Environmentally Benign Phytic Acid-Based Nanocoating for Multifunctional Flame-Retardant/Antibacterial Cotton

Eva Magovac,Ana Budimir,Bojana Vončina,Igor Jordanov,Jaime C Grunlan,Sandra Bischof

doi:10.3390/fib9110069

Abstract

Environmentally benign layer-by-layer (LbL) deposition was used to obtain flame-retardant and antimicrobial cotton. Cotton was coated with 8, 10, and 12 phytic acid (PA) and chitosan (CH)-urea bilayers (BL) and then immersed into copper (II) sulfate (CuSO4) solution. Our findings were that 12 BL of PA/CH-urea + Cu2+ were able to stop flame on cotton during vertical flammability testing (VFT) with a limiting oxygen index (LOI) value of 26%. Microscale combustion calorimeter (MCC) data showed a reduction of peak heat release rates (pHRR) of more than 61%, while the reduction of total heat release (THR) was more than 54%, relative to untreated cotton. TG-IR analysis of 12 BL-treated cotton showed the release of water, methane, carbon dioxide, carbon monoxide, and aldehydes, while by adding Cu2+ ions, the treated cotton produces a lower amount of methane. Treated cotton also showed no levoglucosan. The intumescent behavior of the treatment was indicated by the bubbled structure of the post-burn char. Antibacterial testing showed a 100% reduction of Klebsiella pneumoniae and Staphylococcus aureus. In this study, cotton was successfully functionalized with a multifunctional ecologically benign flame-retardant and antibacterial nanocoating, by means of LbL deposition.

Highlights

Cotton is one of the most frequently used textile materials for a variety of products, such as medical textiles, underwear, sportswear, fashion garments, footwear, safety clothes, etc. [1]
8 BL cotton shows a reduction of peak release rate (ΔHRR) of more than 49%, while a reduction of total heat release rates (ΔTHR) is more than 30%
These results aresulfur, consistent potassium. These results suggest that with the results obtained in a previous study, where only 2.3 wt % of copper is sufficient to the of of phytic acid (PA)/CH-urea

Summary

Introduction

Cotton is one of the most frequently used textile materials for a variety of products, such as medical textiles, underwear, sportswear, fashion garments, footwear, safety clothes, etc. [1]. The reason why cotton is such a favorite material is its softness and water uptake, enabled by highly hydrophilic and reactive hydroxyl groups in the molecule of cellulose The reactivity of these groups, makes cotton fabric very flammable and prone to microbial growth [2]. The greener, formaldehyde-free alternatives for curing FRs and antibacterial finishes on cellulosic fabrics are polycarboxylic acid-based curing agents [8,9]. Another environmentally friendly approach could be layer-by-layer (LbL) deposition, which uses deionized water as a solvent for various active compounds (polymers, nanoparticles, small molecules, etc.) and is applicable to nearly any charged surface, such as textiles [10,11]. 12 BL were sufficient for the self-extinguishing of cotton and to kill almost 100% of the bacteria

Materials and Methods

SEM images of

Findings

Conclusions