No abstract

No abstract

Application of enzymes in the textile industry is becoming increasingly popular because of mild processing conditions and the capability for replacing harsh organic/inorganic chemicals. The combination of ultrasound with conventional enzymatic treatment of cotton offers significant advantages such as less consumption of expensive enzymes, shorter processing time, less fiber damage, and better uniformity of enzymatic treatment. Our laboratory research has shown that introduction of ultrasonic energy during enzymatic treatment resulted in significant improvement in the performance of cellulase enzyme (CELLUSOFT L). It was established that ultrasound does not inactivate the complex structure of the enzyme molecules and weight loss of cotton fabric sonicated and treated with cellulase enzyme increased up to 25−35%. The experimental data indicate that the maximum benefit provided by sonification occurs at relatively low enzyme concentrations. Ultrasonic energy significantly intensified the enzymatic treatment of the cotton fabrics but did not contribute to a decrease in tensile strength of the cotton textiles.

In a series of experiments, untreated and ammonium hydroxide pretreated Klenow lowland variety switchgrasses are converted to reducing sugars using low-frequency (20 kHz) ultrasound and commercially available cellulase enzyme. Results from experiments using untreated and pretreated switchgrasses with and without ultrasound are presented and discussed. In untreated switchgrass experiments, the combination of ultrasound and enzymes resulted in an increase of 7.5% in reducing sugars compared to experiments using just enzymes. In experiments using ammonium hydroxide pretreated switchgrass, the combination of ultrasound and enzymes resulted in an increase of 9.3% in reducing sugars compared to experiments using just enzymes. Experimental evidence indicates that there is a synergistic effect from the combination of ultrasound and enzymes which lowers the diffusion-limiting barrier to enzyme/substrate binding and results in an increase in reaction rate. Scanning electron microscopic images provide evidence that ultrasound-induced pitting increases substrate surface area and affects reaction rate and yield.

A phosphorylated form of cotton gauze for treatment of chronic wounds was designed to improve the wound dressing's capacity to remove harmful proteases from the wound and facilitate healing. Development of the fabric finishing chemistry of the wound dressing with a process suitable for textile mill production required adapting the stationary finishing chemistry of the cotton phosphorylation from a batch-type pad-dry-cure finishing treatment to a continuous pilot scale finishing process. Issues in optimizing the cotton finishing process took into consideration dressing sterilization, the effect of city water versus de-ionized water, retention of the fabric whiteness index and protease sequestration capacity of the dressing, which is the index of the dressing's efficacy. Three types of sterilization approaches were assessed, including gamma ray, ethylene oxide and steam sterilization to determine the effect of sterilization on the phosphorylated cotton dressing and the subsequent efficacy of the sterilized dressing to remove proteases from the wound. Two phosphorylation reagents were compared for their ability to phosphorylate cotton in a urea-based formulation and yield an active, effective dressing, with a high whiteness index. Phosphorylation with a diammonium phosphate (DAP) : urea formulation generally gave a more effective dressing as an active protease sequestrant, and phosphorylation with sodium hexametaphosphate (SMP) : urea gave a higher whiteness index. Finishing formulations combining the Downloaded from two phosphorylating reagents, DAP and SMP : urea, were assessed to improve both whiteness and efficacy. However, sterilization of DAP treated cotton with ethylene oxide eradicated activity through apparent masking of the cellulose phosphate hydroxyls. Side reactions that may occur during ethylene oxide treatment were discussed as the possible origin of the phosphate hydroxyl masking. On the other hand, sterilization with gamma irradiation produced significant yellowing of the dressing. A SMP : urea (16 : 30) formulation was employed in the continuous process finishing treatment, and found to be most optimal for whiteness, efficacy and ease of sterilization, when adapted to industrial scale production of the cotton chronic wound dressing.