Characterization of anisotropic poly(vinyl alcohol) hydrogel by small- and ultra-small-angle neutron scattering

Poly(vinyl alcohol) (PVA) hydrogels are formed from PVA solution when physical cross-links form during freeze/thaw cycling. By applying a stress during the freeze/thaw process, PVA hydrogels with anisotropic mechanical properties are produced. We have used small- and ultra-small-angle neutron scattering to study the structure at length scales of 2 nm to 10 mum. By supplementing the neutron data with data from atomic force microscopy, we have …