PhD defence

Microfluidic analysis of dynamic processes occurring during bubble formation and stabilisation

PhD candidate B (Boxin) Deng MSc
Promotor prof.dr.ir. CGPH (Karin) Schroen
External copromotor Jolet de Ruiter
Organisation Wageningen University, Food Process Engineering
Date

Fri 25 November 2022 16:00 to 17:30

Venue Omnia
Room Groot Auditorium

Summary

Foam is a common structure in food, pharma, and cosmetic products. It consists of bubbles which are formed and stabilised with surface active components (i.e., emulsifiers). In general, to maintain the functional properties of foam structure, both the formation and the stabilisation of individual bubbles need to be precisely-controlled. Ideally, bubbles with uniform size are produced and immediately stabilised. However, in reality, traditional foaming techniques lead to polydispersed bubbles whose size is an equilibrium state of formation and coalescence. To make high-quality foam products, it is crucial to choose a suitable foaming technique and emulsifier, which requires in-depth understanding of the bubble formation mechanism and the interplay between bubble formation and emulsifier adsorption. In this thesis, microfluidic devices are used to make and characterise foams, as well as to study emulsifier adsorption at very short time scales that allow to capture the dynamics of bubble formation and stabilisation against coalescence.