Superhydrophilic and self-cleaning properties of cotton fabric coated with oil palm boiler ash and titanium dioxide

Superhydrophilic and self-cleaning coatings have attracted significant interest across various industries. While multiple approaches exist for creating such coatings, biomass is an environmentally friendly and cost-effective option such as palm oil boiler ash (OPBA). This study investigates the development of superhydrophilic cotton fabric coating and self-cleaning by combining SiO 2 -contained OPBA (SiO 2 -OPBA) with TiO 2 . SiO 2 -OPBA was synthesized from OPBA by calcining OPBA at 500 °C for 5 h then milled in a Ball Mill. Furthermore, OPBA was coprecipitated to produce dominant SiO 2 . Meanwhile, TiO 2 was prepared using TiCl 4 by sol-gel method. SiO 2 -OPBA and TiO 2 are combined with the addition of maleic acid as a compatibilizer and sodium hypophosphite as a catalyst. Coating on the fabric using the dip-pad-dry-cure method. Characterization of coated fabrics by SEM, FTIR, contact angle testing, and self-cleaning activity. SEM characterization shows that SiO 2 /TiO 2 agglomerates can fill the voids, preventing foreign particles from penetrating the fabric structure and limiting their deposition on the outer surface. No significant changes were observed from FTIR of coated fabrics compared to pure cotton fabrics, probably due to overlapping peaks of coating materials and cellulose bandwidth. Carbonyl esters were the major component in all samples. A significant reduction in the contact angle was observed after coating compared with the initial cotton fabric (63°). The Ti1Si1 and Ti1Si2 coated fabrics reached a contact angle of 0°. The presence of SiO 2 in OPBA enhances the surface area of TiO 2 particles, thereby improving the adsorption of stains and the overall self-cleaning mechanism.