Effects of Hydrogen Bonding on the Monolayer Properties of Amphiphilic Double-Decker-Shaped Polyhedral Silsesquioxanes

详细信息    查看全文

• 作者：Asuman C. Kucuk ; Jun Matsui ; Tokuji Miyashita
• 刊名：Langmuir
• 出版年：2011
• 出版时间：May 17, 2011
• 年：2011
• 卷：27
• 期：10
• 页码：6381-6388
• 全文大小：1125K
• 年卷期：v.27,no.10(May 17, 2011)
• ISSN：1520-5827

文摘

鈥淐ore鈥揷orona鈥?type amphiphiles, which comprise double-decker-shaped POSSs (DDSQs) as the core and two or four di(ethylene glycol) (DEG) units as the coronae, have recently been reported to form a stable monolayer at the air鈥搘ater interface. In this paper, another core鈥揷orona amphiphile, 2DEGNH-DDSQ, which has a urethane group at the end of the coronae, was synthesized to elucidate the effects of hydrogen bonding on monolayer properties. The surface pressure鈥揳rea isotherm and Brewster angle microscopy revealed that 2DEGNH-DDSQ initially formed rodlike assemblies. They subsequently coalescence to form a uniform monolayer with compression. Actually, 2DEGNH-DDSQs are well ordered in the rodlike assembly because of the strong hydrogen bonds among the urethane groups, as confirmed by FT-IR spectra. Although the monolayer was not transferred onto a solid substrate, mixing of 2DEGNH-DDSQ with 2DEG-DDSQ, which has already been reported to form a liquidlike monolayer, overcame this problem. The 1:1 molar mixture of 2DEGNH-DDSQ and 2DEG-DDSQ forms a uniform liquidlike monolayer. The mixed monolayer was transferred onto a solid substrate as a Z-type Langmuir鈥揃lodgett film. Atomic force microscopic (AFM) images of the mixed-bilayer film showed a uniform surface with root-mean-square surface roughness of 0.21 nm. The intermolecular hydrogen bonds between the urethane groups in 2DEGNH-DDSQ and the hydroxyl groups in 2DEG-DDSQ improve the monolayer properties, which enable successful transfer of the LB film.