Selective detection of volatile organic compounds using singlewalled carbon nanotube on polyvinylidene fluoride membrane (SWCNT-PVDF)

• Main Author: Png, Chang Hoe
• Other Authors: Alfred Tok Iing Yoong
• Format: Final Year Project
• Language: English
• Published: 2015
• Subjects: DRNTU::Engineering::Materials
• Online Access: http://hdl.handle.net/10356/65566
• Institution: Nanyang Technological University

Detection of Volatile Organic Compound (VOC) with Single-Walled Carbon Nanotubes (SWCNT) on Polyvinylidene Fluoride (PVDF) membrane is relatively new and is gaining interest as a fast, convenient, and low set-up cost method, this technology aims to be applicable for detecting a wide range of gaseous compounds. In this research, this methodology was tested with 2 types of VOC, ethanol and toluene. The presence of toluene in the atmosphere is harmful to not only humans but also the biological balance. It can enter into biological systems through various ways, including inhalation and consumption of water with dissolved toluene. Small amounts of toluene and ethanol were tested using this method and changes in current of the SWCNT were observed. When the measured current on the SWCNT is stable, fixed amounts of VOC were released into the system, allowing them to vaporize. Drop in current showed that vaporized compound has condensed on the SWCNT surface, depleting the carriers’ mobility, and hence affecting conductivity and consequently, the current flow. Limitations of this method were also identified and discussed in this study. The environment where the experiments were carried out was not entirely enclosed, which means there is a possibility that other compounds were present. In order to mimic a closed environment, a cover for the system was made to reduce the possibility of other compounds condensing onto the surface. The present study can be extended by additional functionalization to increase accuracy and specificity. It can also be incorporated into practical applications such as creation of a device for the detection of VOC in areas with many petroleum industries or in residential areas towards improving the lives of people, and enabling actions to be taken once too high amount of toluene and ethanol are detected by the device.