Novel adsorbent, Fe(Ⅲ)-loaded ligand exchange cotton cellulose adsorbent [Fe(Ⅲ) LECCA], was used to in vestigate the adsorption performances and mechanism of fluoride removal from aqueous solutions. The adsorben...Novel adsorbent, Fe(Ⅲ)-loaded ligand exchange cotton cellulose adsorbent [Fe(Ⅲ) LECCA], was used to in vestigate the adsorption performances and mechanism of fluoride removal from aqueous solutions. The adsorbent was found to adsorb fluoride rapidly and effectively. The fluoride removal was influenced by pH. Adsorption mode followed first-order reaction at different temperature, theapparent adsorption activated energy Ea was 6.37 kJ·mol^-1, and adsorption enthalpy △H was 5.35 kJ·mol^-1. The adsorption enfluoride on adsorbent was 3.2 mmol·g^-1 (dry weight). The maximal integer coordination ratio of fluoride with Fe(Ⅲ) LECCA was 3:1. The ligand exchange mechanism of adsorption was elucidated through chemical methods and IR spectral analysis.展开更多
金属-有机框架材料(MOFs)近年得到广泛研究,但不易回收、难处理等缺点使其在实际应用中受到很大限制。通过合适的加工工艺将MOFs加工成型,对促进开发应用很有必要。作为一种可制备杂化微纳米纤维的简单快捷方法,静电纺丝法在制备负载功...金属-有机框架材料(MOFs)近年得到广泛研究,但不易回收、难处理等缺点使其在实际应用中受到很大限制。通过合适的加工工艺将MOFs加工成型,对促进开发应用很有必要。作为一种可制备杂化微纳米纤维的简单快捷方法,静电纺丝法在制备负载功能粒子的复合膜材料领域得到了迅速发展。通过静电纺丝法将MOFs材料负载在纤维当中,将其加工成纤维膜,并探讨了在纤维膜的制备过程中MOFs掺杂量和纺丝电压两个因素对复合纤维形貌的影响。首先采用溶剂热法,通过对苯二甲酸和锆元素的配位作用,制备出典型的锆基金属-有机框架材料UiO-66(UiO=University of Oslo)。然后,以聚丙烯腈(PAN)和UiO-66为基质,通过静电纺丝技术制备PAN/UiO-66复合纳米纤维膜。采用扫描电子显微镜(SEM)、X-射线衍射(XRD)、傅里叶变换红外光谱分析(FT-IR)和N2吸脱附实验等分析测试技术,对UiO-66和PAN/UiO-66复合纳米纤维膜的表面形貌、结构及比表面积等进行表征分析。结果表明:成功制备出金属-有机框架材料UiO-66和PAN/UiO-66电纺纳米纤维膜;静电纺纯PAN纤维的表面光滑平整,掺杂UiO-66后,纤维表面变得粗糙;随着UiO-66掺杂量的增大,嵌入PAN纤维中UiO-66颗粒量有所增多,同时,纤维直径变小。UiO-66掺杂量为40%的纺丝液在18~22 kV电压下均具有可纺性,所制备纤维的平均直径为150~170 nm。展开更多
文摘Novel adsorbent, Fe(Ⅲ)-loaded ligand exchange cotton cellulose adsorbent [Fe(Ⅲ) LECCA], was used to in vestigate the adsorption performances and mechanism of fluoride removal from aqueous solutions. The adsorbent was found to adsorb fluoride rapidly and effectively. The fluoride removal was influenced by pH. Adsorption mode followed first-order reaction at different temperature, theapparent adsorption activated energy Ea was 6.37 kJ·mol^-1, and adsorption enthalpy △H was 5.35 kJ·mol^-1. The adsorption enfluoride on adsorbent was 3.2 mmol·g^-1 (dry weight). The maximal integer coordination ratio of fluoride with Fe(Ⅲ) LECCA was 3:1. The ligand exchange mechanism of adsorption was elucidated through chemical methods and IR spectral analysis.
文摘金属-有机框架材料(MOFs)近年得到广泛研究,但不易回收、难处理等缺点使其在实际应用中受到很大限制。通过合适的加工工艺将MOFs加工成型,对促进开发应用很有必要。作为一种可制备杂化微纳米纤维的简单快捷方法,静电纺丝法在制备负载功能粒子的复合膜材料领域得到了迅速发展。通过静电纺丝法将MOFs材料负载在纤维当中,将其加工成纤维膜,并探讨了在纤维膜的制备过程中MOFs掺杂量和纺丝电压两个因素对复合纤维形貌的影响。首先采用溶剂热法,通过对苯二甲酸和锆元素的配位作用,制备出典型的锆基金属-有机框架材料UiO-66(UiO=University of Oslo)。然后,以聚丙烯腈(PAN)和UiO-66为基质,通过静电纺丝技术制备PAN/UiO-66复合纳米纤维膜。采用扫描电子显微镜(SEM)、X-射线衍射(XRD)、傅里叶变换红外光谱分析(FT-IR)和N2吸脱附实验等分析测试技术,对UiO-66和PAN/UiO-66复合纳米纤维膜的表面形貌、结构及比表面积等进行表征分析。结果表明:成功制备出金属-有机框架材料UiO-66和PAN/UiO-66电纺纳米纤维膜;静电纺纯PAN纤维的表面光滑平整,掺杂UiO-66后,纤维表面变得粗糙;随着UiO-66掺杂量的增大,嵌入PAN纤维中UiO-66颗粒量有所增多,同时,纤维直径变小。UiO-66掺杂量为40%的纺丝液在18~22 kV电压下均具有可纺性,所制备纤维的平均直径为150~170 nm。