Preparation of Hydrophobic Metal Oxides by Dry Coupling Treatment Method Using Alkyltrimethoxysilane Agents

• Published in: Hyōmen gijutsu Vol. 55; no. 3; pp. 186 - 191
• Main Authors: SANUKI, Sumiko, MIYANO, Masahide, YOSHINAGA, Toshihiro, MAJIMA, Hiroshi
• Format: Journal Article
• Language: Japanese; English
• Published: Tokyo The Surface Finishing Society of Japan 2004; Hyomen Gijutsu Kyokai; Japan Science and Technology Agency
• Subjects: Alkyltrimethoxysilane; Coupling Treatment; Hydrophobic Powder; Oligomer Formation; Ti-Fe-Al Composite Oxide; TiO2; α-Fe2O3
• ISSN: 0915-1869; 1884-3409
• DOI: 10.4139/sfj.55.186

Oligomer formation reactions during the preliminary treatment of a solution system consisting of ATMS-EtOH-H2O, and the hydrophobic treatment of TiO2, Ti-Fe-Al composite oxide and α-Fe2O3, which have different numbers of surface OH groups, using various preliminarily treated alkyltrimethoxysilane (ATMS) solutions, were investigated. The main findings were as follows: (1) The maximum M value, which is a parameter of the hydrophobic degree, for the metal oxides investigated showed a tendency to increase with the increase in the carbon number of the alkyl groups composing ATMS. The maximum M values of Ti-Fe-Al composite oxide and TiO2 appeared to be almost the same, whereas those of α-Fe2O3 were 10~20% smaller. The M values obtained with i-BTMS were lower than those with n-BTMS, despite the identities of the oxide tested. (2) There is an intimate relationship between the oligomer states in preliminarily treated solution and the maximum M values obtained for all metal oxides tested. (3) Although the hydrophobic treatment was performed using a theoretical amount of preliminarily treated ATMS, the maximum M values for all metal oxides tested increased with the increase in the number of OH groups on the substrate surface.