Study On The Synthesis And Performances Of Chitosan/AMPS Intelligent Hydrogels

The paper use the cationic natural high molecular chitosan (CS) and anionic2-acrylamido-2-methyl propane sulfonic acid (AMPS) as monomers, CS/AMPS intelligenthydrogels were synthesized by aqueous solution polymerization. The swelling properties,deswelling behavior, on pH/ionic and electrical sensitivity performance of the hydrogels werestudied;and the hydrogel was characterized by using infrared spectroscopy, scanning electronmicroscopy,and differential scanning calorimetry; a preliminary study of the release under theElectrical stimulation of the hydrogel to the model drug was made.In this paper, the total monomer concentration, monomer ratio, amount of crosslinkingagent and initiator dosage on the properties of hydrogels were tested, the effects of thehydrogels with different synthesis process conditions on the equilibrium swelling ratio(ESR)in deionized water and0.9%NaCl solution were studied, and the optimum process conditionsfor synthesis of CS/AMPS hydrogel was determined as40%monomer concentration,monomer mass ratio m(CS):m(AMPS)=1:19, the dosage of crosslinking agent and initiatorboth0.6%of the monomer quality.The structure and properties of hydrogels were characterized by means of Fouriertransform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC).In theinfrared spectra picture we can be seen that the grafting reaction took place in CS and AMPS;DSC analysis proved that there is plenty of free water which can be frozen in the hydrogel.The hydrogels ESR in NaCl solutions with different concentration and different pH valuesolutions were studied. The results showed that the hydrogels with ion and pH sensitivitysignificantly. The CS/AMPS intelligent hydrogels in different NaCl concentration anddifferent pH value solutions of deswelling kinetics were studied, results showed that theresponse to changes in volume shrinkage occurred in NaCl solutions and acid/base solutions,at the initial stage,the gels deswelling rate is larger, and the deswelling rate slower with theextension of time, then gradually leveling off, and the balance is almost the same time. The different power voltage and electrifying time under the contact electric field onhydrogels shrinkage dehydration performance and the bending properties under thenon-contact electric stimulation were investigated; The results showed that: the hydrogelsmade quick response to electrical field stimulation. Under contact field, the relationshipbetween hydrogels quality retention Rmand electrifying time could be well described byfirst-order kinetics equation; hydrogels made a rapid response of bending on non-contactelectric stimulus, water retention property and voltage resistance of the hydrogels wereproved very good, and the hydrogels were expected to be used as drug delivery carrier,artificial muscle, biomimetic materials for further research.The swelling dynamic behavior of CS/AMPS hydrogel was researched and data fittingthe swelling process of the optimized hydrogel sample, the fitting results showed that theswelling process for non-Fickian diffusion model.With salicylic acid and rhodamine B as model drugs, using electric field responsemechanism of release, drug release properties of the optimized CS/AMPS intelligent hydrogelwas studied preliminary. The results showed that the hydrogel has a certain slow releasefunction of salicylic acid and rhodamine B, and at the same conditions, cationic drug releasewas slower; the application of a DC electric field could promote the release of the hydrogel tothe model drug.