The mechanical properties of these hydrogels such as compressive strength, compressive modulus, and work of fracture were significantly enhanced by hybridization with sol-gel derived silica.
Tensile modulus and work input increased significantly with degree of hard phase crystallinity, but were independent of degree of phase separation.
The more homogeneously dispersed composite has a higher storage modulus and work of fracture at temperatures less than the glass transition temperature.
The flexural strength, elasticity modulus and work of fracture reached the maximum values, 97 MPa, 11 GPa and 4.2 kJ/m2, respectively, for the composite with seven-layers of stainless steel mesh.
The elastic modulus and work hardening exponent are independent of elastic or plastic deformation and the evolution of yield strength follows the stress strain curve of Ni thin film due to work hardening.
Such coatings – tailor-made with gradients in hardness and elastic modulus – could work as adhesive and load-supporting layers on polymers bridging the properties from soft substrate to the stiff, wear-resistant hard top coating.
These results are unexpected, as for example, Wang et al. [ 42] report that age-dependent changes are reflected in a decreased strength, elastic modulus and work to fracture.
Past this maximum the bulk modulus and work to fracture results fall dramatically with very low values at 70 and 80% high acyl gellan.
Increasing the proportion of the low acyl variant at low pH during gelation causes a large reduction in bulk modulus and work to fracture; the high acyl variant is much more resistant to the effects of acid during gelation.
At 90% high acyl gellan proportion and above, the high acyl gellan is continuous, with rheology the same as (bulk modulus and work to fracture within error bounds) the rheology of the high acyl variant alone.
