A solution-fabrication formaldehyde sensor based on graphene/PMMA composite materials
Date Issued
2014
Date
2014
Author(s)
Yang, Sung-Yuan
Abstract
In bottom layer of Internet of Things(M2M) , there would be a lot of sensors to detect our environment in several applications such as smart home and air monitoring . Air pollution influences human health and can cause a number of diseases.The one of major air pollutiants is volatile organic compounds (VOCs) especially in BTEX and formaldehyde can cause cancer to human beings .Therefore, developing a low cost,low power consumption and reliable gas sensor is very important for sensing technology. In this work ,we demonstrated graphene material blended with Poly(methyl methacrylate,PMMA,M=15,000) composite inks deposited between gold electrode by spin coating method .The deposited graphene composite films with different mixture concentration are sensing materials for VOCs chemiresister gas sensors in room temperature.The sensor response to several VOCs gas including methanol ,ethanol , acetone , benzene ,toluene , o-xylene, formaldehyde and water vapor are investigated. The sensors selectivity ,repeatability and stability,duration are also examined .The graphene material are prepared and selectively blended with PMMA both in dispersant Tetrahydrofuran(THF) to become conductive self-assembly composite materials . We also tested the difference of sensing VOCs characteristics between spin coated pure graphene films and graphene /PMMA composite films. The optional concentration of graphene composite spin coated films show good sensor response to formaldehyde vapor with resistance change about 0.5%~30% after exposing to each vapor concentration(about 10ppm~600ppm) in room temperature .We finally use instruments such as FTIR,SEM,XRD and Raman to analysis materials .We also infer the possible sensing mechanism between the graphene-PMMA composites and the formaldehyde.
Subjects
Organic Electronic Devices
Formaldehyde chemiresister gas sensors
volatile organic compounds(VOCs)
Graphene-PMMA composites
Solution process
SDGs
Type
thesis