How the molecules organise themselves
Surfactants organise themselves as their concentration or temperature changes: first they form micelles, then, at higher concentrations, cylinders and layers called liquid-crystal phases. Each structure changes how freely the molecules move, so a change in a relaxation time or in diffusion shows where a transition takes place. This matters for detergents, personal care, paints and food emulsifiers.
Where it is used
- Surfactant solutions and mixtures
- Detergent, cleaning and personal care formulations
- Microemulsions and gels
- Formulated products that pass through phase changes with temperature or dilution
Typical tasks are locating the concentration at which micelles form, finding where a liquid-crystal phase appears or disappears, and following a transition with temperature.
Mobility against concentration or temperature
A series of samples with increasing concentration, or one sample at increasing temperature, is measured. The relaxation time, and where available the diffusion, of the solvent and the surfactant is plotted. A change of slope marks a change of structure.
What it adds
- Works on opaque, viscous and coloured samples as they are
- No labels and no dilution beyond the series itself
- Follows a transition in one sample with temperature
- Small samples and quick measurements for mapping a whole phase diagram
Points that matter in practice
- Relaxation times change gradually, so a transition shows as a change of slope and not always as a sharp step
- For a new system, confirm which structure is present with another technique, such as polarised microscopy or scattering, and then use the mobility as a fast screening tool
- Control the temperature carefully, and let viscous samples equilibrate
- Avoid air bubbles when filling thick samples into the tube
From your formulation to a routine method
Describe your system and your question. MSY Consulting runs feasibility measurements, plans the series with you, and supports the interpretation until the method is part of your routine.
Let's talk about your application
Send an email describing your instrument and your application, and you will get a reply.
contact@msyconsulting.euMSY CONSULTING SAS · Wissembourg, France · LinkedIn