FABRICATION OF POLYACRYLONITRILE (PAN)/NICKEL COMPOSITE AS BINDING MATERIAL OF QUARTZ CRYSTAL MICROBALANCE (QCM) FOR DETECTION VOLATILE ORGANIC COMPOUND (VOC) GAS

• Main Author: Mulyadi Rohman, Yadi
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/67216
• Institution: Institut Teknologi Bandung

Economic and technological developments have a negative impact on the environment. Over the last few decades, VOC gas has become a gas that is harmful to humans. VOC gas is an organic gas that is volatile in the environment and is harmful to health even at very low concentrations. This gas continuously evaporates from various human activities such as the painting process, children's toys, vehicle exhaust gases to pesticides. The concentration of VOC gas indoors is much higher than outdoors. Some of the negative impacts when exposed to VOC gas are skin irritation, irritation, headaches, nerve, and genetic damage to cause death. QCM is one of the sensors that can detect the presence of VOCs. The QCM sensor has advantages compared to other sensors, namely fast detection, easy sample preparation process and sensitivity to changes in mass. However, it is necessary to coat the QCM surface to increase the sensitivity of the sensor to various types of VOC gas. Nanofiber-shaped materials have been known to have good adsorption characteristics, high surface area and small size. Nanoparticle composites with nanofibers are known to be able to increase the sensitivity of the QCM sensor. This study aims to make PAN/nickel nanofiber composites as an active layer on the QCM surface to increase the sensitivity of the sensor to VOC gas. Parameter optimization was carried out to determine the optimum PAN/nickel composition. PAN nanofiber was successfully fabricated by electrospinning technique. The optimum concentration of PAN nanofiber solution was 8% based on the analysis of nanofiber shape using a digital microscope. The solution concentration of 8% produces stable nanofibers. Electrospray technique was used to fabricate nickel nanoparticles on the surface of PAN nanofibers. The results of the nickel nanoparticle fabrication obtained an optimum solution concentration of 8% based on the analysis of the shape of the nanofibers and changes in the size of the nanofibers using a digital microscope. The SEM results showed the morphology of the PAN nanofiber, and the PAN/nickel composite showed an elongated and stable shape of the nanofiber. The measurement of the diameter of the PAN nanofiber showed a result of 220,088 nm and increased when given nickel nanoparticles to 335.48 nm. The EDS results show the elements contained in the composite are in accordance with the constituent elements. The presence of FTIR characterization indicates the presence of intermolecular results in PAN and Nickel which is characterized by the appearance of several absorption peaks in the composite. Sensor testing showed very good results for QCM with PAN/nickel composites characterized by a change in frequency of 468 Hz compared to 55.6 Hz PAN-coated QCM and 200.1 Hz nickel nanoparticle-coated methanol gas response. This is an improvement of almost 10 times compared to the blank QCM sensor. The sensitivity of the PAN/nickel composite coated QCM sensor shows very sensitive results compared to other QCMs. Based on linear regression analysis, the sensitivity value was 306.04 Hz/Lminute-1. The LOD and LOQ results show that the PAN/nickel coated QCM sensor has a low value, so it is very sensitive to methanol gas. The selectivity test showed the response of the selective PAN/nickel coated QCM sensor to methanol gas with the highest frequency reduction compared to ethanol, acetone, and formaldehyde gases. The interaction between molecules in PAN nanofibers and Nickel nanoparticles with methanol gas plays an important role in reducing the resonance frequency. The test shows that the QCM sensor response remains stable when used repeatedly for 30 days.