Size and charge characterisation of a submicrometre oil-in-water emulsion using resistive pulse sensing with tunable pores

作者：Somerville James A; Willmott Geoff R^*; Eldridge James; Griffiths Marjorie; McGrath Kathryn M

来源：Journal of Colloid and Interface Science, 2013, 394: 243-251.

DOI：10.1016/j.jcis.2012.11.071

• Tunable pore
• Resistive pulse sensing
• Dynamic light scattering
• Emulsion
• Zeta-potential
• Beta-lactoglobulin

Resistive pulse sensing (RPS) with tunable pores (TPs) has been used to investigate an oil-in-water emulsion stabilised with beta-lactoglobulin (BLG). The mode of the droplet size distribution steadily increased over four months, from less than 150 nm to more than 200 nm. Results suggest that the dominant growth mechanism was migration of oil to relatively large droplets, as in Ostwald ripening. In contrast, the growth dynamics for salt-induced aggregation suggest flocculation and coalescence of droplets coming into contact. The charge measurement method recently developed by Vogel et al. [1] was also applied to the emulsion. The two data analysis methods used yielded average droplet zeta-potentials of -18.9 mV and -21.8 mV, compared with -27.6 mV obtained using light scattering. Methods for measuring emulsion droplet deformation and the charge on individual droplets are under development. Tunable pores are a useful tool for improved characterisation of submicrometre emulsions, as well as other synthetic and biological particles, as they provide better precision than light scattering for particle number distributions.

• 出版日期2013-3-15