Related Experiment Videos
I. Creaming Behavior
Manoj1, Fillery-Travis, Watson
1Institute of Food Research, Norwich Research Park, Norwich, Norfolk, NR4 7UA, United Kingdom
Journal of Colloid and Interface Science
|October 30, 1998
Summary
This study investigates oil-in-water emulsions, finding that hydroxyethylcellulose (HEC) concentration significantly impacts creaming behavior and delays. Emulsions form structures that rearrange, creating channels for continuous phase flow, influencing the creaming delay.
Area of Science:
- Colloid and Surface Science
- Rheology
- Materials Science
Background:
- Flocculation in emulsions affects their stability and separation dynamics.
- Understanding creaming behavior is crucial for emulsion formulation and processing.
- Hydroxyethylcellulose (HEC) is a common depletion flocculant used in emulsions.
Purpose of the Study:
- To experimentally investigate the creaming behavior of flocculated oil-in-water emulsions.
- To elucidate the mechanisms responsible for the delay in creaming.
- To identify factors influencing creaming dynamics, such as polymer concentration and oil volume fraction.
Main Methods:
- Preparation of oil-in-water emulsions with varying hydroxyethylcellulose (HEC) concentrations.
- Experimental observation and analysis of creaming phenomena.
- Measurement of continuous phase viscosity and droplet behavior.
Main Results:
- Creaming behavior depends on oil volume fraction and HEC concentration.
- At low HEC, emulsions cream individually or in two phases; at high HEC, they cream as a single entity.
- A significant delay before creaming initiation was observed, followed by a constant creaming rate.
Conclusions:
- Emulsion creaming is significantly influenced by continuous phase viscosity and HEC-induced flocculation.
- A proposed mechanism involves the formation and rearrangement of space-filling structures leading to channel formation.
- The creaming delay may be related to single-droplet diffusion rates, suggesting structural rearrangement dynamics are key.