Efficient Bleaching of Cotton With Hydrogen Peroxide Using a New [Mn₂O₃(tmtacn)]²⁺ Catalyst Reaction System

This study outlines fundamental aspects of the performance of [Mn2O3(tmtacn)]2+ catalyst (dinulclear μ-oxo bridged Mn(IV) complex of the ligand 1,4,7-trimethyl-1,4,7-triazacyclononane) as a process intensificator for bleaching of cotton with H2O2. This catalyst and related complexes have proven to be very active in the catalysed, and often selective, oxidation of organic substrates with H2O2 in non-aqueous systems [1a] and provide stain bleaching activity in detergent formulations under alkaline conditions [1b].Catalytic bleaching of cotton takes place in a heterogeneous aqueous reactio

Preface [to Advances in textile biotechnology]

This book is a follow-up to Advances in Textile Biotechnology (2010), first edition, and Textile Processing with Enzymes (2003). Advances in Textile Biotechnology, second edition, provide a thorough overview of recent developments and state of the art in enzyme technology for processing, modification, and functionalization of textiles, textile fibers, and polymers.(undefined)info:eu-repo/semantics/publishedVersio

Cellulose Nanofibril-Based Coatings of Woven Cotton Fabrics for Improved Inkjet Printing with a Potential in E‑Textile Manufacturing

The roughness of woven fabrics strongly limits print quality, which is particularly critical in printing of conductive circuits on fabrics. This work demonstrates the use of wood-derived cellulose nanofibrils (CNFs) mixed with a plasticizer as coatings of woven cotton fabrics for inkjet printing using (i) conventional water-based pigment inks and (ii) conductive silver nanoparticle inks. CNFs, being similar in nature to cotton, introduced minimal alteration to woven cotton fabrics by preserving their visual appearance as well as their mechanical properties. We also showed that the use of CNF-based coatings facilitated ink droplet settling on the substrate, which ensured high quality with the potential of higher printing speed production. The coatings of CNFs plasticized with glycerol enabled concentrating the pigment on the surface of the fabric, preventing its penetration into the fabric depth, which allows for increasing the resolution of the printed pattern. When used for color ink printing, it enhanced the print chroma and permitted reducing the amount of deposited ink, yielding similar color lightness. The CNF coatings allowed for substantial reduction of the amount of silver ink when printing the conductive tracks on fabrics. Furthermore, the nature of the coating imparts flexibility to the conductive layer, while maintaining electric signal quality, even when folded. This study provides a platform for manufacturing sustainable and disposable e-textiles

Cellulose Nanofibril-Based Coatings of Woven Cotton Fabrics for Improved Inkjet Printing with a Potential in E‑Textile Manufacturing

The roughness of woven fabrics strongly limits print quality, which is particularly critical in printing of conductive circuits on fabrics. This work demonstrates the use of wood-derived cellulose nanofibrils (CNFs) mixed with a plasticizer as coatings of woven cotton fabrics for inkjet printing using (i) conventional water-based pigment inks and (ii) conductive silver nanoparticle inks. CNFs, being similar in nature to cotton, introduced minimal alteration to woven cotton fabrics by preserving their visual appearance as well as their mechanical properties. We also showed that the use of CNF-based coatings facilitated ink droplet settling on the substrate, which ensured high quality with the potential of higher printing speed production. The coatings of CNFs plasticized with glycerol enabled concentrating the pigment on the surface of the fabric, preventing its penetration into the fabric depth, which allows for increasing the resolution of the printed pattern. When used for color ink printing, it enhanced the print chroma and permitted reducing the amount of deposited ink, yielding similar color lightness. The CNF coatings allowed for substantial reduction of the amount of silver ink when printing the conductive tracks on fabrics. Furthermore, the nature of the coating imparts flexibility to the conductive layer, while maintaining electric signal quality, even when folded. This study provides a platform for manufacturing sustainable and disposable e-textiles

XPS and contact angle study of cotton surface oxidation by catalytic bleaching

Surface chemistry and wetting properties of cotton fibres as affected by catalytic bleaching have been investigated. Two types of cotton fabric have been analysed: the regular and a model cotton fabric. In the regular – double scoured cotton fabric, cellulose was contaminated with both non-removable and removable impurities including different pigments. The model cotton fabric, previously freed of most removable impurities, was stained for the purpose of this study with one pigment only, i.e. morin, a component that is typically found in native cotton fibre. Bleaching effectiveness of the catalyst based bleaches has been compared to the non-catalyst based bleaching systems. Surface chemical changes of cotton have been identified by XPS. Contact angle and capillary constant of the cotton fabric have been measured applying the Washburn method. This approach has provided the tool to explore and to quantify the chemical and physical effects on cotton fibre after catalytic bleaching. The interrelationship between an increase in capillary constant and the removal of non-cellulosic impurities, characterised by the C1 component in C 1s XPS spectrum, has been elucidated

Inkjet printing and UV-LED curing of photochromic dyes for functional and smart textile applications

Health concerns as a result of harmful UV-rays drive the development of UV-sensors of different kinds. In this research, a UV-responsive smart textile is produced by inkjet printing and UV-LED curing of a specifically designed photochromic ink on PET fabric. This paper focuses on tuning and characterizing the colour performance of a photochromic dye embedded in a UV-curable ink resin. The influence of industrial fabrication parameters on the crosslinking density of the UV-resin and hence on the colour kinetics is investigated. A lower crosslinking density of the UV-resin increases the kinetic switching speed of the photochromic dye molecules upon isomerization. By introducing an extended kinetic model, which defines rate constants k(colouration), k(decay) and k(decolouration), the colour performance of photochromic textiles can be predicted. Fabrication parameters present a flexible and fast alternative to polymer conjugation to control kinetics of photochromic dyes in a resin. In particular, industrial fabrication parameters during printing and curing of the photochromic ink are used to set the colour yield, colouration/decolouration rates and the durability, which are important characteristics towards the development of a UV-sensor for smart textile applications

Comparison of the photochromic behaviour of dyes in solution and on polyester fabric applied by supercritical carbon dioxide

Photochromic textiles are of considerable interest for smart and functional textile applications due to their remarkable dynamic colour changing effect when irradiated with light of a certain wavelength. The use of resource efficient processes, such as digital inkjet printing and supercritical carbon dioxide (scCO2) dyeing techniques enables an economic production of those high-end functional products with high material costs. In this study, photochromic polyester fabric has been prepared by applying two commercially important photochromic dyes from spirooxazine (SO) and naphthopyran (NP) dye classes using scCO2-dyeing technique. The properties of scCO2 dyed photochromic fabrics were compared with the properties of the same dyes in a non-polar solvent, hexane. UV-Vis spectroscopy and a specially designed online colour measurement system capable of simultaneous UV irradiation and colour measurement were used to evaluate the photochromic colour behaviour. Both photochromic dye types embedded in textile as well as in solution showed significant reversible colour changing properties when exposed to UV light and revert to their original non-coloured form when the UV light is removed. The scCO2 dyed polyester fabrics exhibited similar trends of colour build-up as in solution, while contrasting behaviour was observed in terms of colour changing rates compared to their behaviour in solution.SMDTe