The cationic modification technology for cotton could greatly enhance colour strength and fixation of reactive dyes. However, it is a two‐step method when cationic modification is applied to salt‐free dyeing. Cotton fabric is initially treated with a cationic compound through exhaust or pad‐cure, acid washing and drying process, then the cationic modified cotton is dyed with reactive dye. In this study, a single‐step pad‐steam cationisation and dyeing process was proposed to shorten the process and improve dye fixation. The fixation reaction between reactive dye and cotton fabrics was conducted at the temperature range 100–140°C and relative humidity range 40–90%. The effects of quaternary ammonium salt and inorganic salt as well as alkaline agent on K/S value and dye fixation were also studied. Furthermore, the drying kinetic of the wet cotton fabric was studied in this article. The result showed that the drying process fitted well to the Page model. The effective moisture diffusivity of wet cotton under different steaming conditions were calculated. An activation energy value of 32.25 kJ/mol was determined. Compared with the conventional process, a single‐step pad‐steam cationisation and dyeing process not only shortened the process but also increased K/S value and dye fixation.

In our work, an urea-free dye fixation process was developed to eliminate the use of urea and improve dye fixation of reactive dye so that decreased the environmental influence of...

Cationic modification of cotton fabric was an effective way to improve the inkjet printing performance with reactive dye ink. However, there were few research studies that focused on the effect of the cationic agent structure, especially the alkyl chain length of the quaternary ammonium salt (QAS) cationic modifier, on the K/S value, dye fixation, and diffusion of inkjet-printed cotton fabric. In our work, different alkyl chain lengths of QAS were synthesized, and the inkjet printing performance of cationic cotton fabrics treated with different QASs was investigated. Compared with untreated cotton fabric, the K/S value and dye fixation of cationic cotton fabric treated with different QASs improved by 10.7 to 69.3% and 16.9 to 27.7%, respectively. With the increase in alkyl chain length of QAS, the interaction force between anionic reactive dyes and cationic QAS gradually increased mainly due to the fact that more N-positive ions on the quaternary ammonium group were exposed under the action of steric hindrance of alkyl chain length through the XPS spectrum. The electrostatic attraction between cationic cotton and reactive dye contributed to the diffusion of reactive dye into the fiber interior and enhanced the reaction probability of nucleophilic substitution reaction between monochlorotriazine reactive dye and the hydroxyl group of cotton fabric. The antibacterial result of the inkjet-printed cotton fabric indicated that when the alkyl chain length of QAS was higher than 8, the cationic cotton fabric obtained good antibacterial property.

To improve inkjet printing performance, surface single encapsulation of nano-TiO2 particles has widely been reported. However, surface single encapsulation has a limited effect on improving the inkjet printing performance of nano-TiO2 particles. In this study, SiO2 nanoparticle-decorated TiO2 (SiO2/TiO2) nanocomposites modified with silane coupling agents were obtained by a two-step method to improve the inkjet printing performance. The effects of different Na2SiO3 concentrations on the morphology, particle size, and opacity performance of SiO2/TiO2 nanocomposites were studied. The results showed that when the molar ratio of Na2SiO3 to TiO2 was 0.06:1, SiO2/TiO2 nanocomposites showed the best dispersibility and the best opacity performance. Then, the effect of different silane coupling agents on the properties of curing films was investigated. The results showed that the properties (opacity performance, tensile properties, thermal stability, and color fastness) of the KH570-SiO2/TiO2 nanocomposite curing film were greatly improved. The characteristic peaks in the Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed that SiO2 nanoparticles were anchored at the nano-TiO2 particle surface via Si–O–Ti bonds, and silane coupling agents were successfully grafted onto the SiO2/TiO2 nanocomposite surface via Si–O–Si/Si–O–Ti bonds. In addition, it was verified that the double bonds of KH570-SiO2/TiO2 nanocomposites participated in the photopolymerization of oligomers/monomers by FTIR.

The grafted modification TiO 2 @SiO 2 composite was fabricated by a liquidphase deposition method with Na 2 SiO 3 and a grafting reaction with a silane coupling agent. First, the TiO 2 @SiO 2 composite was prepared, and the effect of deposition rate and silica content on the morphology, particle size, dispersibility, and pigmentary property of TiO 2 @SiO 2 composites was investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and ζ-potential. The islandlike TiO 2 @SiO 2 composite had a good particle size and printing performance compared with the dense TiO 2 @SiO 2 composite. The presence of Si was confirmed by EDX elemental analysis and XPS, and a peak at 980 cm −1 belonging to Si−O was observed in the FTIR spectrum, confirming the presence of SiO 2 anchored at TiO 2 surfaces via Si−O−Ti bonds. Then, the islandlike TiO 2 @SiO 2 composite was modified by grafting with a silane coupling agent. The effect of the silane coupling agent on the hydrophobicity and dispersibility was investigated. The peaks at 2919 and 2846 cm −1 belong to CH 2 in the FTIR spectrum, and Si−C in the XPS confirmed the grafting of silane coupling agent to the TiO 2 @SiO 2 composite. The grafted modification of the islandlike TiO 2 @SiO 2 composite using 3-triethoxysilylpropylamine endowed it with weather durability, dispersibility, and good printing performance.