Water-in-oil Pickering emulsions stabilized by stearoylated microcrystalline cellulose

Bo Pang; Huan Liu; Peiwen Liu; Xinwen Peng; Kai Zhang

doi:10.1016/j.jcis.2017.11.079

Water-in-oil Pickering emulsions stabilized by stearoylated microcrystalline cellulose

J Colloid Interface Sci. 2018 Mar 1:513:629-637. doi: 10.1016/j.jcis.2017.11.079. Epub 2017 Nov 29.

Authors

Bo Pang¹, Huan Liu¹, Peiwen Liu¹, Xinwen Peng², Kai Zhang³

Affiliations

¹ Wood Technology and Wood Chemistry, Georg-August-University of Goettingen, Büsgenweg 4, 37077 Göttingen, Germany.
² Wood Technology and Wood Chemistry, Georg-August-University of Goettingen, Büsgenweg 4, 37077 Göttingen, Germany; College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, Jiangxi 330022, PR China.
³ Wood Technology and Wood Chemistry, Georg-August-University of Goettingen, Büsgenweg 4, 37077 Göttingen, Germany. Electronic address: kzhang1@uni-goettingen.de.

PMID: 29207345
DOI: 10.1016/j.jcis.2017.11.079

Abstract

Hypothesis: Hydrophobic particles with static water contact angles larger than 90° are more like to stabilize W/O Pickering emulsions. In particular, high internal phase Pickering emulsions (HIPEs) are of great interest for diverse applications. However, W/O HIPEs have rarely been realized using sustainable biopolymers. Herein, we used stearoylated microcrystalline cellulose (SMCC) to stabilize W/O Pickering emulsions and especially, W/O HIPEs. Moreover, these W/O HIPEs can be further used as platforms for the preparation of porous materials, such as porous foams.

Experiments: Stearoylated microcrystalline cellulose (SMCC) was prepared by modifying MCC with stearoyl chloride under heterogeneous conditions. Using SMCC as emulsifiers, W/O medium and high internal phase Pickering emulsions (MIPEs and HIPEs) with various organic solvents as continuous phases were prepared using one-step and two-step methods, respectively. Polystyrene (PS) foams were prepared after polymerization of oil phase using HIPEs as templates and their oil/water separation capacity were studied.

Findings: SMCC could efficiently stabilize W/O Pickering emulsions and HIPEs could only be prepared via the two-step method. The internal phase volume fraction of the SMCC-stabilized HIPEs reached as high as 89%. Diverse internal phase volume fractions led to distinct inner structures of foams with closed or open cells. These macroporous polystyrene (PS) foams demonstrated great potential for the effective absorption of organic solvents from underwater.

Keywords: Foams; Oil-water separation; Pickering emulsion; Stearoylated microcrystalline cellulose; Water-in-oil emulsion.