Effect of Surface Modification with Electrospun Nanofibers on the Performance of an Ultrafiltration Membrane

Abstract

Electrospinning of nanofibrous mats to create new membranes has been widely investigated, however surface modification of commercial membranes by electrospinning of nanofiber layer has received limited attention. In this work, the surface of a commercial polyethersulfone (PES) ultrafiltration membrane was coated with electrospun polyvinylidene fluoride (PVDF) hydrophobic nanofibers (NFs) for different time periods, i.e., 25 min, 125 min, and 250 min., and the effect of coating on the filtration performance was investigated. The membranes were characterized by scanning electron microscopy (SEM), contact angle measurement and further subjected to pure water permeation experiments, as well as the filtration of Ottawa River Water (ORW) and various protein solutes. By a thorough statistical analysis, it was concluded that the coating with the electrospun nanofiber layer enhanced the pure water permeation (PWP) flux. However, the fouling of the composite nanofiber/PES membranes was more severe due to the compaction of the soft nanofiber layer and the entrapment of foulants in the spaces between nanofibers. The nanofiber mat did not impact the separation of protein solutes as the composite and base PES membranes had the same protein removals.