Preparation method for high-strength hydrogel with rapid response to both pH value and temperature

Abstract

The invention relates to a preparation method for a high-strength dual-network hydrogel capable of rapidly responding to both a pH value and temperature. The preparation method comprises the following steps: (1) dissolving temperature-sensitive monomer, pH-sensitive monomer and inorganic cross-linking agent modified nanometer clay in water together, placing the obtained solution in a container, carrying out stirring in an ice bath with a temperature of 0 DEG for 60 min under the protection of nitrogen until the solution is uniform and transparent, then adding an aqueous solution of a silica network precursor and continuing stirring for 30 min until the obtained mixture is uniform and transparent; (2) adding an aqueous solution of a redox initiator and a catalyst, carrying out uniform mixing under stirring, introducing nitrogen for 5 min and pouring the obtained mixture in a die with a certain shape; (3) subjecting the die to a reaction at 20 DEG C for 30 min and then to a reaction at -28 DEG C for 24 h; and (4) taking the product out and carrying out repeated water changing and soaking so as to obtain the finished hydrogel. The hydrogel prepared in the invention has obvious dual response to temperature and the pH value, excellence strength and an ultra-fast response rate; moreover, raw materials used in the invention are cheap; the preparation method is simple; and the hydrogel is expected to be used in fields like drug sustained release and dye absorption.

Description

technical field [0001] The invention belongs to a method for preparing a hydrogel, in particular to a method for preparing a double-network hydrogel with excellent mechanical properties that can produce rapid response to changes in ambient temperature and pH value, thereby producing volume transformation. Background technique [0002] Polymer gel refers to a system composed of a three-dimensional network structure of polymer compounds and a solvent, in which the polymers are connected by van der Waals force, chemical bond force, physical winding force, hydrogen bond force, etc. Since it is a three-dimensional network structure, it cannot be dissolved by solvents, and at the same time, it can be dispersed in solvents and can maintain a certain shape. Although the solvent cannot dissolve the polymer with a three-dimensional network structure, the solvophilic group in the polymer compound can be affected by the solvent to swell the polymer, which is also the reason for the form...

AI Technical Summary

Problems solved by technology

However, due to the pore-forming effect of freezing on the gel, this method will inevitably affect the gel network structure, which will inevitably lead to a decrease in the mechanical properties of the gel, resulting in an inability to balance the mechanical properties and response rate of the gel.