THE POSITIVE ROLE OF B/OMS-2 MATERIAL IN THE DEGRADATION OF POLYSTYRENE IN THE AID OF UV LIGHT

Abstract

This work presents a potential boron-modified cryptomelane (B/OMS-2) material in phtocatalysis of
polystyrene (PS) degradation. B/OMS-2 was prepared by using a reflux method and characteristics of
crystalline cryptomelane and morphologies of nanorods were observed by conducting evidences of X-Ray
diffraction patterns and scanning electron microscope images. Inductively Coupled Plasma Mass
Spectrometry was also utilized to determine elemental composition of B/OMS-2 sample. The average
oxidation state of manganese of the synthesized B/OMS-2 was 3.88 providing a high oxidation ability of the
synthesized B/OMS-2. A hand-made polystyrene sheet (2.54 cm x7.62 cm) with 1 wt.% of B/OMS-2 (denoted
by PS-B/OMS sample) and a sheet excluding B/OMS-2, namely PS sample were prepared for testing of
polystyrene degradation under UV light. After the first 2 days with UV irradiation, the weight loss were
12.700  0.525 mg/cm2
and 5.667  0.400 mg/cm2 for PS-B/OMS and PS samples, respectively. The wetting
angle over PS-B/OMS surface noticeably decreased from 87.5  1.9  (for initial time) to 35.3  5.0  (after
the two days of UV testing) while that over PS sheet slightly declined from 84.9  4.0  to 78.6  3.3 . By
comparison with the PS sheet, the surface of PS-B/OMS became dull and less shiny after long term exposure
to UV light suggesting a positive role of B/OMS-2 material in accelerating the polystyrene degradation
under UV light