Elucidating Interactions and Conductivity of Newly Synthesised Low Bandgap Polymer with Protic and Aprotic Ionic Liquids

Pankaj Attri,Gi-Chung Kwon,Seung-Hyun Lee,Sang Woo Lee,Joong I L Kim,Sun Woo Hwang,In Tae Kim,Eun Ha Choi,Dennis Salahub

doi:10.1371/journal.pone.0068970

Abstract

In this paper, we have examined the conductivity and interaction studies of ammonium and imidazolium based ionic liquids (ILs) with the newly synthesised low bandgap polymer (Poly(2-heptadecyl-4-vinylthieno[3,4-d]thiazole) (PHVTT)). Use of low bandgap polymers is the most suitable way to harvest a broader spectrum of solar radiations for solar cells. But, still there is lack of most efficient low bandgap polymer. In order to solve this problem, we have synthesised a new low bandgap polymer and investigated its interaction with the ILs to enhance its conductivity. ILs may undergo almost unlimited structural variations; these structural variations have attracted extensive attention in polymer studies. The aim of present work is to illustrate the state of art progress of implementing the interaction of ILs (protic and aprotic ILs) with newly synthesised low bandgap polymer. In addition to this, our UV-Vis spectroscopy, confocal Raman spectroscopy and FT-IR spectroscopy results have revealed that all studied ILs (tributylmethylammonium methyl sulfate ([N1444][MeSO4] from ammonium family) and 1-methylimidazolium chloride ([Mim]Cl, and 1-butyl-3-methylimidazolium chloride ([Bmim]Cl from imidazolium family) have potential to interact with polymer. Our semi empirical calculation with help of Hyperchem 7 shows that protic IL ([Mim]Cl) interacts strongly with the low bandgap polymer through the H-bonding. Further, protic ILs shows enhanced conductivity than aprotic ILs in association with low bandgap polymer. This study provides the combined effect of low bandgap polymer and ILs that may generate many theoretical and experimental opportunities.

Highlights

The blend of polymers and ionic liquids (ILs) has charmed the modern research, [1,2,3,4,5,6,7,8,9,10] as replacements for current solid-state polyelectrolytes in energy devices, such as dye-sensitized solar cells, [11] supercapacitors, [12] lithium ion batteries, [13] and fuel cells [14]
Gwee et al, [37] showed that mixtures of a block copolymer, poly(styrene-b-methyl methacrylate) (SbMMA), and 1-ethyl-3-methylimidazolium bisimide (EMIm-TFSI) IL, has significant impact on the both morphology and microdomain orientation that leads to increase in high ionic conductivity and this system has enhanced conductivity as compared to homopolymer/IL mixture
We have revealed the interaction of this low band gap polymer with ammonium and imidazolium family ILs and exposed that there is an increase in conductivity of polymer when interacted with ILs

Summary

Introduction

The blend of polymers and ionic liquids (ILs) has charmed the modern research, [1,2,3,4,5,6,7,8,9,10] as replacements for current solid-state polyelectrolytes in energy devices, such as dye-sensitized solar cells, [11] supercapacitors, [12] lithium ion batteries, [13] and fuel cells [14]. Still there is lack of research on the interaction and conductivity of ILs with low bandgap polymers. We have revealed the interaction of this low band gap polymer with ammonium and imidazolium family ILs and exposed that there is an increase in conductivity of polymer when interacted with ILs. Materials and Methods

Results

Conclusion