A New Generation Co-Assembled Small Molecular Gel with Polyaniline: Exciting Mechanical, Electronic and Photovoltaic Properties

Summary Folic acid (F), Fmoc-protected phenylalanine (FP) and 5,5′-(1,3,5,7-tetraoxopyrrolo[3,4-f]isoindole-2,6-diyl) diisophthalic acid (PMDIG) are used to produce co-assembled gels with polyaniline(PANI). The formation of PANI inside the gel matrices are confirmed by FTIR and UV-vis spectroscopy. UV-vis spectra also exhibit the polaron band transitions of the doped PANI. Both F-PANI and PMDIG-PANI gels exhibit fibrillar network morphogy but the branching is more in the F-PANI gel. The FP-PANI gel however exhibits nanotubular morphology. The dc conductivity values of F-PANI, FP-PANI and PMDIG-PANI xerogels are 0.14 × 10^-4, 0.12 × 10^-1 and 0.3 × 10^-4 S/cm, respectively. The current-voltage (I-V) curves of the F-PANI gel shows a negative differential resistance(NDR) property both at forward and backward bias. The I-V property of the FP-PANI xerogel resembles to the behavior of a semiconductor-metal junction and that of PMDIG-PANI xerogel exhibits a signature of rectification property. A dye-sensitized solar cell is also fabricated using the PMDIG-PANI gel with a power conversion efficiency of 0.1%.