They dance around us with such invisible elegance. Elongated shiny legs hold together their heavy waterlogged heads as they embark in synchronized choreography all around us every morning. We impolitely disregard their show and let them slip down the drain: In the end, what matters is a clean face for a fresh onset feeling. During breakfast, they beg for attention once again by whispering chemical love notes to our ears while we drink a delicious chocolat chaud. Again, we take no notice. So, they return during lunch with our mayonnaise sandwich and during our dishes clean-up after dinner. In total despair, they give their final master show under the shower where they englobe our hair in a hula-hula shampooing contest. Wow! What dancing molecules are these, and how come are they everywhere? Well, stay put: I will unravel part of this mystery in the next few lines.
These enigmatic molecules are the protagonists of my research. They are called surfactants – which is the contraction of ‘surface-active agents’ – and as their name suggests, they go into action at the interfaces of two different chemical surfaces. These molecules possess an affinity to water on one hand and to oil on the other. In other words, they serve as connectors to blend two incompatible components. Such a cool chemical property, isn’t it? Thanks to them, you can clean off your greasy pans, wash your hair, mix your cocoa butter-rich chocolate powder with milk and eat a delicious sandwich with mayonnaise sauce.
Right! Another important thing to keep in mind, which I won’t go into extensively, is that there are – chemically-speaking – different types of surfactants. For instance, the ones contained in your shampoo flask are not exactly the same as the ones in foodstuff. In my project, I work with one that would be potentially used in food or drug formulations. Its peculiarity is the long sugar head (water-loving part), which ensures its biocompatibility and biodegradability. My two main study objectives were to characterize this newly synthesized surfactant in water to shed light into the molecular arrangement it forms. These investigations are extremely relevant to understand the stability of such systems, which may translate into novel products one day.
Why are surfactants so important? These molecules allow scientists to create incredible food textures or even elaborate, highly sophisticated pharmaceutical medications. They can also act as powerful invisible killer weapons by breaking apart the cellular walls or membranes of microbes. This is the reason that, if you run out of shampoo, you shouldn’t use your toilet cleanser instead!
Text by Fernanda Haffner
Illustration by Laurene Gattuso
This article was written for outreach purposes (Esperluette project).