以回溶糖浆代表性色素——己糖碱性降解色素为吸附模型底物,考察糖用脱色树脂对其吸附性能,并采用4种新型吸附传质现象学模型,即外部传质阻力(external mass transfer resistance,EMTR)、内部传质阻力(internal mass transfer resistanc...以回溶糖浆代表性色素——己糖碱性降解色素为吸附模型底物,考察糖用脱色树脂对其吸附性能,并采用4种新型吸附传质现象学模型,即外部传质阻力(external mass transfer resistance,EMTR)、内部传质阻力(internal mass transfer resistance,IMTR)、活性位点吸附(adsorption on active sites,AAS)及EMTR-IMTR组合模型,解析树脂吸附色素传质机理。在色素初始质量浓度为60、90 mg/L及120 mg/L条件下,树脂对色素平衡吸附量分别为190、270 mg/g及326 mg/g,对应脱色率分别为95%、90%及82%。树脂吸附色素限速步骤由EMTR和IMTR共同决定,但AAS步骤不可忽略。EMTR-IMTR组合模型可准确求解吸附体系任意时刻树脂周围液膜及其内部孔道对色素吸附量,AAS模型可准确计算吸附过程任意时刻物理及化学吸附速率大小,可为阐明吸附传质机理提供新视角。展开更多
High quality nano-sized zirconium carbide （ZrC） powders were successfully fabricated via a developed chemical active dilution self-propagating high-temperature synthesis （SHS） method assisted by ball milling pretr...High quality nano-sized zirconium carbide （ZrC） powders were successfully fabricated via a developed chemical active dilution self-propagating high-temperature synthesis （SHS） method assisted by ball milling pretreatment process using traditional cheap zirconium dioxide powder （ZrO2）, magnesium powder （Mg） and sucrose （C12H22Oll） as raw materials. FSEM, TEM, HRTEM, SAED, XRD, FTIR and Raman, ICP- AES, laser particle size analyzer, oxygen and nitrogen analyzer, carbon/sulfur determinator and TG-DSC were employed for the characterization of the morphology, structure, chemical composition and thermal stability of the as-synthesized ZrC samples. The as-synthesized samples demonstrated high purity, low oxygen content and evenly distributed ZrC nano-powders with an average particle size of 50nm. In addition, the effects of endothermic rate and the possible chemical reaction mechanism were also discussed.展开更多
A pH-responsive ceramic composite membrane was prepared by chemical graft polymerization of acrylic acid (AA) onto the KH-570 modified α-alumina membrane. The influence of monomer concentration on the gating characte...A pH-responsive ceramic composite membrane was prepared by chemical graft polymerization of acrylic acid (AA) onto the KH-570 modified α-alumina membrane. The influence of monomer concentration on the gating characteristics of the pH-responsive membrane was investigated. The FT-IR spectrum, contact angle and water filtration rate of the membrane were measured. The monomer concentration was found to have a remarkable effect on the pH-response coefficient and the water filtration rate. In addition, the grafted membrane exhibited fast and reversible response to the pH change in the external solution.展开更多
文摘以回溶糖浆代表性色素——己糖碱性降解色素为吸附模型底物,考察糖用脱色树脂对其吸附性能,并采用4种新型吸附传质现象学模型,即外部传质阻力(external mass transfer resistance,EMTR)、内部传质阻力(internal mass transfer resistance,IMTR)、活性位点吸附(adsorption on active sites,AAS)及EMTR-IMTR组合模型,解析树脂吸附色素传质机理。在色素初始质量浓度为60、90 mg/L及120 mg/L条件下,树脂对色素平衡吸附量分别为190、270 mg/g及326 mg/g,对应脱色率分别为95%、90%及82%。树脂吸附色素限速步骤由EMTR和IMTR共同决定,但AAS步骤不可忽略。EMTR-IMTR组合模型可准确求解吸附体系任意时刻树脂周围液膜及其内部孔道对色素吸附量,AAS模型可准确计算吸附过程任意时刻物理及化学吸附速率大小,可为阐明吸附传质机理提供新视角。
基金Funded by the Program for New Century Excellent Talents in University(No.NCET-12-0655)the Guangxi Natural Science Foundation(No.2014GXNSFFA118004)the Self-determined and Innovative Research Funds of WUT(Nos.136643002 and No.2013IV058)
文摘High quality nano-sized zirconium carbide （ZrC） powders were successfully fabricated via a developed chemical active dilution self-propagating high-temperature synthesis （SHS） method assisted by ball milling pretreatment process using traditional cheap zirconium dioxide powder （ZrO2）, magnesium powder （Mg） and sucrose （C12H22Oll） as raw materials. FSEM, TEM, HRTEM, SAED, XRD, FTIR and Raman, ICP- AES, laser particle size analyzer, oxygen and nitrogen analyzer, carbon/sulfur determinator and TG-DSC were employed for the characterization of the morphology, structure, chemical composition and thermal stability of the as-synthesized ZrC samples. The as-synthesized samples demonstrated high purity, low oxygen content and evenly distributed ZrC nano-powders with an average particle size of 50nm. In addition, the effects of endothermic rate and the possible chemical reaction mechanism were also discussed.
基金Supported by the National Natural Science Foundation of China(Grant No.20776067)Natural Science Research Foundation of Jiangsu Education Office(Grant Nos.07KJA15012and05KJB530009)
文摘A pH-responsive ceramic composite membrane was prepared by chemical graft polymerization of acrylic acid (AA) onto the KH-570 modified α-alumina membrane. The influence of monomer concentration on the gating characteristics of the pH-responsive membrane was investigated. The FT-IR spectrum, contact angle and water filtration rate of the membrane were measured. The monomer concentration was found to have a remarkable effect on the pH-response coefficient and the water filtration rate. In addition, the grafted membrane exhibited fast and reversible response to the pH change in the external solution.
