Cellulose hydrogels are potential candidates to remove water from oil–water emulsions. However, their practical application has been limited by complex processing procedures and low separation rates limited by high water holding rates. Therefore, in this work, natural bacterial cellulose (BC) hydrogel with the characteristics of underwater superoleophobicity/underoil superhydrophilicity is introduced to remove water from oil-in-water and water-in-oil emulsions. Also, the influence of the treatment process of BC hydrogel on the separation rate was studied. The results showed that the separation rate of treated BC hydrogel was significantly higher than that of the original BC hydrogel, and the maximum separation flux could reach 180,000 ± 50 Lm⁻³ h⁻¹ MPa⁻¹. The mechanism has been investigated by the small-angle X-ray scattering and atomic force microscope, which was attributed to the decrease of the capability to confine water caused by the bundling of cellulose microfibrils during freezing or drying. The work might provide an alternative approach for improving the separation rate of cellulose materials for oil/water separation.

纤维素水凝胶是从油水乳液中去除水的潜在候选者。然而，它们的实际应用受到复杂的处理程序和受高保水率限制的低分离率的限制。因此，在这项工作中，引入了具有水下超疏油/下油超亲水特性的天然细菌纤维素（BC）水凝胶来去除水包油和油包水乳液中的水分。此外，研究了BC水凝胶处理工艺对分离率的影响。结果表明，处理后的BC水凝胶分离率明显高于原BC水凝胶，最大分离通量可达180,000±50 Lm ^-3  h ^-1  MPa ^-1. 其机理已通过小角 X 射线散射和原子力显微镜进行了研究，这归因于在冷冻或干燥过程中纤维素微纤维的聚集导致限制水的能力下降。这项工作可能为提高用于油/水分离的纤维素材料的分离率提供一种替代方法。