Effect of calcium carbonate particle size and content on the thermal properties of PVC foamed layer used for coated textiles.

The goal of this research is to see how the amount and particle size of calcium carbonate (CaCO3) used in the foamed layer in use for PVC-coated textiles affects the thermal properties of the material. Two different particle sizes were used at various concentrations. The impact of different CaCO3 loadings and particle sizes on the PVC foamed layer's thermal properties were examined. Thermogravimetry (TGA and DTG) and differential scanning calorimetry (DSC) measurements were utilized to investigate the thermal properties of the PVC foamed layer and the samples have been also characterized by FTIR spectroscopy. According to the findings, the thermal stability of the foamed layer was improved with the addition of calcium carbonate. Through the higher surface area between the filler and the PVC matrix, smaller particle sizes have produced the best results. The PVC foamed layer shows also changes in FTIR spectra after adding CaCO3, and the intensity of peaks increases with decreasing CaCO3 particle size.

Polydopamine-modified interface improves the immobilization of natural bioactive-dye onto textile and enhances antifungal activity.

Dermatomycosis, such as candidiasis and mycosis among others, has emerged recently as the most frequent fungal infection worldwide. This disease is due to the skin's exposure to microorganisms that are able to pass through skin barrier defects. Therefore, textiles in direct contact with skin can serve as a source of contamination and fungus spread. In the current study, a sustainable and eco-friendly method for antifungal cotton finishing using Curcuma longa L extracted from rhizomes was investigated. To enhance the natural bioactive dye uptake and attachment, cellulosic cotton fibers were chemically modified using dopamine, a biocompatible molecule, leading to the deposition of a hydrophilic layer of polydopamine. The efficiency of the polydopamine coating on the cotton surface has been assessed by x-ray photoemission spectroscopy analyses, with the detection of nitrogen, and by water contact angle for the wettability enhancement. Furthermore, characterization of the modified samples confirms that the modification did not affect either the cellulosic fiber morphology or the mechanical properties. The dyeability and bioactive dye immobilization were then assessed by colorimetry. Finally, the effectiveness of the finished fabrics against Trichophyton (rubrum/mentagrophytes) and Candida albicans strains was evaluated and was shown to induce growth inhibition mainly on Candida albicans strains.

Development and characterization of antibacterial braided polyamide suture coated with chitosan-citric acid biopolymer.

Braided polyamide sutures are frequently used in dermatologic surgery for wound closure. However, braided sutures promote bacteria proliferation. In order to prevent wound complications due to this effect, antibacterial sutures should be used. The main objective of this study is the development of new non-absorbable antibacterial polyamide braided suture. This paper suggests new coating process that leads to obtain suture uniformly covered by antibacterial film enclosing chitosan, which is known for its antibacterial benefit. Mechanical properties and surface morphology of developed sutures were investigated by using mechanical tests. Sutures surfaces were also examined by scanning electron microscope, to perceive spreading of coating product on suture surface. In order to identify potential reactions between chemical compounds present in coating solution and suture material, sutures were analyzed by ATR-IF spectroscopy. It has been demonstrated that many eventual bonds between compounds present in coating solutions and polyamide macromolecular chain may occur. The existence of these bonds implies the fixation of biopolymer coating on suture surface. It has been demonstrated that uniform surface may be obtained by progressively applying coating solution containing little amount of chitosan on suture surface. We have also found that developed coating process has not affected mechanical properties of suture, which still meet United States Pharmacopeia requirement. Finally, antibacterial effects against four colonies, very widespread in hospitals, were studied. Prominent antibacterial effects of braided polyamide suture against two gram-positive ( S Aureus, S epidermidis) and two gram-negative ( E coli and P aeruginosa) colonies are presented. Optimal result of best properties is obtained by applying three layers of biopolymer coating comprising 1% chitosan and 10% citric acid. The new developed suture coating process appears as a promising method for obtaining important antibacterial effect with smooth suture surface.

Enhancing the functionality of cotton fabric by physical and chemical pre-treatments: A comparative study.

Recently, antimicrobial and decontaminating textiles, such as cotton a natural carbohydrate polymer, are generating more attention. Plant materials used for natural dyes are expected to impart biofunctional properties and high added valued functional textiles. In the current study, surface modification of cotton to maximize the dye amount on the surface has been investigated. Physical modification using nitrogen-hydrogen plasma, chemical modification using chitosan and chemical modification using dopamine as biopolymers imparting amino groups were explored. Furthermore, dye exhaustion of curcumin, as a natural functional dye has been studied. Dye stability tests were also performed after fabric washing using hospital washing protocol to predict the durability of the functionalizations. The results demonstrated that cotton surfaces treated with dopamine exhibit a high level of dye uptake (78%) and a good washing fastness. The use of non-toxic and natural additives during cotton finishing process could give the opportunity of cradle to cradle design for antimicrobial textile industries.