Surface functionalization of wool via microbial-transglutaminase and bentonite as bio-nano-mordant to achieve multi objective wool and improve dyeability with madder.

Recently, natural dyes have a widening scope in various traditional and advanced applications due to their eco-friendly environment. However, improved dyeability of natural dyes still remains a challenging task. This research was aimed to achieve multi-objective wool with improved dyeability using bio-nano-mordant composed of m-Trans-glutaminase, m-TGase, and bentonite nanoclay. Wool fiber was treated through sonochemical method using different concentrations of m-TGase and bentonite. The surface morphology of wool fabric samples was examined by field emission-scanning electron microscopy (FESEM), and Fourier transform Infrared Radiation (FTIR). Further, wool samples treated at different conditions were applied to madder for dyeability examination. The optimum conditions of color coordinates, color strength, K/S, and washing fastness of madder on treated wool fabric with m-TGase and bentonite, were also examined. The results revealed well-made interactions among m-TGase, bentonite, and wool fibers. In addition, surface morphology was strongly influenced by variations in enzyme concentrations so that extra addition of m-TGase lead to clear damage scales or less cuticle surface in SEM images. Moreover, the results showed that the value of K/S for treated wool samples was better than untreated samples. Indeed, amongst all, 5% concentrations of bio-nano-mordant for m-TGase and bentonite have the most constructive K/S values. Similarly, results of ΔE and antibacterial investigations also confirmed its superiority.

Exhaust reactive dyeing of lyocell fabric with ultrasonic energy.

Successful dyeing of lyocell, a biodegradable regenerated cellulose fiber, in fabric form is a challenging job. This article reports the successful reactive dyeing of lyocell fabrics with assistance of ultrasonic (US) energy via exhaust process, and compares the results with conventional (CN) exhaust dyeing process. Two commercial reactive dyes CI Reactive Red 195 and CI Reactive Blue 250 were used. Factors affecting dyeing such as fixation time, temperature and dyeing auxiliaries were compared for both processes. Under identical dyeing conditions, US dyed samples offered significantly much higher dyeing performance (i.e. color yield (>40%), dye fixation (>17%)) compared to CN process. Additionally, US exhaust process resulted in significant savings in terms of thermal energy (10 °C), capital (20 g/L NaCl and 2 g/L Na2CO3), and offered 33% higher production rate with yet improved dyeing performance (color yield up to ~7%, dye fixation up to ~5%) when compared under recommended conditions for two processes. Moreover, US dyeing poses considerably lower pollution (chemical oxygen demand 15-18% and total dissolved solids 32-36%) to the effluent in comparison to CN exhaust dyeing process. Furthermore, nearly identical colorfastness results and fiber surface morphology endorse use of US energy as a better, cost effective and relatively environment friendly technique for successful reactive dyeing of lyocell.

A Novel In Situ Self-Assembling Fabrication Method for Bacterial Cellulose-Electrospun Nanofiber Hybrid Structures.

Self-assembling fabrication methodology has recently attracted attention for the production of bio-degradable polymer nanocomposites. In this research work, bacterial cellulose/electrospun nanofiber hybrid mats (BC/CA-ENM) were formed by incorporating cellulose acetate electrospun nanofiber membranes (CA-ENMs) in the fermentation media, followed by in situ self-assembly of bacterial cellulose (BC) nanofibers. ENMs exhibit excessive hydrophobicity, attributed to their high crystallinity and reorientation of hydrophobic groups at the air/solid interfaces. We aimed to improve the hydrophilic and other functional properties of ENMs. As-prepared nanohybrid structures were characterized using SEM and FTIR. SEM results revealed that in situ self-assembling of BC nanofibers onto the electrospun membrane's surface and penetration into pores gradually increased with extended fermentation periods. The surface hydrophilicity and water absorption capacity of as-prepared hybrid mats was also tested and analyzed. Hybrid mats were observably more hydrophilic than an electrospun membrane and more hydrophobic compared to BC films. In addition, the incorporation of CA electrospun membranes in the culture media as a foundation for BC nanofiber growth resulted in improved tensile strength of the hybrid nanocomposites compared to ENMs. Overall, the results indicated the successful fabrication of nanocomposites through a novel approach, with samples demonstrating improved functional properties.