Nanofibrous coating on cotton fabrics: exploring low-risk chemical protection with retained comfort
Creators: name: GAVRILENKO, Olga
Publisher: name: RMIT University
Year: 2024
Subjects: classificationCode: 330315
subject: Textile and fashion design

description: The use of specialised clothing is essential for protection against chemicals in many hazardous environments, but often the use of chemical protective clothing (CPC) in warmer working environments presents a potential heat stress risk. While research into high-risk CPC materials for protection against life-threatening chemicals is well established, research into materials for low-risk categories is limited. There is a need for development of such low-risk chemical protective materials for re-usable comfortable CPC suitable for warmer working environments. Cotton provides superior comfort qualities, but the chemical protection offered by the conventional finishing of cotton fabrics is not sufficient and compromises the comfort. Electrospun nanofibrous membranes have demonstrated many protective functionalities. Therefore, it is of interest to develop a new type of protective coating for cotton fabrics, based on lightweight functionalised electrospun nanofibrous membranes.

As the morphology of the membrane is critical for protective performance, this research examined the effects of the electrospinning parameters on nanofibrous morphologies. The fabrication method, using electrospinning technology, was suggested and validated for direct application and functionalisation of the coating onto various cotton fabrics. The novel method of functionalisation for cotton fabrics has been identified as a combination of an electrospun multilayered polyurethane nanofibrous coating, which adds a specific hierarchical structure over the inherent surface texture of fabrics, and an electrosprayed finish with a low surface free energy chemical. The relationships were established between the coating parameters and protective, comfort and durability performance, and the coating parameters were optimised. 

In this research, a new multilayered coating on cotton fabrics, based on electrospun polyurethane nanofibrous membranes, has been developed with protective functions such as liquid repellency (for water, oils, and liquid chemicals), waterproofing and self-cleaning.

For coated fabrics, the advantageous comfort properties of cotton fabrics such as air permeability and moisture management, thermal and water vapour resistance, hand and surface roughness were maintained. Acceptable durability of the protective functions against abrasion and laundering has been demonstrated.

The fabrication process has been developed for the application of the coating with the consecutive functional layers including a binder layer that provides bonding between the polyurethane layers and cotton fabrics, multiple electrospun polyurethane layers with merged beads-on-string morphology that enhanced the original micro-scale texture of fabrics with added nano-scale texture of coating, and a layer of oil/water repellent to lower the surface free energy of the coating. All layers were applied using the solution electrospinning method, eliminating water and chemical waste associated with the use of conventional finishing methods. Also, the fabrication method allowed the chemicals to be applied only to the outer side of cotton fabrics, preserving the advantageous comfort qualities of the inner side.

This research contributes to knowledge in the field of low-risk CPC materials. The multilayered coatings developed have already demonstrated the repellency of water, oils and liquid chemicals, waterproofing and self-cleaning protective functions, but the range of functionalities can be further extended with additional functional agents. The significance of the developed coatings and method is that the coatings can be applied directly over cotton fabrics with an extensive range of weights and various weaves to produce functional, comfortable and re-usable garments with added low-risk chemical protection and other desired functionalities.