Charge-Functionalized and Structurally Enhanced (Cryo)Hybrids from Acrylic (Co)Monomers and Kaolin: Altering Physicochemical Properties via Cryotropic Gelation

The potential to improve mechanical, structural, and mechanochemical properties of charge-functionalized poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA)-based hybrid cryogels is investigated. The simple and versatile synthesis of hybrid cryogels with high strength and toughness using cationic DMAEMA and ionic comonomer 2-acrylamido-2-methyl-1-propane sulfonic acid has been proposed via in situ free-radical crosslinking (cryo)polymerization by which the properties of virgin polymer can be modulated to required applications by incorporation of inorganic filler kaolin (KLN). Two factors affecting swelling and elasticity of hybrid gels (referred as PDA/KLNm), KLN content and gel preparation temperature, are studied. The optimum KLN concentration for desired swelling and modulus of elasticity is determined as 0.80% (w/v). Effective crosslinking density of hybrid hydrogels increases with KLN addition and this dependence is expressed by a quadratic polynomial as a function of KLN concentration. The results show that obtained hybrid gels with multiresponsive properties could be regarded as “smart materials” in sensing and actuation applications.