Enhanced Acetone-Sensing Properties of PEI Thin Film by GO-NH2 Functional Groups Modification at Room Temperature

Qiuni Zhao,Hongru Wu,Huiling Tai,Chenliang Su,Yadong Jiang,Zaizhou He,Zhen Yuan

doi:10.3389/fmats.2018.00082

Abstract

The functional groups of organic gas-sensing materials play a crucial role in adsorbing specific gas molecules, which is significant to the sensing performances of gas sensor. In this work, amido-graphene oxide (GO-NH2) loaded poly(ethyleneimine) (PEI) composite thin film (PEI/GO-NH2) with abundant amino functional groups -NH2 was successfully prepared on quartz crystal microbalance (QCM) by a combined spraying and drop coating method for acetone detection at room temperature (25℃). The morphological, spectrographic and acetone-sensing properties of composite film were investigated. The results demonstrated that a wrinkled surface morphology was formed and the ratio of nucleophilic -NH2 was increased for PEI/GO-NH2 composite film. Meanwhile, the composite film sensor possessed excellent acetone-sensing performances, and its sensitivity was about 4.2 times higher than that of pure PEI one owing to the increased -NH2 groups. This study reveals the important role of absorbing favorable functional groups and provides a novel method for the rational design and construction of acetone-sensing materials.

Highlights

Acetone is a volatile, flammable and deleterious industrial product that widely used in our daily life (Jia et al, 2014)
PEI film loaded GO-NH2 (PEI/GO-NH2, for short) with abundant -NH2 was prepared by a combined spraying and drop coating method, and characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV-vis)
NH2 are nucleophilic while -NH2H+ are not nucleophilic, so the increased ratio of nucleophilic -NH2 in PEI/GO-NH2 can increase the acetone gas molecules adsorption and enhance the acetone-sensing properties of composite thin film (Smith and March, 2007)

Summary

Introduction

Flammable and deleterious industrial product that widely used in our daily life (Jia et al, 2014). As a typical organic polymer, poly(ethyleneimine) (PEI) can be used in QCM-based acetone sensors due to the amino functional groups (-NH2, for short) that can adsorb acetone molecules through nucleophilic addition reaction (Smith and March, 2007).

Results

Conclusion