Tuesday July 5, 2005
Wednesday July 6, 2005

"Nanoparticles at Polymer Surfaces"
Mr. Yavuz Yuce
Koç University,

The surface properties of polymers can be tuned by nanoparticles. Nanoparticles dispersed on polymer surfaces change both the surface roughness and the surface composition, the two parameters that affect the surface hydrophobicity. Surface hydrophobicity of composite films containing polymer and nanoparticles can thus be changed from that of polymer to that of rough surface of nanoparticles by adjusting the amount of nanoparticles. The presence of nanoparticles introduces nanometer scale roughness on the surface. Hydrophobicity together with surface roughness results in water repellent surfaces with contact angle of a water drop changing between 90o to 165o for polystyrene containing hydrophobic silica particles. Nanoparticles can also be put on different parts of a surface selectively and in order. Selective adsorption of nanoparticles on patterned surfaces will be introduced as another method to control surface morphology and hydrophobicity.