Inutsuka Manabu, Horinouchi Ayanobu, Tanaka Keiji
Department of Applied Chemistry and ‡International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan.
Department of Applied Chemistry and International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan.
ACS Macro Lett. 2015 Oct 20;4(10):1174-1178. doi: 10.1021/acsmacrolett.5b00592. Epub 2015 Oct 6.
Aggregation states of polystyrene (PS) and poly(methyl methacrylate) (PMMA) at hydrophobic deuterated-octadecyltrichlorosilane (OTS-) and hydrophilic SiO interfaces are discussed, focusing on the interaction strength between polymer and substrate. Sum-frequency generation spectroscopy revealed that PS exhibited oriented phenyl groups along the normal direction at the interface in a spin-coated film because of the centrifugal force generated during the film solidification process, whereas it did not in a solvent-cast film. This result was common for both hydrophobic and hydrophilic substrates. That is, the aggregation states of PS depended little on which kind of substrate was used. This is because the interaction between PS and the surfaces is weak. In the case of a PMMA film on the hydrophobic OTS- substrate, the interfacial local conformation was also dependent on the method of film preparation. PMMA at the hydrophilic SiO interface, however, exhibited oriented ester methyl groups along the direction normal to the interface, regardless of the film preparation method. This is due to a stronger interaction via hydrogen bonding between carbonyl groups of PMMA and the substrate surface.
讨论了聚苯乙烯（PS）和聚甲基丙烯酸甲酯（PMMA）在疏水的氘代十八烷基三氯硅烷（OTS-）和亲水的SiO界面处的聚集状态，重点关注聚合物与基材之间的相互作用强度。和频振动光谱表明，由于在薄膜固化过程中产生的离心力，PS在旋涂膜的界面处沿法线方向呈现取向的苯基，而在溶剂浇铸膜中则没有。这一结果在疏水和亲水基材上都是常见的。也就是说，PS的聚集状态几乎不依赖于使用哪种基材。这是因为PS与表面之间的相互作用较弱。在疏水的OTS-基材上的PMMA薄膜的情况下，界面局部构象也取决于薄膜制备方法。然而，在亲水的SiO界面处的PMMA，无论薄膜制备方法如何，都沿垂直于界面的方向呈现取向的酯甲基。这是由于PMMA的羰基与基材表面之间通过氢键形成的更强相互作用。
