DEVELOPMENT OF AGRO-BASED NANOFILTERS TO CAPTURE SUSPENDED TITANIUM IN AIR

Abstract

Nanosilica and nanozeolite synthesised from rice husk (RH) were investigated for their potential to develop a low-cost nanofilter membrane as an alternative to replace nylon membrane used in the Nanoparticle Respiratory Deposition (NRD) sampler for capturing titanium dioxide (TiO2) nanoparticles suspended in the air. Due to its exceptional adsorption capacity to many inorganic materials, graphene oxide was also investigated for its potential to capture the TiO2 nanoparticles to compare its performance with the newly developed agro-based nanofilters. All nanofillers were developed by depositing the synthesised nanomaterials on a polyvinylidene fluoride (PVDF) membrane using the layer deposition method and characterised by Field Emission Scanning Microscopy/Energy Dispersive X-ray (FESEM-EDX) analysis. Each nanofilters developed were exposed to TiO2 nanoparticles for 15 minutes with an average airflow of 2.5 L/minutes and were compared with the conventional nylon membrane used in NRD. Among all nanofilters developed, nanozeolite filter (0.1% w/v) showed the highest concentration of Ti captured (81.7 μg/g) compared to nanosilica (56.7 μg/g) and graphene oxide (8.2 μg/g) filters. Interestingly, all developed nanofilters did not show any presence of Ti in their background levels, further suggesting its purity in capturing Ti nanoparticles in the air.