title: Solvent-dependent properties of poly(vinylidene fluoride) monolayers at the air-water interface.
abstract: The present work addresses the solvent-dependent properties of Langmuir films of poly(vinylidene fluoride) (PVDF) and amphiphilic poly(N-dodecylacrylamide) (pDDA) at different mixing ratios. After introducing pDDA nanosheets, PVDF Langmuir films obtain a tremendously enhanced modulus as well as high transfer ratios using the vertical dipping method caused by the support of the pDDA two-dimensional hydrogen bonding network. Brewster angle microscopy (BAM) was used to investigate PVDF monolayers at the air-water interface in situ. Spreading from different solvents, the PVDF molecules take completely different aggregation states at the air-water interface. The PVDF molecules aggregate to become large domains when spread from N-methyl-2-pyrrolidone (NMP). However, the volatile and low-polarity methylethyl ketone (MEK) made the PVDF molecules more dispersive on the water surface. This study also discovers a versatile crystallization control of PVDF homopolymer from complete β phase (NMP) to complete α phase (MEK) at the air-water interface, thereby eliciting useful information for further manipulation of film morphologies and film applications.
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan. masaya@tagen.tohoku.ac.jp.
authors.forename: Huie
authors.initials: H
authors.lastname: Zhu
authors.forename: Jun
authors.initials: J
authors.lastname: Matsui
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Tokuji
authors.initials: T
authors.lastname: Miyashita
authors.forename: Masaya
authors.initials: M
authors.lastname: Mitsuishi