Self-sterilizing diblock polycation-enhanced polyamidoxime shape-stable blow-spun nanofibers for high-performance uranium capture from seawater

Nowadays, marine bacteria are abundant in marine ecosystems and considered to be one of the main causes of biofouling. Microbial films formed on adsorbent surfaces play a vital role in marine biofouling and lead to a decrease in uranium extraction. Therefore, developing efficient antibacterial and antibiofilm sorbents for uranium enrichment is an urgent demand. In this work, a novel composite nanofibrous adsorbent, comprising of amidoximated polyacrylonitrile (AOP) and poly(ethylene glycol) methyl ether-b-poly(L-arginine) (PPLA), was prepared via solution blow spinning for potential uranium seawater recovery. The effect of initial pH, adsorbent composition, sorbent dose and contact time on the sorption of uranyl ions and antibacterial assay were investigated. The introduced polycationic diblock PPLA with guanidines not only showed improved shrinkage deformations from negatively charged AOP fibers and excellent antibacterial and antibiofilm activities, but also enhanced the adsorption capacity of the adsorbents, even after eight cycles of adsorption-desorption in uranium-spiked seawater. The adsorption equilibrium could be achieved with a capacity of 10.31 mg/g within 35 d in unfiltered natural seawater. These findings suggest that the blown-spun AOP@PPLA composite nanofibers may be conducive to the evolution of new antifouling adsorbents for uranium separation from seawater.