Highly tough and ionic conductive starch/poly(vinyl alcohol) hydrogels based on a universal soaking strategy.

High-performance hydrogels with favorable mechanical strength, high modulus, sufficient ionic conductivity and freezing resistance have far-ranging applications in flexible electronic equipment. Nevertheless, it is challenging to combine admirable mechanical properties and high ionic conductivity into one hydrogel. Herein, a facile strategy was developed for the preparation of the hydrogel with excellent strength (1.45 MPa), super Young's modulus (8.85 MPa) and high conductivity (1.47 S/m) using starch and poly(vinyl alcohol) (PVA) as raw materials. The starch/PVA/Gly/Na3Cit (SPGN) gel was firstly cross-linked by crystalline regions of PVA upon freezing-thawing cycles. It was further immersed in the saturated Na3Cit solution to enhance the interaction between the substrates through the salting-out effect. The effect of soaking time on the crystallinity, intermolecular interactions, mechanical and electrical properties of SPGN gel was demonstrated by X-ray diffraction, Fourier transform infrared spectroscopy, tensile and impedance testing measurements. The introduction of glycerol and Na3Cit also endowed SPGN gels with favorable anti-freezing properties. The SPGN gel could maintain high mechanical flexibility and ionic conductivity at -15 °C.

A facile preparation method for anti-freezing, tough, transparent, conductive and thermoplastic poly(vinyl alcohol)/sodium alginate/glycerol organohydrogel electrolyte.

Facile preparation of organohydrogel electrolyte integrated with good anti-freezing property, toughness, transparency, conductivity and thermoplasticity is important and still remains challenging. Novel conductive and tough poly(vinyl alcohol)/sodium alginate/glycerol (PVA/SA/Gly) composite organohydrogel electrolytes were obtained by a simple method in this paper. PVA and SA was firstly dissolved in a mixed solution of distilled water and glycerol and the PVA/SA/Gly organohydrogel was obtained by the freezing-thawing process, then PVA/SA/Gly organohydrogel was immersed into the saturated NaCl aqueous solution. During the soaking process NaCl would enter into the PVA/SA/Gly organohydrogel to increase the gel strength and conductivity. The PVA/SA/Gly organohydrogel electrolytes performed the high toughness with the tensile strength and elongation at break of 1.43 MPa and 558%, respectively. Moreover, the PVA/SA/Gly organohydrogel electrolytes behaved high transparency, anti-freezing property, conductivity and thermoplasticity due to the incorporation of glycerol. This paper provides a new preparation method for the high-performance organohydrogel electrolyte.