Chemically robust carbon nanotube – PTFE superhydrophobic thin films with enhanced ability of wear resistance

A chemically robust superhydrophobic nanocomposite thin film with enhanced wear resistance is prepared from a composite comprising polytetrafluoroethylene(PTFE) and carbon nanotubes.The superhydrophobic thin films with hierarchical structure are fabricated by spraying an environmentally friendly aqueous dispersion containing carbon nanotubes and PTFE resin on silicon wafer.Thin films with a contact angle of 154.1°± 2° and a sliding angle less than 2° remain superhydrophobic after abrading over 500 times under a pressure of 50 g/cm~2.The thin film is also extremely stable even under much stress conditions.To further the understanding of the enhancement of wear resistance,we investigated the formation of microsized structure and their effects.The growth of microbumps is caused by attracting solution droplet to the hydrophilic islands on hydrophobic surface.     

Characterization and application of Cu based superhydrophobic catalyst

Superhydrophobic (SH) Copper salt was prepared with the help of three different chemical etching agents and characterized by various analytical techniques like Fourier transform infrared (FTIR) spectroscopy, UV–visible spectroscopy, X-ray diffractogram (XRD), X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM). The SH nature of the material was confirmed by water contact angle (WCA) measurement. Cu surface with the etching agent was made to produce SH Cu surface. Among the chemical etching agents the system with Cl, F and Si exhibited the SH character. The SH hierarchically structured heterogeneous materials produced were used as a catalyst for the reduction of Cr(VI) and 4-nitrophenol (NiP). The catalytic activities of the materials were compared on the apparent rate constant (k_app) and induction time (T_i). Among the catalyst systems used, the Cu-Trichoropentaflourooctylsilane (TCPFOSi) system exhibited the highest k_app and T_i values.