Assoc. Prof. Wojciech Zając
(Institute of Nuclear Physics PAS, Poland)
Lithocholic acid as a molecular crystal, glass-former and a low molecular weight organic gelator
Lihocholic acid (LCA), i.e. 3α-hydroxy-5β-cholanic acid, or secondary bile acid, has a steroid framework with two functional end groups: the carboxyl hydroxyl ones. This structure makes it an interesting, if not a model material for the study of aggregation processes, both in bulk and in solution. Bulk properties were studied, among others, by thermal analysis, including a high precision modulated DSC (MDCS), by infrared spectroscopy via moving-window two-dimensional correlation analysis. LCA is a co-called low molecular weight organic gelator to some organic solvents such as DMSO or ethanol. The structure of the gels was studied by small angle neutron scattering as well as by optical and electron microscopy and, complementarily, by MDSC. SEM and TEM images reveal hierarchical, self-similar structure of fibrillar matter. Apparently, this structure is responsible for the gelation fenomena.