Thai silk is woven from silk thread having long, elastic, soft, and natural shiny characteristics. The silk also holds thermal regulation property which “helps wearer feeling cool amidst hot weather and warm even when wearing only the thin-layer in the cold”. However, natural color of silk fabric usually does not meet consumer’s requirement. Additional colors are then required in production such as color from butterfly pea and synthetic color such as acid blue-185 (AB-185), etc.
When natural dye color is removed into river during the production process of silk cloth, it causes low or no impact on the environment. In contrast, synthetic dye color made by chemical process negatively affects the environment including aquatic animals and plants as well as other organisms living in contaminated water.
A research team led by Dr. Sittichai Kulawong, Department of Chemistry, Faculty of Science and Technology, Nakhon Ratchasima Rajaphat University realized this contamination problem and studied to synthesize for absorbing material to absorb synthetic dye color in contaminated water prior to releasing into natural water resources. The synthesized material is NaY zeolites which is high in porosity, good in ionic exchange, and great in absorption. In general, the zeolite can be synthesized from the mixed stock solution having silica and alumina as main components. Instead, the team extracted zeolite from cogon which is the hard-removed weed found in wasteland. After that, the microwave-assisted hydrothermal method was used. By applying various techniques, the research team discovered that the synthesized material is good at color absorption and can be reused up to 5 times.
Figure (left) displaying absorption of acid blue-185 dye color by using NaY zeolites and another figure (right) showing XPS spectrum detecting component element of dye color on zeolite surface (Source: S. Kulawong. et. al. 2020. Journal of Environmental Chemical Engineering, 8(5), 104114.)
To examine interaction of absorption between dye color and zeolite on the zeolite surface, the research team applied X-ray Photoelectron Spectroscopy (XPS) technique at Synchrotron Light Research Institute (Public Organization). The result indicated existence of component element of dye color on zeolite surface, showing capability of cogon extract in removing synthetic dye color. The extract will be developed later on to reduce chemical contamination in water resource and absorb other liquefied substances.
Article by: Dr. Supinya Nijpanich, Beamline Scientist
Dr. Narong Chanlek, Beamline Manager and Scientist
 S. Kulawong. et. al. 2020. Journal of Environmental Chemical Engineering, 8(5), 104114. (Doi:10.1016/j.jece.2020.104114)
 P. Patichol. et. al. 2014. Journal of Fashion Marketing and Management, 18(1), 20. (Doi:10.1108/JFMM-09-2011-0059)
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