Eco-Friendly And Low-Cost Nano-Hybrid Superabsorbent Synthesis Based On Polysaccharides And Diatomite

The simultaneous introduction of green polysaccharides and low-cost inorganic clay into a superabsorbent(SAP)polymeric networks,has witnessed growing interest in developing of eco-friendly and low-cost SAP since the last decade.In this dissertation,two types of high performance nano-hybrid SAP composites were prepared through the graft polymerization of acrylic acid either into Hydroxyethyl Cellulose(HEC-g-PAA/diatomite)or xyloglucan(XG-g-PAA/Diatomite)backbone chains under the aqueous solution,in the presence of diatomite clay as inorganic nano-filler,N,N'methylenebisacrylamide(MBA)as cross-linker,ammonium persulfate(APS)as initiator.In this work,the Fourier Transform Infra-Red Spectroscopy(FTIR),X-ray Diffraction(XRD)and Scanning Electron Microscopy(SEM)investigations,all confirmed the successful synthesis of both HEC-g-PAA/diatomite and XG-g-PAA/Diatomite nano-hybrid SAP composites with high porosity on the surface.The nano-hybrid SAP composites prepared at the optimized conditions presented a significantly enhanced thermal stability according to the Thermogravimetric Analysis(TGA)and Differential Scattering Calorimeter(DSC)analysis and remarkably improved water-retention property at various temperatures,compared with clay-free counterpart SAP composites.Moreover,the properties such as swelling and water retention behavior of the HEC-g-PAA/diatomite and XG-g-PAA/Diatomite were investigated and the influence of each individual starting materials content on water absorbency property of synthesized nano-hybrid SAP composites was systematically studied.The results showed that the water absorbency capacity for nano-hybrid SAP composite synthesized under the optimized condition was:1174.85 g/g in distilled H2O and 99.55 g/g in 0.9 wt%NaCI salt solutions for HEC-g-PAA/diatomite and 1057.06 g/g in distilled H2O and 65.67 g/g in 0.9 wt.%NaCI salt solution for XG-g-PAA/diatomite.The excellent properties of the prepared nano-hybrid SAP composites suggested that they could find diverse range of applications such as in hygienic products,agriculture and waste-water treatment.Furthermore,being biodegradable and low-cost could be the added advantages for HEC-g-PAA/diatomite and XG-g-PAA/Diatomite nano-hybrid SAP composites.