Thiol–ene click reaction was employed to synthesize a flexible hydrophilic cellulose sponge. The reactive vinyl group was introduced by silanization treatment with vinyl-trimethoxysilicane (VTMO), and the resulting silylated cellulose sponge (SCS) can be subsequently functionalized with various thiol-containing compounds such as 3-mercaptopropionic acid, via temperature induced thiol–ene reactions. The hydrophilic cellulose sponge thus prepared displayed an excellent mechanical strength of 70 KPa at 80% compression strain. The prepared sponge features hydrophilic and underwater oleophobic properties and was used in gravity-driven removal of oil from oil-in-water emulsions and oil/water mixtures with a high separation efficiency. The separation efficiency remained 100% after 10 cycles for an oil/water mixture and 95% after 6 cycles for an oil-in-water emulsion.
26 November 2019 in Journal of Materials Chemistry C
Textile-based electronics hold great promise as they can endow wearable devices with soft and comfortable characteristics. In this work, a multifunctional conductive yarn was fabricated by coating a commercial regenerated cellulose (lyocell) yarn with polypyrrole (PPy). The method is simple, low-cost, and highly scalable and it endows the common lyocell yarn with flame-retardant as well as good electrical heating properties and excellent electrochemical performance. The PPy-coated lyocell yarn (PCLY) behaved as a regular yarn and could be hand-knitted into a full fabric. The PCLY fabric demonstrated high conductivity, allowing its use as a wearable Joule heater. The polypyrrole coating significantly improved the limiting oxygen index (LOI) of the lyocell yarn from 21.7% to 40.2%, endowing the yarn with an excellent flame-retardant property. PCLY was stitched into a fabric to form interdigitated electrodes and further assembled into flexible textile micro-supercapacitors. The resulting device with 10 interdigitated electrodes exhibited high areal specific capacitance of 663 mF cm−2 and energy density of 21.6 μW h cm−2 at 1 mA cm−2. Furthermore, six devices in series could power a blue light-emitting-diode (LED) of 3 V for more than 30 seconds. This facile fabrication provides novel and practical insights toward wearable textile-based electronics.
A novel low add-on dyeing process of cotton fabric with C.I. Reactive Black 5 has been implemented successfully with the assistance of dye-jet ejector units to produce precise wet pick-up ranging from 20% to 50%. The steaming process of the low add-on technology was investigated through evaluating the effects of relative humidity, steaming temperature, steaming time and water ratio on the surface temperature of the wet fabric and their influence on the dye properties, as well as the effect of the wet pick-up on dye properties. The optimal dyeing process was also conducted, including build-up properties and the concentrations of the alkaline agent and the electrolyte via the evaluation of the color strength (K/S value) and dye fixation rate. A comparison was made between the novel low add-on dyeing process and conventional dyeing process by assessing the dye properties, color shade and color levelness. The results indicated that the fabric dyed with the low add-on process had excellent washing fastness, rubbing fastness, a similar color shade and superior levelness in comparison with conventional one-bath pad-steam dyeing.