Preparation of Sulfonated Polyarylene Ether Nitrile Hollow Fiber Membrane Adsorbent and Its Potential in Separation Lithium Ion from Brine

摘要

In this paper, a series of sulfonated polyarylene ether nitriles copolymers (SPEN) with adjustable sulfonic acid groups are synthesized through nucleophilic substitution reaction. Then, the SPEN hollow fiber membrane (SPENH) adsorbents are successfully prepared by dry-wet phase conversion. Due to the increase of hydrophilic groups sulfonic acid (-SO3H) and increases surface roughness, the water contact angle of SPENH- 60 is as low as 46.97°, and the wettability of SPENH adsorbent is improved. In addition, SPENH-60 adsorbent has a high porosity of 97.87% and -SO3H groups (1.53 mmol g~(-1)), which shows an excellent Li~+ adsorption uptake of up to 20.54 mg·g~(-1). The adsorption kinetics of Li~+ follows the pseudo-second-order adsorption kinetic and the adsorption isotherm data conforms to the Langmuir model. The selectivity factors of Li~+ to Na~+, K~+, Ca~(2+) and Mg~(2+) are 5.019, 4.038, 2.726 and 48.348, respectively. After 10 times of adsorption-desorption cycles, the adsorption uptake decrease by only 4.3%. Therefore, SPENH adsorbent has the potential to selectively separate and recycle Li~+ from brine.