RSC Advances
·
2013
·Vol. 4
·期 5
·2550-2556
·
IF 2.562
Liuting Zhang,Xuezhang Xiao,Xiulin Fan,Shouquan Li,Hongwei Ge,Qidong Wang,Lixin Chen
A simple approach to dramatically enhance the dehydrogenation properties of sodium borohydride is achieved by ball milling NaBH4 with fluorographite (FGi). It was found that the ball-milled NaBH4–FGi composite starts to release hydrogen without impurity gas at a lower temperature of 125 °C, and obtains a hydrogen desorption capacity of ca. 4.8 wt% below 130 °C in seconds, which is improved markedly compared to the ball-milled pristine NaBH4. The significant thermodynamic and kinetic improvement of the NaBH4–FGi composite can be ascribed to the reaction between NaBH4 and FGi as well as the formation of micro-scale NaBH4. Moreover, since the dehydrogenation process of NaBH4–FGi composite is exothermal, the fully reverse reaction is not feasible. In-depth investigations show that the partial rehydrogenation is due to the formation of Na2B12H12 and another new borohydride.
研究领域:
材料科学
·
能源化学
·
纳米科技
·
物理化学
✓ 已验证
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2016
·
IF 2.848
Zhanjing Guo,Xiongmin Liu,Hongmiao Huang,Lingfeng Jiang
The strong acidic cationic exchange fiber (SACEF) was used to adsorb yohimbine from alcoholic solution. Batch experiments were performed to examine the effects of adsorbent dosage, solution pH and temperature in the adsorption process. The thermodynamics and kinetics of adsorption were also analyzed. The optimum yohimbine adsorption onto the SACEF was found at pH = 5 of solution and equilibrium could be attained within 20 min. The equilibrium adsorption data were preferably modeled with the Freundlich isotherm model and the thermodynamic parameters were calculated to be: 11.99 kJ/mol < Δ H < 13.72 kJ/mol, −21.17 kJ/mol < Δ G < −17.87 kJ/mol and 63.18 J/mol K < Δ S < 65.60 J/mol K. The results demonstrated that the adsorption was an endothermic, spontaneous and feasible process of physisorption . Meanwhile, yohimbine adsorption on SACEF fitted well to the pseudo-second-order kinetic model and the adsorption rate was limited by film diffusion. The activation energy Ea was calculated to be 14.39 kJ/mol. Furthermore, the surface morphologies of the SACEF before and after yohimbine adsorption were analyzed by SEM and the adsorption mechanism was discussed by FTIR analysis. SACEF could effectively adsorb yohimbine from alcoholic solution and could be used repeatedly for more than five cycles.
研究领域:
药物化学
·
药剂学
·
物理化学
·
分离科学
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吸附科学
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天然产物提取
·
药物代谢
✓ 已验证
DOI
高影响因子
APPLIED ENERGY
·
2024
·
IF 10.1
Yaning Kong,Honglin Yu,Mengqi Liu,Guodong Zhang,Fei Wang
Hydrate was considered to be the next generation hydrogen storage material , and hydrate-based hydrogen storage (HBHS) would play an important role in future hydrogen economy, but sluggish hydrate formation kinetics presents huge technological challenge for its application. Herein, a nano promoter of -SO 3 − @PSNS was prepared by soap-free emulsion polymerization , and a dual kinetic promoter system (L-methionine/-SO 3 − @PSNS) was applied to enhance the formation kinetics of mixed H 2 /DIOX hydrate. At a moderate condition (12 MPa and 274.15 K), hydration efficiency under a driving force of 2.1 MPa is significantly enhanced by the synergy of the dual kinetic promoters, hydrate induction time reduces from 443.2 ± 209.73 min to 24.7 ± 17.16 min, while hydrate growth rate increases by 43.75%, and hydrogen storage capacity is up to 0.473 ± 0.041 wt% that increases by 62.8%. At a more moderate condition (10 MPa and 274.15 K) with an extremely low driving force of 0.1 MPa, enhanced hydrate formation was obtained in a composite promotion system of the dual kinetic promoters and dual thermodynamic promoters (THF/DIOX), which also performs exceptionally in term of recycling. The presence of a small amount (0.35 mol%) of THF reduces the induction time by 93.5%, and hydrate growth rate increases by 130.18%, while satisfactory hydrogen storage capacity (0.346 ± 0.017 g/g) is still remained in mixed H 2 /DIOX/THF hydrate, the structure of which was confirmed by Raman spectrum . This work presents an effect approach on enhancing the formation kinetics of H 2 -contained hydrate under low driving force, and this finding provides important insight for HBHS.
研究领域:
物理化学
·
能源材料
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气体储存
·
化学工程
·
纳米材料科学
·
分子模拟
·
可持续能源
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Bo Wang,Jinyu Wang,Yuan Chen,Zhiyong Xu,Wenbo Zhao
N-Benzyl-N-methyl-1-(methyl diphenyl silyl) methanamine (MPSA) with high thermal stability was synthesized for the absorption of SO 2 in the present work. The absorption capacity was measured at low partial pressures ranging from 0.002 to 0.016 bar and thermodynamic parameters, including enthalpy change (Δ H ) and entropy change (Δ S ) were calculated to analyze the absorption behavior. The desulphurization rates and absorption capacities at different temperatures and partial pressures were simulated based on thermodynamic parameters. An optimal absorption temperature T 1 that maximizes the absorption capacity, and an optimal desorption temperature T 2 that minimizes the desorption residual capacity and thermal desorption energy consumption were defined, and a function was proposed to calculate them. The kinetic behavior of the absorption was described using a pseudo-first-order model, and kinetic data at different temperatures and partial pressures were simulated based on a combination of kinetic and thermodynamic parameters. Ultimately, selectivity and cycles experiment showing MPSA has excellent CO 2 selectivity and thermal regeneration performance.
研究领域:
环境化学
·
气体分离
·
热力学
·
化学工程
·
功能材料
·
大气污染控制
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2021
·
IF 5.455
Zhe Zhang,Lei Xu,Yani Liu,Runtian Feng,Tong Zou,Yuanshuo Zhang,Yuru Kang,Pengxin Zhou
In order to improve the efficiency of the removal of methylene blue from wastewater, we synthesized activated carbon by thermally activating phosphoric acid-treated mangosteen peels. This activated carbon possessed a great specific surface area (1832 m 2 /g) and exhibited excellent adsorption capacity (871.49 mg/g) for methylene blue. In this study, we varied the impregnation ratios, activation temperatures, and activation time to determine the best conditions for preparing the mangosteen peel activated carbon (MPAC). The optimal conditions included a 1:3 impregnation ratio with activation for 60 min at 450 °C. We characterized the MPAC using a scanning electron microscope, powder X-ray diffraction, thermogravimetric analysis , differential scanning calorimetry , and Fourier transform infrared spectroscopy together with the Brunauer–Emmett–Teller approach. The adsorption experiment results conformed to the pseudo-second-order kinetic model and the Langmuir isotherm model. This proved that physical adsorption dominates in this adsorption process . The synthesized MPAC-5 showed great adsorption performance for a variety of dye wastewater. After three times of recycling, the removal rate of methylene blue is still above 40%. Compared with other biowastes, mangosteen peel has the potential to be synthesized into activated carbon with a high adsorption capacity for dyes.
研究领域:
环境科学
·
材料科学
·
化学工程
·
污染控制
·
吸附技术
·
废物资源化
✓ 已验证
DOI
高影响因子
POLYMER TESTING
·
2021
·
IF 4.282
Tongtong Zhang,Jihuai Tan,Xue Han,Qinghe Fu,Muhua Chen,Yong Xu,Xinbao Zhu
Families of bio-based hyperbranched epoxy (HBPEEs) were successfully prepared using renewable xylitol, bisphenol A and epichlorohydrin as feedstocks. The structure and physical performances of HBPEEs were characterized by FTIR, NMR, GPC and viscosity evaluation. Then, they were used as high efficient tougheners for diglycidyl of bisphenol A/diethylenetriamine (DGEBA/DETA) networks. The results indicated that the incorporation of HBPEEs into the DGEBA system can significantly enhance the mechanical properties and solvent resistance properties of the hybrid (HBPEEs/DGEBA). In particular, toughened hybrids with 15 wt% HBPEE-2 exhibited the outstanding impact strength than that of neat DGEBA (37.4 kJ/m 2 vs. 11.8 kJ/m 2 ) due to its excellent compatibility of with DGEBA. Simultaneously, the ductile fracture morphology of the modified hybrids was also confirmed by SEM. In addition, the activation energies of HBPEE-2/DGEBA hybrids calculated from the non-isothermal curing kinetics were lower than that of neat DGEBA. All of the results suggested that the bio-based HBPEEs could be used as efficient tougheners applied in epoxy resins industry.
研究领域:
高分子化学
·
材料科学
·
绿色化学
·
复合材料
·
聚合物改性
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2019
·
IF 2.29
Junjie Chen,Bo Jin,Guan Luo,Huihui Liu,Qingchun Zhang,Qi Huang,Rufang Peng
The thermodynamics and kinetics of the curing reactions between polyglycidyl nitrate (PGN) and toluene diisocyanate, isophorone diisocyanate, and polyaryl polymethylene isocyanate (PAPI) were studied by microcalorimetry. The reaction rate between PGN and PAPI was the fastest among the three reactions above. Three thermodynamics ( i.e. , activation enthalpy, entropy, and free energy), rate constant, and three thermokinetic parameters ( i.e. , activation energy, pre-exponential constant, and reaction order) of the curing reactions were obtained by calculating the results of the reaction between PGN and PAPI at a series of temperature from 303.15 K to 318.15 K. The linear relationship between ln k and the mole ratio of the isocyanate and hydroxyl groups was observed. The corresponding kinetic equation describing the curing reaction between PGN and PAPI was d α /d t = 10 −3.83 (1 − α ) 3.04 at 318.15 K.
研究领域:
高分子化学
·
热力学
·
反应动力学
·
功能材料
·
含能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2013
·Vol. 129
·期 4
·2313-2320
·
IF 1.395
Mingchao Luo,Xiaoxue Liao,Shuangquan Liao,Yanfang Zhao
Waste rubber powder (WRP) was modified by microwave, sol–gel method, and both microwave and sol–gel method, respectively. The mechanical and dynamic mechanical properties of natural rubber (NR)/modified WRP composite were investigated. The influence of bis-(3-(triethoxysilyl)-propyl)-tetrasulfide (TESPT) content on curing characteristics and mechanical properties of vulcanizate was also studied. The results showed that NR/WRP modified by both microwave and sol–gel method composite owned the best mechanical properties. Rubber processing analyzer was used to characterize the interaction between silica and rubber chains and the dispersion of silica. With increase of TESPT content, the Payne effect decreased. Scanning electron microscopy indicated the coherency and homogeneity of in situ generated silica filled vulcanizate. Dynamic mechanical analyzer showed that NR/WRP modified by both microwave and sol–gel method composite with 5 phr TESPT exhibited the lower tan δ at temperature range of 50–80°C, compared with composite without TESPT and the higher tan δ at temperature of 0°C, compared with the conventional modification of WRP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
研究领域:
高分子材料科学
·
橡胶工程
·
复合材料学
·
材料化学
·
高分子物理
·
功能材料
·
可持续材料技术
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Weiyi Zhang,Haozhen Zhang,Xinglian Xu,Xue Zhao
The oil polarity was hypothesized to significantly influence the microscopic conformation of interfacial myofibrillar protein (MP) and thus the mesoscopic interfacial rheology of MP film , which ultimately tuned the macroscopic stability of MP-stabilized emulsions. In this research, the inner mechanism was revealed hierarchically based on emulsions multi-scale properties, by a combination of in vitro interfacial concentration measurement, dynamic interfacial tension measurement and interfacial dilatational rheology (highlighting Lissajous plots). Then, the above conclusion was verified through in silico molecular dynamic simulation. At macroscopic level, the light scattering results showed that emulsion prepared with higher polarity oil exhibited higher physical stability. This could be explained from the mesoscopic perspective that: (1) the adsorption dynamics of MP was faster (though lower diffusion rate, but higher penetration and rearrangement rate) on the higher polarity interface, which decreased interfacial tension more efficiently; (2) adsorption ratio, surface load and desorption ratio indicated that ‘multilayer interfacial film’ was formed by loosely-bound MP on the lower polarity interface, which decreased the effective interfacial coverage to impair emulsions stability; (3) Lissajous plots showed that interfacial structure with higher stability against large deformation was formed on the higher polarity oil interface. Finally, the microscopic molecular mechanism for explaining the above findings was revealed by in silico molecular dynamic simulation: though MP was less unfolded on the higher polarity interface leading to weaker intermolecular hydrophobic interactions, this compact molecular structure with stronger intramolecular rigidity predominantly contributed to steadier interfacial film structure. This multi-scale study provides a deep insight into the inner relationship between oil polarity and emulsions stability.
研究领域:
食品科学
·
胶体与界面化学
·
蛋白质构象
·
软物质物理
·
分子模拟
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
·
2016
·
IF 1.938
Lipeng Wang,Fucheng Zhang,Yongping Bai,Liping Ding
The kinetic of non-isothermal crystallization of Poly (ethylene terephthalate-co-sodium-5-sulfo- iso -phthalate) (PETI) was investigated using differential scanning calorimetry (DSC). Various macrokinetic models namely the Avrami, Tobin, Ozawa, and Ziabicki were used to describe the non-isothermal crystallization process of PETI. Both of the Avrami crystallization rate constant and the Tobin crystallization rate constant were observed to increase with increasing cooling rate. The Avrami model is better than the Tobin model to describe the non-isothermal crystallization process of PETI. The Ozawa crystallization rate K O was found to decrease with increasing cooling rate, while Ziabicki’s kinetic crystallizability parameter G Z was found to increase with increasing cooling rate. The effective energy barrier △E for non-isothermal crystallization process of PETI, analyzed based on the differential iso-conversional method of Friedman, was found to be an increasing function of the relative crystallinity.
研究领域:
高分子化学
·
材料科学
·
物理化学
·
热分析
·
聚合物结晶
✓ 已验证
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2018
·
IF 3.849
Yafei Guo,Chang Tan,Peng Wang,Jian Sun,Junjie Yan,Weiling Li,Chuanwen Zhao,Ping Lu
Coal and biomass fly ash was impregnated with tetraethylenepentamine (TEPA) to prepare solid CO 2 sorbent. Experimental CO 2 adsorption capacities of the sorbent in fixed-bed column were fitted to several kinetic equations. The modified Avrami fractional kinetic model could accurately predict the CO 2 adsorption kinetic behaviors of the sorbent under different conditions. CO 2 adsorption rate increases with the increase in temperature, initial CO 2 concentration and gas flow rate, as a result of the decreased CO 2 diffusion resistance. A mathematical model was proposed and demonstrated to well predict the CO 2 adsorption breakthrough curves in the fixed-bed column. Effects of temperature, initial CO 2 concentration and gas flow rate on the mass transfer kinetic behaviors of the desired sorbent were investigated. The positive effect of these factors on promoting the overall mass transfer coefficient and the internal mass transfer coefficient is not significant. The external mass transfer coefficient will be remarkably reinforced with the increase in these operating parameters, due to the change in viscosity and density of the gas phase and the reduced external mass transfer resistance. Internal mass transfer process is determined as the rate-limiting step for CO 2 adsorption. The results will lay the groundwork for future scale-up application of the sorbent in post-combustion CO 2 capture.
研究领域:
环境科学
·
化学工程
·
能源工程
·
大气污染控制
·
碳捕集与封存
✓ 已验证
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2020
·Vol. 22
·期 11
·2000519
·
IF 3.217
Chuan Zong Wu,Zhu Yin Chen,Xinli Liu,Ting Shen,LiGuo Zu,Lei Zhang
Porous titanium scaffolds with high porosity and connected macropores are fabricated by adding zirconium acetate to control the ice crystal growth during freeze casting. The influences of zirconium acetate additives on the phase composition, pore structure, and mechanical properties of porous titanium are studied. As modified by zirconium acetate, the X-ray diffraction peaks of titanium moves to a smaller angle, and the zirconium is evenly distributed on the titanium matrix. With the increase in the concentration of zirconium from 0 to 60 g L −1 , the pore morphology of porous titanium changes from typical lamellar to the honeycomb, the pore size distribution becomes wider. The average pore size and porosity increases from 44 ± 11 to 126 ± 35 μm and from 46.4 ± 1.3 to 59.1 ± 1.3%, respectively. As the concentration of zirconium acetate is 40 g L −1 , the porosity and the pore size of the porous titanium scaffolds are comparable with those modified by 10 g L −1 zirconium acetate, but the compressive strength is 2.3 times higher. Zirconium acetate as an additive has an excellent performance in optimizing the pore structure and mechanical properties of water-based freeze-cast porous titanium.
研究领域:
生物材料学
·
组织工程
·
金属材料科学
·
医用植入材料
·
多孔材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）