title: Hydrodynamic transformation of a freestanding polymer nanosheet induced by a thermoresponsive surface.
abstract: Freestanding quasi-two-dimensional ultrathin films (e.g., 41 nm thick polymer nanosheets) were produced, on which stimuli-responsive 47 nm thick 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 nanosheet was also monitored with the addition of a surfactant such as sodium n-dodecylsulfate to reduce the hydrophobicity of the surface. It was then demonstrated that the highly flexible freestanding polymer nanosheet is capable of acting as a unique platform for inducing stimuli-responsive behavior in nanomaterials.
authors.affiliation: Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University (TWIns), 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Fujie
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Park
authors.forename: Atsushi
authors.initials: A
authors.lastname: Murata
authors.forename: Nicel C
authors.initials: NC
authors.lastname: Estillore
authors.forename: Maria Celeste R
authors.initials: MC
authors.lastname: Tria
authors.forename: Shinji
authors.initials: S
authors.lastname: Takeoka
authors.forename: Rigoberto C
authors.initials: RC
authors.lastname: Advincula
mesh_terms: D000388:Air; D017738:Alkanesulfonic Acids / Q000737:chemistry; D006358:Hot Temperature; D008422:Materials Testing; D018625:Microscopy, Atomic Force / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods; D013055:Spectrophotometry, Infrared / Q000379:methods; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D017738:Alkanesulfonic Acids; D011108:Polymers; D013501:Surface-Active Agents; D014867:Water; C017273:dodecylsulfonic acid