This grant provides funding for the manufacture of hybrid hydrogels, wherein physical and cross-linked networks are incorporated into a single multi-component polymer. Hydrogels are three-dimensional networks composed of chemically and/or physically-crosslinked hydrophilic polymers that have applications in diverse technologies such as drug or agrochemical delivery, food and personal care products, optics, fluidics, wound healing and tissue engineering. Chemical hydrogels formed from covalent bonds have permanent shapes, but they generally exhibit poor mechanical strength and toughness, while physical hydrogels exhibit good toughness, but lack the creep resistance of covalent gels. The research includes the synthesis of hybrid hydrogels and the characterization of the microstructure, swelling behavior, flow and viscoelastic properties and mechanical properties of neutral and charged materials. The objectives are to develop strong, tough hydrogels, understand the mechanism of toughening in hybrid hydrogels and the development of manufacturing methods for producing shaped gel objects by solvent or melt injection, melt shaping and electrospinning of nanofibers.
The results of this research will lead to improvements in the mechanical properties and manufacturing methods for producing hydrogel products. The development of an understanding of the mechanism by which strong, tough materials that are mostly water (i.e., hydrogels) are achieved will lead to the design of improved soft materials for existing applications and expand the application of hydrogels into technologies for which they are currently unsuitable, because of poor stiffness, strength and/or fracture toughness. In addition to the expansion of commercial applications of hydrogels, the substitution of hydrogels for many existing material applications should also have positive environmental implications, in that most hydrogels are environmentally benign. The nano-structured morphology expected for hybrid hydrogels may also lead to smart applications of these materials, such as shape memory and/or self-healing behavior.
