Superhydrophobic and Highly Oleophobic Nylon Surface

Superhydrophobic and superoleophobic surfaces are desirable for many practical applications. Creating a rough structure on polymer surface then modified by materials with low surface free energy can broaden the potential applications of polymers. In this research, we used three different methods to modify nylon 6 surface, then compared their effect on preparing nylon 6 surface roughness. Activation of amides by chemical reduction with borane-THF complex resulted in secondary amine groups, which could absorb silica spheres with different sizes driven by electrostatic attraction. On the other side, alkylation with (3-glycidoxypropyl) triethoxysilane (GPTES) was utilized to introduce silica-like reactivity to the surface, while plasma-treatment could import hydroxyl groups on nylon 6 surface. Then silica layer was generated and covalently bonded to the nylon 6 in situ. After treated with 3-aminopropyl-triethoxysiloxane (APS), silica spheres could be introduced to the sample more evenly than the first method, and then reacted with silicon tetrachloride to enhance mechanical robustness. Plasma-treatment was more fast and clean in preparing the stable roughness, which made this modification a favorable method. Different size silica spheres were used to construct roughness on nylon textile. After being modified with a perfluoroallcyl silane, the surface with all roughness had superhydrophobic property, while the wettability of low-energy liquid on the surface was depending on the micro structure size. Silica spheres with size between 500 nm and 900 nm were propitious to achieve stable Cassie state, which could cause high contact angles (about 140 degrees) and low roll-off angles (about 20 degrees) for 3 mu L hexadecane droplets. On the other hand, for the samples adsorbed silica spheres with size between 20 run and 200 urn, the contact angles and roll-off angles for 3 mu L hexadecane were about 125 degrees and 40 degrees, respectively. Because of the air trapped between the roughnesses, the obtained superhydrophobic and highly oleophobic nylon textile also show high resistance to bacterial contamination. This may broaden the application of nylon.