Conformational transition of a non-associative fluorinated amphiphile in aqueous solution. II. Conformational transition vs. supramolecular assembly

Unlike many known amphiphiles, the fluorinated amphiphilic dendrimer studied in this work demonstrated a concentration-dependent conformational transition rather than micellization or assembly. Hydrophobic and hydrophilic interactions with water were suggested as the most probable driving force of this transition. This assumption was consistent with the observed (19)F chemical shift changes of the dendrimer compared to a known micelle-forming fluorinated amphiphile. Since water is an important factor in the process, trends of the concentration-dependent changes in water proton transverse relaxation rate served as an indicator of structural changes and/or supramolecular assembly. The conformational transition process was also confirmed by ion-mobility mass-spectrometry. We suggested that structural features, namely, steric hindrances, prevented the micellization/assembly of the dendrimer of this study. This conclusion might inform the approach to develop novel unconventional amphiphiles.