Alignment of gold nanorods in directionally solidified polymer blends

Abstract

We studied the alignment of gold nanorods (Au NRs) in polymer blends that were directionally solidified in the crystallizable organic solvent trichlorobenzene (TCB). The polymer blends/Au NRs were dissolved or dispersed in TCB at 80 °C between two glass plates. By cooling the sample, the polymer blends and Au NRs were directionally solidified as the liquid TCB transformed into large single crystals. With poly(3-hexylthiophene-2,5-diyl)/polyethylene glycol (P3HT/PEG) used as the polymer blend pair, PEG-modified Au NRs predominantly localized inside the PEG domains of the solidified films. In contrast, with a P3HT/poly(2-vinylpyridine) blend, PEG-modified Au NRs mostly localized at the interface between the polymers. These results show that directional solidification in crystallizable organic solvents is an effective one-step process for the alignment of Au NRs in polymer matrices.