Separation of 2-methylfuran(2-MF)and methanol(MeOH)azeotropes is a key challenge in biofuel production because of the efficiency and sustainability issues of conventional methods.In this study,ionic liquids(ILs)were i...Separation of 2-methylfuran(2-MF)and methanol(MeOH)azeotropes is a key challenge in biofuel production because of the efficiency and sustainability issues of conventional methods.In this study,ionic liquids(ILs)were introduced as green solvents for separation of 2-MF/MeOH through liquid–liquid equilibrium(LLE)experiment.Three ILs,namely 1-ethyl-3-methylimidazole dihydrogen phosphate([EMIM][H_(2)PO_(4)]),1-propyl-3-methylimidazole dihydrogen phosphate([PMIM][H_(2)PO_(4)])and 1-butyl-3-methylimidazole dihydrogen phosphate([BMIM][H_(2)PO_(4)]),were screened out from 425 candidates using the conductor-like screening model for real solvents(COSMO-RS).Then,the ternary LLE data of 2-MF(1)+MeOH(2)+ILs(3)were determined at 30℃ and 101.32 kPa.Results confirmed[EMIM][H_(2)PO_(4)]as the best performer,achieving a selectivity of 343.86 and a distribution coefficient of 36.66 for MeOH—significantly higher than[PMIM][H_(2)PO_(4)]and[BMIM][H_(2)PO_(4)].The accuracy of the LLE data was verified by Othmer–Tobias and Hand equations(R^(2)>0.90).The non-random two liquid model was used to correlate the experimental data(RMSD<2%).Besides,the combination of electrostatic surfaces potential,independent gradient model based on Hirshfeld partition,mean square displacement and radial distribution functions revealed strong electrostatic interactions between[H_(2)PO_(4)]^(–) and MeOH.Interaction energy analysis further emphasizes the mechanism of MeOH separation from a mixture of 2-MF and MeOH by ILs.This work provides a multiscale strategy for the separation of 2-MF and MeOH azeotropes,highlighting the potential of ILs to improve biofuel purification while reducing energy and environmental costs.展开更多
酸碱度(potential of hydrogen,pH)的计算长期以来以氢离子浓度为核心变量进行近似处理,但随着溶液体系的复杂化,该方法在准确性上的局限愈加凸显。活度系数的引入,为酸碱平衡提供了更贴近实际的描述路径,尤其在高离子强度、混合电解质...酸碱度(potential of hydrogen,pH)的计算长期以来以氢离子浓度为核心变量进行近似处理,但随着溶液体系的复杂化,该方法在准确性上的局限愈加凸显。活度系数的引入,为酸碱平衡提供了更贴近实际的描述路径,尤其在高离子强度、混合电解质和复杂配位体系中,其修正作用不可忽视。从pH定义与计算逻辑出发,逐步解析活度系数的物理基础与数学表达,结合常见水体与工艺溶液的实际条件,剖析活度系数修正的影响因素,以及其在预测、控制与决策层面所引发的偏差及后果。最终构建出一套基于离子强度、价态结构与应用容差的判断框架,尝试为现行检测与计算方法之间的落差提供系统化过渡路径。展开更多
Ionic liquids(ILs)have exhibited great application potential in many fields due to their unique properties.Molecular dynamics(MD)simulation has been widely employed to investigate their microscopic structure.However,c...Ionic liquids(ILs)have exhibited great application potential in many fields due to their unique properties.Molecular dynamics(MD)simulation has been widely employed to investigate their microscopic structure.However,classical molecular dynamics simulations struggle to accurately describe the complex interactions in ILs using the existing parameterized force fields.Recently,the MD simulations based on machine learning force fields(MLFFs)trained by first-principles calculations have attracted considerable attentions due to their abilities to balance computational accuracy and efficiency.Herein,we report the Bayesian-based MLFFs which can be successfully applied in IL systems and accelerate MD simulation.The calculated atomic forces,structures,and vibrational behaviors were validated to match the accuracy of firstprinciples calculations.Properties of the imidazolium-based ILs,including density,self-diffusion coefficients,viscosity,and radial distribution functions were predicted at the extended scales.Z-bonds that describe the unique structures in ILs were analyzed and the influences of Cpositions,temperature,and solvent H2O on Z-bonding configurations were systematically investigated.Our results confirmed that MLFFs presented the strong feasibility to investigate the large and complex systems,especially to predict structures and properties of the ILs.And the procedure described for MLFFs provides valuable guidance for researchers who are studying ILs.展开更多
A novel room-temperature ionic liquid (RTIL),1-allyl,3-methylimidazolium chloride (［AMIM］Cl),was synthesized,ch aracterized and used for dissolving cellulose.The solubility of cellulose in ［ AMIM］Cl was better tha...A novel room-temperature ionic liquid (RTIL),1-allyl,3-methylimidazolium chloride (［AMIM］Cl),was synthesized,ch aracterized and used for dissolving cellulose.The solubility of cellulose in ［ AMIM］Cl was better than in 1-butyl,3-methylimidazolium (［BMIM］Cl).The pris tine cellulose and two cellulose samples regenerated from ［AMIM］Cl and ［BMIM ］Cl solutions were compared by FTIR,WAXD and TGA measurements.Results show t hat these two RTILs are non-derivatizing solvents for cellulose.After regenera tion from RTIL solutions,the crystalline form of cellulose films is completely transformed from cellulose Ⅰ to cellulose Ⅱ.Compared to pristine cellulose,t he regenerated cellulose exhibits a lower onset temperature of thermal decomposi tion,with a higher char yield.展开更多
基金supported by the National Natural Science Foundation of China(22278272)Natural Science Foundation of Liaoning Province(2024-MS-129).
文摘Separation of 2-methylfuran(2-MF)and methanol(MeOH)azeotropes is a key challenge in biofuel production because of the efficiency and sustainability issues of conventional methods.In this study,ionic liquids(ILs)were introduced as green solvents for separation of 2-MF/MeOH through liquid–liquid equilibrium(LLE)experiment.Three ILs,namely 1-ethyl-3-methylimidazole dihydrogen phosphate([EMIM][H_(2)PO_(4)]),1-propyl-3-methylimidazole dihydrogen phosphate([PMIM][H_(2)PO_(4)])and 1-butyl-3-methylimidazole dihydrogen phosphate([BMIM][H_(2)PO_(4)]),were screened out from 425 candidates using the conductor-like screening model for real solvents(COSMO-RS).Then,the ternary LLE data of 2-MF(1)+MeOH(2)+ILs(3)were determined at 30℃ and 101.32 kPa.Results confirmed[EMIM][H_(2)PO_(4)]as the best performer,achieving a selectivity of 343.86 and a distribution coefficient of 36.66 for MeOH—significantly higher than[PMIM][H_(2)PO_(4)]and[BMIM][H_(2)PO_(4)].The accuracy of the LLE data was verified by Othmer–Tobias and Hand equations(R^(2)>0.90).The non-random two liquid model was used to correlate the experimental data(RMSD<2%).Besides,the combination of electrostatic surfaces potential,independent gradient model based on Hirshfeld partition,mean square displacement and radial distribution functions revealed strong electrostatic interactions between[H_(2)PO_(4)]^(–) and MeOH.Interaction energy analysis further emphasizes the mechanism of MeOH separation from a mixture of 2-MF and MeOH by ILs.This work provides a multiscale strategy for the separation of 2-MF and MeOH azeotropes,highlighting the potential of ILs to improve biofuel purification while reducing energy and environmental costs.
文摘酸碱度(potential of hydrogen,pH)的计算长期以来以氢离子浓度为核心变量进行近似处理,但随着溶液体系的复杂化,该方法在准确性上的局限愈加凸显。活度系数的引入,为酸碱平衡提供了更贴近实际的描述路径,尤其在高离子强度、混合电解质和复杂配位体系中,其修正作用不可忽视。从pH定义与计算逻辑出发,逐步解析活度系数的物理基础与数学表达,结合常见水体与工艺溶液的实际条件,剖析活度系数修正的影响因素,以及其在预测、控制与决策层面所引发的偏差及后果。最终构建出一套基于离子强度、价态结构与应用容差的判断框架,尝试为现行检测与计算方法之间的落差提供系统化过渡路径。
基金supported by the National Natural Science Foundation of China(Nos.22278397)the Fundamental Research Funds for the Central Universities(2024SMECP01).
文摘Ionic liquids(ILs)have exhibited great application potential in many fields due to their unique properties.Molecular dynamics(MD)simulation has been widely employed to investigate their microscopic structure.However,classical molecular dynamics simulations struggle to accurately describe the complex interactions in ILs using the existing parameterized force fields.Recently,the MD simulations based on machine learning force fields(MLFFs)trained by first-principles calculations have attracted considerable attentions due to their abilities to balance computational accuracy and efficiency.Herein,we report the Bayesian-based MLFFs which can be successfully applied in IL systems and accelerate MD simulation.The calculated atomic forces,structures,and vibrational behaviors were validated to match the accuracy of firstprinciples calculations.Properties of the imidazolium-based ILs,including density,self-diffusion coefficients,viscosity,and radial distribution functions were predicted at the extended scales.Z-bonds that describe the unique structures in ILs were analyzed and the influences of Cpositions,temperature,and solvent H2O on Z-bonding configurations were systematically investigated.Our results confirmed that MLFFs presented the strong feasibility to investigate the large and complex systems,especially to predict structures and properties of the ILs.And the procedure described for MLFFs provides valuable guidance for researchers who are studying ILs.
文摘A novel room-temperature ionic liquid (RTIL),1-allyl,3-methylimidazolium chloride (［AMIM］Cl),was synthesized,ch aracterized and used for dissolving cellulose.The solubility of cellulose in ［ AMIM］Cl was better than in 1-butyl,3-methylimidazolium (［BMIM］Cl).The pris tine cellulose and two cellulose samples regenerated from ［AMIM］Cl and ［BMIM ］Cl solutions were compared by FTIR,WAXD and TGA measurements.Results show t hat these two RTILs are non-derivatizing solvents for cellulose.After regenera tion from RTIL solutions,the crystalline form of cellulose films is completely transformed from cellulose Ⅰ to cellulose Ⅱ.Compared to pristine cellulose,t he regenerated cellulose exhibits a lower onset temperature of thermal decomposi tion,with a higher char yield.
