Hierarchical Patterning of Nanoparticles using Laser Interference Ablation and Block Copolymer Phase Separation

Abstract

We report on a novel approach that combines pulsed laser interference ablation and block co-polymer phase separation to enable the formation of periodic metallic and ceramic nanostructures having a primary ordering (in the 30-100 nm range) conforming with the domain spacing in a phase separated PS-P4VP polymer, and a secondary ordering (in the 200 nm to 2 microns range) conforming with the periodicity of the interfering laser beams. The primary domain spacing of the metallic and ceramic structures was varied through tuning of the loading time of the block copolymer thin films and by changing the length of the P4VP chain of the block copolymer. The secondary ordering was varied by changing either the intensity of Nd:YAG nanosecond light source, the angle of interfering beams, or the number of interfering beams. The nanostructures were characterized with AFM, SEM and XPS characterization techniques. (Alabi)