嵌段共聚物模板法制备超高排列密度的二氧化钛纳米柱结构

In this paper, a fabrication approach of the ultra high density TiO2 nanorod arrays is presented by highly ordered block copolymer templates and the subsequent sol-gel process driven by the solvent evaporation. For this purpose, amphiphilic side group liquid-crystal (SGLC)-coil diblock copolymer (BCP) {poly(ethyleneoxide-block-{11-[4-(4-butylphenylazo)phenoxy]undecyl methacrylate} [PEO-b-PMA(Az)] 1-3 wt% toluene or chloroform solutions are spin-coated to form thin films. After following thearmal annealing, highly ordered vertical or parallel arrangement structures with PEO hexagonal cylindrical domains dispersed in PMA(Az) matrix phase are formed easily. Subsequently, the titania sol is introduced into the PEO cylindrical domains, and the BCP templates are removed by calcination. Hence, perpendicular or parallel hexagonal TiO2 nanorod arrays can be copied out. By changing the repeat units of BCPs, the obtained nanoarrays diameter and spacing are tunable from (11.6 ± 1.2) nm to (23.2 ± 3.0) nm and (25.2 ±1.8) nm to (32.1 ± 3.2) nm, respectively. Its array density is up to 2.4×1011 pillars/cm2. It is significantly meaningful in the solar cell applications of titanium dioxide arrays.