Research On The Contact Electrification Based Volatile Organic Compounds Sensors

Volatile organic compounds(VOCs)are a ubiquitous chemical substance in the atmosphere,which poses a serious threat to human health,so the detection and control of VOCs is of great significance to human life.As a key component of the detection system,gas sensors can effectively detect toxic and harmful VOCs.The traditional gas sensor detection equipment is either bulky,expensive,or complicated in detection process.This paper proposes a completely new gas detection mechanism,which uses different modifications to the interface silica nanoparticles to adjust the device’s contact charged output signal to achieve efficient detection of VOCs.In this paper,a contact-charged VOCs gas sensor with simple operation,safety,high efficiency,good selectivity,high sensitivity,and room temperature detection is prepared.In this paper,silica nanoparticles are first prepared and then surface modified to obtain silica nanoparticles(m SNPs)with orientation-controlled surface groups and chain lengths.Then,the m SNPs/PVDF composite film is obtained by spinning coating of the solution containing m SNPs and PVDF,and finally the basic structure of the device is assembled to obtain the contact charged device.Subsequently,the effect of different organic groups at the interface of the m SNPs/PVDF composite film on the charged output signal of the device was studied.From three important aspects of the accumulation,saturation and attenuation of electrical signals,the effect of different organic groups on the device’s contact charging output performance was evaluated.The experimental results show that the interface have different physical and chemical properties owning to different organic groups,thus different contact charged output signals were observed.Finally,14 kinds sensors based on m SNPs/PVDF with different organic group are used to study the gas sensing performance of six VOCs of acetone,formaldehyde,ethanol,n-hexane,toluene and triethylamine.The atmosphere will cause the functional groups at the internal interface of the device to swell or shrink to varying degrees,resulting in change of the microstructure at the interface,thereby changing the contact electrical signal of the device,that is,it can produce a certain sensor response output for a specific gas.The array of these14 kinds of sensors is selective for the six kinds of gases,and further combined with the PCA algorithm,the detection and identification of the six kinds of gases can be realized.