Synthesis, Functionalizahon and Application of Stimuli-responsive Polymer Porous Membranes

Background: Porous stimuli-responsive polymer membranes are a series of membrane devices with not only common separating and mechanical properties, but also stimuli-responsive capabilities. In recent decades, there is an increasing interest in utilizing track-etch polymer membranes with single or array nanochannels on them as sensing elements in smart responsive membrane devices. Objective: We review the synthesis and functionalizations of track-etch membranes and their sensing applications, in order to expand possible applications of functional organic molecules, and also supply a novel potential platform for specific analysis of organic chemistry. Method: We introduced the membrane preparation and the sensing mechanism of membrane devices, summarized recent approaches to optimize membrane functionalization. Applications: Induced by external stimuli in solutions, functional molecules fixed on track-etch membranes change their structure and ionization, which impact on the ionic permeation and ionic rectifying of these nanofluid devices. Based on this mechanism, sensing to aqueous environmental stimuli (including temperature, pH and light), specific ions and molecules have been achieved by different groups. Conclusion: For controllable pore sizes, simple modifications and regular shapes of track-etch membranes, the track-etch membranes devices exhibit specific and reliable responses to various stimuli. We hope in the future, more smart materials with specific affinities could be utilized to functionalize track-etch membrane devices, and their applications could be broadened from chemical analyses to industrial separation and purification processes.