The Synthesis of Air Filters from Silk Cocoons Coated TiO₂ for Use in Air Purifier

Abstract

The purpose of this research was to synthesize and form fibroin silk air filter (SF filter) coated and non-coated with titanium dioxide. For use in indoor air pollution treatment. The main air pollutant to be treated is PM2.5. However, VOC removal also investigaed in this study. The synthesis involved degumming process using 0.5 wt % Na2CO3 at 90°C for 60 minutes. Titanium dioxide (TiO2) used in the study was a catalyst Tipaque brand (code A-220 (Anatase)). Results from studying on physical property by scanning electron microscope found that silk fibre was an ununiformly arrangement structure. SF filter coated with TiO2 showed that TiO2 distributed uniformly on the filter. The silk fibroin filters were brought to analyze for the energy band gap in order to find the energy value that the catalyst was needed to stimuate reaction in the photocatalytic process. It was found that TiO2 1-7.5 %(w/v) catalyst coated on the silk fibroin filters had the highest value of light absorption at 390 nanometers, which agreed with the value of energy level in the band gap period of 3.18 eV.The results from efficiency studies of SF filters in the treatment of indoor air pollution (generated from incense fume of 0-2 micron in size) indicated that the best treatment efficiency was 99.76%. In which SF filter non-coated with TiO2 was used, and initial PM2.5 concentration was 5 mg/m3, air flow rate was 3.93 m3/min. Treatment period was 8 hours.