特集：界面水の構造と制御
酸化物表面の親水性・疎水性と表面濡れ性の評価
2009 年 30 巻 3 号 p. 148-156
詳細
2009 年 30 巻 3 号 p. 148-156
The interaction of H2O molecules with various oxide surfaces were investigated by using middle-infrared (MIR) and near-infrared (NIR) spectroscopies. The physicochemical properties of oxide surfaces such as hydrophilicity or hydrophobicity were then discussed from the viewpoint of the intermolecular hydrogen bonds in the H2O clusters. SiO2 surface showed hydrophobic property as compared to TiO2 or Al2O3 surfaces. However, smaller amount of H2O molecules on SiO2 surface can easily spread out to form H2O thin layer due to small contribution of intermolecular hydrogen bonds in the H2O clusters. As a result, such hydrophobic SiO2 surface shows high wettability. On the other hand, TiO2 or Al2O3 surfaces adsorbed large amounts of H2O and hydrocarbons because such polar molecules preferentially interact with such cationic (Ti4+ or Al3+) sites, showing both hydrophilic and oleophilic properties. However, larger amount of H2O molecules on the TiO2 or Al2O3 surfaces strongly interacted with each other to form aggregated bulky H2O clusters on the surfaces. As a result, such hydrophilic surfaces show low wettability.
