Interfacial and emulsion characterisation of chemically modified polysaccharides through a multiscale approach

Yue Wei; Yanping Xie; Zhixiang Cai; Yalong Guo; Min Wu; Pengguang Wang; Ruiqi Li; Hongbin Zhang

doi:10.1016/j.jcis.2020.07.048

Interfacial and emulsion characterisation of chemically modified polysaccharides through a multiscale approach

J Colloid Interface Sci. 2020 Nov 15:580:480-492. doi: 10.1016/j.jcis.2020.07.048. Epub 2020 Jul 16.

Authors

Yue Wei¹, Yanping Xie¹, Zhixiang Cai¹, Yalong Guo¹, Min Wu¹, Pengguang Wang¹, Ruiqi Li¹, Hongbin Zhang²

Affiliations

¹ Advanced Rheology Institute, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, Shanghai 200240, China.
² Advanced Rheology Institute, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: hbzhang@sjtu.edu.cn.

PMID: 32711199
DOI: 10.1016/j.jcis.2020.07.048

Abstract

Hypothesis: The structural modification of natural emulsifiers may greatly impact their interfacial behaviours and bulk properties. The relationship between the microscopic interfacial viscoelasticity and the macroscopic emulsion stability in emulsifiers with different degrees of modification can be clarified using a multiscale approach.

Experiments: A polysaccharide emulsifier of corn fibre gum (CFG) with different octenyl succinate anhydride (OSA) contents was used to obtain a broad variety of interfacial properties. Interfacial adsorption kinetics and viscoelastic responses were measured by combining interfacial shear rheology and quartz crystal microbalance with dissipation monitoring, and the emulsion properties (droplet size and physical stability) at other scales were evaluated.

Findings: Compared with native CFG, esterified CFG formed thick interfacial films with higher elasticity and viscosity, and their corresponding emulsions showed greater stability. There exists a satisfactory correlation between interfacial rheological properties and emulsion stability. However, such a satisfactory correlation can not be established among the degree of esterification of CFG, interfacial viscoelasticity and stability since depletion flocculation might occur in the emulsion stabilized by the OSA-CFG with the highest OSA content, which induced inferior bulk stability but exerted no impact on the measured interfacial properties. We propose that the depletion flocculation is responsible for this imperfection and provide detailed explanations.

Keywords: Corn fibre gum; Emulsion stability; Interfacial viscoelasticity; Multiscale approach; Natural emulsifier; Polysaccharide; Quartz crystal microbalance with dissipation monitoring; Shear rheology.