Preparation and Characterization of pH‐sensitive Hydrogel Film of Chitosan/Poly(acrylic acid) Copolymer

Abstract

A hydrogel film of chitosan/poly(acrylic acid) (CS/PAAc) copolymer with the property of pH sensitivity, was prepared by irradiating the chitosan film, which was then swelled by aqueous AAc solutions of different concentrations. The effects of the feed ratio of chitosan and AAc on the properties of the hydrogels, such as swelling ratio and pH‐sensitivity, were determined. Fourier transform infrared (FT‐IR) spectroscopy was applied in the attenuated total reflectance (ATR) mode for analyzing the structure change of the hydrogels after the treatment in buffer solutions of different pHs.

Features of the intramolecular structure of branched polymer systems in solution

“…Although the synthesis of branched polymers by radiating the reaction mixture is widely spread [98,105,106], however, it is characterized by a large number of disadvantages, for example, it can be accompanied by the destruction of the main chain or the stitching of the macromolecules. Under these conditions it is difficult to control the length and the number of grafts in the synthesized copolymer because radicals appear in accordance with the probability theory rather than in exactly determined places [98].…”

Surface molecular imprinting on polypropylene fibers for rhodamine B selective adsorption

“…As a result, the volume of MIF-B appeared to be small. Whereas at pH above the pK a of acrylic acid (4.25), the carboxylic acid groups of PAA were ionized to ACOO À [35]. The negative charge repulsion between ACOO À groups allowed the chain segments of PAA to stretch in the polymer network upon volume expansion [36].…”

Chitosan cross-linked poly(acrylic acid) hydrogels: Drug release control and mechanism

“…While cross-linking through physical interactions such as hydrogen bonding or hydrophobic interactions has been proposed to avoid toxicity problems [11][12][13], such cross-linking may be not be strong enough to produce a sufficiently stable hydrogel for effective drug loading. Fortunately, polysaccharides may be used as chemical cross-linkers to produce biocompatible hydrogels which present attractive applications in drug delivery [14][15][16][17].…”