Papers by Keyword: Ionic Liquid (IL)

Abstract: In this paper, the effects of the concentration, temperature, and run-time of ionic liquids solution, on the rejection capacity of home-made hollow fiber composite nanofiltration membrane were studied. Then the nanofiltration membrane was used to the recover ionic liquids by concentrating spinning wastewater. The results shows that: The rejection rate of the composite nanofiltration membranes and its water fluxes lightly down with the concentration of ionic liquids increase; with running-time and temperature of ionic liquid solution increase, the rejection rate of the composite nanofiltration membranes decreases, but its water flux increases; the nanofiltration membrane can be use for recovering ionic liquid from the spinning wastewater and get very good recovery effects.

Abstract: Three binary solutions composed of ionic liquid (IL), 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM] [DEP]), and selected refrigerants (water, ethanol or methanol) were proposed as new working pairs for absorption heat pumps or absorption refrigerators. The vapor–liquid equilibrium (VLE) data were measured by a static method at different temperatures and at different ILs mole factions and correlated by the None-Random Two Liquids (NRTL) activity coefficient models, and the average relative deviation were less than 3.3%. The solutions showed strong negative deviation from the Raoult's Law and were able to absorb vapor of water, ethanol or methanol. The excess enthalpies were measured and correlated at 298.15 K and atmospheric pressure. The results indicated that the mixing of [EMIM] [DEP] with water, ethanol or methanol were exothermal. The proposed solutions were proved to possess one of the fundamental features that a working pair must have in absorption cycle.

Abstract: In present research ionic liquid, 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP]) and water were taken as the new working pair for absorption heat transformer (AHT). The thermodynamic cycle performance for this working pair was simulated based on its thermodynamic data, mass and energy balance for each component in a AHT. The effects of absorption and condensing temperature on the coefficient of performance (COP), exergy efficiency (ECOP), concentration deference between dense and dilution solutions and flow rate ratio were analyzed. The cycle performance comparison for AHT using two working pairs, H₂O + [MMIM][DMP] and H₂O + LiBr was carried out. The results indicate that the COP and ECOP of AHT for H₂O+ [MMIM][DMP] are all lower than those for H₂O + LiBr, but they can still reach 0.4 and 0.5 respectively when condensing and generation temperatures are 35 and 90 °C respectively. The excellent physical and chemical properties of ionic liquid mentioned above together with suitable cycle performance make this new working pair to have the potential application in absorption heat pump or absorption heat transformer.

Abstract: Pseudo ternary phase diagrams of bmimPF₆/Tween80/fatty acid/toluene systems were constructed with different linear-chain fatty acid. The results demonstrated that when surfactant/fatty acid weight ratio increased, the microemulsion domain became larger, but was less than that in the absence of fatty acid. Moreover, the different chain length of fatty acid affected the extent of microemulsion region, and medium-chain length of fatty acid maximized the single-phase area of bmimPF₆-based microemulsion. In addition, the influence on the microstructure of the single-phase area in the different linear-chain length fatty acids was conducted by studying the electrical conductivity behavior. Preliminary investigation suggested that the O/IL (oil /ionic liquid) microemulsion in the presence of C₅H₁₁COOH and the IL/O (ionic liquid/oil) microemulsion in the presence of C₃H₇COOH were max.

Abstract: A series of blend films of cellulose and chitosan were prepared from 1-ethyl-3-methyl imidazole acetate ([Emim] Ac) by coagulating with ethanol. Structure, mechanical properties, thermal stability and antibacterial properties were investigated. The results showed that there were strong interactions and good compatibility between cellulose and chitosan in blend films. The blend films possess good mechanical properties and thermal stability, and the existence of chitosan endows blend films with antimicrobial property.

Abstract: Ionic liquids 1-brutyl-3-methylimidazolium Tetrafluoroborate [BMIM]BF4 and 1-brutyl-3-methylimidazolium hexafluorophosphate [BMIM]PF6 were synthesized directly from 1-butylbromide, 1-methylimidazole, sodium tetrafluoroborate or hexafluorophosphate using microwave by one-pot under solvent-free conditions in an unmodified household oven. This method requires only a few minutes of reaction time, in contrast to the several hours needed using conventional methods by two pots that requires a lot of organic solvent. The reaction yield of ionic liquids with intermittent microwave heating is much higher than that of ionic liquids with conventional microwave heating. Thus the intermittent microwave heating is a good method for the reaction. The yield of the two ionic liquids increased slightly with increment of molar ratio of sodium tetrafluoroborate or potassium hexafluorophosphate.

Abstract: Montmorillonite is usually modified with ammonium salts, in our study the selected ionic liquids were applied as modifying agents for the intercalation of montmorillonite. Surface properties of modified fillers, the zeta potential of suspended solids in the water, the oil absorption number, the impact of modifications on the tendency to agglomerate in the non-polar and polar medium were studied. The modified fillers were used in two matrices with different polarity: the ethylene-propylene copolymer EPM and hydrogenated acrylonitrile-butadiene rubber HNBR. Elastomers were crosslinked with dicumyl peroxide DCP. The influence of the variously modified fillers on the cross-linking density of the vulcanizates, rheometric and mechanical properties of filled systems were investigated. The ageing studies (thermal, atmospheric and under UV radiations) were conducted.

Abstract: Ce4+-doped zinc oxide was prepared by Ionic liquid assisted sol - gel method using oxalic acid and zinc acetate as starting material for the first time. And rhodamine B as the target material to study ionic liquid assisted preparation of Ce4+-doped ZnO photocatalytic performance. ZnO was determined by SEM and XRD for introduction of ionic liquids and Ce4+ derived from nano-ZnO surface morphology and crystal before and after. The results show that the Ce4+-doped nano-ZnO crystal structure of a rod. In ionic liquids based on the Ce4+-doped photocatalytic properties of ZnO better. The degradation of rhodamine B 30min when the degradation rate of 90%.

Abstract: In the present work ionic liquid has been used for the regeneration of cellulose from waste writing paper. The regenerated cellulose was characterized by TGA, FTIR and XRD analyses. Kinetics of thermal degradation of this cellulose was carried out under dynamic condition using thermogravimetry. Coats-Redfern kinetic model was used to determine the kinetic parameters for the degradation process. The activation energy for the thermal degradation of the regenerated cellulose has been found to be less than the precursor waste paper.

Abstract: Electrophoretic deposition is a promising method for the near net shaping of ceramics if deposit damage during removal from the electrode can be prevented. The latter can be achieved by providing a lubricated interface between electrode and deposit. During application of such a lubricant care must be taken that none of the electrode surface details are lost. Hence thins layers which closely represent the original electrode surface are needed. In the present work electrophoretic deposition of alumina powder on a thin layer of ionic liquid applied on polymer electrodes is described. After deposition this ionic liquid layers serves as a shear plane during the deposit removal. The resulting deposits exhibit a smooth surface quality and high green density. Furthermore experiments show that the ionic liquid can be used as a means for producing electrodes with areas at which deposition is locally prevented.