigated using attenuated total reflection Fourier transform infrared (ATR-FTIR), X-ray photoelectron (XPS) spectroscopy and pyrolysis gas chromatography-mass spectrometry (Py-GC/MS). The obtained results suggest that the THM densification treatment resulted in significant chemical changes on the wood surface. The results of the ATR-FTIR spectra confirmed the decomposition of hemicelluloses and the relative increase of cellulose and lignin contents on the wood surface. The Py-GC/MS and XPS results show an increase of the oxygen/carbon atomic (O/C) ratio, which indicated that chemical substances containing oxygenated functionality were formed through the densification process. The densification treatment favored the depolymerization of hemicelluloses and cellulose as indicated by an increased anhydrous sugar (levoglucosan) release during the pyrolysis process. Densification also facilitated the cleavage of the lignin side chains, resulting in increased phenyl units with short chains released during the pyrolysis process.

scholarly journals Are agricultural plastic covers a source of plastic debris in soil? A first screening study

2021 ◽  
Author(s):  
Zacharias Steinmetz ◽  
Paul Löffler ◽  
Silvia Eichhöfer ◽  
Jan David ◽  
Katherine Muñoz ◽  
...  
Keyword(s):  
Attenuated Total Reflection ◽  
Gas Chromatography Mass Spectrometry ◽  
Short Term ◽  
Pyrolysis Gas ◽  
Wind Drift ◽  
Plastic Debris ◽  
Fine Soil ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Screening Study ◽  
External Sources

Abstract. Agricultural plastic covers made from polyethylene (PE) and polypropylene (PP) offer increased yields and an improved crop quality. However, such covers are suspected of partially breaking down into smaller debris and thereby contributing to soil pollution with microplastics. To scrutinize this, we randomly sampled 240 topsoil cores (0–5 cm) from eight fields covered with fleeces, perforated foils, and plastic mulches for less than two years. Samples from the field periphery (50 m perimeter) served as reference. Visual plastic debris > 2 mm was analyzed by Fourier transformed infrared spectroscopy with attenuated total reflection (FTIR–ATR). Smaller, soil-associated plastic debris was dispersed from 50 g of fine soil (≤ 2 mm) using sodium hexametaphosphate solution and density-separated with saturated NaCl solution. The collected PE, PP, and polystyrene (PS) debris was selectively dissolved in a mixture of 1,2,4-trichlorobenzene and p-xylene at 150 °C and quantified by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). We counted six PE and PS fragments > 2 mm in two out of eight fields. By contrast, Py-GC/MS analysis revealed PE, PP, and PS contents > 1 µg g−1 in seven fields (17 % of all samples). In three fields, PE levels of 3–35 µg g−1 were associated with the use of thinner and less durable perforated foils (40 µm thickness). This was slightly more pronounced at field edges where the plastic covers are turned and weighted down. By contrast, 50 µm thick PE films were not indicated to emit any plastic debris. PP contents of 5–10 µg g−1 were restricted to single observations in the field centers of three sites. On one site, we found expanded PS particles >2 mm that concurred with elevated PS levels (8–19 µg g−1) in the fine soil. Both PP and PS were distributed indistinctly across sites so that their source remained unresolved. In addition, the extent to which plastic contents of up to 7 µg g−1 in the field periphery of some sites were attributed to wind drift from the covered fields or from external sources needs to be investigated in future studies. Yet, our results suggest that the short-term use of thicker and more durable plastic covers should be preferred to limit plastic emissions and accumulation in soil.

Production of Phenolic Compounds from Low Temperature Catalytic Fast Pyrolysis of Biomass with Activated Carbon

2014 ◽  
Vol 541-542 ◽  
pp. 190-194 ◽  
Author(s):  
Zhi Bo Zhang ◽  
Xiao Ning Ye ◽  
Qiang Lu ◽  
Chang Qing Dong ◽  
Yong Qian Liu
Keyword(s):  
Activated Carbon ◽  
Phenolic Compounds ◽  
Fast Pyrolysis ◽  
Product Distribution ◽  
Catalytic Performance ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Process ◽  
Pyrolysis Gas ◽  
Catalytic Fast Pyrolysis ◽  
Pyrolysis Of Biomass

Activated carbon (AC) was reported as a promising catalyst to selectively produce phenolic compounds from biomass using the micro-wave assisted catalytic pyrolysis technique. In order to evaluate the catalytic performance of the AC under the traditional fast pyrolysis process, analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) technique was applied for the catalytic fast pyrolysis of biomass mixed with the AC. Polar wood was selected as the feedstock, and experiments were conducted to reveal the AC-catalyzed poplar wood pyrolysis behavior and product distribution. The results indicated that the AC was also effective for the phenolics production in the traditional fast pyrolysis process at 350 °C. It could promote the formation of phenolic compounds, and inhibit most of the other pyrolytic products. The maximal phenolics yield was obtained at the biomass to catalyst ratio of 1:4, with the peak area% over 50%.

scholarly journals Material Analysis and a Visual Guide of Degradation Phenomena in Historical Synthetic Polymers as Tools to Follow Ageing Processes in Industrial Heritage Collections

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 121
Author(s):  
Till Krieg ◽  
Cristian Mazzon ◽  
Elena Gómez-Sánchez
Keyword(s):  
Synthetic Polymers ◽  
Attenuated Total Reflection ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Industrial Heritage ◽  
Visual Damage ◽  
Material Information ◽  
Underlying Processes ◽  
Heritage Collections

Identifying the most vulnerable plastics and monitoring their deterioration is one of the main problems within heritage collections with historical synthetic polymers. Gathering and interpreting data about material and degradation phenomena in a collection reveals its conservation needs. A systematic survey of the collection can help towards this purpose. Surveys aiming at inspecting and documenting damages rely on several tools in order to fulfill their purpose. Firstly, objective descriptions of the damages that may appear, and secondly, the means of acquiring and interpreting material information. To address these needs, this article presents (a) a visual damage catalogue of degradation phenomena in plastic and rubber materials, and (b) the implementation of Fourier-transform infrared spectroscopy (FTIR) and pyrolysis–gas chromatography–mass spectrometry (py-GCMS) for the identification of analytically challenging rubber materials and of blooming phenomena. The damage catalogue is based solely on visual and olfactory signs, so that the assessment is independent of possible causes of damages and underlying processes, with the purpose of allowing objectivity to prime over interpretation. The limitations of the use of FTIR in the identification of heavily compounded rubbers in museum surveys is highlighted, and examples are presented. The use of py-GCMS on these cases conveniently allowed the identification of the constituting monomers of several rubber materials where FTIR could not provide a univocal classification of the material present. The study of several cases of blooming allowed the identification of diverse compositions and origins, showing that the description of a degradation phenomenon is only the first step towards its understanding. Unveiling the nature of a particular case of blooming is particularly critical when conservation treatments, such as the removal of a (potentially protecting) layer, are planned. For this purpose, attenuated total reflection-FTIR (ATR-FTIR) as a surface technique was particularly useful.

scholarly journals Analysis of paint traces to determine the ship responsible for a collision

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
H. Lee ◽  
D. Lee ◽  
J. M. Seo
Keyword(s):  
Electron Microscopy ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
X Ray ◽  
Pyrolysis Gas Chromatography ◽  
Ship Collision ◽  
Derivative Thermogravimetry ◽  
Scanning Electron

AbstractAlthough there have been many instances of ship collision at sea in recent times, not much research has been conducted on the topic. In this study, paint from an actual site of ship collision was collected and analyzed as evidence. The amount of evidence collected from the ships involved in the collision is either small or has inconsistent morphology. In addition, the contaminants and samples are often mixed in this evidence, making its analysis difficult. Paint traces of the damaged ship and the ship suspected to be responsible for the collision were compared through scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDS), attenuated total reflection–Fourier transform infrared spectroscopy (ATR–FTIR), thermogravimetry (TG) and derivative thermogravimetry (DTG), and pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) analyses. The ship responsible for the collision could be identified by characterization and by performing a comparative analysis of the extracted paint. Among the methods used in this study, Py–GC/MS can sensitively analyze even similar paints, and identified styrene and phthalic anhydride as the most prominent components of the paint used as evidence. The results obtained can be used to investigate the evidence collected from collision sites and to determine the ship responsible for the collision.

scholarly journals On the Set of Fellini’s Movies: Investigating and Preserving Multi-Material Stage Costumes Exploiting Spectroscopic and Mass Spectrometric Techniques

2021 ◽  
Vol 11 (7) ◽  
pp. 2954
Author(s):  
Francesca Sabatini ◽  
Jacopo La Nasa ◽  
Camilla Guerrini ◽  
Francesca Modugno ◽  
Sara Bonadio ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Performance ◽  
Chemical Properties ◽  
Attenuated Total Reflection ◽  
Array Detector ◽  
Synthetic Dyes ◽  
Pyrolysis Gas ◽  
Art Objects ◽  
Synthetic Materials ◽  
The 19Th Century

Since the second half of the 19th century, the world of textile production was radically changed both in terms of esthetics and of the performances leading to industrial products whose chemical properties were totally unknown and unexplored. Stage costumes are typical examples of multi-material art objects where different natural and synthetic materials were used to fulfil specific purposes. This research was performed in the framework of a diagnostic and restoration campaign of dresses of two Federico Fellini’s movies (“Il Casanova” and “Roma”). For the characterization of the textile fibers, Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Pyrolysis Gas Chromatography coupled with Mass Spectrometry (Py-GC/MS) were employed. The structure of the metallic threads was investigated by Scanning Electron Microscopy coupled with Energy-Dispersive X-ray Spectroscopy (SEM-EDX). Dye identification was carried out by High Performance Liquid Chromatography coupled with Diode Array Detector and mass spectrometry (HPLC-DAD, HPLC-ESI-Q-ToF). The analytical approach adopted allowed us to fully characterize the costumes composed of natural, synthetic and artificial fibers dyed with complex mixtures of last generation synthetic dyes. The results collected were fundamental to fine-tune an effective restoration aimed at minimizing the damages due to ageing, inaccurate home-made restoration interventions, or poor conservation conditions.

scholarly journals An easy and reliable method for syringyl: guaiacyl ratio measurement

TAPPI Journal ◽  
2017 ◽  
Vol 16 (03) ◽  
pp. 145-152
Author(s):  
Raquel Prado ◽  
Lisa Weigand ◽  
Shikh M.S.N.S. Zahari ◽  
Xabier Erdocia ◽  
Jason Hallett ◽  
...  
Keyword(s):  
Quantum Coherence ◽  
Partial Least Squares Regression ◽  
Attenuated Total Reflection ◽  
Gas Chromatography Mass Spectrometry ◽  
Least Squares Regression ◽  
Pyrolysis Gas ◽  
Simple Method ◽  
Ratio Measurement ◽  
Complex Process ◽  
G Ratio

Lignin structure elucidation is one of the main targets for biorefinery related research. Because of its complexity, obtaining reproducible results in a straight-forward way is very important. One of the values that is used to compare different lignins is the syringyl:guaiacyl (S/G) ratio, which has been measured in different ways. The most reliable result is obtained for nitrobenzene oxidation, but this involves a complex process. In this work, the S/G ratios measured by pyrolysis-gas chromatography mass spectrometry (py-GCMS) and heteronuclear single quantum coherence-nuclear magnetic resonance (HSQC-NMR) spectroscopy were compared with attenuated total reflection infrared (ATR-IR) spectroscopy results to establish a reliable, quick, and simple method for the measurement. To achieve this, two mathematical models were applied with multivariate data analysis software. A partial least squares regression model for py-GCMS gave the best result.

Thermo-Oxidative Decomposition of Lovage (Levisticum officinale) and Davana (Artemisia pallens) Essential Oils under Simulated Tobacco Heating Product Conditions

2020 ◽  
Vol 29 (1) ◽  
pp. 27-43
Author(s):  
Emma Jakab ◽  
Zoltán Sebestyén ◽  
Bence Babinszki ◽  
Eszter Barta-Rajnai ◽  
Zsuzsanna Czégény ◽  
...  
Keyword(s):  
Low Temperature ◽  
Essential Oils ◽  
Relative Yield ◽  
Gas Chromatography Mass Spectrometry ◽  
Intramolecular Rearrangement ◽  
Oxidation Reactions ◽  
Pyrolysis Gas ◽  
Oxidative Decomposition ◽  
Oxidative Pyrolysis ◽  
Artemisia Pallens

SummaryThe thermo-oxidative decomposition of lovage (Levisticum officinale) and davana (Artemisia pallens) essential oils has been studied by pyrolysis-gas chromatography/mass spectrometry in 9% oxygen and 91% nitrogen atmosphere at 300 °C to simulate low-temperature tobacco heating conditions. Both lovage and davana oils contain numerous chemical substances; the main components of both oils are various oxygen-containing compounds. Isobenzofuranones are the most important constituents of lovage oil, and their relative intensity changed significantly during oxidative pyrolysis. (Z)-ligustilide underwent two kinds of decomposition reactions: an aromatization reaction resulting in the formation of butylidenephthalide and the scission of the lactone ring with the elimination of carbon dioxide or carbon monoxide. Davanone is the main component of davana oil, which did not decompose considerably during low-temperature oxidative pyrolysis. However, the relative yield of the second most intensive component, bicyclogermacrene, reduced markedly due to bond rearrangement reactions. Davana ether underwent oxidation reactions leading to the formation of various furanic compounds. The changes in the composition of both essential oils could be interpreted in terms of bond splitting, intramolecular rearrangement mechanisms and oxidation reactions of several constituents during low-temperature oxidative pyrolysis. The applied thermo-oxidative method was found to be suitable to study the stability of the essential oils and monitor the decomposition products under simulated tobacco heating conditions. In spite of the complicated composition of the essential oils, no evidence for interaction between the oil components was found. [Beitr. Tabakforsch. Int. 29 (2020) 27–43]

CHARACTERISATION OF DISSOLVED ORGANIC CARBON (DOC) LEACHED FROM LEAVES IN WATER

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Markus Heryanto Langsa
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Total Organic Carbon ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Pyrolysis Gas Chromatography ◽  
Chromatography Mass Spectrometry ◽  
Pinus Radiate

<p>Penelitian ini bertujuan untuk menentukan senyawa organik khususnya organic karbon terlarut (DOC) dari dua spesies daun tumbuhan (<em>wandoo eucalyptus </em>and <em>pinus radiate, conifer</em>) yang larut dalam air selama periode 5 bulan leaching eksperimen. Kecepatan melarutnya senyawa organic ditentukan secara kuantitatif dan kualitatif menggunakan kombinasi dari beberapa teknik diantaranya Total Organic Carbon (TOC) analyser, Ultraviolet-Visible (UV-VIS) spektrokopi dan pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS).</p><p>Hasil analisis DOC dan UV menunjukkan peningkatan yang tajam dari kelarutan senyawa organic di awal periode pengamatan yang selanjutnya berkurang seiring dengan waktu secara eksponensial. Jumlah relatif senyawa organic yang terlarut tergantung pada luas permukaan, aktifitas mikrobiologi dan jenis sampel tumbuhan (segar atau kering) yang digunakan. Fluktuasi profil DOC dan UV<sub>254</sub> disebabkan oleh aktifitas mikrobiologi. Diperoleh bahwa daun kering lebih mudah terdegradasi menghasilkan senyawa organic dalam air dibandingkan dengan daun segar. Hasil pyrolysis secara umum menunjukkan bahwa senyawa hidrokarbon aromatic dan fenol (dan turunannya) lebih banyak ditemukan pada residue sampel setelah proses leaching kemungkinan karena adanya senyawa lignin atau aktifitas humifikasi mikrobiologi membuktikan bahwa senyawa-senyawa tersebut merupakan komponen penting dalam proses karakterisasi DOC.</p>

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