Design and study of multifunctional fabrics

Abstract

The increasing demands to address the flammability of cotton fabrics, lead to a substantial growth of applying flame retardant (FR) systems to cotton fabrics in recent years. Nevertheless, due to the growing need for multiple functionalities and sophisticated applications, a combination of several properties become a development tendency in meeting expectations for today's high-performance functional fabrics. Notably, everlasting challenge for functional fabrics is the washing fastness. Therefore, aiming to fabricate target multifunctional fabrics, a novel FR molecule was designed to impart cotton fabrics FR and hydrophobic properties simultaneously. Furthermore, in order to address the durability issues, surface engineering was constructed by introducing polydopamine (PDA) as a "molecular glue" to stack the FRs on cotton robustly. Finally, multifunctional fabrics with high-performance and simultaneously improved washing fastness was realised. To well illustrate mechanism behind the improved FR, self-cleaning, UV-protection properties and washing durability, influence of synthesized functional molecular to decomposition of cellulose, the role of BiVO4 in Chapter 5 as a new introduction in the catalytic charring process, and the interaction between PDA cover and FR molecular or BiVO4 which lead to durability have been systematically investigated. The details of the work are presented as follows:In Chapter 3, non-halogen functional coatings consisted of water-soluble phenylphosphinyl and amine-containing silanol (WPAS) were prepared, in which functional cotton fabrics embraced with FR and hydrophobic properties simultaneously. The prepared WPAS-coated functional fabrics reached as high as 30.4% for limiting oxygen index (LOI) value, and extinguished immediately after removing the ignitor in vertical fire test. PO• free radicals released by WPAS which was detected by TG-MS and TG-FTIR, captured radicals such as H• or HO• radicals in the gas-phase. The char residue study from SEM, FTIR, Raman and XPS results found that P/Si/N thermostable ceramic char layer and aromatic carbonaceous structures formed which could provide a good barrier effect, effectively hindering diffusion of oxygen and transferring of heat into the flame zone. Additionally, water contact angle of functional cotton fabrics increased to 145° compared with that of pristine cotton fabrics (0°). As a result, it displayed hydrophobic self-cleaning property towards a series of common liquids in daily life. This convenient, eco-friendly one-pot approach is promising, and feasible for large-scale production of functional cotton fabrics with both excellent FR and hydrophobic self-cleaning properties to end-use industrial applications.In Chapter 4, The layers consisted of phenylphosphonic acid (PHA) and 3aminopropyltriethoxysilane (APTES) was deposited on PDA-coated cotton by Lay-by-Layer (LbL) assembly. The prepared cotton reached 31.4% of LOI value, and extinguished immediately after removing the ignitor. Peak of heat release rate (pHRR) attenuated around 3...