Control of structures of self-supported assembly of nanoparticles by dissipative process

We have already reported about mesoscopic patterning of nanoparticles by simply casting onto solid substrates. In this report, We will describe about self-supporting fibrous assembly formed from two-dimensional pattern of colloidal dispersion of silica particles. When the glass substrate was dipped into and withdrawn from highly concentrated dispersion of silica particles, self-supported assembly of silica particles were formed parallel to the receding direction. The assembly of silica particles was spontaneously removed from glass substrate. By SEM, it was cleared that the assembly of silica particles had strap-like structure. The condition for preparing self-supporting assembly of nanoparticles was investigated by changing deposition speed, ionic strength, concentration and pH of silica particles dispersion.