Understanding the fundamentals of molecular self-assembly behaviours is a critical  step in the manufacturing of functional macrostructures.These processes find applications in various fields such as molecular biology, chemistry, engineering, materials science or polymer science.

Steroidal surfactants, such as bile salts, have a rigid facial amphiphilic structure significantly different from the typical head–tail detergents. These molecules show peculiar features in their complex and adaptable self-assembly behavior, at the basis of their physiological activities and bio-applications. They can self-organize in rather ordered supramolecular assemblies and are also particularly attractive for the bottom-up construction of nanostructures. Sodium deoxycholate (NaDC) is representative of the complex aggregation behaviour of these biological surfactants in aqueous solution. In conditions fitting its physiological working environment NaDC can adjust its arrangement among micelles, bilayers and helices, showing remarkable adaptability to all the allowable phases expected for surfactants.

Small angle X-ray scattering measurements, performed at the SAXSLab Sapienza, have been used to characterize each phase and the transitions among them.