# Surface Induced Order in Room Temperature Ionic Liquids and Its Effect on Piezoelectric Response

## TL;DR

This study shows that adding a single layer of a special molecule to an interface increases the piezoelectric response of a room temperature ionic liquid.

## Contribution

The novel finding is that a monolayer of pyridinium amphiphile enhances the piezoelectric effect in RTILs.

## Key findings

- A monolayer of pyridinium amphiphile increases the piezoelectric response of C4Py TFSI.
- The structural order induced by the monolayer is limited by the ITO surface's roughness and irregularity.

## Abstract

We compare the direct
piezoelectric response of the room temperature
ionic liquid (RTIL) N-butylpyridinium bis­(trifluoromethyl-sulfonyl)­imide
(C4Py TFSI) under conditions where pressure is applied
to the bulk RTIL in a vessel with a bare ITO interface and a vessel
with an ITO interface modified with a monolayer of a pyridinium-containing
amphiphile. We find that the presence of a single monolayer of the
pyridinium amphiphile poises the RTIL structurally to produce a measurably
larger piezoelectric response. The extent of order imposed by the
presence of the monolayer is likely limited by the intrinsic surface
roughness and structural irregularity of the ITO-coated glass support
used.