Water retention and controlled release of KCl by using microwave-assisted green synthesis of xanthan gum-cl-poly (acrylic acid)/AgNPs hydrogel nanocomposite

Abstract

A novel ecofriendly microwave-assisted xanthan gum-cl-poly (acrylic acid)/AgNPs (MW-XG-cl-pAA/AgNPs) hydrogel nanocomposite has been synthesized by using free radical graft polymerization method. Xanthan gum (XG) acts as stabilizer to produce stable uniform AgNPs in the presence of stem extract of Nepeta leucophylla inside the polymer network. The evidence of incorporation of AgNPs inside the polymer matrix, grafting of acrylic acid (AA) onto backbone XG, surface morphology, crystallinity, thermal properties and effective loading of KCl inside the synthesized hydrogel nanocomposite are attained by using various analytical techniques, such as ultraviolet–visible, Fourier transform infrared, field emission scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction and thermogravimetric analysis. The influence of incorporation of silver nanoparticles inside polymer matrix is also examined. Moreover, in order to explore the swelling and releasing kinetic behavior of synthesized nanocomposite mathematical modeling (Fick’s law) has been used here. Here, the resulting nanocomposite is used for the application of water retention potential of different soil samples and controlled release of KCl. It is evident from the studies that the synthesized nanocomposite acts as water reservoir in different types of soil and maintains the moisture for more than 60 days. Further, the high value of initial diffusion coefficient ( $$ 5.458 \times 10^{ - 6}\,{\text{m}}^{2} /{\text{h}} $$ ) as compared to late diffusion coefficient ( $$ 1.453 \times 10^{ - 7} {\text{m}}^{2} /{\text{h}} $$ ) represents the controlled release of KCl. Hence, the synthesized nanocomposite with controlled release and decent water retention can prevent the serious environmental hazards.