Pattern formation of gold-PVA nanomix spin coated on different substrates

The patterns arising from the interplay of colloidal gold nanoparticles solutions containing polyvinyl alcohol spin coated on different substrates have been investigated. High Resolution Transmission Electron Microscope results show chain-like assemblies and direct attachment of spherical shape gold nanoparticles with different size in the polyvinyl alcohol matrix. X-ray photoelectron spectroscopy analysis of the C 1s peak shows three different Au-polyvinyl alcohol bands (CH2, COH and CO) which accounts for the effect of the Au particle size in the gold-PVA films. Dewetting of indium tin oxide substrates by 6 nm Au nanoparticles/polyvinyl alcohol colloidal solution induces concentration dependent cellular structures and fingering instability patterns which were duly reproduced using Monte Carlo simulations. Our results ascertain the importance of nanoparticle size, substrate type, oriantation and surface roughness on the pattern formation. In addition, we demonstrate that pattern formation on different substrates takes two different routes based on nanoparticle mobility rate, evoparation chemical potential and nanoparticle density.