Enhanced biocompatibility in poly(3-hexylthiophene)-based organic thin-film transistors upon blending with poly(2-(2-acetoxyacetyl)ethyl methacrylate)

Polymer blends with both biocompatibility and organic thin film transistor (OTFT) characteristics are developed by mixing a biocompatible polymer, poly(2-(2-acetoxyacetyl)ethyl methacrylate) (PHEMAAA) and a conducting polymer, poly(3-hexyl thiophene) (P3HT) at different weight ratios (i.e. P3HT/PHEMAAA = 75/25, 50/50, 25/75). Their OTFT performances were maintained at a similar level to those of pristine P3HT in spite of adding an insulator in the form of PHEMAAA. On the other hand, the biocompatibility of the P3HT/PHEMAAA blend films was found to be as good as that of PHEMAAA, indicating the successful contribution of the biocompatible polymer. In particular, these combined properties were optimized at a 25/75 weight ratio as described above. These results could be correlated with surface properties such as molecular orientation, morphology, and composition that change upon blending. Such P3HT/PHEMAAA blends are promising materials for applications in biomedical fields where materials come into contact with the human body.