Multiwalled-Carbon-Nanotubes (MWCNTs)–GPTMS/Tannic-Acid-Nanocomposite-Coated Cotton Fabric for Sustainable Antibacterial Properties and Electrical Conductivity

Modification of halloysite lumen with dopamine derivatives as filler for antibiofilm coating

HYPOTHESIS

Development of nanocomposite coating with antibiofilm properties is of fundamental importance to efficient fight biofilm formation preventing infections in biomedical area. In this context, halloysite nanotubes (HNTs), biocompatible and low-cost clay mineral, have been efficiently used as filler for different polymeric matrices affording several nanocomposites with appealing antimicrobial properties. The modification of HNTs surfaces represents a valuable strategy to improve the utilization of the clay for biological purposes.

EXPERIMENTS

Herein, the covalent modification of the HNTs lumen with properly designed dopamine derivatives with different perfluoroalkyl chain length is reported. The obtained nanomaterials are thoroughly characterized by several techniques. As proof of concept the antibiofilm properties on E. coli strain of the nanomaterials are assayed as well. Finally, the HNTs fillers were introduced into a polydopamine matrix allowing for the preparation of functional coatings, resistant to formation of microbial biofilms.

FINDINGS

All characterization methods proved the selectivity of the modification and the increased hydrophobicity of the lumen. In particular 27Al solid state nuclear magnetic resonance (NMR) spectra showed a upfield shift of the Al signal. Studies on the antibiofilm properties highlighted different activities according to the length of perfluoroalkyl chains of organic molecules as proved by 19F solid state NMR spectra. The synthetized materials were promising for future application as coatings on medical implants.

Synthesis and Characterization of Pyridine Acetohydrazide Derivative for Antimicrobial Cotton Fabric

An increase in textile resistance to antimicrobial agents has posed a pressing need for the development of new antimicrobials. Therefore, the antimicrobial characteristics of thiophene and pyridine acetohydrazide derivatives have been developed as novel textile-modified complexes exhibiting antibacterial agents. Synthesis and characterization of pyridyl-thienyl acetohydrazide derivative (AHZ) using NMR (¹³C and ¹H) and FTIR. Modification of cotton fabric (CF) with acetohydrazide (AHZ) and metal chlorides of divalent Cr, Mn, Co, Ni, Cu, and Zn and trivalent Fe, and Cr. SEM-EDX and Fourier-transform infrared were utilized to characterize cellulose-based cotton fabric (CF) attached to AHZ and their metal (M) complexes. Antimicrobial activity was examined against two types of bacteria, namely S. aureus and E. coli, and two types of fungi, namely C. albicans and A. flavus. All modified samples exhibited higher efficiency towards bacterial strains than fungal strains. In addition, cellulose modified with Ni (II) confers the most antibacterial protection efficiency.

Highly Durable Antibacterial Properties of Cellulosic Fabric via β-Cyclodextrin/Essential Oils Inclusion Complex

Essential oils (EO_S), which naturally come from plants, have significant antibacterial properties against a variety of pathogens, but their high volatility and poor water solubility severely restrict their use in the textile industry. In this study, an inclusion complex based on β-cyclodextrin (β-CD)/EO_S was prepared by two different simple methods: pad dry cure (method 1) and pad batch (method 2). A glyoxal crosslinking agent was used for the fixation of the inclusion complexes on the surface of the fabric. Lavender, rosemary, salvia, and lemon essential oils were applied. The structure of the β-CD/EOs inclusion complex was investigated using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and weight gain (%), which indicated that the β-CD/EOs were successfully deposited on cellulose-based fabric. The results demonstrated that β-CD enhanced the oils' scent stability, with the advantage of exhibiting no major change in the tensile strength or permeability of cotton. Lavender oil had the highest stability scent with a value of 3.25, even after 30 days of evaluation. The antibacterial activity showed that EO_S/βCD-impregnated fabrics for method 1 had an inhibition zone ranging from 33 to 23 mm, while the inhibition zone for method 2 ranged from 39 mm to 29 mm, indicating that our treatment was able to control the growth of bacteria, even after five washing cycles. This study confirmed that the EOs/βCD inclusion-complex-deposited cotton fabric might hold further promise for medical and hospital use.

A Review of Electro Conductive Textiles Utilizing the Dip-Coating Technique: Their Functionality, Durability and Sustainability

The presented review summarizes recent studies in the field of electro conductive textiles as an essential part of lightweight and flexible textile-based electronics (so called e-textiles), with the main focus on a relatively simple and low-cost dip-coating technique that can easily be integrated into an existing textile finishing plant. Herein, numerous electro conductive compounds are discussed, including intrinsically conductive polymers, carbon-based materials, metal, and metal-based nanomaterials, as well as their combinations, with their advantages and drawbacks in contributing to the sectors of healthcare, military, security, fitness, entertainment, environmental, and fashion, for applications such as energy harvesting, energy storage, real-time health and human motion monitoring, personal thermal management, Electromagnetic Interference (EMI) shielding, wireless communication, light emitting, tracking, etc. The greatest challenge is related to the wash and wear durability of the conductive compounds and their unreduced performance during the textiles' lifetimes, which includes the action of water, high temperature, detergents, mechanical forces, repeated bending, rubbing, sweat, etc. Besides electrical conductivity, the applied compounds also influence the physical-mechanical, optical, morphological, and comfort properties of textiles, depending on the type and concentration of the compound, the number of applied layers, the process parameters, as well as additional protective coatings. Finally, the sustainability and end-of-life of e-textiles are critically discussed in terms of the circular economy and eco-design, since these aspects are mainly neglected, although e-textile' waste could become a huge problem in the future when their mass production starts.