Swelling Behavior and Complex Formation Ability of Ternary Amphoteric Gels based on Allylamine Derivatives and Maleic Acid

Abstract

Summary: The swelling behavior of an amphoteric gel composed of 50 mol‐% of maleic acid (MA), 25 mol‐% of N,N′‐dimethyldiallylammonium chloride (DMDAAC) and 25 mol‐% of diallylamine (DAA) was studied in aqueous and aqueous‐salt solutions. The isoelectric point (IEP) of the MA‐DMDAAC‐DAA gel determined from swelling experiments was about pH 4.6. Considerable gel swelling with increasing ionic strength was observed at the IEP. Dynamic swelling properties of the amphoteric gel in water with and without added salt were measured at various pH values including the IEP. The swelling behavior of the amphoteric gel was found to depend on the ionization state of the functional groups. It can be described by either a relaxation‐controlled or non‐Fickian (anomalous) mechanism. Swelling‐deswelling properties of the amphoteric gel were also studied in mixtures of water and organic solvents. The amphoteric gel was able to complex sodium poly(styrene sulfonate), sodium lauryl sulfate, the cationic drug richlocain, and the bivalent transition metal ions Cu2+, Ni2+, Co2+, and Zn2+. The sorption of polyelectrolyte, surfactant, drug, and metal ions by the amphoteric gel is accompanied by the contraction of the gel network. Partial release of the cationic drug molecules entrapped into the gel volume takes place at the IEP of the amphoteric gel with low activation energy, while neither the anionic polyelectrolyte nor the surfactants are released from the gel interior at the IEP. The swelling‐shrinking behavior of gel‐polyelectrolyte and gel‐surfactant complexes in dependence of pH and ionic strength of the outer solution is similar.

Salt and pH responsive property of a starch‐based amphoteric superabsorbent hydrogel with quaternary ammonium and carboxyl groups (II)

“…The swelling reaches 64 g/g in 0.9% NaCl solution for hydrogel with 30 mL AA of feed composition. However, no obvious polyampholyte behaviors were observed among three polymer hydrogels 25. This may be because the added salt may not break the interchain association so easily, or because the polymer gels mainly show anionic property because cationic groups in the starch is in a small fraction compared with anionic groups.…”

“…It can be concluded that water transport is controlled by polymer relaxation process. In the case of amphoteric gels, the polymer relaxation is significantly affected by the ionization degree of the functional groups 25. The electrostatic repulsion between adjacent carboxyl groups or ammonium groups leads to macromolecular chain expansion, making the mechanism more relaxation‐controlled.…”

Effect of the anionic‐group/cationic‐group ratio on the swelling behavior and controlled release of agrochemicals of the amphoteric, superabsorbent polymer poly(acrylic acid‐co‐diallyldimethylammonium chloride)

“…Kudaibergenov et al21 studied the behavior of amphoteric hydrogels based on vinyl 2‐aminoethyl ether and sodium acrylate under the influence of the pH, ionic and solvent compositions, temperature, and electric field. With good biocompatibility and peculiar characteristic, amphoteric, absorbent polymers are applied to the therapy of cardiovascular diseases,22 intelligent materials,23 and the controlled release of drugs 24…”

Intra- and Interpolyelectrolyte Complexes of Polyampholytes

“…The swelling–deswelling behavior of amphoteric gel which was made of maleic acid (MA), N , N ’-dimehyldiallylammonium chloride (DMDAAC) and diallylamine (DAA) was studied in the presence of NaPSS [133]. The swelling degree of the amphoteric gel–NaPSS is minimally in the pH range between 4 and 8 (Figure 13) and increases significantly in the strong acidic and alkaline regions.…”

“…pH dependent swelling of amphoteric gel MA-DMDAAC-DAA (1) and complexes of amphoteric gel with NaPSS (2). (Updated from [133]).…”