(744a) Development of Novel Multifunctional Flame Retardant Fabrics By Nanocoating Based on Biomineralization

Flame retardant clothing (FRC), as an important component of personal protective equipment (PPE), is a last line of defense designed to protect workers in chemical industries. However, workers in chemical industries often face harsh conditions that are far less common in other industries, such as fires, electric arcs, oil spills, or harmful chemicals. Single protective clothing currently in use may not adequately protect workers from these multiple hazards. Surface nanocoating is a process by which a thin layer is deposited on the substrate for improving some property or for imparting new functionality. Inorganic coating of metal oxides on a nanoscale may mimic the formation of a char layer to protect the substrate from burning underneath it. Moreover, metal oxide coating may also bring other functions that the base textile does not possess, such as oil repellency and chemical resistance. Biomineralization is one facile and scalable approach in preparing metal oxides nanocoating. It is a biomimetic synthesis process that composes and disperses metal oxides, especially TiO₂, in an affordable, environmentally and energy-efficient manner. In this study, the approach of biomineralization was applied to produce thin, uniform, and durable TiO₂ coatings on the surface of cotton to form multi-purpose FR systems for the first time. For treated fabrics, their flammability was comprehensively evaluated using different techniques from macro- to micro-scale. From cone calorimeter test results, it was found after the treatment the maximum burning intensity of cotton can be reduced by 30.6%. From microscale combustion calorimeter test results, it was found the maximum pyrolysis rate of cotton can be reduced by 45.5%. Based on the investigation, it was identified that the nanocoating of TiO₂ provided effective barriers on the surface of cotton by slowing down the rapid release of volatile products and the heat transfer during the burning of resultant fabrics. The work will advance the fundamentals of materials combustion and surface chemistry. The work also has broad impacts on the technological development of less expensive but highly functional FR fabrics in chemical industries.