Application of Low-Frequency Raman Spectroscopy to Probe Dynamics of Lipid Mesophase Transformations upon Hydration

Low-frequency Raman (LFR) spectroscopy is presented as a viable tool for studying the hydration characteristics of lyotropic liquid crystal systems herein. Monoolein was used as a model compound, and its structural changes were probed both in situ and ex situ which enabled a comparison between different hydration states. A custom-built instrumental configuration allowed the advantages of LFR spectroscopy to be utilized for dynamic hydration analysis. On the other hand, static measurements of equilibrated systems (i.e., with varied aqueous content) showcased the structural sensitivity of LFR spectroscopy. The subtle differences not intuitively observed between similar self-assembled architectures were distinguished by chemometric analysis that directly correlated with the results from small-angle X-ray scattering (SAXS), which is the current "gold standard" method for determining the structure of such materials.