Effect of Surface Properties of Substrate on Structure of Closely Packed Colloidal Crystal Deposited on Fiber Surface through Dip-coating

The effects of hydrophilicity and charge of the fiber surface on the formation of closely packed colloidal crystals on the fiber was investigated. Surface-treated polyester fiber was dip-coated with water suspension of uniform-sized silica particles. Hexagonal and square arrangements were observed for the particles deposited on the fiber surface by scanning electron microscopy (SEM). The crystallinity of deposited particles was estimated with the number ratio of arranged particles to all particles in the SEM image. Colloidal crystal with mainly hexagonal arrangement was formed on the fiber with high wettability irradiated with oxygen plasma. The crystallinity was increased and the ratio of hexagonal arrangement in the crystalline region was decreased with increasing the wettability of the plasma treated fiber surface. Colloidal crystal with mainly square arrangement was formed on the fiber with cationic charge derived from the amino groups induced with a sol-gel method using 3-aminopropyltriethoxysilane (APS). Crystallinity was decreased and ratio of square arrangement in the crystalline region was decreased with increasing the amount of amino group accompanying with decreasing the wettability on the APS treated fiber surface.