FLUID PHASE EQUILIBRIA
·
2014
·
IF 2.241
Ye Yuan,Yixin Leng,Hui Shao,Chunxiang Huang,Kai Shan
The solubility of dl -malic acid in water, ethanol and ethanol + water mixtures was investigated by a static analytical technique using the acid–base titration method at temperatures ranging from 298.15 to 333.15 K. The experimental results indicated that the solubility of dl -malic acid in the binary solvent mixtures increases with increasing temperature and decreases with increasing mass fraction of ethanol. The measured solid–liquid equilibrium (SLE) data were correlated by the modified Apelblat, λh and van’t Hoff equations. The calculated solubility demonstrated good agreement with the experimental data. It was found that the modified Apelblat equation could give the best correlation results, and subsequently used to derive the standard enthalpy, entropy and Gibbs energy change of solution of dl -malic acid in ethanol + water binary mixtures.
研究领域:
化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Membranes
·
2025
·
IF 9.5
Zhibin Ma,Peitong Lian,Jie Li,Yanxiong Ren,Yonghui Shi,Hanze Ma,Yuhang Guo,Qianfeng Pan,Sheng Yuan,Yutong Wang,Heyang Liu,Lixuan Liu,Yuao Dong,Yanlei Su,Jing Zhao,Quanfu An,Guangwei He,Zhongyi Jiang
Polydimethylsiloxane (PDMS) membranes are commonly utilized for ethanol-water separation. However, the separation performance is insufficient owing to the inherent trade-off between permeability and selectivity. In this study, we reported the incorporation of methyl-functionalized covalent organic framework (COF, TpBD-CH 3 ) into PDMS membranes to prepare mixed matrix membranes (MMMs), greatly increasing ethanol flux by 2.7 times. Under testing conditions of 60 °C with a feed solution containing 5 wt% ethanol in water, the permeation flux of the membrane incorporating 0.1 wt% TpBD-CH 3 significantly increased from 1738 g/(m 2 ·h) to 4648 g/(m 2 ·h) compared to the original PDMS membrane, while the separation factor improved from 7.32 to 8.40. The improved separation performance is attributed to that the incorporation of the COF enhances the hydrophobicity as well as the free volume cavities of the membranes as evidenced by the significantly increased gas permeability (CO 2 permeability reaches 26720 Barrer). This study indicates the potential of COF in the development of PDMS-based MMMs for the separation of organic aqueous solutions or gas components.
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
CARBOHYDRATE POLYMERS
·
2021
·
IF 9.381
Jing Du,Yan Hong,Li Cheng,Zhengbiao Gu,Zhaofeng Li,Caiming Li
Acetylated acid-ethanol hydrolyzed (AHS) and acetylated debranched starch (ADS) were investigated as prospective nanocarriers . Both acid-ethanol hydrolysis and debranching decreased the molecular weight and viscosity of starch. Acid-ethanol hydrolyzed starch remained the original microstructure, which was confirmed by results of scanning electron microscopy. New absorption peaks in FTIR spectra of starch confirmed the occurrence of acetylation . The substitution degree (DS) of ADS could reach up to 1.18, while that of AHS could be improved by increasing the ethanol concentration. The developed nanoparticles showed uniform spherical structure and the size of that approximated 180–260 nm. The critical micelle concentration was 0.049 mg/mL, and the shift in fluorescence spectra confirmed the interaction between starch and curcumin . These results indicate show that high DS of AHS and ADS could be used as a potential carrier for curcumin delivery.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 14
·6054-6064
·
IF 9.931
Lechen Diao,Jian Qin,Naiqin Zhao,Chunsheng Shi,Enzuo Liu,Fang He,Liying Ma,Jiajun Li,Chunnian He
Hollow β-Mo2C/N-doped carbon composite nanospheres constructed by mesoporous ultrathin carbon nanosheets anchored with ultrasmall β-Mo2C nanoparticles were synthesized through a facile green process. Nanobubbles generated by ethanol–water exchange were utilized as templates for the core, while the precipitates in the solution were directly adopted as the emulsion stabilizer and the shell. Upon the self-polymerization of dopamine, a robust shell consisting of the Mo–polydopamine complex was formed. The size of the as-obtained hollow Mo–polydopamine nanospheres can be tuned by varying the type of gas, which is proportional to the supersaturation of gas. These precursors of hollow Mo–polydopamine nanospheres were then converted into hollow β-Mo2C/N-doped carbon composite nanospheres by high-temperature carbonization treatment. The N-doped carbon matrix can act as an electron conductor and facilitate the prevention of the migration and aggregation of the Mo2C nanoparticles, while the ultrafine Mo2C nanoparticles can achieve maximum material utilization for hydrogen evolution electrocatalysis. In addition, the mesoporous 2D nanosheets combined with their constructed 3D hollow structures can expose numerous active catalytic sites while enabling free diffusion of the electrolyte and mass transfer. As a result, the hollow β-Mo2C/N-doped carbon composite nanospheres exhibit low overpotentials and robust cycling stability in both acidic and alkaline electrolytes.
研究领域:
材料科学
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电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2014
·
IF 2.045
Qinghua Luan,Yongli Wang,Guan Wang,Jingxiang Yang,Hongxun Hao
The solubility of calcium-l-lactate pentahydrate (CLLP) in binary ethanol + water and acetone + water solvent mixtures was measured in the temperature range of 278.15 K to 313.15 K by using a synthetic method. The solubility of CLLP increases with increasing temperature, whereas it decreases with the increase of the initial mole fraction of ethanol or acetone. The solubility data were correlated by using the modified Apelblat equation, the CNIBS/R-K equation, and the hybrid model, respectively. It was found that the modified Apelblat equation could give better correlation results both in ethanol aqueous solutions and in acetone aqueous solutions. The dissolution enthalpy, entropy, and Gibbs energy change of dissolution of CLLP in these solvent mixtures were obtained by using the modified van’t Hoff equation.
研究领域:
化学工程
·
热力学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2015
·Vol. 91
·期 4
·977-984
·
IF 2.349
Hong Li,Yiming Liu,Xin Gao,Xingang Li
Background Dehydration of biomass-based fermentation product is an essential process in the production of biofuels ethanol for industrial applications. Cassava starch, an adsorbent with high efficiency, can be fermented after saturating with water, which overcomes the shortcomings of high energy consumption bioethanol production. Therefore, the aim of the present study was to prepare cassava starch-based adsorbents with high adsorption efficiency that do not affect fermentative production. Results Porous cassava starch granules, which can be fermented to produce biofuel ethanol, were formed through the partial hydrolysis of starch using amylase and ultrasonication. The structural changes in cassava starch granules were also studied to prove that porous starch could be reused as feedstock for biomass-based fuel ethanol production after adsorption. Finally, an adsorption experiment proved that the modified cassava adsorbents had better absorptive properties than the native cassava. Conclusion These structural changes in cassava starch granules showed that porous starch is an efficient adsorbent that can be reused after adsorption as feedstock for fuel ethanol, which increases the energy efficiency of ethanol–water azeotrope separation. © 2015 Society of Chemical Industry
研究领域:
生物工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2016
·
IF 3.847
Chao Zhou,Xiangdong Zhu,Feng Qian,Wei Shen,Hualong Xu,Shicheng Zhang,Jianmin Chen
This work investigated the yields of monomeric phenols in bio-oil derived from hydrothermal liquefaction of rice straw (RS) in water and ethanol mixtures using a reductive CuZnAl catalyst. Based on the results of an initial analysis, five monomeric phenolic compounds were selected for research due to their higher concentrations, namely phenol, 4-ethyl-phenol, 2-methoxy-phenol, 2-methoxy-4-ethyl-phenol and 2,6-dimethoxy-phenol. The optimized conditions for the production of monomeric phenols can be determined as: 2 g of CuZnAl catalyst, a ratio of 50% ethanol/50% water (v/v), a temperature of 300 °C and a reaction time of 30 min. Results suggested that the maximum yield of total monomeric phenols could reach as high as ~ 26.8% (based on the mass of RS lignin), and that the aqueous phase yielded 95.5% of the monomeric phenols due to the solubilization of the ethanol. The CuZnAl catalyst was recycled five times, and a slight loss in activity was observed and examined using a number of technologies, including inductively coupled plasma , X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and energy dispersive X-ray detection. The low-cost nature of the CuZnAl catalyst makes it an ideal catalyst for the enhancement of monomeric phenols yields in water and ethanol mixtures.
研究领域:
生物化学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2023
·
IF 7.8
Yue Zong,Song Su,Ruijun Zhang,Yan Sun,Jiayu Tian,Bart Van der Bruggen
How to simultaneously improve the water permeance and antibiotics/minerals selectivity is one of the key issues for promoting the efficiency of drinking water treatment with nanofiltration (NF) technology . In this study, the post-treatment with a ternary complex of ethanol-water-NaOH (denoted as EWN) was used on four commercial NF membranes (NF270, NF90, HS-200C, and DF100) to understand its modification mechanism and promote the tetracycline removal efficiency. It was confirmed that the polyamide layers of all four commercial NF membranes were thinner after EWN post-treatment along with a slight increase in the pore size and enhancement in hydrophilicity and electronegativity . As a result, the water permeation of NF270 was improved by 70% and that of the other three membranes was increased by 19–20% while keeping a high tetracycline rejection of over 99%. Simultaneously, mineral ions such as K + , Ca 2+ , Mg 2+ , and Cl - passed the post-treated commercial NF membranes more easily. This yields a facile strategy for the performance regulation of existing, or commercial NF membranes.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2022
·
IF 10.53
Li Peng,Zhengqi Wu,Boxuan Wang,Hua Liu,Chun Zhang,Xuehong Gu
Pure silica MFI (Si-MFI) zeolite membranes with desirable hydrophobicity have the potential to separate ethanol/water mixture. However, its separation performance would significantly decrease in the long-term operation due to the presence of silanol groups formed in alkaline media. In this work, silanol-free MFI zeolite membranes were prepared by the incorporation of tungsten in MFI framework. The occurrence of silanol group can be prevented by formation of W–O–Si bridges. The synthesis parameters affected the W-MFI zeolite membranes’ microstructure and separation performance. For 5 wt% ethanol solution, the W-MFI zeolite membranes prepared at optimum condition showed stable separation performance of permeation flux as 2.81 kg m −2 h −1 with separation factor as 32 over 80 h at 60 °C. The membrane was characterized by XRD , DR UV–vis, XPS and 29 Si NMR, and the results confirmed the incorporation of W and the absence of silanol groups. This research showed that W-MFI zeolite membranes are promising candidates for ethanol extraction with high stability.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2020
·
IF 4.3
Yong Pan,Tengyang Zhu,Qing Xia,Xi Yu,Yan Wang
Emerging pervaporation technology is very promising to realize clean and renewable bioethanol recovery from biomass fermentation broth. The huge challenge of this technology is the need for a pervaporation membrane with high separation performance. Based on the solution-diffusion mechanism, pervaporation membrane for ethanol recovery should possess hydrophobic selective layer to improve sorption ability toward ethanol molecules, thereby enhancing the separation performance. In this study, a superhydrophobic zeolitic imidazolate framework-8 (ZIF-8) layer with a nano-level bud-like surface morphology was grown on polydimethylsiloxane (PDMS) composite membrane via ZIF-8 particle dip-casting, secondary seeded growth, and hydrophobic modification by n-octadecylphosphonic acid for highly efficient ethanol/water separation. The mole ratio of 2-methylimidazole and zinc nitrate (Hmim/Zn 2+ ) in the process of ZIF-8 secondary growth was systematically studied to construct appropriate micro-nano structure on PDMS composite membrane. The resultant optimal composite membrane exhibited a water contact angle of about 163° and an ethanol contact angle of 0°. In addition, it also displayed an outstanding separation factor of 17.4 corresponding to a total flux of 0.64 kg/m 2 h with 5 wt% ethanol aqueous solution at 30 ℃, and thus the superior pervaporation performance to most other reported PDMS-based mixed matrix membranes. The strategy of constructing superhydrophobic layer on PDMS composite membrane may provide a meaningful guidance for preparing high-performance pervaporation membrane for organic recovery from aqueous solution.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Matter
·
2024
·
IF 17.3
Xiaotao Yang,Jia Zheng,Xianfeng Luo,Hongyan Xiao,Peijia Li,Xiaodong Luo,Ye Tian,Lei Jiang,Dong Zhao
Alcoholic beverages are conventionally classified by alcohol by volume (ABV) based on ethanol-water mixture (EWM) concentrations, which is regarded as empirical with little scientific explanation. Here, we find that contact angles of EWMs with different ethanol fractions on highly oriented pyrolytic graphite are non-linear but steplike, while the critical points at step edges surprisingly fit the distributions of ABV. High-frequency proton nuclear magnetic resonance and molecular dynamics confirm different ethanol-water clusters in EWMs, whose structures undergo transitions at the critical points and keep stable in step ranges. Detailed cluster structures contain symmetric tetrahedral and chain-like clusters, and the ratio of the latter increases with higher ethanol fraction, further characterized by attenuated total reflectance infrared spectroscopy. Influence of temperature on clusters probably accounts for preferable changes of “ethanol-like tastes” of low-ABV beers or white wine after cooling and high-ABV shochu or Chinese baijiu after heating.
研究领域:
化学
·
物理学
·
食品科学
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2015
·Vol. 17
·期 15
·10080-10085
·
IF 4.493
Zhaoming Liu,Yadong Hu,Hongqing Zhao,Yang Wang,Xurong Xu,Haihua Pan,Ruikang Tang
Living organisms such as corals can carry out CO2 looping efficiently via biomineralization under ambient conditions. Inspired by this natural process, we establish a solution system of calcium acetate–ethanol–water (Ca(Ac)2–C2H5OH–H2O) for CO2 chemical looping at constant room temperature. The CO2 capture is achieved by its reaction with Ca(Ac)2 to form calcium carbonate (CaCO3) mineral and HAc in the binary solvent with a high C2H5OH content. However, an increase in the H2O content in the system triggers acetic acid (HAc)-induced CaCO3 dissolution to release CO2. The system can be recovered for CO2 capture readily by the replenishment of C2H5OH. This biomimetic mineralization-based CO2 capture/release is controlled by the ionization states of the electrolytes, and is precisely regulated in the C2H5OH–H2O binary solvent. Our attempt highlights the fundamental principle of solution chemistry in reaction control and provides a bioinspired strategy for CO2 capture/release with very low cost and easy availability.
研究领域:
化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）