JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2016
·Vol. 100
·期 3
·968-974
·
IF 2.787
Ang Qiao,Haizheng Tao,Yuanzheng Yue
In this work we succeeded in synthesizing a chalcogenide glass, that is, the Ag 3 PS 4 glass, by milling the mixture of the crystalline Ag 2 S and P 2 S 5 powder. In terms of potential energy, the glass was excited by the milling process. The evidence for the energy excitation was the occurrence of the sub- T g relaxation recorded by a differential scanning calorimeter (DSC). The relaxation behavior in the milling-derived Ag 3 PS 4 glass was found to significantly differ from that of a hyperquenched oxide glass. We observed two decoupled peaks of the energy release during a DSC scan, which are in contrast to the single asymmetric peak of the hyperquenched glass. The low-temperature peak could be attributed to the β-relaxation of the Ag–S ionic bonds, whereas the high-temperature peak could arise from the α-relaxation of the distorted rigid [PS 4 ] units involving covalent bonds. The decoupling between the two peaks implies the fragile nature of the Ag 3 PS 4 glass. Upon the dynamic heating and the sub- T g annealing we found that the relaxation of the Ag 3 PS 4 glass is of high nonexponentiallity, and hence, of high structural heterogeneity.
研究领域:
材料科学
·
玻璃科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2017
·
IF 2.236
Jing Liu,Rujuan Li,Mengya Guo,Hairong Tao,Donglan Sun,Chengxing Zong,Chunjing Liu,Fengzhi Fu
We recently found that the introduction of benzene ring as connection block improved the thermal stability of glycerol carbonate derivatives. To further explore how polysubstitution on benzene influences their thermal stability, another two derivatives, benzene-1,3,5-tricarboxylic acid tris-(2-oxo-[1,3]dioxolan-4-ylmethyl) ester (BATE1) and benzene-1,2,4,5-tetracarboxylic acid tetrakis-(2-oxo-[1,3]dioxolan-4-ylmethyl) ester (BATE2), were synthesized and characterized by a combined TG–FTIR and theoretical calculation. TG results showed that both BATE1 and BATE2 had three weight loss stages. FTIR spectra of evolved gases and the bond dissociation energy for the two compounds indicated that during the pyrolysis process, the C C, C O bonds of five-membered cyclic carbonate fractured preferentially to produce volatile carbonates and CO 2 , and then the nearby C O bond of esters continued to crack to produce more fragments. Finally, benzene ring still remains in the solid pyrolysis products. Therefore, improving the thermal stability of compound cannot be achieved simply by increasing the number of substituents on the benzene ring.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2018
·Vol. 132
·期 3
·1729-1740
·
IF 2.209
Yuan Jiao-jiao,Tu Jun-ling,Xu Yong-jun,Qin Frank G. F.,Li Bing,Wang Cheng-zhang
Olive leaf extract pretreated by enzymolysis was selected for studying the thermal stability at different heating rates by thermogravimetric coupled with infrared spectroscopy (TG–FTIR) and nonisothermal theoretical analysis, and products analysis by pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS). Results revealed that thermal decomposition of ethyl acetate extract from olive leaf extract pretreated by enzymolysis (EAEEH) consisted of two steps and had a lower thermal stability. The nonisothermal decomposition kinetics mechanism of EAEEH was D3 model (three-dimensional diffusion, Jander equation, the first step) and F3 model (chemical reaction, n = 3, the second step). TG–IR showed –CH 3 , –C=C–, –OH, –C–O were continuously accelerated to produce, and evolved gas were CO 2 , water, CO and CH 4 at the end. In addition, it was found that there were mainly polyphenols with phenolic hydroxyl groups in the pyrolysis products by Py–GC–MS, and it was also explained for the thermal stability results. This will provide a theoretical guidance for thermal application of EAEEH in the safe natural food additives, cosmetic and medicine.
研究领域:
食品科学
·
化学工程
·
植物化学
✓ 已验证
DOI
高影响因子
RENEWABLE ENERGY
·
2023
·
IF 8.7
Yun Zhang,Chuanbiao Zhang,Wenjuan Li,Qiuping Xiao,Fengyuan Jiao,Sen Xu,Yanhua Lan,Yizheng Fu,Chi-Min Shu,Weiguo Cao
Stearic acid provides a basis for developing renewable energy, such as solar energy and biomass energy. A thermogravimetric-infrared spectroscopy (TG-IR) experimental test is conducted to obtain the thermal decomposition progress and the main gaseous products of stearic acid. The result shows that small gaseous products (H 2 O, CO 2 , CO, alkanes, olefins , etc.) are released. Furthermore, the method of reactive molecular dynamics simulation (ReaxFF-MD) is utilized to look into the pyrolysis reaction mechanism of stearic acid. The main pyrolysis products of stearic acid received by ReaxFF-MD are C 2 H 4 , H 2 , C 2 H 2 , CH 4 , H 2 O, CO 2 , and CO, consisting of the result of the TG-IR test. The effect of the simulated system density and temperature on the distribution of main products is also explored. Also, the thermal kinetic analysis is conducted by the initial consumption of stearic acid under different temperatures. The primary reaction mechanism of stearic acid pyrolysis is that the stearic acid molecules dissociate through C–C bonds break to generate C 2 H 4 , CH 4 , C 2 H 2 , C 3 H 6 , and other small molecules and radicals, and a typical reaction mechanism scheme of stearic acid pyrolysis is presented. The results provide a reference for explaining the macroscopic explosion characteristics of dust at the microscopic mechanism level.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2022
·
IF 6.437
Jianwei Zhang,Ling Chen,Liangyou Zhao,Guorui Jin,Weidong He
Nitrogen heterocycles as Nitrogen-rich energetic material has been widely popularized due to their desirable properties like low sensitivities, excellent stability, and lower environmental impact, less erosive and less toxic combustion gases , especially in gun propellant application areas. The focus of this study is on investigating interaction mechanism of 1 H-tetrazole (1 H-TZ) and nitrocellulose (NC) by kinetics methods and TG-DSC-FTIR analysis. The mixture (NC-TZ) between 1 H-TZ and NC was prepared by means of physical blending. DSC experiments indicated that the open and closed environment can generate different and important influence on the chemical reaction between 1 H-TZ and NC. Combined with the change of activation energy , it illustrated that the gas 2 H-tetrazole, the isomer of 1 H-TZ, had a significant influence on the thermal decomposition of NC. In comparison with kinetic models of NC and NC-TZ, it can be found that the addition of 1 H-TZ mainly affected the contribution factor and m value in the first stage. The value of m decreased from 1.00 to 0.15, meanwhile, the contribution factor was decreased from 0.50 to 0.12. It showed that NO 2 , the initial decomposition product of NC, had taken part in the thermal decomposition process of 1 H-TZ. TG-DSC-FTIR experiments indicated that there was a chemical reaction between 2 H-tetrazole and the initial decomposition product of NC, NO 2 , to form CO, N 2 O and HN 3 .
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Zhanshi Ni,Zhihui Song,Haobo Bi,Chunlong Jiang,Hao Sun,Zhicong Qiu,Liqun He,Qizhao Lin
Facing the severe environmental and energy crisis, how to use solid waste cleanly and efficiently is imminent. In this study, coal slime and cellulose are used for co-combustion experiments. Coal slime and cellulose are tested at mass ratios of 10:0, 9:1, 7:3, 5:5, 3:7, 1:9, and 0:10. When 10 % cellulose is added to the coal slime, the ignition temperature decreases by 169.3 °C, and the ignition characteristic index increased by 2.9 times. The addition of cellulose makes the comprehensive combustion performance of the sample increase exponentially. By analyzing the dominant reaction in the co-combustion process of coal slime and cellulose, the variance contribution rates of the first principal component and the second principal component are 67.84 and 29.18 %, respectively. Co-combustion of coal slime and cellulose enhances the release and combustion of early volatiles. In addition, the evolution law of gaseous products and the temperature dependence of gaseous products in the co-combustion process of coal slime and cellulose are analyzed by fourier transform infrared spectroscopy and two-dimensional correlation spectroscopy, respectively. This study provides a theoretical basis for the large-scale application of co-combustion of coal slime and biomass.
研究领域:
能源与环境科学
·
燃烧化学
✓ 已验证
DOI
高影响因子
Cell Death & Disease
·
2023
·Vol. 14
·期 2
·1-17
·
IF 9
Chen Yulian,Jiang Huanguo,Zhan Zhikun,Lu Jindi,Gu Tanwei,Yu Ping,Liang Weimin,Zhang Xi,Liu Shuwen,Bi Huichang,Zhong Shilong,Tang Lan
Converting lipid disturbances in response to energy oversupply into healthy lipid homeostasis is a promising therapy to alleviate hepatosteatosis. Our clinical studies found that a further elevation of triglyceride (TG) in obese patients with the body mass index (BMI) greater than 28 was accompanied by a further reduction of phosphatidylethanolamine (PE). Shorter survival and poor prognosis were shown for the patients with high TG and low PE levels. Liver X receptor alpha ( LXRα ) knockout mice aggravated high-fat diet (HFD)-induced obesity and lipid disorders, making the TG enrichment and the PE decrease more pronounced according to the liver lipidomics analysis. The RNA-seq from mice liver exhibited that these metabolism disorders were attributed to the decline of Atgl (encoding the TG metabolism enzyme ATGL) and Ept1 (encoding the PE synthesis enzyme EPT1) expression. Mechanistic studies uncovered that LXRα activated the ATGL and EPT1 gene via direct binding to a LXR response element (LXRE) in the promoter. Moreover, both the supplement of PE in statin or fibrate therapy, and the LXRα inducer (oridonin) ameliorated cellular lipid deposition and lipotoxicity. Altogether, restoration of lipid homeostasis of TG and PE via the LXRα-ATGL/EPT1 axis may be a potential approach for the management of hepatosteatosis and metabolic syndrome.
研究领域:
分子生物学
·
代谢学
·
肝病学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2019
·
IF 6.669
Yuan Zhang,Liping Kang,Hongmei Li,Xianzhang Huang,Xiaoyu Liu,Lanping Guo,Luqi Huang
The combustion of moxa floss was investigated by thermogravimetric/differential scanning calorimeter (TG/DSC), thermogravimetric/Fourier transform infrared spectroscopy (TG-FTIR) and an infrared radiation spectrum-detecting system. The average mass loss rate at the major stage of combustion was 1.08%/min with a peak at 7.86%/min. Moxa floss burning released the integral heat of 9188 mJ/mg from the temperature of 200 °C to 500 °C. The peak heat flow during char combustion stage was higher than those of other stages. The results indicated the combustion of moxa floss was a mild and slow process, releasing heat continuously and steadily. The infrared radiation spectra of burning moxa stick were in a range of 2.5–13.0 µm and showed double peaks at 3.75 µm and 8.75 µm. Thus, this study provided insight into why moxa floss biomass is the optimal material for thermal therapy and is beneficial for the development of electric thermal stimulation alternative.
研究领域:
热疗研究
·
生物医学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2025
·
IF 6.2
Longfei Wang,Yuanjun Tang,Guoneng Li,Jun Dong,Yao Fang,Wenwen Guo,Chao Ye
This study systematically investigates the effects of Fe-loading on the pyrolysis behavior of three key biomass components: cellulose , xylan , and lignin . Complementary analytical techniques, thermogravimetric analysis (TGA), thermogravimetry-mass spectrometry (TG-MS), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), were utilized to assess the impact of Fe-loading on: ( i ) pyrolysis characteristics, ( ii ) the combined pyrolysis index ( CPI ), ( iii ) small-molecule gas evolution, and ( iv ) tar product distribution. Results demonstrate that the loading of Fe(NO 3 ) 3 significantly reduced the initial pyrolysis temperatures of cellulose and xylan by ∼140 °C and ∼62 °C, respectively, resulting in 58 % and 37 % decreases in CPI values. Conversely, lignin exhibited a 111 % CPI increase under Fe loading conditions, attributable to accelerated aryl-ether bond cleavage. The presence of Fe enhanced CO 2 evolution while suppressing H 2 O and CO generation in cellulose / xylan conditions. In contrast, it promoted CH 4 , H 2 , CO, and CO 2 evolution during lignin pyrolysis. Py-GC/MS analysis indicated that the presence of Fe drives aromatization through deoxygenation pathways while inhibiting ring-opening depolymerization, consequently shifting tar composition toward higher-carbon-number aromatic hydrocarbons. The findings can serve as a valuable reference for the application and promotion of the high-value valorization of waste biomass.
研究领域:
生物能源
·
生物质转化
·
热化学
·
分析化学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2024
·
IF 5.9
Yinhai Pan,Du Wei,Shuo Yao,Haijun Zhang,Quanzhi Tian
Coal gasification slag (CGS) is rich in Li and Ga. However, few studies have focused on the extraction of Li and Ga from CGS. In the present study, the leaching of Li and Ga from CGS calcined with the alkali reagents including NaOH, KOH, Na 2 O 2 , Na 2 CO 3 and K 2 CO 3 were studied through water leaching and solid characterizations including XRD, TG-DSC and NMR. The best leaching percentages of Li and Ga from NaOH-, KOH-, Na 2 O 2 -, Na 2 CO 3 - and K 2 CO 3 -roasted products were 40.81% and 47.89%, 41.19% and 31.60%, 28.04% and 52.40%, 28.21% and 48.58%, and 34.29% and 38.61%, respectively, showing Li and Ga are difficult to be leached out. It has been proven that the formation of insoluble crystal substances (such as NaAlSiO 4 ) in alkali fusion products inhibits the leaching of Li and Ga. In addition, Li and Ga can be released from the insoluble crystal substances due to Na 2 SiO 3 in alkali fusion products can promote the dissolution of insoluble crystal substances into SiO 4 and AlO 4 species, which can improve the leaching of Li and Ga. However, part of the released Li and Ga are stabled in the structure of amorphous substances generated by SiO 4 and AlO 4 species in the form of isomorphism, reducing the leaching of Li and Ga. Thus, this work would provide guidance for the leaching of Li and Ga from CGS.
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2018
·
IF 1.047
Li Zhang,Xian Wu,Shanyou Liu,Jinwu Peng,Baijun Liu
Some multi-ether linked polyimides (PIs) derived from two diamine monomers containing various amount of cyano groups are synthesized by a typical two-step polymerization. Meanwhile, the PIs with similar chemical structure but without cyano groups are prepared as counterparts for comparison purposes. The obtained PIs exhibit low glass transition temperature values of 211–258°C, which are associated with their multi-ether chemical structure. Furthermore, these PIs have high thermal stability, and the temperatures at 10% weight loss are in the range of 524–616°C under nitrogen atmosphere. It is found that the introduction of cyano groups would have a great influence on the properties of the PIs. The tensile strength and Young’s modulus of one cyano-containing PI reach 121 MPa and 1.4 GPa, respectively, which are much higher than those cyano-free ones. In addition, the cyano-containing PIs exhibit different behaviors of dielectricity and solubility in comparison with the corresponding cyano-free counterparts.
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
EUROPEAN POLYMER JOURNAL
·
2022
·
IF 5.546
Yanliu Zhu,Jinggang Wang,Sakil Mahmud,Xiaoqin Zhang,Xiaoqing Liu,Jin Zhu
The polyesters derived from renewable resources with both high transparency and good heat resistance are urgently desirable. Destroying the crystallization of a material and achieving an amorphous state can ensure high transparency, while good heat resistance can be provided by rigid monomers. Herein, the fluorinated rigid diol 2,3,5,6-tetrafluoro-1,4-benzenedimethanol (TFBDO) was introduced into 2,5-furandicarboxylic acid (FDCA)-based copolyesters to synthesize a series of new bio-based polymers called poly(ethylene-1,4-cyclohexyldimethylene-2,3,5,6-tetrafluoro-1,4-benzenedimethanol 2,5-furandicarboxylate) (PECFF) with different TFBDO contents via a two-step melt polycondensation. The number average molecular weight ( M n ) of 24,200 ∼ 46,700 g/mol and the polydispersity index (PDI) of 1.28 ∼ 1.74 for synthesized PECFFs showed the high reaction activity as a rigid diol of TFBDO. As the increasing of tetrafluoro-1,4-benzenedimethanol unit, the T g was improved from 91 °C for PECFF-15 to 118 °C for PECFF-75, and the thermal stability of T d,5% in nitrogen increased from 371 to 393 °C as well as the hydrophobicity, and gas barrier properties were also improved. When the content of the tetrafluoro-1,4-benzenedimethanol unit was up to 60 %, the copolyester PECFF-60 exhibited the T g of 113 °C, T d,5% of 421 °C, Young’s modulus of 2460 MPa, and tensile strength of 71 MPa. Moreover, the surface water contact angle increased from 85° to 101° as well as the CO 2 and O 2 barrier properties improved 43.3-fold and 8.6-fold compared with PET. These studies have shown that the new bio-based polyester could be a potential application in many fields, such as transparent sheet in outdoor, architectural materials or electronic equipment, and non-food contact packaging.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）