Hydrodynamic Transformation of a Freestanding Polymer Nanosheet Induced by a Thermoresponsive Surface

Freestanding quasi-two-dimensional ultrathin films (e,g., 41 nm thick polymer nanosheets) were produced. on which stimuli-responsive 47 nm chick polymer brushes were constructed by atom transfer radical polymerization (ATRP) of poly(N-isopropylacrylamide). The resulting surfaces of the multilayered polysaccharide ultrathin films were evaluated by ellipsometry, IR imaging, In situ variable-temperature atomic force microscopy (AFM), and contact angle measurements. The morphological transformation of the freestanding polymer nanosheet bearing thermoresponsive polymer brushes was observed macroscopically through reversible structural color changes at the air-water interface. The dynamic shape change of the nanosheetwas also monitored with the addition of a surfactant such as sodium n-dodecylsulfate to reduce the hydrophobicity of the surface, It was then demonstrated chat the highly flexible freestanding polymer nanosheet is capable of acting as a unique platform for inducing stimuli-responsive I behavior in nanomaterials.