Cellulose nanocrystals from underutilized Polythia longifolia seed

Abstract

Polythia longifolia seed (PL), an underutilized seed in Nigeria was used as a starting material to prepare Polythia longifolia cellulose nanocrystals (PLN). Polythia longifolia cellulose (PLC) was first isolated and subjected to sulfuric acid hydrolysis followed by ultrasonication and homogenization. PL, PLC and PLN were characterized using Fourier transformed infrared (FTIR), x-ray diffraction (XRD), thermogravimetric analysis (TG) and scanning electron microscopy (SEM). PLC and PLN were evaluated for their heavy metal adsorption capacity, swelling capacity, water holding capacity and oil holding capacity. SEM images reveal elliptical granules of PLN while XRD shows a mixture of polymorphs of cellulose I and cellulose II. PLN displayed a better water holding, oil holding and swelling capacities. PLN also exhibited a higher adsorption capacity towards Cu2+ and Pb2+ ions than PLC. The results showed that Polythia longifolia seed can serve as a potential source of cellulose nanocrystals which might be useful in other applications.