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

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

JOURNAL=Frontiers in Materials

VOLUME=5

YEAR=2019

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2018.00082

DOI=10.3389/fmats.2018.00082

ISSN=2296-8016

ABSTRACT=<p>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-NH<sub>2</sub>) loaded poly(ethyleneimine) (PEI) composite thin film (PEI/GO-NH<sub>2</sub>) with abundant amino functional groups -NH<sub>2</sub> was successfully prepared on quartz crystal microbalance (QCM) by a combined spraying and drop coating method for acetone detection at room temperature (25°C). 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 -NH<sub>2</sub> was increased for PEI/GO-NH<sub>2</sub> 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 -NH<sub>2</sub> 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.</p>