Enhancing inkjet image quality through controlling the interaction of complex dye and diol molecules

Fabrication of conductive Ag/AgCl/Ag nanorods ink on Laser-induced graphene electrodes on flexible substrates for non-enzymatic glucose detection

An unusual strategy was designed to fabricate conductive patterns for flexible surfaces, which were utilized for non-enzymatic amperometric glucose sensors. The Ag/AgCl/Ag quasi-reference ink formulation utilized two reducing agents, NaBH[Formula: see text] and ethylene glycol. The parameters of the ink, such as sintering time and temperature, NaBH[Formula: see text] concentration, and layer number of coatings on flexible laser-induced graphene (LIG) electrodes were investigated. The conductive Ag/AgCl/Ag ink was characterized using electrochemical and surface analysis techniques. The electrocatalytic activity of Ag/AgCl/Ag NRs can be attributed to their high surface area, which offer numerous active sites for catalytic reactions. The selectivity and sensitivity of the electrodes for glucose detection were investigated. The XRD analysis showed (200) oriented AgCl on covered Ag NRs, and with the addition of NaBH[Formula: see text], the intensity of the peaks of the Ag NRs increased. The wide linear range of non-enzymatic sensors was attained from 0.003 to 0.18 mM and 0.37 to 5.0 mM, with a low limit of detection of 10 [Formula: see text]M and 20 [Formula: see text]M, respectively.The linear range of enzymatic sensor in real sample was determined from 0.040 to 0.097 mM with a detection limit of 50 [Formula: see text]M. Furthermore, results of the interference studies demonstrated excellent selectivity of the Ag/AgCl/Ag NRs/LIG electrode. The Ag/AgCl/Ag NRs on the flexible LIG electrode exhibited excellent sensitivity,long-time stablity,and reproducibility. The efficient electroactivity were deemed suitable for various electrochemical applications and biosensors.

Performance of Washing-Free Printing of Disperse Dye Inks: Influence of Water-Borne Polymers

Dye-containing wastewater discharge from the textile industry poses a serious pollution hazard that can be overcome by eliminating the washing step following the dyeing process. To study the washing-free printing of disperse dye ink, a number of water-borne polymers were selected and added to the ink, and the properties of the inks were discussed. By optimizing the ink formulation, printed fabrics with high color strength and color fastness were produced. The effects of the addition of polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), and polyethylene glycol (PEG) on the ink jetting performance and printing performance were intensively investigated. The migration–diffusion–fixation behavior of disperse dyes in inks on the polyester fiber was explored. The disperse dye ink with 0.075 wt.% PVA exhibited the strongest migration–diffusion effect. The PVA ink exhibited excellent jetting performance and printing color fastness, and the printing color strength was better than that of the PVP and PEG ink. The addition of PVA increased the difference between the solubility parameter of the disperse dyes and ink system, which improved the migration of disperse dyes from the ink system to the polyester fabric. Meanwhile, PVA could form a protective layer on printed fabrics because of its excellent film-forming properties at room temperature. The washing-free inkjet printing method developed in this study provides a theoretical basis for screening water-borne polymers and an environmentally friendly pathway for the printing of textiles.

Insights into coloration enhancement of mercerized cotton fabric on reactive dye digital inkjet printing

Mercerization can improve the utilization rate of dyes in the dyeing process, and reduce the discharge of washing wastewater. However, the effect and mechanism of mercerization is not clear on digital inkjet printing of cotton fabric. In this work, two kinds of cotton fabrics (original and mercerized) were used for reactive dye digital inkjet printing, and the color improvement mechanism of caustic soda mercerization was investigated. It was found that the crystallinity of cotton fibre was adjusted from 73.9% to 58.5% by caustic mercerization, and the breaking strength did not decrease compared with original cotton fibre. Thus, the accessible reactive hydroxyl groups and the wettability were enhanced for treated cotton fibres, which promoted the inks' wick into the fibres. Interestingly, the penetration of ink droplets between the yarns and fibres after caustic mercerization was decreased, thus the dyes mainly gathered on the surface of cotton fabric. The cotton fibres' cross section structure changed from flat oval to round, which increased the contact area between reactive dyes and fibres. At a certain amount of ink, the optimal K/S value of 23.47 was achieved for treated cotton fabrics, which was higher than that of untreated cotton fabrics (17.15). Meanwhile, the printed fabrics displayed good washing fastness, rubbing fastness and glossiness. This work has important theoretical guiding significance for producing high quality mercerized cotton fabric digital printing products and reducing printing wastewater discharge.

Mercerization can control the crystallinity of cotton fiber, promote the absorption of ink droplets' wick into the fiber and inhibit ink droplets from penetrating the back of fabric. Therefore, the printing quality was extremely enhanced.

Effects of alkanolamine solvents on the aggregation states of reactive dyes in concentrated solutions and the properties of the solutions

The aggregation of dyes is a common phenomenon in solutions, particularly concentrated solutions, which seriously affects the dyeing and printing processes. In this study, the effects of alkylamine solvents on the reactive dye aggregation behavior in highly concentrated solutions was studied. Typical cases were conducted with two slightly toxic and environmentally friendly solvents, namely diethanolamine (DEA) and triethanolamine (TEA), and two reactive dyes, namely C. I. Reactive Red 218 (R-218) and C. I. Reactive Orange 13 (O-13). Aggregation states were studied by ultraviolet-visible (UV-Vis) absorption spectroscopy, Gaussian-peak-fitting method and fluorescence spectroscopy. The results showed that both the additives DEA and TEA could reduce the dye aggregation because the solvents, DEA and TEA, can break the iceberg structure and allow easy entry of the molecules into the dye aggregates. Also, the disaggregation caused by DEA was higher as compared with TEA, which may be caused by the weaker hydrogen bond and the relatively smaller steric hindrance effects of DEA. The schematic of disaggregation between R-218 and DEA was also discussed. For R-218, the dimers were disaggregated to monomer, while the higher-ordered aggregates were disaggregated to trimers and dimers for O-13. Moreover, physical properties such as viscosity and surface tension of the solutions were measured. This investigation is instructive for the further dyeing progress with organic bases in the textile industries.

Effect of Diethylene Glycol on the Inkjet Printability of Reactive Dye Solution for Cotton Fabrics

Digital inkjet printing technology plays an increasingly important role in textile printing. The printing printability of reactive dye inks is the key to improving the quality of printed fabrics. In this study, an eco-friendly and simple method to improve the inkjet printability of reactive dye solutions was proposed. The influence of diethylene glycol on the surface tension, rheology, and dye molecule aggregation properties for three reactive dye solutions was investigated. The jetting performance of dye solutions was explored by observing droplet formation. Moreover, the color performance of printed cotton fabrics, including reactive dye solution penetration, colorimetric values, and color strength, was evaluated. Addition of diethylene glycol could change the aggregation of dye molecules by hydrophobic forces and hydrogen bonds. Diethylene glycol could inhibit formation of satellite droplets by changing the viscosity and surface tension of solutions, which made the pattern printed on cotton fabrics show regular edge sharpness. Furthermore, the dye solutions containing 10% DEG not only satisfied various properties of reactive dye inks but also had the highest color strength and the deepest and brightest colors.

Effect of ethylene glycol and its derivatives on the aggregation properties of reactive Orange 13 dye aqueous solution

The aggregation behavior of dyes especially in the dyeing and printing of different textile materials is an important phenomenon which affects the process of dye adsorption and diffusion. In order to avoid the aggregation of dyes, scientists are looking for materials which can inhibit the aggregation process by fabricating the dye solution. Organic solvents have found important influence in the aggregation of dye molecules. Therefore, herein, we report the fabrication of reactive orange 13 dye solutions with the aid of ethylene glycol and its derivative organic solvents to investigate the aggregation behavior of dye molecules by UV-vis absorption spectrum, fluorescence spectrum, surface tension, rheological and particle size measurements. IR spectra were performed to understand the effect of hydrogen bonding on the aggregation behavior of dye molecules. Moreover, transmission electron microscopy was also tested to confirm the effect of organic solvents on the surface morphology of dye molecules. The results show that the reactive Orange 13 dye molecules show aggregation in terms of dimeric and multimeric structures at high dye concentrations due to π–π interaction of naphthalene rings. Moreover, on introducing the ethylene glycol and its derivatives, the dye molecules disaggregate by hydrophobic interactions of dye molecules and organic solvents which destroyed the ice-like structure between the dye molecules and the water molecules. Among the three organic solvents, DME solvent caused more disaggregation of reactive Orange 13 dye molecules due to extra hydrophobic methyl groups in its structure. The results also show that the interaction between Orange 13 dyes and ethylene glycol and its derivatives could decrease the surface tension and particle size of the dye, and increase the quantum yield and viscosity. This research will help to understand the aggregation behavior of dyes and help the textile industries to choose the suitable formulations of dye solutions for coloration of different textile substrates via dyeing and printing methods.

The interaction between Orange 13 dye and ethylene glycol and its derivatives was determined by the dispersion force.

Effects of Viscosity and Surface Tension of a Reactive Dye Ink on Droplet Formation

In textile inkjet printing, understanding the effect of viscosity and surface tension of a reactive dye ink on droplet formation is of great significance. As an organic ecofriendly solvent, polyethylene glycol with a molecular weight of -400 g/mol (PEG400) was used to prepare reactive dye inks with or without Surfynol 465 (S465) to explain separately how viscosity and surface tension affect the droplet formation of a reactive dye ink. The intermolecular interactions in the ink and physical properties of the ink were investigated by measuring the visible absorption spectra, hydrodynamic radius, viscosity, and surface tension. Droplet formation under a single variable influence of viscosity or surface tension was observed by taking photographs using a high-speed camera. Results show that a high ink viscosity condition generates no satellite droplet formation and a slower droplet velocity, and a higher surface tension tends to cause ligament rupture from the nozzle tip and the droplet. Moreover, a twill cotton fabric printed using the PEG-S465-dye ink at a 30% PEG400 concentration showed higher ink penetration, dye fixation rate, ideal color strength, and rubbing fastness.