电控离子交换技术(electrochemically switched ion exchange,ESIX)是将电活性离子交换材料(EXIMs)沉积或涂覆在导电基底上,通过电化学控制导电基底上活性材料氧化还原状态实现目标离子置入与释放,从而实现离子的分离。该技术具有痕量...电控离子交换技术(electrochemically switched ion exchange,ESIX)是将电活性离子交换材料(EXIMs)沉积或涂覆在导电基底上,通过电化学控制导电基底上活性材料氧化还原状态实现目标离子置入与释放,从而实现离子的分离。该技术具有痕量提取、无二次污染、速率可控、高选择性等优点。通过共沉淀法制备Ni Fe Mn LDH,并将其与碳纳米管(CNTs)、聚偏二氟乙烯(PVDF)混合涂覆到石墨板上,制得NiFeMn LDH/CNTs/PVDF膜电极。NiFeMn LDH层板上具有丰富的羟基官能团,可与W(Ⅵ)发生羟基配位;层间的阴离子与W(Ⅵ)进行离子交换,可为W(Ⅵ)提供丰富的活性位点。在ESIX系统中,膜电极对W(Ⅵ)的吸附容量可达122.10 mg·g^(-1),且W(Ⅵ)与Mo(Ⅵ)、Cl^(-)、■分离因子(■)分别为1.25、19.60、35.80,实现了W(Ⅵ)选择性分离。此外,该膜电极具有优异的循环稳定性,为钨的高效分离提供了新的方向。展开更多
Polyvinylidene fluoride/lead zirconate titanate(PVDF/PZT)composite films have been prepared by direct ink writing and the effect of PZT content on crystallization behavior and electrical properties of film were system...Polyvinylidene fluoride/lead zirconate titanate(PVDF/PZT)composite films have been prepared by direct ink writing and the effect of PZT content on crystallization behavior and electrical properties of film were systematically investigated.The composite films were characterized by scanning electron microscope(SEM),X-ray diffractometer(XRD),Flourier transform infrared spectroscope(FTIR)and differential scanning calorimeter(DSC).The results show that,surface modified PZT powder(PZT@PDA)is successfully coated by polydopamine(PDA),resulting in a large number of polar groups that interact with the-CF_(2)-groups in PVDF,inducing the generation of polarβphase due to hydrogen bonding formed in the interaction.Theβphase content in composite film increases with increasing PZT@PDA content,up to 28.09%as with 5 wt.%PZT@PDA.PZT@PDA plays a role of nucleating agent to promote the generation of polar phases in the film and also acts as an impurity hindering the growth of nuclei to reduce crystallinity.Moreover,the presence of PZT@PDA in interfaces provides more sites for the occurrence of interfacial polarization and thus improving the electrical properties of films.The composite film with 5 wt.%PZT@PDA possesses the highest dielectric constant(8.61)and residual polarization value(0.6803μC/cm^(2)).展开更多
文摘电控离子交换技术(electrochemically switched ion exchange,ESIX)是将电活性离子交换材料(EXIMs)沉积或涂覆在导电基底上,通过电化学控制导电基底上活性材料氧化还原状态实现目标离子置入与释放,从而实现离子的分离。该技术具有痕量提取、无二次污染、速率可控、高选择性等优点。通过共沉淀法制备Ni Fe Mn LDH,并将其与碳纳米管(CNTs)、聚偏二氟乙烯(PVDF)混合涂覆到石墨板上,制得NiFeMn LDH/CNTs/PVDF膜电极。NiFeMn LDH层板上具有丰富的羟基官能团,可与W(Ⅵ)发生羟基配位;层间的阴离子与W(Ⅵ)进行离子交换,可为W(Ⅵ)提供丰富的活性位点。在ESIX系统中,膜电极对W(Ⅵ)的吸附容量可达122.10 mg·g^(-1),且W(Ⅵ)与Mo(Ⅵ)、Cl^(-)、■分离因子(■)分别为1.25、19.60、35.80,实现了W(Ⅵ)选择性分离。此外,该膜电极具有优异的循环稳定性,为钨的高效分离提供了新的方向。
基金Project(22020JJ4729)supported by the Natural Science Foundation of Hunan Province,China。
文摘Polyvinylidene fluoride/lead zirconate titanate(PVDF/PZT)composite films have been prepared by direct ink writing and the effect of PZT content on crystallization behavior and electrical properties of film were systematically investigated.The composite films were characterized by scanning electron microscope(SEM),X-ray diffractometer(XRD),Flourier transform infrared spectroscope(FTIR)and differential scanning calorimeter(DSC).The results show that,surface modified PZT powder(PZT@PDA)is successfully coated by polydopamine(PDA),resulting in a large number of polar groups that interact with the-CF_(2)-groups in PVDF,inducing the generation of polarβphase due to hydrogen bonding formed in the interaction.Theβphase content in composite film increases with increasing PZT@PDA content,up to 28.09%as with 5 wt.%PZT@PDA.PZT@PDA plays a role of nucleating agent to promote the generation of polar phases in the film and also acts as an impurity hindering the growth of nuclei to reduce crystallinity.Moreover,the presence of PZT@PDA in interfaces provides more sites for the occurrence of interfacial polarization and thus improving the electrical properties of films.The composite film with 5 wt.%PZT@PDA possesses the highest dielectric constant(8.61)and residual polarization value(0.6803μC/cm^(2)).
