Photocatalytic discoloration of denim using advanced oxidation process with H2O2/UV

Preparation of Filter Paper from Bamboo and Investigating the Effect of Additives

As air pollution escalates, the need for air filters increases. It is better that the filters used be based on natural fibers, such as non-wood fibers, which cause low damage to the environment. However, the short fiber lengths, low apparent densities, and high volumes of non-wood materials can make it challenging to prepare filter paper with the required mechanical and physical properties. In that context, this study focused on utilizing bamboo fibers to fabricate filter paper by employing the anthraquinone soda pulping method. The pulp underwent bleaching and oxidation processes, with the incorporation of cationic starch (CS) and polyvinyl alcohol (PVA) to enhance resistance properties, resulting in the creation of handmade filter papers. The findings revealed that the tear, burst, and tensile strength of filter paper increased with the oxidation and addition of CS and PVA. Air permeability increased with addition of PVA and combination of CS and PVA. FTIR demonstrated the conversion of hydroxyl groups in cellulose chains to carboxyl groups due to oxidation. SEM images illustrated alterations in the fiber structure post-oxidation treatment, with CS reducing pores while PVA and the CS-PVA combination enlarged pore size and enhanced porosity. The BET surface area surface area expanded with oxidation and the addition of the CS-PVA blend, indicating heightened filter paper porosity. Notably, the combined inclusion of CS and PVA not only augmented mechanical strength but also increased porosity while maintaining pore size.

Critical Review on Sustainability in Denim: A Step toward Sustainable Production and Consumption of Denim

The exponential development in knowledge on the health and environmental concerns linked to conventional denim processing is directly responsible for the continuous increase in demand for the exploitation of sustainable denim. Research is essential to explore alternative methods to reduce the environmental impact caused by these industries. This review examines the many sustainable ways to produce denim, keeping in mind the problems that the denim industry is now facing in finding alternatives to conventional manufacturing practices. The most current advancements in environmentally friendly dyeing techniques for denim have been extensively discussed. These processes include the production of indigo from bacteria as well as different dyeing processes, such as digital spray, microbially assisted dyeing, and foam dyeing denim with indigo. In addition, this review covers the many environmentally friendly finishing methods for denim garments, such as ozone fading, e-flow, enzyme-based bleaching, water, laser fading, and so on. Finally, it is described how the chemical and mechanical processes used to finish denim might affect the amount of microplastics and microfibers released from the denim garment during domestic washing. As a result, the content presented in this review aims to address the importance of sustainable denim processing, that is, something that can be rethought, reevaluated, renewed, and restructured within the scope of conventional denim processes, while taking eco-responsible solutions for increased environmental sustainability into account.

New Laccase-Mediated System Utilized for Bio-Discoloration of Indigo-Dyed Denim Fabrics

In this study, indigo-dyed denim fabric was decolorized via separate and simultaneous applying of laccase, sodium hydrosulfite, and cellulase. In this regard, the surface reflectance and color coordinates of the discolored fabrics were evaluated and scanning electron microscopy (SEM) images of the cellulase treated fabric were prepared to analyze their surfaces. Finally, the characterization of the treated samples was investigated, including moisture content, crease recovery angle, air permeability, and abrasion resistance. The color experiments showed that simultaneous applying of laccase, sodium hydrosulfite, and cellulose had a 55.79% improvement in the samples' lightness (L*). Furthermore, the color coordinate test of specimens revealed that the hue of the treated samples was changed to blue and green, and the purity of color (C*) was modified. The increment in the moisture content and air permeability of the treated specimens indicated that the comfort of the jeans clothing had been enhanced. As a result, sodium hydrosulfite demonstrates a high-efficiency denim discoloration in the laccase-mediated system.

A Computer Color-Matching Study of Reverse Micellar Dyeing of Wool with Reactive Dyes

Computer color-matching (CCM) and the levelness of poly(ethylene glycol)-based reverse-micellar dyed wool fabrics in octane and nonane were investigated and compared with a conventional water-based dyeing system. Reflectance curves and calibration curves exhibited no chromatic change and maintained high linearity in both dyeing systems. The linearity of water-dyed calibration curves was slightly higher than that of the reverse-micellar dyed curves. The color yield, in term of K/Ssum values, of solvent-dyed samples was found to be generally higher than that of water-based dyed samples at various calibrated dye concentrations. The concentrations predicted by CCM were close to the theoretical concentrations for both dyeing methods. This indicates that octane- and nonane-assisted reverse-micellar dyeing of wool is able to generate color recipes comparable to the conventional water-based dyeing system. The solvent-dyed samples, measured by the relative unlevelness indices (RUI), exhibit good-to-excellent levelness, which is highly comparable with the water-dyed samples.