Robust, self-healing superamphiphobic fabrics prepared by two-step coating of fluoro-containing polymer, fluoroalkyl silane, and modified silica nanoparticles

A robust, superamphiphobic fabric with a novel self-healing ability to autorepair from chemical damage is prepared by a two-step wet-chemistry coating technique using an easily available material system consisting of poly(vinylidene fluoride-co-hexafluoropropylene), fluoroalkyl silane, and modified silica nanoparticles. The coated fabrics can withstand at least 600 cycles of standard laundry and 8000 cycles of abrasion without apparently changing the superamphiphobicity. The coating is also very stable to strong acid/base, ozone, and boiling treatments. After being damaged chemically, the coating can restore its super liquid-repellent properties by a short-time heating treatment or room temperature ageing. This simple but novel and effective coating system may be useful for the development of robust protective clothing for various applications.

One-step vapour-phase formation of patternable, electrically conductive, superamphiphobic coatings on fibrous materials

Patternable, electrically conductive coatings having a superhydrophobic and superoleophobic surface have been prepared by one-step vapour-phase polymerisation of polypyrrole in the presence of a fluorinated alkyl silane directly on fibrous substrates. The coated fabrics showed a surface resistance of 0.5-0.8 kΩ □^-1 with water and hexadecane contact angles of 165° and 154°, respectively.

A superamphiphobic coating with an ammonia-triggered transition to superhydrophilic and superoleophobic for oil-water separation

Superhydrophilic and superoleophobic materials are very attractive for efficient and cost-effective oil-water separation, but also very challenging to prepare. Reported herein is a new superamphiphobic coating that turns superhydrophilic and superoleophobic upon ammonia exposure. The coating is prepared from a mixture of silica nanoparticles and heptadecafluorononanoic acid-modified TiO2 sol by a facile dip-coating method. Commonly used materials, including polyester fabric and polyurethane sponge, modified with this coating show unusual capabilities for controllable filtration of an oil-water mixture and selective removal of water from bulk oil. We anticipate that this novel coating may lead to the development of advanced oil-water separation techniques.

Experimental studies on comparison of microwave curing and thermal curing of epoxy resins used for alternative mould materials

In this present work attempts have been made to study the glass transition temperature of alternative mould materials by using both microwave heating and conventional oven heating. In this present work three epoxy resins, namely R2512, R2515 and R2516, which are commonly used for making injection moulds have been used in combination with two hardeners H2403 and H2409. The magnetron microwave generator used in this research is operating at a frequency of 2.45 GHz with a hollow rectangular waveguide. In order to distinguish the effects between the microwave and conventional heating, a number of experiments were performed to test their mechanical properties such as tensile and flexural strengths. Additionally, differential scanning calorimeter technique was implemented to measure the glass transition temperature on both microwave and conventional heating. This study provided necessary evidences to establish that microwave heated mould materials resulted with higher glass transition temperature than the conventional heating. Finally, attempts were also made to study the microstructure of microwave-cured materials by using a scanning electron microscope in order to analyze the morphology of cured specimens.