Antimicrobial wool, polyester and a wool/polyester blend created by silver particles embedded in a silica matrix

Surface Functionalization of Wool via Microbial-Transglutaminase as Bio-Mordant to Improve Dyeability with Madder in the Presence of Alum

Herein, the wool fabric was mordanted with alum, treated with microbial transglutaminase (m-TGase), and then dyed with madder. Different concentrations of alum and m-TGase were used to find out the optimum condition to achieve the best color after dyeing the wool fabrics with aqueous extract of madder. FT-IR spectroscopy and scanning electron microscopy (SEM) methods were applied to characterize the as-prepared samples. Contact angle measurements showed that the water uptake capability was increased in the case of the wool sample treated with alum and enzyme. Moreover, the samples were assessed for color strength (K/S) and color fastness. Our results showed that the optimal condition to get the highest color value was for the sample with 10% owf (of weight of fabric) alum and 5% owf m-TGase. Furthermore, it was found that there was a critical concentration for enzyme so that an increase in m-TGase amount would cause damage to the scales of fibers. The best condition of the dyeing process was discussed in this study, and also the proposed mechanism was presented. Indeed, treatment of wool with m-TGase led to a reduction in the amount of consumed alum, while investigations in color performances demonstrated the enhancement in color fastness, as well as color strength.

Biofunctionalization of Natural Fiber-Reinforced Biocomposites for Biomedical Applications

In the last ten years, environmental consciousness has increased worldwide, leading to the development of eco-friendly materials to replace synthetic ones. Natural fibers are extracted from renewable resources at low cost. Their combination with synthetic polymers as reinforcement materials has been an important step forward in that direction. The sustainability and excellent physical and biological (e.g., biocompatibility, antimicrobial activity) properties of these biocomposites have extended their application to the biomedical field. This paper offers a detailed overview of the extraction and separation processes applied to natural fibers and their posterior chemical and physical modifications for biocomposite fabrication. Because of the requirements for biomedical device production, specialized biomolecules are currently being incorporated onto these biocomposites. From antibiotics to peptides and plant extracts, to name a few, this review explores their impact on the final biocomposite product, in light of their individual or combined effect, and analyzes the most recurrent strategies for biomolecule immobilization.

Unraveling the Complexity in the Aging of Nanoenhanced Textiles: A Comprehensive Sequential Study on the Effects of Sunlight and Washing on Silver Nanoparticles

The scientific understanding of nanoparticle (NP) release and transformations they undergo during the product life cycle is hampered by the narrow scope of many research endeavors in terms of both breadth of variables and completeness of analytical characterization. We conducted a comprehensive suite of studies to reveal overarching mechanisms and parameters for nanosilver transformations either still adhered to the fabric or when released after washing. Laboratory prepared nanoenhanced fabrics were investigated: three Ag variants and one Au used as an unreactive reference to separate mechanical from chemical releases. Sequential combinations of sunlight irradiation and/or washing in seven different detergent formulations was followed by NP characterization divided into two groups: (1) dissolved and particulate matter in the wash solutions and (2) the fraction that remained on the fabric. Analytical techniques included spICP-MS, XANES, TEM, SEM, and total metals analysis of fabric digests and wash water filtrates. Sunlight irradiation stabilizes metallic Ag upon washing. Detergents containing oxidizing agents assisted with Ag particle release but not Au NPs, inferring additional chemical mechanisms. While particle size played some role, the NP capping agent/fabric binder combination was a key factor in release. When particles were released, little alteration in size was observed. The use of well-controlled fabrics, unreactive reference materials, and a life-cycle based experimental regime are paramount to understanding changes in Ag speciation and release upon use of nanoenhanced textiles.

Biopolymers from Composted Biowaste as Stabilizers for the Synthesis of Spherical and Homogeneously Sized Silver Nanoparticles for Textile Applications on Natural Fibers

The use of bio-based substances (BBS) obtained from composted biowaste as stabilizers for the production of silver nanoparticles (AgNPs) in substitution to citrate is investigated herein, evaluating the functionalization of natural fibers for textile antibacterial applications. The results obtained evidenced that BBS can substitute citrate as reducing/stabilizing agent in the synthesis, inducing a geometrical control (in shape and size) of the AgNPs. Two different substrates were selected (wool and cotton) and two dip-coating deposition techniques investigated. The release of AgNPs from the supports in water was evaluated under two different experimental conditions: 1) soaking (static conditions) for 7 and 15 days, simulating the contact with sweat, and 2) centrifugation (dynamic conditions), simulating a washing machine treatment. A wide physicochemical characterization was carried out to evaluate the effects of BBS on the morphology and stability of AgNPs suspensions as well as the functionalization effectiveness.