Zhu Huie, Matsui Jun, Yamamoto Shunsuke, Miyashita Tokuji, Mitsuishi Masaya
Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
Soft Matter. 2015 Mar 14;11(10):1962-72. doi: 10.1039/c4sm02800g.
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.
本工作研究了不同混合比例下聚偏氟乙烯（PVDF）和两亲性聚（N-十二烷基丙烯酰胺）（pDDA）的Langmuir膜的溶剂依赖性性质。引入pDDA纳米片后，由于pDDA二维氢键网络的支撑，PVDF Langmuir膜通过垂直浸渍法获得了极大增强的模量以及高转移率。采用布鲁斯特角显微镜（BAM）原位研究了空气-水界面处的PVDF单分子层。从不同溶剂铺展时，PVDF分子在空气-水界面呈现出完全不同的聚集状态。当从N-甲基-2-吡咯烷酮（NMP）铺展时，PVDF分子聚集形成大的区域。然而，挥发性和低极性的甲乙酮（MEK）使PVDF分子在水面上更分散。本研究还发现了在空气-水界面将PVDF均聚物从完全β相（NMP）到完全α相（MEK）的通用结晶控制方法，从而为进一步操纵薄膜形态和薄膜应用提供了有用信息。
