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
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
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
CRYSTAL GROWTH & DESIGN
·
2018
·
IF 3.972
Lihua He,Xiao Zou,Xiang He,Fengying Lei,Na Jiang,Qiaoji Zheng,Chenggang Xu,Yongfu Liu,Dunmin Lin
A variety of NaYF4:Yb/Er upconversion materials were successfully synthesized via a facile hydrothermal method by altering the volume ratios (0:1, 1:1, 2:1, 3:1, 4:1, 5:1) of ethanol to water and various alcohols (methanol, n-propyl alcohol, isopropyl alcohol, ethylene glycol, polyethylene glycol, and phemethylol), and the grain size and luminescence of the materials were effectively tailored. The addition of alcohol effectively reduces the grain size of the materials and simultaneously leads to the surprising enhancement of the UC emission. The increase in the volume ratio of EtOH/H2O causes the transformation of the crystal structure of the materials from hexagonal to cubic phase. The particle size of the material with the EtOH/H2O of 2:1 is almost 1000 times smaller than that of the material without EtOH, and the strongest luminescence is observed at the EtOH/H2O of 2:1. The type of alcohol in the solvent exhibits a significant influence on the luminescent properties of the materials. The NaYF4:Yb/Er nanocrystals obtained using different alcohols as solvent possess much a smaller grain size and stronger upconversion luminescence than that using water as solvent, and the NaYF4:Yb/Er materials with n-propyl alcohol exhibit the strongest luminescence intensity. The mechanism of the reduction of grain size and enhancement in the luminescence of the NaYF4:Yb3+, Er3+ upconversion materials has been proposed. This study may suggest a simple method to significantly reduce the grain size and improve the upconversion luminescence properties of NaYF4-based fluorescence material.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
高影响因子
BioEnergy Research
·
2018
·Vol. 11
·期 3
·665-676
·
IF 2.938
Shi Jinghao,Liu Jing,Li Meng,Huang Liulian,Chen Lihui,Luo Xiaolin
Lignin deposition phenomenon during the liquid-hot-water (LHW) pretreatment negatively affects substrate enzymatic digestibility (SED). To overcome this limitation of LHW, acid-free ethanol-water (EW) pretreatment with low ethanol concentration was developed. With less cellulose loss and similar hemicellulose removal, adding 10% ( v / v ) ethanol into water (EW10 pretreatment) resulted in a lignin removal of 5.8% higher than that of LHW pretreatment conducted at the same conditions (such as 200 °C for 40 min). Although the lignin removal did not increase significantly, differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS) characterizations indicated that LHW pretreatment-induced lignin condensation was alleviated by EW10 pretreatment, leading less lignin condensates deposited on the corresponding surface of solid substrate. Moreover, compared with lignin separated from LHW-pretreated substrate, the non-productive adsorption between EW10 pretreatment-induced lignin and cellulase was significantly weakened. As a result, the SED of EW10 pretreatment was improved to 91.7%, which was higher than LHW pretreatment by 19.5%. Due to the advantages of suppressing the deposition of lignin condensates and employing ethanol at low concentration, EW10 pretreatment shows practical significance for producing fermentable sugar from abundant non-woody biomass (bamboo) in China.
研究领域:
生物能源
·
植物学
✓ 已验证
DOI
高影响因子
POWDER TECHNOLOGY
·
2014
·
IF 2.269
Jixiang Xu,Wenbo Wang,Aiqin Wang
The nanorods of natural palygorskite exist as aggregates or bundles. High-pressure homogenization technology can disaggregate effectively the bundles or aggregates of palygorskite in water. In order to further explore the effect of the dispersion medium on the dispersion efficiency, in this paper, palygorskite was dispersed in ethanol–water mixture with the aid of high-pressure homogenization. The effects of various ethanol/water ratios on the microstructure and colloidal properties of palygorskite were investigated. It was found that the dispersion efficiency of aggregates during the homogenization process was affected as increasing the ethanol/water ratio from 0:10 to 4:6. The introduction of ethanol into the aqueous suspension of palygorskite could weaken the van der Waals forces and hydrogen bonding interaction among rods , and a stable suspension with higher shear stress and shear modulus was obtained at the ethanol/water ratio of 6:4 ( v / v ).
研究领域:
材料科学
·
胶体化学
✓ 已验证
产品关联
DOI
高影响因子
Colloid and Interface Science Communications
·
2022
·
IF 5.633
Zhiguo Zhang,Zilong Guo,Wensheng Yang
Coating silica on Au particles has been known to be effective to improve their stability and performance. In this work, we demonstrated a cetyltrimethylammonium bromide (CTAB) assisted approach for preparation of Au@SiO 2 particles in ethanol/water mixtures. At ethanol content of 0.25, Au particles were well dispersed, while at ethanol content of 0.50, the aggregated Au particles were gradually dispersed with increasing CTAB concentration, attributed to the gradual formation of CTAB bilayer on the particle surface. When tetraethyl orthosilicate and ammonia were added directly to the Au particle dispersions, the Au@SiO 2 particles formed at the low ethanol content (0.25) were red in color and spherical in shape with a core composed of single Au particles, and these formed at the medium ethanol content (0.50) were purple in color and fractal-like in shape with a core composed of multiple Au particles.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）