静电纺杯芳烃纤维的制备及其对Pt(Ⅳ)选择性吸附性能

摘要

In order to absorb noble metals ions,calixarene-polyimide (calixarene-PI) fibers were fabricated by design and synthesis of 5,17-diamino-26,28-(1',8'-dioxa-4',5'-dithiaoctane)-calix [4] arene monomer,preparation of calixarene-polyamide acid (calixarene-PAA) spinning solution by amidation,fabrication of the calixarene-PAA fibers by electrospinning,and preparation of calixarene-PI fibers by thermal imidization on calixarene-PAA fibers.Calixarene-PI fibers were characterized by Fourier transform infrared spectrography and scanning electronic microscopy,and their adsorption on Pt (Ⅳ),Ag (Ⅰ) and Au (Ⅰ) was studied.FT-IR indicates calix [4] arene monomer is incorporated into calixarene-PI fibers.SEM image shows the diameter of calixarene-PI fiber is (400-40) nm.Calixarene-PI fibers display strong adsorption on Pt(Ⅳ) rather than Ag (Ⅰ) and Au (Ⅰ),which fit with Langmuir isothermal adsorption model.The saturated amount of Pt (Ⅳ) adsorbed by calixarene-PI fibers is 3.1 mmol/g.The electron distribution in the outermost of Pt(Ⅳ) is 5d6,which indicates the 5d electron layer of Pt(Ⅳ)is not fully occupied by electrons.Pt(Ⅳ)can accept electrons of O or S in 1,8-dioxa-4,5-dithiaoctane attached in calixarene-PI fibers.Therefore,the coordinative adsorption between Pt (Ⅳ) and calixarene-PI fibers can be formed.%为选择性吸附贵重金属离子,设计并合成5,17-二氨基-26,28-(1',8'-二氧杂-4',5'-二硫杂正辛烷基)-杯[4]芳烃单体,通过酰胺化法合成杯芳烃聚酰胺酸纺丝液,用静电纺丝法制备杯芳烃聚酰胺酸纤维,再对杯芳烃聚酰胺酸纤维进行热酰亚胺化,制备出杯芳烃聚酰亚胺纤维.采用红外光谱和扫描电镜对纤维进行表征,并研究了纤维对Pt(Ⅳ)、Ag(Ⅰ)、Au(Ⅰ)的选择性吸附性能.结果表明,自制杯芳烃单体已成功引入到杯芳烃聚酰亚胺纤维中,纤维直径为(400±40)nm,它仅对Pt(Ⅳ)有很强的选择性吸附作用,吸附行为符合Langmuir等温吸附模型,纤维对Pt(Ⅳ)的饱和吸附量为3.1 mmol/g.选择性吸附的原因是Pt(Ⅳ)最外层电子排布为5d6,未占满,Pt(Ⅳ)可进入纤维中杯芳烃下缘的1,8-二氧杂-4,5-二硫杂正辛烷基的空腔中,并接受O、S的电子,形成配位吸附.