Wettability Controlled Fabrication of Highly Transparent and Conductive Carbon Nanotube/Silane Sol Hybrid Thin Films

The stable few-walled carbon nanotube (FWCNT)/methyluimethoxysilane Sol mixture solution was successfully prepared by direct mixing of H2O2-treated FWCNT solution and silane sol. The stabilization of the solution was achieved by the intermolecular interaction between the hydroxyl groups on the FWCNTs and silanol groups in silane sol. FWCNT/silane Sol hybrid thin films were then deposited on the model surfaces treated with piranha solution and silane molecules containing different end functionalities of NH2, CH3, and CF3 by spraying. The water contact angles of the model surfaces could be tuned from 112 degrees to below 5 degrees. It was found that a hydrophilic surface is more effective than a hydrophobic one in improving the conductivity of thin films by forming the uniform film structure, while the dewetting of the FWCNT/silane sol mixture solution on the most hydrophobic surface (CF3) slightly improved the transparency of the films.