乙醇/水溶液中魔芋葡甘聚糖流变性能研究

初步研究了魔芋葡甘聚糖(KGM)在不同乙醇浓度的乙醇/水溶液中的流变性能,运用粘度法分析了KGM溶胶的溶胀速率、峰值粘度及其稳定性与乙醇浓度的相关性。结果表明,KGM的流变性能与乙醇浓度存在明显的依赖关系,当乙醇浓度=11%时产生突变。KGM溶胶的溶胀时间与稳定性随乙醇浓度增加而逐渐延长;其最大溶胀速率和峰值粘度随乙醇浓度的增加而减小。这些规律均为KGM在流体中的实际应用提供了参考依据。

乙醇/水溶液对天然棕色棉色素提取的影响

为研究天然棕色棉色素的有效提取条件,对乙醇/水溶液体系提取天然棕色棉色素的组分进行了研究。不同浓度乙醇溶剂对棕色棉色素的提取组分有明显影响。研究表明：棕色棉色素提取物的有色成分分为较易分离（保留时间1-5 min）和难分离（保留时间7-17 min）2部分;棕色棉色素具有很强的亲水特性,体积分数为90%以上乙醇水溶液的提取效率很低,不适宜对棕色棉色素物质的提取;纯水溶液适合保留时间为1.4 min色素物质的提取;体积分数为30%乙醇/水溶液适合保留时间为1.7、2.2和9.6 min色素物质的提取;体积分数为50%乙醇/水溶液适合保留时间为14.9 min色素成分的提取。

乙醇/水溶液中魔芋葡甘聚糖特性及结构研究

研究了乙醇/水溶液中魔芋葡甘聚糖(KGM)溶胶的流变曲线和透光率与乙醇浓度(c乙醇)的相关性,运用原子力显微镜观察了KGM分子链的微观形貌。结果显示:溶胶流变特性与c乙醇存在明显的依赖关系,c乙醇=11%时产生突变;透光率随c乙醇增加而减小;分散的KGM分子链在乙醇作用下发生了缠结。同时表征了KGM膜的结构和性能,结果表明随c乙醇增加,KGM膜的局部有序层叠排列明显,结晶度逐渐提高,透光率和吸水率降低。

水/乙醇溶液在聚乙烯醇聚电解质膜中的吸附特性

将季胺阳离子化聚乙烯醇膜材料和磷酸酯化阴离子聚乙烯醇膜材料按不同摩尔比共混制备了一系列膜 ,用等温吸附的方法测定了不同浓度的乙醇 /水溶液在各种膜中的吸附量及吸附选择性 .结果表明 ,与聚乙烯醇膜相比 ,水 /乙醇在各种聚电解质膜中的吸附量均有不同程度的提高 ,当两种膜材料以接近 1∶1的比例共混时 ,各种浓度的乙醇 /水溶液在该膜中的吸附量为最大 ,水

三嵌段共聚物EO_(20)PO_(70)EO_(20)相分离行为的耗散粒子动力学模拟

采用耗散粒子动力学(DPD)方法研究了嵌段共聚物EO20PO70EO20(P123)在水、乙醇/水溶液及二氧化硅溶胶体系中的相分离行为.不同质量分数的P123在水溶液中共形成4种相分离状态:球状胶束(10%);椭球胶束(20%)、棒状胶束(30%)和三维立方胶束(50%).在模板剂质量分数为10%的乙醇/水溶液中,模板剂胶束稳定性随着乙醇含量的增加而变差.在二氧化硅溶胶体系中,模板剂质量分数低于5%时无胶束形成;模板剂质量分数增至10%时,P123发生相分离形成三维球状胶束;随着模板剂质量分数的进一步增加,模板剂分子夹含着水分子形成三维椭球状结构(20%)、三维立方结构(40%)和层状结构(60%).模拟结果与实验结果一致,说明DPD模拟可以从计算角度推测模板剂对介孔材料结构的影响.

Process Characteristics of CO2 Absorption by Aqueous Monoethanolamine in a Microchannel Reactor

Process characteristics of CO2 absorption using aqueous monoethanolamine （MEA） in a microchannel reactor were investigated experimentally in this work. A T-type rectangular microchannel with a hydraulic diameter of 408μm was used. Operating parameters, i.e. temperature, pressure and molar ratio of MEA to CO2 were studied. Under 3 MPa pressure, the mole fraction of CO2 in gaslphase could decrease from 32.3% to 300×10-6 at least when gas hourly space velocity ranged from 14400 to 68600 h- and molar ratio of MEA to CO2 was kept at 2.2. In particular, the effects of temperature on CO2 absorption flux, mass transfer driving force, gas-liquid contact time and en- hancement factor were analyzed in detail and found that mass transfer enhancement by chemical reaction was a crucial factor for the orocess of CO9 absorotion.

A rapid one-step electrodeposition process for fabrication of superhydrobic surfaces on anode and cathode

This work presents a method to solve the weak solubility of zinc chloride(ZnCl_2) in the ethanol by adding some reasonable water into an ethanol electrolyte containing ZnCl_2 and myristic acid(CH_3(CH_2)_(12)COOH).A rapid one-step electrodeposition process was developed to fabricate anodic(2.5 min) and cathodic(40 s) superhydrophobic surfaces of copper substrate(contact angle more than 150°) in an aqueous ethanol electrolyte.Morphology,composition,chemical structure and superhydrophobicity of these superhydrophobic surfaces were investigated by SEM,FTIR,XRD,and contact angle measurement,respectively.The results indicate that water ratio of the electrolyte can reduce the required deposition time,superhydrophobic surface needs over 30 min with anhydrous electrolyte,while it needs only 2.5 min with electrolyte including 10 mL water,and the maximum contact angle of anodic surface is 166° and that of the cathodic surface is 168°.Two copper electrode surfaces have different reactions in the process of electrodeposition time,and the anodic copper surface covers copper myristate(Cu[CH_3(CH_2)_(12)COO]_2) and cupric chloride(CuCl);while,zinc myristate(Zn[CH_3(CH_2)_(12)COO]_2) and pure zinc(Zn) appear on the cathodic surface.

The Swelling Equilibria of N-isopropylacrylamide Based Hydrogel in Aqueous Solution of Ethanol

N-isopropylacrylamide (NIPAAm) was used to synthesize NIPAAm homopolymer (nonionized) and NIPAAm-sodium methacrylate copolymer (ionized). The swelling equilibria for both gels were obtained in aqueous solution of ethanol with concentration ranging from 0 to 100%(by mass) at 25℃. The swollen gel in water shrank first with the addition of a small amount of ethanol and then reswelled with further addition of ethanol showing not only a discontinuous volume phase transition but also a typical reentrant phenomenon. A thermodynamic model based on the UNIQUAC with the 'free-volume' contribution was applied to correlate and predict the swelling behavior of the poly(NIPAAM)-gels in ethanol-water mixture.

Effect of Mono- and Di-ethanolammonium Formate Ionic Liquids on the Volatility of Water, Ethanol, and Methanol

Vapor pressures were measured for six binary systems containing water, ethanol, or methanol with one of the two ionic liquids(ILs) at different component concentrations and temperatures using a quasi-static ebulliometer,with the ILs mono-ethanolammonium formate([HMEA][HCOO]) and di-ethanolammonium formate([HDEA][HCOO]).The vapor pressures of the IL-containing binary systems are well correlated using the NRTL model with an overall average absolute relative deviation(AARD) of 0.0062. The effect of ILs on the vapor pressure depression of solvents at 0.050 mole fraction of IL is that [HDEA][HCOO]>[HMEA][HCOO], and the vapor pressure lowering degree follows the order of water>methanol>ethanol. Further, the activity coefficients of three solvents(viz. water,ethanol, and methanol) for the binary systems {solvent(1) + IL(2)} predicted based on the fitted NRTL parameters at T 333.15 K indicate that the two ILs generate a negative deviation from Raoult's law for water and methanol and a positive deviation for ethanol to a varying degree, change the relative volatility of a solvent. [HMEA][HCOO]may be a promising entrainer to efficiently separate ethanol aqueous solutions by special rectification.

Corrosion protection of AZ91 magnesium alloy in cooling systems

The effect of a salicylic Schiff base componnd （Salcn） on the corrosion of AZ91 alloy in 30% ethylene glycol aqueous solution （30% EG/W） was investigated by electrochemical methods. Scanning electron microscope was used to observe the alloy surface in corrosive solution before and after the addition of inhibitor. There was no significant corrosion inhibition at the room temperature but high inhibition efficiencies were obtained at elevated temperatures due to the formation of chemisorbed inhibitor monolayer. As the inhibitor concentration increased, the inhibition efficiency increased probably due to more inhibitor adsorption on the alloy surface.

Heat Transfer Properties and Chaotic Analysis of Parallel Type Pulsating Heat Pipe

The refrigerant mixture of ethanol aqueous was applied to the parallel type pulsating heat pipe (PHP). The operation characteristics of the PHP were analyzed by means of experiment and nonlinear chaotic theory. Moreover, the relationship between the running state and attractor was described. The results indicate that starting power, stable running power and dry burning transition power are about 64.08 W, 148.68 W and 234.0 W respectively. The cycle and amplitude of PHP initially decrease and then increase with the increasing power. However, the data are welldistributed in a certain range. The running state is in agreement with the attractors, and the changing process for attractors is as follows: the attractors first disperse in the whole phase space, then present mass status, and finally show band distribution.

A New Method to Solve Film Model for CO_2 Absorption with Aqueous Solution of AT-Methyldiethanolamine

The shooting method and the difference method are used for numerical simulation of CO2 absorption with aqueous solution of methyldiethanolamine (MDEA). It is demonstrated that these methods are available for the steady-state model, which may be expressed as a set of differential algebraic equations (DAEs) with two-point boundary values. This method makes it possible not only to obtain the concentration profiles for MDEA system, but also to reveal the effect of CO2 interfacial concentration on the enhancement factor. With this numerical simulation, the mass transfer process with multicomponent diffusion and reactions can be better understood.

Effect of Zn content on tensile and electrochemical properties of 3003 Al alloy

The effect of Zn addition on the microstructure, tensile properties and electrochemical properties of as-annealed 3003 Al alloy was investigated through TEM observations, tensile tests and Tafel polarization analysis. High density precipitates are observed in the Zn-containing alloys and the alloy with 1.8% Zn addition also has rod-like precipitates. Tensile test results indicate that Zn has a great effect on tensile strength of 3003 Al alloy. The alloy with 1.5% Zn addition has the highest ultimate tensile strength. The electrochemical results indicate that Zn addition to 3003 Al alloy also has great impact on the corrosion potential of the 3003 A1 alloy in 0.5% NaCl solution and ethylene glycol-water solution. The corrosion potential varies with the Zn content and shifts negatively.

Distribution and transformation behaviors of heavy metals during liquefaction process of sewage sludge in ethanol-water mixed solvents

Liquefaction of sewage sludge(SS)in ethanol-water cosolvents is a promising process for the preparation of bio-oil/biochar products.Effect of the combined use of ethanol and water on the distribution/transformation behaviors of heavy metals(HMs)contained in raw SS is a key issue on the safety and cleanness of above liquefaction process,which is explored in this study.The results show that pure ethanol facilitates the migration of HMs into biochar products.Pure water yields lower percentages of HMs in mobile/bioavailable speciation.Compared with sole solvent treatment,ethanol-water cosolvent causes a random/average effect on the distribution/transformation behaviors of HMs.After liquefaction of SS in pure water,the contamination degree of HMs is mitigated from high level(25.8(contamination factor))in raw SS to considerable grade(13.4)in biochar and the ecological risk is mitigated from moderate risk(164.5(risk index))to low risk(78.8).Liquefaction of SS in pure ethanol makes no difference to the pollution characteristics of HMs.The combined use of ethanol and water presents similar immobilization effects on HMs to pure water treatment.The contamination factor and risk index of HMs in biochars obtained in ethanol-water cosolvent treatment are 13.1-14.6(considerable grade)and 79.3-101.0(low risk),respectively.In order to further control the pollution of HMs,it is preferentially suggested to improve the liquefaction process of SS in ethanol-water mixed solvents by introducing conventional lignocellulosic/algal biomass,also known as co-liquefaction treatment.

Hydrothermal Liquefaction of Wheat Straw in Sub-critical Water/Ethanol with Ionic Liquid for Bio-oil Production

Hydrothermal liquefaction of wheat straw in sub-critical water with ionic liquid was investigated in an autoclave. The product distribution at different temperatures and pressures was studied. The liquid oil and the residuals were tested by 1H NMR, FTIR and SEM techniques. The results indicated that under the same conditions, the oil yield from liquefaction of wheat straw in water/ethanol was higher than that in sub-critical water. The result also showed that under the investigated conditions, adding 1-butyl-3-methylimidazolium chloride([Bmim]Cl) could increase the total conversion and gas yield, while at the same time the yield of n-hexane insoluble fraction and the tetrahydrofuran soluble fraction was reduced. Moreover, the results also showed that upon adding [Bmim]Cl the contents of the aliphatic hydrogen and phenols in liquid oil also increased along with improved oil quality.

Effect of Extractive-Dissolving Treatment on the Characteristics of Laminated Wood Assembled from Oily Keruing Wood

Utilization of oily keruing wood for laminated wood product has not been optimal yet because of the appearance of extractive substance as oil on wood surface and hence disturbing the bonding process. A study has been conducted by manufacturing laminated wood from oily keruing wood （Dipterocarpus hasseltii） after extracting its oil by boiling the wood in the mixture of water and ethanol solution in several proportions. The assessment on the treated wood and the resulting laminated wood covered some characteristics i.e., wettability, static bending, bonding strength, ethanol-water solution can improve wetting properties significantly and delamination. The results show that boiling treatment in The extractive does not affect mechanical characteristics of the laminated wood. Increasing of water proportion in ethanol-water solution causes the decreasing of the bonding strength and increasing delamination value of the laminated wood. The result also shows that oily keruing wood after the treatment can be used as material for laminated wood.

One-Stage Technology for Production of Concentrated Ethylene Glycol-Water Solutions （Automotive Antifreeze）

The reactor unit for one-stage technology for production of concentrated ethylene glycol-water solutions is described.Such solutions could be useful for production of automotive antifreezes. The technology is based on the highly selective hydration ofethylene oxide in the presence of heterogeneous catalyst-anion-exchange resin in HCO3-/CO/3/2-_form. The mathematical model of reactor allowed evaluating of economical benefit in comparison with conventional method.

Phase Separation Behavior of Cocamidopropyl Betaine/Water/Polyethylene Glycol System

Phase separation behavior of cocamidopropyl betaine/water/polyethylene glycol （PEG） system was studied. The effects of concentration and molecular weight of PEG on the phase separation behavior were investigated. Clouding occurred when the concentration of PEG was large enough in the betaine aqueous solution, and the concentration of PEG at cloud point decreased with the increase of PEG molecular weight for a constant betaine concentration. The bottom phase was the PEG-rich phase, and the upper phase was the betaine-rich phase. The volumetric ratio of PEG-rich phase to betaine-rich phase, at the same difference between the PEG concentration and the one at the cloud poim, △Ccp （0.1 g.ml^-1）, decreased as the PEG molecular weight increased and approached 1 for higher PEG molecular Weiglai （about 20000）, which was similar to the typicai-aqueous two-phase system. This volumetric ratio depended on the initial PEG concentration, but independent of PEG molecular weight. The concentration ratio of betaine to PEG in both phases depended on the △Ccp independent of PEG molecular weight.

Density and Viscosity of Ternary Systems(Poloxamer 188+Ethanol/ Acetone+Water)at Temperatures from 288.15 K to 308.15 K

The densities and viscosities of ternary systems(Poloxamer 188+ethanol/acetone+water)were meas- ured at 288.15,293.15,298.15,303.15,308.15 K and atmospheric pressure for different mass fractions of Poloxamer 188(0 to 0.02)in aqueous solution and different solvent volume fractions of ethanol/acetone(0 to 0.3)in Poloxamer 188 aqueous solution.The densities were measured by a pycnometer,while the viscosities were measured using two Ubbelohde capillary viscometers.The correlations of density and viscosity of these ternary systems are obtained by fitting the experimental data at different temperatures,mass fractions and volume fractions.

Ionic liquid assisted synthesis of flowerlike Cu_2O micro-nanocrystals

Novel flowerlike Cu20 micro-nanocrystals were prepared by a greener reductive reaction of cupric acetate monohydrate with ethylene glycol in aqueous solutions of [C8mim]X （X = CI-, Br-, BF4-, PFr-） and [C,,mim][BF4] （n = 4, 6, 8）. The obtained mi- crostructures of Cu2O were characterized by Scanning Electron Microscopy （SEM）, X-ray diffraction （XRD） and Fourier Transform Infrared （FT-IR）. The effects of cations, anions and concentration of the ionic liquids on the morphology of Cu20 were examined in some details. The results suggest that the formation of flowerlike Cu20 was governed by a [Csmim][BF4] controlled reductive reaction mechanism. As one of their applications, the Cu20 nanoparticles were used for the photocatalytic degradation of methylene blue in aqueous solution, and high photocatalytic activity was observed.