CATALYSIS LETTERS
·
2017
·Vol. 147
·期 7
·1631-1639
·
IF 2.799
Zhang Zhengwei,Xiao An,Yan Kun,Liu Yanhua,Yan Zhengyu,Chen Jianqiu
Abstract Herein, the CuInS 2 /ZnS/TGA quantum dots (QDs) were prepared by the oil phase reaction containing thioglycolic acid (TGA) as a functional modification agent under a nitrogen atmosphere. The CuInS 2 /ZnS/TGA QDs using as the photocatalysts exhibited high photocatalytic activity for the degradation of Rhodamine B (RhB) under ultraviolet irradiation. The photocatalytic conditions were optimized to degrade RhB with superior performances, including the initial RhB and CuInS 2 /ZnS/TGA QDs concentrations, solution pH values and ultraviolet light intensities. Furthermore, the kinetic equations of photocatalytic reaction and possible photocatalytic degradation mechanism were investigated. The results indicated that it belongs to the typical first order kinetic in accordance with the Langmuir–Hinshelwood mechanism, and the electrons and holes on the surface of the CuInS 2 /ZnS/TGA microspheres are the main acting forces during the RhB photocatalytic degradation. Graphical Abstract
研究领域:
材料科学
·
环境科学
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高影响因子
Polymers
·
2022
·Vol. 14
·期 15
·3158
·
IF 4.967
Chunxia Zhu,Shuyu Pang,Zhaoxia Chen,Lehua Bi,Shuangfei Wang,Chen Liang,Chengrong Qin
At present, the synthesis methods of crystalline porous materials often involve powder products, which not only affects the practical application but also has complex synthesis operations and limited scale. Based on the mechanochemical method, we choose COF-TpPa-1, preparing TpPa-1-DANC composites. Covalent organic frameworks (COFs) are a kind of crystalline material formed by covalent bonds of light elements. COFs possess well pore structure and high thermal stability. However, the state of synthesized powders limits their application. Cellulose nanocrystals (CNCs) are promising renewable micron materials with abundant hydroxyl groups on their surface. It is possible to prepare high-strength materials such as film, water, and aerogel. Firstly, the nanocellulose was oxidized by the sodium periodate method to obtain aldehyde cellulose nanocrystals (DANC). TpPa-1-DANC not only had the crystal characteristic peak of COFs at 2θ ≈ 5° but also had a BET surface area of 247 m2/g. The chemical bonds between COFs and DANC formed by Schiff base reaction appeared in FTIR and XPS. The pyrolysis behavior of the composite was characterized by TG-IR, which showed that the composite had good thermal stability. With the advantages of nanocellulose as a material in every dimension, we believe that this method can be conducive to the large-scale synthesis of COFs composites, and has the possibility of multi-form synthesis of COFs.Keywords:covalent organic frameworks;aldehyde cellulose nanocrystals;mechanochemistry;TGA/FTIR
研究领域:
材料科学
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化学工程
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分析化学
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DOI
PubMed
高影响因子
JOURNAL OF FLUORESCENCE
·
2015
·Vol. 25
·期 4
·897-905
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IF 1.927
Li Li,Zhang Qiaolin,Ding Yaping,Lu Yaxiang,Cai Xiaoyong,Yu Lurong
Based on the quenching of the fluorescence intensity of thioglycolic acid (TGA)-capped core-shell CdTe/ZnS nanoparticles (NPs) by vanillin, a novel, simple and rapid method for the determination of vanillin was proposed. In aqueous medium, the functionalized core-shell CdTe/ZnS NPs were successfully synthesized with TGA as the capping ligand. TGA-capped core-shell CdTe/ZnS NPs were characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. Factors affecting the vanillin detection were investigated, and the optimum conditions were also determined. Under the optimum conditions, the relative fluorescence intensity of CdTe/ZnS NPs was linearly proportional to vanillin over a concentration range from 9.4 × 10 −7 to 5.2 × 10 −4 M with a correlation coefficient of 0.998 and a detection limit of 2.6 × 10 −7 M. The proposed method was also employed to detect trace vanillin in cookies with satisfactory results.
研究领域:
分析化学
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纳米技术
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食品科学
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DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2020
·
IF 3.905
Mudassir Hussain Tahir,Xingxing Cheng,Rana Muhammad Irfan,Rizwan Ashraf,Yiteng Zhang
The present study proposed successfully TG-FTIR as a novel technique for high quality bio oil production having desirable concentration of targeted products especially phenols and acids. TG-FTIR analysis of pine waste was performed to calculate yield of desirable chemical compounds at different temperature ranged 350−600 °C. While, bio oil was produced at each corresponded temperatures and GC–MS analysis was carried out to support TG-FTIR analysis which showed high consistency. Additionally, efficient extraction of phenolic compounds was performed via complex method using Ca 2+ as a complex agent under alkaline conditions which showed that 95 % phenols were extracted successfully. Meanwhile, production of calcium acetate in residue bio oil turns this study highly valuable for future scientific research.
研究领域:
生物质能
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分析化学
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环境科学
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DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2020
·Vol. 38
·期 3
·4241-4249
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IF 5.627
Gongxin Dai,Guanyu Wang,Kaige Wang,Zhongyue Zhou,Shurong Wang
As one of the major components of lignocellulosic biomass , the current understanding on pyrolysis mechanism of hemicellulose is relatively limited compared to that of cellulose due to its random and complicated structure. Here, we reported an in-depth study on hemicellulose pyrolysis by combining advanced experimental techniques and quantum chemical calculation , using xylose , xylobiose and xylan as the model compounds. The structural evolution during pyrolysis was firstly characterized via in-situ diffuse reflectance infrared Fourier transform spectroscopy . The corresponding two-dimensional perturbation correlation infrared spectroscopy analysis shows that the dissociation of side chains dominates in the initial stage of xylan pyrolysis, followed by the cleavage of glycosidic bond and the opening of xylopyranose ring. The release behaviors of condensable vapors from hemicellulose pyrolysis obtained by thermogravimetric analyzer coupled with photoionization mass spectrometry indicate that the pyrolysis of xylan polymer with more side chains is prone to produce small compounds via ring rupture reactions compared to that of xylose and xylobiose . The possible reaction pathways of xylan pyrolysis were proposed based on the experimental results and were further confirmed via quantum chemical calculation. This work expands the size of model compounds from common monomers and dimers without side chains to larger tetramers with side chains. It was found that the dissociation of side chains and the cleavage of glycosidic bonds are competitive reactions. The backbone of xylan is decomposed following the dissociation of side chains to yield furfural , dianhydro xylose and other small compounds.
研究领域:
生物质能源
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热化学转化
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分析化学
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量子化学
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聚合物热解
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DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 67
·38196-38203
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IF 2.936
Haihui Chen,Hongfu Fan,Yi Zhang,Xingguang Xu,Long Liu,Qingfeng Hou
Spontaneous imbibition is crucial for the development of matrix-fractured petroleum reservoirs. To improve the ultimate oil recovery, it is essential to demonstrate the role of the surfactant solution on the imbibition process. In this study, spontaneous imbibition experiments were carried out using self-prepared oil sand that to investigate the dependence of oil recovery on the concentration of a fluorocarbon surfactant (FS-30). Emulsion and solubilization were assessed to identify the correlation between oil-water interface properties and spontaneous imbibition. Moreover, thermogravimetric analysis (TGA) was also applied to accurately determine the imbibition recovery and look into the influence of components of crude oil on spontaneous imbibition. The maximum ultimate oil recovery in this work was 70.8% using 0.3 wt% FS-30, when the oil-solid adhesion tension, the capillary pressure (PC) and solubilization factor (SF) attained extreme values of −3.7002 mN m−1, 4.8751 MPa and 242.7 mL g−1, respectively. It was found that the surface activator played a critical role in promoting the imbibition process through altering the contact angle and interfacial tension. A negative adhesive tension and a positive capillary pressure would accordingly be generated, which facilitated the departure of oil droplets from the rock surface. In addition, it was observed that a lower solubilization factor and higher emulsion stability could favour spontaneous imbibition. Finally, heavier components in oil sands were more prone to be displaced than lighter counterparts, especially when the surfactant concentration was relatively high. This study may shed light on the effect of surfactants on spontaneous imbibition and thus is of great significance in understanding the underlying mechanism of the imbibition process.
研究领域:
石油工程
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化学工程
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DOI
PubMed
高影响因子
JOURNAL OF POLYMER RESEARCH
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2024
·Vol. 31
·期 7
·1-11
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IF 2.6
Yang Rui,Dai Zilin,Kong Zhenxing,Ou Juhua
Procuring silicone rubber composite with different content of vinyl MQ silicone resin was prepared and its thermal stability was evaluated. A total of 50 wt% MQ resin containing 5 wt% vinyl MQ exhibited optimal thermal stability and was consequently chosen. This silicone rubber composite was blended with TPU at high temperature using an internal mixer to produce a modified TPU. The TPU modified by silicone rubber was firstly investigated by Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). The FTIR results indicated that negligible chemical reactions occurred between TPU and silicone rubber during the mixing process. Furthermore, the TGA results demonstrated that the silicone rubber composite positively influenced the thermal stability of TPU. Additionally, the modified TPU displayed satisfactory thermal stability even after aging. Moreover, Scanning Electron Microscope (SEM) results indicated that uniform dispersion of silicone rubber was facilitated by the banburying method. The tensile strength of modified TPU initially increased and then decreased when the content of silicone rubber reached 3 wt%. On the other hand, the elongation at break of modified TPU demonstrated continuous improvement. Furthermore, the mechanical properties of the modified TPU were still acceptable after aging.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
POLYMER SCIENCE SERIES B
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2021
·Vol. 63
·期 4
·358-366
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IF 1.049
Danbo Mao,Yuechuan Wang
Abstract Four 2,5-dicholorobenzoate monomers were prepared by chlorination and esterification and then polymerized to ester substituted poly( p -phenylene)s through Ni/Zn catalyzed coupling reaction. The thermal stability and pyrolysis behavior of ester substituted poly( p -phenylene)s were investigated through TGA method. The possible mechanism of thermal modification of the polymers was proposed that included de-esterification, dehydration and decarboxylation, and finally de-anhydridization. Only pyrolysis of esters substituted poly( p -phenylene)s containing two neighboring carboxyl groups may result in the formation of the corresponding anhydride.
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2026
·
IF 4.6
Y. Yan,F.F. Huang,D.W. Wu,L. Li,N. Zhang,M.L. Huang
MPS-TGA synergy enables stable, controllable cyanide-free Au Sn co-deposition. • MPS selectively coordinates with Au + , while TGA coordinates with both Au + and Sn 2+ . • Au Sn co-deposition follows an irreversible, diffusion-controlled mechanism. • Baths remain stable for six months, consistently yielding reproducible Au Sn coatings. • Au Sn eutectic coating is mirror-bright, flat ( R a < 30 nm) and homogeneous after reflow. To replace toxic cyanide-based and unstable complex systems, a cyanide-free Au Sn electroplating bath using sodium 3-mercapto-1-propanesulfonate (MPS) and thioglycolic acid (TGA) as coordinating ligands, and the underlying co-deposition mechanism is systematically elucidated. The bath enables green processing, high bath stability (stable for six months) and superior coating quality. Electrochemical analyses reveal that MPS selectively coordinates with Au + , whereas TGA coordinates with both Au + and Sn 2+ , forming stable Au-MPS-TGA and Sn-TGA complexes. This synergistic coordination negatively shifts the deposition onset potentials of Au and Sn to −0.99 V and − 1.09 V (vs. SCE), respectively, narrowing their gap to 0.1 V and establishing the Au Sn co-deposition onset at −1.03 V (vs. SCE). Optimal concentration ratios are c (MPS): c (Au) = 8:1–12:1, c (SnCl 2 ): c (Au) = 3.0:1–4.0:1 and c (TGA): c (Au) = 8:1–10:1, under which Sn deposition is accelerated and the operating current density range is broadened to 2–6 ASD, yielding controllable and reproducible coating compositions (16.7–50.0 at.%Sn). The Au Sn co-deposition follows an irreversible, diffusion-controlled mechanism with a low activation energy ( E a ) of 9.50–27.36 kJ/mol, driven by sufficient overpotential to overcome the initial energy barrier for complex dissociation, thereby promoting fine-grained nucleation and growth. Consequently, the mirror-bright, flat Au Sn eutectic coating electroplated at 3 A/dm 2 (ASD) exhibits dense, uniform and residue-free deposits, which transform into a homogeneous eutectic microstructure after reflow. Download: Download high-res image (499KB) Download: Download full-size image
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Shengbo Zhu,Wei Li,Bingyang Lu,Weixing Chen,Wenzhi Zhang,Xiaoling Niu,Xinbing Chen,Zhongwei An
Two series of terminal epoxy compounds, PmOBC (m = 1, 2, 3, 4) and P1OBEn (n = 6, 8, 10, 12), were synthesized for investigating the effect of epoxidation on mesomorphic and thermal stabilities. Molecular polarization and configuration obtained by DFT calculations can provide theoretical perspective. In addition, thermal stability is evaluated by the combination of DSC , TGA , and 1 H NMR. Compared with the corresponding alkenyl compounds, epoxidation reduces the molecular dipole moment and increase the molecular steric effect , which is not conducive to the formation of LC phases, but the reduced intramolecular energy may be helpful to improve thermal stability. Therefore, these terminal epoxy LCs are very promising for application in display devices requiring extremely high-temperature environments.
研究领域:
材料科学
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物理化学
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DOI
高影响因子
Journal of Materials Chemistry A
·
2014
·Vol. 3
·期 4
·1696-1702
·
IF 0
Zhonghui Han,Gang Chen,Chunmei Li,Yaoguang Yu,Yansong Zhou
The one-dimensional (1D) cubic Cd0.8Zn0.2S solid-solution nanowires are first prepared by the “levelling effect” of thioglycolic acid (TGA) in a solvothermal process. It exhibits the enhanced transfer and separation efficiency of carriers to improve the photocatalytic H2-production activity. TGA not only serves as the sulphur source but also plays a template medium agent role. Furthermore, no TGA selectivity for diverse solvents to prepare 1D Cd0.8Zn0.2S solid solutions suggests that it also may be extended to the preparation of other 1D metal sulphide solid solutions in diverse solvents.
研究领域:
材料科学
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化学工程
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DOI
BIOMASS & BIOENERGY
·
2022
·
IF 5.774
Beier Jiang,Yuanyuan Ma,Lijing Wang,Zhou Guo,Xinyu Zhong,Tongtong Wu,Yuanyuan Liu,Haigang Wu
Molecular structure of hyperbranched polyglycerols (hbPGs) strongly affected the thermal stability as the critical heat transfer medium to maintain thermal homeostasis during working of heat engine. Here, thermogravimetric analysis (TGA)-fourier-transform infrared spectroscopy (FTIR)-gas chromatography (GC)-mass spectroscopy (MS) and reactive force-field (ReaxFF) techniques were utilized to identify major thermal decomposition products and explore the molecular mechanism. TGA-FTIR-GC/MS results showed that the major products were CO, CO 2 , water molecules and C3 organic moieties. To perform ReaxFF molecular dynamic simulation, timestep-dependent images revealed that C3 molecules were mainly originated from glycerol units and hydroxyl groups played an essential role in catalyzing thermal decomposition. To examine our hypothesis, different methoxylation levels of hbPGs were prepared, and TGA analysis of these methoxylated hbPGs polymers clearly corroborated that lower percentage of hydroxyl groups in the hbPGs can significantly increase maximum peak temperature from ∼400 °C to ∼460 °C. Our investigation clearly provided the molecular mechanism of hbPGs thermal decomposition and identified a potential way to improve thermal stability of hbPGs.
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高影响因子
危险品化学品经营许可证（带存储）