A Fibrous Nonwoven Hydrogel Composite for Shoe Insole with Enhanced Mechanical and Comfort Properties.

A shoe insole material was created by combining eco-friendly natural fibers with alginate hydrogel, which is known for its biocompatibility. The sol–gel technique was used to create a composite by cross-linking the Bamboo/hemp and Tencel/Flax nonwoven, produced by the needle-punching method, with alginate solution using CaCl₂ as a crosslinking agent. The composite was then dried at 30 °C for 24 h. To determine the effects of different alginate concentrations and nonwoven GSM (g/m²) on the composite's properties, three concentrations (0.5%, 0.75%, and 1%) and three GSM values (60 gm⁻², 120 gm⁻² and 180 gm⁻²) were used. The composite's properties were evaluated using SEM, FTIR, tensile strength, elongation, water absorbency, air permeability, overall moisture management, and anti-bacterial properties. The SEM and FTIR analyses have confirmed the successful synthesis of a composite material comprising alginate hydrogel reinforced with nonwoven fabric. Compared to Tencel/flax-reinforced hydrogel composites (117.6 N), the bamboo/hemp-reinforced hydrogel composites exhibited superior tensile strength (186.2 N) and water absorption properties. On the other hand, the Tencel/flax hydrogel composites (402 mm/sec) demonstrated better air permeability than the bamboo/hemp-reinforced hydrogel composite (321 mm/sec). In addition, both composites displayed antibacterial properties, making insoles made from these materials effective in controlling odors. [ABSTRACT FROM AUTHOR]