Recent Advances in Sol-gel and Layer-by-layer Coatings for Flame-retardant Cotton Fabrics

Surface-engineered coatings for the fire protection of cotton are being increasingly used thanks to the ease of application of the coatings and their effectiveness in preventing flame propagation and improving resistance to irradiative heat flux exposure. Two main approaches have been extensively investigated in this context, namely sol-gel derived coatings and layer-by-layer assemblies. On the other hand, these approaches can provide treated fabrics with outstanding flame-retardant features. Notwithstanding, according to the composition of the sol-gel recipes and the type of deposited layers in layer-by-layer assemblies, it is possible to design multifunctional (for example, hydrophobic, oil repellent, self-clean, anti-bacterial, electrically conductive, etc.) treatments. Therefore, this review discusses recent advances concerning both sol-gel and layer-by-layer strategies, highlighting current limitations, open challenges, and possible advances. In addition, an attempt has been made to give a brief overview of the works done in this field.