Physical Chemistry

Lund University

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Johan Larsson, PhD Student


Surfactants, short for surface active agents, are amphiphilic molecules, meaning that one part is hydrophobic and the other is hydrophilic. They are, as the name suggests, drawn to surfaces and interfaces, where they adsorb and decrease the surface tension. When dissolved in water at a sufficient concentration surfactants self-assemble into various structures. The shape of these structures varies – e.g. spheres, cylinders and sheets – depending on the surfactant, but what they all have in common is that the hydrophobic parts are grouped up and shielded from the water by the hydrophilic parts to reduce unfavourable interactions. These properties make surfactants highly useful in a lot of products as e.g. soap, paint, food and drugs as detergents, wetting agents and emulsifiers.

The increasing demand for environmentally friendly products and materials have resulted in a comprehensive research to identify surfactants that are biodegradable, non-toxic and produced from sustainable raw materials. Alkylglycosides, which are surfactants with a hydrophilic group made of carbohydrates, have shown not only promising surface properties but also favourable characteristics regarding sustainability.

In my research I study the adsorption and self-assembly of alkylglycosides and how it is affected by the structure of the surfactant and changes in the environment. In collaboration with Enza Biotech AB, using an enzymatic method, I am able to synthesize alkylglycosides with an elongated hydrophilic head group, called oligomeric alkylglycosides. These are novel type of surfactants and have thus not been thoroughly studied. The preliminary studies reveal that they do not behave as conventional non-ionic surfactants. In this work I use tensiometry and ellipsometry to look at the adsorption and different scattering techniques to elucidate the self-assembly of the alkylglycosides. By acquiring more knowledge about the behaviour of alkylglycosides they can be better utilised in their applications. This means that they can replace some of the fossil-based surfactants that are mostly used today.



+46-46-222 82 16
johan [dot] larsson [at] fkem1 [dot] lu [dot] se