Stable cellular foams and oil powders derived from methylated microcrystalline cellulose stabilized pickering emulsions

The objective of this work was to methylate the microcrystalline cellulose (MCC) with methylcellulose (MC), investigate the ability of modified methylated MCC (Mmcc) to stabilize the emulsions and understand their role in the preparation of solid foams and oil powders. The Mmcc was prepared by thermally cross-linking MCC, and MC at 80 °C for 4 h followed by homogenization and lypholization without any additional wall materials. The FTIR spectroscopy confirmed an increase in the intensity of –CH 2 - associated band from 1400 cm −1 to 1456 cm −1 which corresponded to MCC and methylated MCC respectively. The methylation of the MCC with MC-a, MC-b, MC-c was evidenced by an increase in the particle size from 8.381 ± 0.17 to 12.41 ± 0.16, 12.51 ± 0.03, and 15.15 ± 0.75, respectively. The Mmcc and their corresponding emulsions expressed typical shear thinning behavior. The Pickering emulsions expressed improved resistance to environmental stresses and coalescence during storage. The microstructure of the solid foams observed with scanning electron microscopy revealed porous, spherical, polyhedral, and closely packed droplets. We found that the oil powders could be rehydrated in water. Their re-dispersibility index demonstrated that the wet oil powders attained re-dispersibility. The results open up new routes to engineer long term stabilization of the Pickering emulsions, solid foams, and oil powders for different applications.