Development of Sol-Gel technology for textile surface coating to achieve self-cleaning and antibacterial properties

With advancements in technology and its influence on most industries, the textile industry continues to pursue innovative techniques to create and meet the growing demand for technical textiles. Self-cleaning textiles have become popular due to promising positive impacts on not just the textile industry, but also on global efforts to improve industrial waste and its impact on the environment. Polyfluorinated chemicals are widely known to provide excellent self-cleaning properties to achieve water and oil repellence, mirroring that of the botanical lotus leaf. Due to their toxic effects on consumers and the environment, research focus, in the pursuit to achieve technical textiles, has been to replace these toxic polyfluorinated chemicals with alternative substances capable of achieve functional properties that these fluorinated substances provide. Various technologies utilised to impart functional properties that include the sol-gel technology, have gained popularity in recent years due to its simpler and cost-effective processes. This sol-gel technology utilises silane precursors, modified easily to incorporate various additives that are applied onto textiles through hydrolysis and condensation reactions, in the presence of a catalyst, to produce an extensive functionalised nanoparticle network on the textile surface. Alkoxysilanes and quaternary ammonium compounds modified with long carbon chains were used to develop a sol solution that could be applied onto 100% knitted cotton fabric. To involve the fabric in the building of the sol-gel network, 100% treated cotton was agitated in sol solution for 4 hours at 40°C. The soft feel of the cotton fabric was retained when treated cotton fabrics were padded at high pad pressure. This treatment method resulted in treated cotton fabric demonstrating hydrophobicity with water contact angles of 142° and roll-off angles of 16° for self-cleaning properties. The 3-(Trimethoxysilyl) propyloctadecyldimethylammonium chloride silane provided an antibacterial activity of log reduction in CFU/mL of 3 against S.aureus and was seen to influence the hydrophobic property. Prolonged contact between fabric and sol demonstrated better durability of properties for sol-gel treated cotton fabric when tested for its durability to washing. Though acidic medium reduced resistance to abrasion, XIX cotton samples treated in acidic conditions with varying silane content regained abrasion resistance and demonstrated an improvement in burst strength. SEM-EDX and ATR / FT-IR analyses were able to illustrate the presence of sol-gel coating and the siloxane bonding on the treated cotton surface, respectively.