Abstract:

In order to adsorb 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 is （400±40）nm. Calixarene-PI fibers display strong adsorption on Pt（Ⅳ）rather than Ag (Ⅰ) and Au (Ⅰ), which fit with the Langmuir isothermal adsorption model. The saturated amount of Pt（Ⅳ）adsorped 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.

Key words: calixarene fiber, selective adsorption, Pt（IV）, isothermal adsorption model