Journal of Environmental Biology

Preparation and characterization of TiO₂-coated silk fibroin filters for photocatalytic oxidation of formaldehyde using waste silk cocoons

J. Triped¹, W. Sanongraj²* and W. Khamwichit³

¹International Postgraduate Programmes in Environmental Management, Graduate School,

Centre for Excellence on Hazardous Substance Management, Chulalongkorn University, Bangkok-10330, Thailand

²Research Excellence on Hazardous Substance Management, Department of Chemical Engineering, Faculty of Engineering,

Ubonratchathani University-34190, Thailand

³School of Engineering and resources, Walailak University, Nakhonsithammarat-80160, Thailand

*Corresponding Author E-mail: wipadadechapanya@yahoo.com

Key words

Biomaterials,

Photocatalytic oxidation,

Silk cocoons,

Silk fibroin,

Titanium dioxide

Publication Data

Paper received : 07.04.2016

Revised received : 19.08.2016

Re-revised received : 02??????????? .11.2016

Accepted : 22.12.2016

Abstract

Aim: The possibility of producing valued devices from low cost natural resources is a subject of broad interest. The present study explored the preparation and characterization of pure silk fibroin (SF) filters and TiO₂-coated SF filters for indoor air purification using waste silk cocoons generated from silk textile processing.

Methodology: Silk fibroin (SF) filter samples were characterized mainly by scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy and mechanical analyses.

Results: The SEM results indicated that TiO₂ particles adhered well onto the silk fibroin filters. Compared to pure SF filters, the mechanical and thermal properties of TiO₂ SF filters were improved due to the conformational transition of silk fibroin to ?silk II structure. The percentage of catalyst (TiO₂) doses varied from 1.0, 2.5, 5.0, and 7.5 % (wt.cat.^-1 vol.sol.).? The results derived from the kinetic model revealed that the photocatalytic rate followed the first order reaction. The highest removal efficiency of 68.21% was obtained at initial formaldehyde concentration of about 5.00 ppm and TiO₂-coated SF filters of 5.0 % TiO₂ wt.vol^-1.sol.. The successful preparation of TiO₂-coated SF filters from waste silk cocoons provide a promising opportunity to widen potential applications of SF in the biomaterial field.  

Interpretation: The successful preparation of TiO₂-coated SF filters from waste silk cocoons not only provides a? promising opportunity to widen potential application of SF in indoor air purification but also enhances a waste minimization from silk textile processing.

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