Hydrophobic metal organic framework for enhancing performance of acoustic wave formaldehyde sensor based on polyethyleneimine and bacterial cellulose nanofilms

Jinlong Wang, Jihua Shang*, Yuanjun Guo*, Y.Y. Jiang, W.K. Xiong, J.S. Li, X. Yang, Hamdi Torun, Richard Fu, Xiaotao Zu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

A surface acoustic wave (SAW) formaldehyde gas sensor was fabricated on a 42°75' ST-cut quartz substrate, with a composite sensing layer of zeolitic imidazolate framework (ZIF)-8 on polyethyleneimine (PEI)/ bacterial cellulose (BC) nanofilms. The addition of snowflake-like ZIF-8 structure on the PEI/BC sensitive film significantly improves the hydrophobicity of the SAW sensor and increases its sensitivity to formaldehyde gas. It also significantly increases surface roughness of the sensitive film. The hydrophobic nature of ZIF-8 prevents water molecules from entering into the internal pores of the BC film, thereby avoiding a significant mass loading caused by humidity when the sensor is used to detect low-concentration formaldehyde gas. The Zn2+ sites at the surface of ZIF-8 improves the sensor's response to formaldehyde gas through enhanced physical adsorptions of gas molecules. Experimental results show that the ZIF-8@PEI/BC SAW sensor has a response (e.g., frequency shift) of 40.3 kHz to 10 ppm formaldehyde gas at 25℃ and 30% relative humidity (RH). When the relative humidity is increased from 30% to 93%, the response of the sensor only varies ~5%, and the change in response is negligible at medium humidity levels (~50 to 60% RH).
Original languageEnglish
Pages (from-to)18551–18564
JournalJournal of Materials Science: Materials in Electronics
Volume32
Issue number14
Early online date7 Jul 2021
DOIs
Publication statusPublished - Jul 2021

Fingerprint

Dive into the research topics of 'Hydrophobic metal organic framework for enhancing performance of acoustic wave formaldehyde sensor based on polyethyleneimine and bacterial cellulose nanofilms'. Together they form a unique fingerprint.

Cite this