Super-flexible, moldable, injectable, self-healing PVA/B/CMC hydrogels synthesis and characterization, as potential water-retaining agent in agriculture

In this study, a moldable, the injectable and self-healing poly(vinyl alcohol)/carboxymethyl cellulose (PVA/CMC) hydrogel was synthesized, cross-linked with borax (B), to produce a new type of water-retaining material in soil. This material was characterized by Fourier transform infrared spectroscopy, thermogravimetric analyses, X-ray diffraction, nanoindenter and scanning electron microscopy, and its structure was elucidated. According to the gravimetrically determined swelling results, while the PVA/B hydrogel swells by 271%, the swelling ratio increases as the CMC percentage increases in PVA/B/CMC hydrogels. The water absorption capacity of loamy soil was investigated by mixing it with hydrogel soil and PVA/B/CMC was evaluated as a water retention agent. Addition of 1.0% by weight hydrogel increased the water holding capacity of loamy soil from 48.8 to 58.8%. It was observed that the soil containing the PVA/B/CMC-2.5 hydrogel showed very good water retention. At the end of 7 days, it was observed that it lost only 51% of its water. This environmentally friendly and easily synthesized hydrogel is thought to have great application potential in agriculture for soil water conservation.