Impact of Drying Regimes and Different Coating Layers on Carboxymethyl Cellulose Cross-Linked with Citric Acid on Cotton Thread Fibers for Wound Dressing Modification

Preparation of Ceramic Fiber Threads with Enhanced Abrasion Resistance Performance

Ceramic fiber thread is one of the key components in flexible external thermal insulation blankets, and it has been applied in various fields as a flexible ceramic fibrous material with excellent deformability and high-temperature resistance. However, ceramic fiber threads are often subjected to reciprocating friction motion at specific bending angles, making them highly susceptible to abrade and fracture. Enhancing the abrasion resistance performance of ceramic fiber threads under bending conditions is the future trend and remains a significant challenge. Hence, we design and construct a novel polyurethane-modified coating on the ceramic fiber threads to improve their abrasion resistance performance. The effects of the types and concentrations of modifiers on the microstructure, abrasion resistance property, and tensile property of ceramic fiber threads are systematically investigated. The ceramic fiber threads, after modification with hexamethylene diisocyanate waterborne polyurethane (HDI-WPU) with a concentration of 3%, exhibit excellent abrasion resistance properties. The number of friction cycles at fracture of the modified ceramic fiber thread is more than three times, and the tensile strength is more than one and a half times, that of the original ceramic fiber thread, demonstrating the great potential of the HDI-WPU modifier for enhancing the abrasion resistance performance of ceramic fiber threads.

Crosslinked carboxymethyl cellulose colloidal solution for cotton thread coating in wound dressing: A rheological study

Cotton thread therapeutic properties as a wound dressing can be enhanced by utilising carboxymethyl cellulose-nanoparticles (CMC/NPs) colloidal solution as a coating solution. Nanoparticles such as graphene oxide (GO), graphene quantum dots (GQD), and silver nanoparticles (AgNP) stability in CMC was investigated through the rheological analysis and UV-Vis spectroscopy of the colloidal solutions. Citric acid (CA) acted as a crosslinker and was utilised to crosslink the colloidal solution with cotton thread. These CMC/NPs coated threads were subjected to mechanical properties and antibacterial activity analysis. Results obtained indicate less nanoparticle agglomeration and were stable in the CMC-based nanofluid. CMC/NPs rheological study suggested that colloidal solutions exhibited shear thinning behaviour and behaved as non-Newtonian fluids with n < 1. Crosslinked CMC/NPs appeared in a gel-like state as the viscoelasticity of the solution increased. Among the colloidal solutions, CMC/AgNP showed the highest enhancement with a significant difference at p < 0.05 in terms of mechanical and antibacterial properties. Consequently, the rheological properties and stability of CMC/NPs might influence the coating solution's appearance and refine the cotton thread's microstructure for a functional wound dressing to be further utilised as a coating solution for antibacterial cotton thread wound dressing material.

Macro-Size Regenerated Cellulose Fibre Embedded with Graphene Oxide with Antibacterial Properties

Macro-size regenerated cellulose fibres (RCFs) with embedded graphene oxide (GO) were fabricated by dissolving cellulose in a pre-cooled sodium hydroxide (NaOH)/urea solution and regenerated in sulphuric acid (H₂SO₄) coagulant. Initially, GO was found to disperse well in the cellulose solution due to intercalation with the cellulose; however, this cellulose-GO intercalation was disturbed during the regeneration process, causing agglomeration of GO in the RCF mixture. Agglomerated GO was confirmed at a higher GO content under a Dino-Lite microscope. The crystallinity index (CrI) and thermal properties of the RCFs increased with increasing GO loadings, up to 2 wt.%, and reduced thereafter. Cellulose-GO intercalation was observed at lower GO concentrations, which enhanced the crystallinity and thermal properties of the RCF-GO composite. It was shown that the GO exhibited antibacterial properties in the RCF-GO composite, with the highest bacterial inhibition against E. coli and S. aureus.

Special Issue "Mechanical Performance of Sustainable Bio-Based Compounds"

The global production of plastic is increasing, and plastic represents one of the most popular materials, widespread in countless applications in commercial and industrial fields and everyday life [...].