Development of inkjet printing ink based on component solubility parameters and its properties

Rheological Properties and Inkjet Printability of a Green Silver-Based Conductive Ink for Wearable Flexible Textile Antennas

The development of e-textiles necessitates the creation of highly conductive inks that are compatible with precise inkjet printing, which remains a key challenge. This work presents an innovative, syringe-based method to optimize a novel bio-sourced silver ink for inkjet printing on textiles. We investigate the relationships between inks' composition, rheological properties, and printing behavior, ultimately assessing the electrical performance of the fabricated circuits. Using Na-alginate and polyethylene glycol (PEG) as the suspension matrix, we demonstrate their viscosity depends on the component ratios. Rheological control of the silver nanoparticle-laden ink has become paramount for uniform printing on textiles. A specific formulation (3 wt.% AgNPs, 20 wt.% Na-alginate, 40 wt.% PEG, and 40 wt.% solvent) exhibits the optimal rheology, enabling the printing of 0.1 mm thick conductive lines with a low resistivity (8 × 10-3 Ω/cm). Our findings pave the way for designing eco-friendly ink formulations that are suitable for inkjet printing flexible antennas and other electronic circuits onto textiles, opening up exciting possibilities for the next generation of E-textiles.

Study on the quality and inkjet printing effect of the prepared washing-free disperse dye ink

With the rapid development of digital inkjet printing, it will inevitably lead to the uneven quality of inkjet printing ink products on the market. Therefore, making a more comprehensive and accurate quality evaluation of digital printing ink is particularly important. In this study, a short process and environment-friendly washing-free disperse dye ink was prepared based on the research on ink quality. The quality of printing ink is closely related to its physical properties, printing ink stability, inkjet performance, and inkjet printing effect. The microdistribution state of water for washing-free disperse dye ink was analyzed by LF-NMR, and the influence of the microstate of water on the macro physical properties of the ink was clarified. The physical properties (particle size, pH value, surface tension, viscosity, rheological properties, etc.) of the washing-free disperse dye ink were systematically tested and analyzed. At the same time, the stability (weatherability, the temperature sensitivity of viscosity, and shear stability) and inkjet performance (drive waveform A, B, and C) of washing-free disperse dye ink were systematically investigated. Finally, the inkjet printing effect of washing-free disperse dye ink was evaluated. This study systematically examined the quality and printing effect of the prepared washing-free disperse dye ink and provided quality evaluation reference for the development of high-quality washing-free disperse dye ink.

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.

Magnetic hydrogels with ordered structure for biomedical applications

Magnetic hydrogels composed of hydrogel matrices and magnetic nanomaterials have attracted widespread interests. Thereinto, magnetic hydrogels with ordered structure possessing enhanced functionalities and unique architectures, show tremendous advantages in biomedical fields. The ordered structure brought unique anisotropic properties and excellent physical properties. Furthermore, the anisotropic properties of magnetic ordered hydrogels are more analogous to biological tissues in morphology and mechanical property, showing better biocompatibility and bioinducibility. Thus, we aim to systematically describe the latest advances of magnetic hydrogels with ordered structure. Firstly, this review introduced the synthetic methods of magnetic hydrogels focus on constructing ordered structure. Then, their functionalities and biomedical applications are also summarized. Finally, the current challenges and a compelling perspective outlook of magnetic ordered hydrogel are present.

Inkjet-Printed Silver Nanowire Ink for Flexible Transparent Conductive Film Applications

The development of flexible transparent conductive electrodes has been considered as a key issue in realizing flexible functional electronics. Inkjet printing provides a new opportunity for the manufacture of FFE due to simple process, cost-effective, environmental friendliness, and digital method to circuit pattern. However, obtaining high concentration of inkjet- printed silver nanowires (AgNWs) conductive ink is a great challenge because the high aspect ratio of AgNWs makes it easy to block the jetting nozzle. This study provides an inkjet printing AgNWs conductive ink with low viscosity and high concentration of AgNWs and good printing applicability, especially without nozzle blockage after printing for more than 4 h. We discussed the effects of the components of the ink on surface tension, viscosity, contact angle as well as droplet spreading behavior. Under the optimized process and formulation of ink, flexible transparent conductive electrode with a sheet resistance of 32 Ω·sq⁻¹–291 nm·sq⁻¹ and a transmittancy at 550 nm of 72.5–86.3% is achieved. We investigated the relationship between the printing layer and the sheet resistance and the stability of the sheet resistance under a bending test as well as the infrared thermal response of the AgNWs–based flexible transparent conductive electrode. We successfully printed the coupling electrodes and demonstrated the excellent potential of inkjet-printed AgNWs—based flexible transparent conductive electrode for developing flexible functional electronics.

Inkjet Printing of Flexible Transparent Conductive Films with Silver Nanowires Ink

The inkjet printing process is a promising electronic printing technique for large-scale, printed, flexible and stretchable electronics because of features such as its high manufacturing speed, environmental friendliness, simple process, low cost, accurate positioning, and so on. As the base material of printed conductive patterns, conductive ink is the foundation of the development of printed electronics technology, and directly affects the performance and the quality of electronic products. In this paper, conductive ink with silver nanowires (AgNWs) was prepared, with AgNWs of lengths of 2–5 µm and diameters of 20 nm or so, isopropyl alcohol and ethylene glycol as the mixed solvents, and modified polysilane as the wetting agent. We discussed the relationship between the formula of the AgNWs ink and the surface tension, viscosity, contact angle between ink droplet and poly(ethylene) terephthalate (PET) surface, as well as the film-forming properties of the ink. Further, we analyzed the effects of the number of printed layers and the ink concentration of the AgNWs on the microstructures, photoelectric properties and accuracy of the printed patterns, as well as the change in the sheet resistance of the film during different bending cycles. The experimental results show that flexible transparent conductive patterns with a light transmittance of 550 nm of 83.1–88.4% and a sheet resistance of 34.0 Ω∙sq⁻¹–78.3 nm∙sq⁻¹ can be obtained by using AgNWs ink of 0.38 mg∙mL⁻¹ to 0.57 mg∙mL⁻¹, a poly (ethylene terephthalate) (PET) substrate temperature of 40 °C, a nozzle temperature of 35 °C, and heat treated at 60 °C for 10 min. These performances indicate the excellent potential of the inkjet printing of AgNWs networks for developing flexible transparent conductive film.

Abdel Mageid R, Radwan EK, Khattab TA, Olson MA, El Malah T. Adsorption isotherms and kinetic studies for the removal of toxic reactive dyestuffs from contaminated water using a viologen-based covalent polymer

A polyviologen-based adsorbent was prepared via polymerization of a viologen-dialdehyde with a hydroxyl-substituted aryl-dihydrazide in acidified water.