There are increasing demands to substitute the plastic from the petrochemical industry with bacterial cellulose which were produced from microorganisms as Acetobactor xylinum strain. The aim of this study was to produce bacterial cellulose from banana peels which are agricultural waste around Walailak University area. The banana peels were used as a carbon source together with nutrient medium for the growth of bacteria. The ratio between Hestrin and Schramm nutrient medium (HS) with banana peel to DI water was 1:0.5, 1:1, and 1:1.5 (%V/V). Sugar content in banana peel (control) was 4.0% Degree Brix. The initial pH was 6.0 and sugar contents varied in this study were 5.5%, and 11% Degree Brix. A.xylinum dosages used in the cultivation were 5, 6.67, and 8.33 (%V/V) respectively. The cultivation times were 15 days at the temperature of 30 °C. As a result, the highest yield of produced bacterial cellulose was 19.46 gram and the best condition which maximum yield of bacterial cellulose 1.95% can be obtained was 11% (Brix) of sugar content, 6.67 (%V/V) of A.xylinum added, and 1:1.5 of banana peel to DI water. The physical properties of bacterial cellulose were studied with ATR-FTIR spectroscopy which shown adsorption spectrum at 3279, 2915, 1627 and 1013 cm-1 corresponding to the-OH,-CH,-CH2 and carboxyl function groups, respectively. Glass transition Temperature (Tg) was 116.85°C. Tensile strength was measured with UTM and had average value of 41.13±5.43 Mpa. The bacterial cellulose had moisture content of 90.00±0.02%. The synthesized bacterial cellulose can be used as adsorption media and also has its chemical properties like petroleum polymer. Result suggested that the similar property can be observed when compared with petroleum plastic, however with the exception of methyl group (CH3). Methyl group which can be found in plastic synthesized from petrochemical is responsible for the strength of plastic. Thus, bacterial cellulose, synthesized in this study, is not as strong as petrochemical plastic. But it can be used to produce bio-plastics because of the-CH and-CH2 functional group attached. With the similar physical and chemical properties to those of petrochemical plastic, bacterial cellulose can be used as biopolymer.

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.

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The main objectives of this research are the synthesis and characterization of the TiO2 coated silk fiborin filters for indoor air contaminant removal. Silk fibroin was degummed from silk sericin using sunlight soap solutions at 90 °C for 60 mins. Next it was washed with distilled water, reformed into a rectangle shape, and dried at 80 °C for 3 hrs in a vacuum oven. Silk fibroin filters were then coated with TiO2 solution at different dosages and dried in sunlight. Morphological structure of the TiO2 coated silk fiborin filters was analyzed using a scanning electron microscope (SEM). The band gap energies of the filters were measured using a UV/VIS/NIR spectrophotometer. Pressure drop across the filters was also examined using the manometer technique. SEM micrographs revealed the fibrous morphology of the SF fiber. An average diameter of the SF fiber was estimated to be approximately 10 μm. The spectral data recorded from the UV/VIS spectrophotometer showed the strong cut off at 390 nm. Therefore, the band gap engergy can be caculated to be approximately 3.17 eV. From the pressure drop testing, differential pressure of the filters without TiO2 was very small, and it was relatively increased with percent TiO2 coated on the SF filters. However, the differential pressures of the SF filter are less than that of the commercial air filter. The VOCs removal efficiency of the synthesized filters will be further investigated.