Synthesis and surface modification of cellulose cryogels from coconut peat for oil adsorption

Oil spillage is one of the world’s biggest environmental problems and its various impacts included shifting the balance of the ecosystem, affecting marine animals, and inhibiting economical activities. Therefore, the efficient resolution of this issue is a topic of great interest. In this work, cellulose coconut peat cryogel (CCPC) is synthesized by freeze-drying technique with cellulose extracted from coconut peat and poly(vinyl alcohol) (PVA) as a binder. The CCPC is furthermore dip-coated in poly(dimethylsiloxane) (PDMS) to obtain PDMS-coated cellulose coconut peat cryogel (CCPC-P) with hydrophobic property for the studying of oil adsorption. The characteristics of CCPC and CCPC-P are evaluated by density and porosity, specific surface area following Brunauer–Emmett–Teller (BET) theory, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), and water contact angle (WCA) measurements. Results showed that CCPC-10 with the mass ratios of cellulose to PVA 10:1 had the lowest density of 28.21 mg/cm³, highest porosity of 98.15 %. Furthermore, after coating with PDMS, the obtained hydrophobic CCPC-P10 had maximum adsorption capacities of up to 2.083 and 2.452 mg/mg for the static adsorption model and dynamic adsorption model, respectively. This indicates that coconut peat is a viable material for cryogel synthesis in oil adsorption applications.