No abstract

Polyacrylamide-based hydrogels are popular materials that have been extensively studied for their applications in the field of biomaterials due to their permeability and biological compatibility. A major limitation of this polymeric material, however, in biological applications stems from their limited mechanical stiffness. The current study examines the mechanical properties of polyacrylamide-polyacrylic acid-based hydrogels at varying volume fractions and compositions using oscillatory rheology. For a fixed chemical cross-linker concentration, an increase in the volume fraction of hydrogel resulted in an increase in the shear elastic modulus of the hydrogel. Additionally, varying the relative ratio of polyacrylamide to polyacrylic acid resulted in modest changes in the shear elastic modulus.

Polyacrylamide is a popular material for many bio-related applications ranging from electrophoretic separation to cellular supports. A limitation of polyacrylamide-based hydrogels, however, is their mechanical compliance. The current study examines the effect of colloidal particles as a reinforcing filler phase to enhance the mechanical stiffness of polyacrylamide-polyacrylate hydrogels. Measurements with oscillatory rheology show that for a fixed polymer volume fraction, the presence of colloidal particles with various surface modifications generally results in an increase of the shear storage modulus of the hydrogel-particle composite. Interestingly, this study indicated that no discernable trends can be linked between the values of the shear storage modulus and the particle surface characteristics.