JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Xiao-Li Zhou,Pin-Jing He,Wei Peng,Shou-Xin Yi,Fan Lü,Li-Ming Shao,Hua Zhang
Polyvinyl chloride (PVC) is one of the most commonly used plastics. The treatment and recycling of PVC waste is still challenging, due to its non-biodegradability, low thermal stability, high Cl content and low product value. In this study, a one-pot method was developed to upcycle PVC into valuable carbon materials, pipeline-quality pyrolysis gas and chlorides. The well-designed process included dechlorination by Cl-fixative (ZnO or KOH), carbonization of dechlorinated polyenes, and modification of carbon materials in sequence. ZnO and KOH converted 84.48% and 94.15% of total Cl into corresponding chlorides, respectively. CH 4 and H 2 accounted for 81.87–99.34 vol% of pyrolysis gas with higher heat values of 30.11–32.84 MJ m −3 , which can be used as substitute natural gas. As high as 83.13% of the C element was converted into carbon materials. The morphology, structure and property of carbon materials can be modified by different Cl-fixatives. Millimeter-scale carbon spheres with mono-dispersity and porous carbon with a high specific surface area of 1922 m 2 g −1 were obtained when ZnO and KOH were added, respectively. Moreover, the reaction mechanisms of PVC with Cl-fixatives were also deciphered through thermogravimetric analysis and thermodynamic simulation.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
iScience
·
2025
·
IF 4.1
Kaiyun Zhang,Lei Yu,Laiqiang Qu,Na Hui,Li Chen,Jiameng Wang,Hong Yan
Microplastics (MPs), an emerging global pollutant, pose potential risks to human health and have garnered increasing attention. Previous research has identified MPs in various human tissues and organs, but not in the aqueous humor of the eyes. This study used pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) to explore MPs in aqueous humor. Five types of MPs—polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polyamide 66 (PA66), and polystyrene (PS)—were found, with PE and PVC being most common. PP was more prevalent in children, while PA66 was more common in adults. MPs abundance generally followed the trend: adults > children > elders among age groups, and females > males between gender groups. Notably, this study is the first to confirm MPs in human aqueous humor, providing a foundation for future research on their impact on intraocular health and enhancing our understanding of the MPs’ body distribution.
研究领域:
环境科学
·
医学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2015
·
IF 2.746
Na Wang,Ling He,Xiang Zhao,Stefan Simon
The mostly used drying-oils as binding media in historical artworks of eastern tung-oil and western linseed-oil, poppy-oil, walnut-oil are comparatively identified by on-line methylated pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS). Based on the analysis of un-pigmented and pigmented reference samples after treated by natural aging, hydro-thermal aging and UV aging, respectively, the characteristic pyrolysis products of all drying-oils are classed into mono-carboxylic acids (C6–8, 14, 16, 18, 20), di-carboxylic acids (2C6–12), glycerol, erythritol , 2-tridecanone, 8-hydroxy-octanoic acid, 3-octyl-oxiraneoctanoic acid and 2,6,10-trimethyl-9-undecenoic acid. Both benzene derivative and 9,10-dihydroxy-octadecanoic acid are suggested as the marked components for distinguishing eastern and western drying-oil. The investigated pigments of malachite, cinnabar, azurite and ochre do not show obvious influence on the detection of characteristic pyrolysis products of drying-oil, but they are proved to accelerate the aging and hydrolyzing rate of drying-oil, especially the pigment of cinnabar. The established on-line methylated Py–GC/MS procedure and the summarized data have been successfully applied on the identification of raw tung-oil and boiled tung-oil in historical painting samples collected from Drum Tower (Ming Dynasty), Bell Tower (Ming Dynasty), and Thousand-Buddha Cliff Grotto (Tang Dynasty). It is believed that the established Py–GC/MS procedure is able to provide wide application in archeological research.
研究领域:
考古学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Qinqi Zhan,Yanhong Yin,Ke Zhang,Peng Deng,Min Wen,Xianbin Liu,Yesheng Li,Ziping Wu
Tungsten carbide-cobalt (WC-Co) mixtures is the most critical material for cemented carbide . However, traditional preparation methods by using various carbon sources (e. g. carbon black, glucose, methane, carbon monoxide) cause severe carbon deposition. Consequently, traditional WC-Co mixtures exhibits uncontrollable carbon content. To address the challenge, we investigate the in-situ synthesis of WC-Co mixtures by supplying successive liquid methanol as a carbon source and nitrogen gas as a diluent. The as-prepared WC-Co mixture possesses clean surface and controllable carbon content, which are no need for removing excess carbon deposition by washing with water. The carbon nanolayers derived from methanol cracking gas appear on the surface of the intermediates, which can effectively prevent particle aggregation, efficiently increase the intimate contact probability of WC particles and Co particles, and greatly reduce the appearance of excess carbon deposition during subsequent carbonization processes. The present study offers insights on employing quantitative methanol cracking gas as reductive and carbonaceous atmosphere to mediate carbon content in the WC-Co composite powder, which presents a more economical and efficient pathway for large-scale synthesis of high-quality WC-Co mixtures with clean surface and controllable carbon content.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2023
·
IF 7.4
Peiru Luo,Mengke Bai,Qingyun He,Zifang Peng,Lingyun Wang,Chuan Dong,Zenghua Qi,Wenfen Zhang,Yanhao Zhang,Zongwei Cai
The broad application of plastic products has resulted in a considerable release of microplastics (MPs) into the ecosystem. While MPs in other environmental matrices (e.g., soil and water) have been studied for a long time, the atmospheric fine particulate matter (PM2.5)-bound MPs are rarely investigated due to the lack of an appropriate analytical approach. The prevalently used visual and spectroscopic means (e.g., optical microscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy) suffer from obvious drawbacks that cannot precisely detect MPs of tiny sizes and provide quantitative information. In the present study, a novel strategy that does not require sample pretreatment was developed to first effectuate accurate quantification of polyethylene MP (PE-MP) in PM2.5 based on pyrolysis-gas chromatography–tandem mass spectrometry (Pyr-GC-MS/MS). It featured acceptable recoveries (97%–110%), high sensitivity (LOD = 1 pg), and qualified precisions (RSD of 3%–13%). Employing this approach, for the first time, exact atmospheric concentrations of PE-MPs in PM2.5 from megacities in North (Zhengzhou and Taiyuan) and South (Guangzhou) China were obtained, and relatively serious pollution was found in Taiyuan. The 100% sample detection rates also suggested the widespread occurrence and possible human exposure risks of PM2.5-bound PE-MPs. In brief, the new strategy could conduct direct, sensitive, and accurate quantification of PE-MP in PM2.5, favoring further studies of environmental fates, distributions, and toxicities of atmospheric MPs.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Science China-Technological Sciences
·
2023
·Vol. 66
·期 8
·2258-2270
·
IF 4.6
Wang Na,Gu An,Lei Yong
Lacquer is the main raw material of lacquerware, while UV-irradiation is an important factor leading to its aging. In order to investigate the aging behavior of urushi lacquer film under UV-irradiation, and to propose parameters that can be used to evaluate its aging degree, the micro-UV/Py-GC/MS system has been applied in the present work to enrich and identify volatile products released by urushi film during aging on the one hand, and to investigate micro-amount and conventional urushi films with different aging degrees on the other hand, in addition, representative historical samples have also been investigated. Volatile products released by urushi film demonstrate that during UV-irradiation, polysaccharides wrapping urushiol polymer would be first degraded to generate furans and alcohols, and then urushiol polymer would undergo photo-oxidation and break of molecular chain, mainly generating oxidation products including aldehydes, organic acids, and ketones, as well as a small number of alkyl benzenes and hydrocarbons. Py-GC/MS analysis of micro-amount urushi films with different aging degrees indicates that UV-irradiation is more destructive to aliphatic chains in urushiol polymer, but it also can accelerate the polymerization of micro-amount urushi film. Py-GC/MS analysis of conventional urushi films indicates that with the increase of aging degree, the total chromatographic peak area ratio of hydrocarbons to benzene derivatives gradually increases, the peak area ratio of 3-pentadecenyl-catechol to 3-pentadecyl-catechol gradually decreases, and the peak area ratio of aging products of urushiol to 3-pentadecyl-catechol gradually increases. The above parameters were further used to evaluate the aging degree of two urushi-contained samples separately collected from the surface and interior of a carved lacquer panel in the Forbidden City, and evaluation results are in accord with the natural aging law and further verify the reliability of the proposed parameters. Research results of the present work can lay a foundation for the in-depth study of the UV-irradiation aging mechanism of urushi.
研究领域:
材料科学
·
文物保护
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2020
·
IF 7.539
Jiayan Ge,Yuting Wu,Yushan Han,Chengrong Qin,Shuangxi Nie,Shijie Liu,Shuangfei Wang,Shuangquan Yao
Effective removal of alkali and alkaline earth metals (AAEM) is of great significance for promoting biomass pyrolysis. In this study, demineralization via hydrothermal pretreatment was performed, and the effect on the pyrolysis behavior was evaluated by thermogravimetric analysis (TGA) and thermal pyrolysis–gas chromatography-mass spectrometry (Py–GC/MS). The effects of reaction temperature, time, and pH on the dissolution rate of K + , Ca 2+ , and Mg 2+ were investigated. The optimal total dissolution rate of the metal elements was 42.10%. Compared with acid leaching, hydrothermal pretreatment allowed a higher crystallinity index. It significantly changed the pyrolysis behavior. The relative content of sugar in pyrolysis products was as high as 58%. The chemical compound distribution was concentrated in the range between C6 and C9, which was conducive for the refinement of gasoline by upgrading. This means that hydrothermal pretreatment has efficient demineralization, which promoted the thermal degradation behavior of biomass.
研究领域:
生物质能源
·
化学工程
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2023
·Vol. 148
·期 10
·4211-4221
·
IF 4.4
Dai Shuming,Song Ping,Jiao Ziyue,Cheng Yi,Shang Jingzhao,Leng Xuefei,Wei Zhiyong,Li Yang
A series of bisphenol A-based polyarylates was synthesized by using 2,2-bis (4-hydroxyphenyl) propane (BPA), terephthaloyl dichloride (TPC), and isophthaloyl dichloride (IPC) as raw materials and p-tert-butylphenol as a capping agent through interfacial polymerization to investigate the effect of end group structure on polymer properties. And the polymer films could be obtained by solvent casting method. The successful introduction of p-tert-butylphenol into the backbone adjusted molecular masses and achieved a regulable improvement of the polymer’s thermal properties. The thermal mass loss 5% temperature of the polymers raised above 470 °C, which indicated the thermal properties were broadly in line with that of the commercial product U-100. Besides, the addition of capping agent also improved the light transmission of the polymers and the transmittance reached above 83% at a wavelength of 450 nm. In addition, the thermal degradation mechanism of polyarylate and U-100 was investigated by simultaneous thermal analysis (STA)-IR and Py/GC–MS. It was discovered that PAR decomposed thermally at their end groups and ester groups first, followed by the breakage of their carbon–carbon bonds, which coincided with U-100’s thermal degradation mechanism. The thermal degradation mechanism of bisphenol A-based polyarylates was proposed. Graphical abstract
研究领域:
高分子科学
·
材料科学
·
热分析
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Han Gao,Shang Gao,Lei Wang,Zhen Song,Xiaolei Qu,Minli Wang,Tao Long,Jinzhong Wan
Thermal treatment is a commonly applied soil remediation technique that can also change the properties of soil. However, few studies looked into the transformation and mechanism of soil organic matter (SOM) at the molecular level when contaminated soil undergoes thermal remediation. Herein, FT-ICR MS, pyrolysis gas chromatography mass spectrometry (Py-GC–MS), and size exclusion chromatography-diode array detector-fluorescence detector-organic carbon detector (SEC-DAD-FLD-OCD) were used to unveil the molecular transformation mechanism of SOM under 100 °C and 400 °C treatments. The macromolecules transformed to humic and fulvic components after 400 °C treatment, while few transformations occurred after 100 °C treatment. The molecules decreased with the increase in temperature. After 400 °C treatment, over 99 % of the molecules were newly produced, which were mainly aromatic (66 %) and lignin-like (19 %) components. After 100 °C treatment, most of the molecules (73.6 %) were reserved. The unsaturation and aromatic structures of SOM increased significantly after the 400 °C treatment, while the changes were relatively minor after the 100 °C treatment. The fracture of the carbon skeleton, cyclization, and H abstraction reactions were the main mechanisms for the molecular transformation of SOM during 400 °C treatment, while volatilization was the main transformation scheme during 100 °C. Statistical results of pyrolysates show the increase of aromatic components, and the molecular markers reflected the increase of condensed organic carbon and the decrease of phenols, alkene components during 400 °C treatment. The sorption of PAHs for soil decreased after treatment, owing to the loss and transformation of SOM. This study advances the mechanistic understanding of transformation in SOM molecular signatures during thermal treatment.
研究领域:
环境科学
·
土壤化学
·
分析化学
·
有机地球化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）