Abstract: The effects of the amount of magnetic cellulose microcrystalline complex added, oil/water ratio and the number of homogenization cycles on properties of O/W Pickering emulsions stabilized by magnetic cellulose microcrystalline were studied. The results showed that the average size of Fe3O4 particles prepared was approximately 10 nm, and the average length of cellulose microcrystals modified by Fe3O4 was about 14.2 μm. The surface morphology of cellulose microcrystals was changed from smooth rod to rough morphology. The Fourier transform infrared (FTIR) spectra of cellulose microcrystals showed that the absorption peak of Fe–O bond appeared at 565 cm-1, and that the contact angles of Fe3O4, cellulose microcrystallites and magnetic cellulose microcrystalline complexes were 46.67°, 42.48° and 69.58°, respectively. The optimal conditions for stabilizing Pickering emulsion were determined as follows: addition of 1.5 g/100 mL of magnetic microcrystalline composite, oil/water ratio 3:7 and two homogenization cycles. The initial magnetization value of the magnetic microcrystalline composite was 56.8 emu/g, which was reduced to 4.2 emu/g after fifth repeated use.

Key words: magnetic; cellulose microcrystal; O/W type; stability; Pickering emulsion