Manufacturing of superabsorbent membranes of PVA and rice husk fibres reinforced with nanosilica for agricultural and horticultural applications

Abstract

ABSTRACTNovel superabsorbent membranes (SMs) consisting of polyvinyl alcohol (PVA), cellulose nanocrystals (CNCs) originated from rice husk (RH), nanosilica, glutaraldehyde and glycerine (G) were manufactured by a compression moulding process. RHs were used to isolate pure CNCs via mechanical and chemical treatments. RHs were used to improve water retention. These SMs were characterised by Fourier-transform infrared spectroscopy, scanning electron microscopy, mechanical testing and differential scanning calorimetry. SMs showed a greater equilibrium swelling capacity than neat cross-linked PVA. Moreover, the water transport mechanism of all SMs was found to follow Fickian diffusion. SMs exhibited good pH-dependent swelling reversibility and high-water retention capacity, making them more efficient water retention materials. The biodegradability of SMs was evaluated under environmental changes. The biodegradability of SMs was evaluated against environmental changes. The SM was also investigated for antimicrobial activity against pathogenic bacteria such as Candida albicans (fungus), Bacillus subtilis (Gram-positive), Staphylococcus aureus (Gram-positive), Proteus vulgaris (Gram-negative) and Erwinia carotovora (Gram-negative). SMs have been found to act as a useful water reservoir, which may make it useful in agricultural applications.Abbreviation: Novel superabsorbent membranes (SMs) consisting of polyvinyl alcohol (PVA), cellulose nanocrystals (CNCs) originated from rice husk (RH), nanosilica (NS), glutaraldehyde (GLA) and glycerine (G) were manufactured by a compression moulding process. RHs were used to isolate pure CNCs via mechanical and chemical treatments. RHs were used to improve water retention. These SMs were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Mechanical Testing and Differential Scanning Calorimetry (DSC).