Utilization of multiwalled carbon nanotube/poly(p-phenylene) composite for gas detection

Abstract

One of problems emerging in modern live is how to detect the existence of a gas in a room or space. The detection could be achieved by a sensor. The motivation of this work is to develop a sensor material consists of multiwalled carbon nanotubes (MWNTs), polymers, and metal oxides. Recently the combination of CNTs and polymer or metal oxides gains serious attention since the CNTs have unique electrical properties. Poly(p-phenylene) (PPP) is known as a potential conductive polymer due to the existence of double bond. Based on information in published reports, the synthesizing of the PPP and the metal oxide successfully conducted. To observe comprehensively of materials synthesized, several characterizations were conducted such as FTIR, TGA, SEM, SPM, XRD. The materials then combined using a method to get a kind of composite as a sensor material. Several variables such as sonication time, amount of dispersant, types of gas, and gas concentration were varied to investigate the performance of the composite. A certain ratio of MWNTs with nominal size of 20 nm and synthesized-PPP was compounded with the presence of terpineol as a dispersant. To investigate an optimal condition for homogenizing all constituents, ultrasonication with 750 watts was employed with compounding time of 3, 10, 20, 30 min. It was found that the composite film could be prepared with ultrasonication within 10 minutes. The ratio of constituents and the dispersant was also conducted. The composite then put into a system of sensing by which the response of the sensor material recorded automatically every second. A very important conclusion of this study is that the combination of MWNTs and PPP and tungsten oxide could be used as a sensor material. Typically results show sensitivity of MWNTs gained more than 40%, 11-15% for MWNT/WO₃, and 12-30% for MWNT/PPP/WO₃