We report on the fundamental architecture and its effect on the physical properties of layer-by-layer assembled hydrogel networks and hydrogen-bonded films via neutron reflectometry. The relative stratification of films prepared from either spin-coated or dipped assembly and from polymers of differing molecular weight was compared by using spaced layers of deuterated poly(methacrylic acid) in hydrogen bonded films of poly(methacrylic acid) and poly(N-vinylpyrrolidone). The degree of stratification owing to the assembly conditions was found have observable consequence in terms of the swelling behavior of hydrogel prepared from these films. We reveal the relationship between the internal structure of hybrid and stacked hydrogel films of poly(N-vinylcaprolactam) and poly(N-vinylpyrrolidone) and their temperature-dependent swelling and hydration. The stacking order of stratified and mixed component hydrogels had clear effects on the hydration and swelling ability both above and below the lower critical solution temperature of the poly(N-vinylcaprolactam) component. These studies offer new insights into the unique temperature-dependent behavior of multi-component polymer networks and provide enhanced detail that can be useful in creating advanced materials with finely-tuned properties.

Internal structure and properties of stimuli-responsive multilayer hydrogels probed by neutron reflectometry

254th National Meeting (2017)

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