Comparative study of poly(vinyl alcohol)/poly(N-vinyl-2-pyrrolidinone) hydrogels induced by ultrasound and gamma rays for ionoprinting technique

Abstract

I N THIS STUDY, polyvinyl alcohol (PVA) and poly (N-vinyl-2-pyrrolidinone) (PNVP) hydrogels were prepared by two techniques of irradiation; ultrasound and gamma rays, respectively in purpose of comparative study. The formed hydrogels from both approaches were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry, (DSC), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray spectroscopy (XRD), hardness and inductively coupled plasma optical emission spectroscopy ((ICP-OES). Moreover, the swelling behavior and gel faction were studied for the produced hydrogels of both approaches. The results indicate that hydrogels were prepared by both approaches are having the similar physical and chemical properties. The hydrogels formed were used in the ionoprinting technology. The ionoprinting technology has ability to topographically structure and actuates hydrogels by locally patterning ions via complexation assisted by electric fields. The significant features of ionoprinted hydrogels are stable for 36 days. Further, the ionoprinting process is fully reversible by immersion the ionoprinting hydrogels into a chelator.

Dual-Responsive Hydrogels for Mercury Ion Detection and Removal from Wastewater

“…As can be observed from Figures 2b and S1a,b,c, the other four types of hydrogels, which contain chelating agents, possess a morphology comprised of interconnected polyhedral [34] cavernous pores, with more continuous pore walls than the blank sample, probably due to a denser network created through the supplementary intermolecular interactions (hydrogen bonding) induced by the presence of the chelating agents inside the polymeric network [6,35] and the additional ionic interactions established by the sulfonate groups from AMPSA or by the NVP moieties with the chelates [35][36][37][38]. The structure of these lyophilized hydrogels may be explained by the effect induced by the freezing of free water inside the polymer network meshes, which may lead to the deformation of the pores, by stretching the hydrated chains around the ice crystals formed [34].…”