We report on controllable bending and twisting and internal structure of temperature-responsive clay/polymer layer-by-layer films. Solely, temperature-responsive films were constructed using poly(N-isopropylacrylamide) (PNIPAM) and montmorillonite clay nanosheets. Assemblies of clay platelets with polyethyleneimine (BPEI) were studied for comparison.  In situ X-Ray scattering technique was applied to investigate changes in internal structure of multilayer film upon exposure to water. The interparticle distance increased from 2.85 nm in the dry state to 22.0 nm in the swollen state. In contrast, BPEI/clay multilayers showed significantly smaller water uptake due to stronger electrostatic interactions. Confocal laser microscopy showed that clay/PNIPAM films swelled up to ~16 times of their dry thickness in solutions at 25 oC, and showed reversible deswelling at temperatures higher than PNIPAM's lower critical solution temperature of 32 oC. Hybrid systems composed of PNIPAM/clay and BPEI/clay multilayer stacks demonstrated controllable bending and/or twisting driven by different swelling degrees in two nanocomposite stacks.

Bending and twisting of hybrid clay-polymer multilayers: Control through internal structure

245th National Meeting (2013)

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