Dynamic Processes in Supramolecular Gels

Supramolecular gels are self-assembled solid-like materials with a large solvent component making up a liquid-like phase. The 3D scaffold, which is self-assembled from low-molecular-weight building blocks, and is present in form of nanostructured fibres, holds the mobile liquid phase, preventing bulk flow. As a consequence, these gels have interesting dynamic properties, which were the subject of study in this thesis. Chapter One provides an introduction to dynamic processes in gels. Chapter Two focusses on the thermodynamics and kinetics of a two-component gelator system based on a peptide dendron acid combined with an amine. We used rheology, CD spectroscopy and NMR to characterise the gelation process at different length scales (macroscopic, nanoscale and molecular scale respectively). We conclude that thermodynamic stability of the gel network does not correlate with the rate of network formation. Chapter Three reports diffusion across a gel-gel interface, comparing the diffusion of self-assembling small molecules with those which do not form gel fibres. Chapter Four reports the gelation capabilities of certain gelator in deep eutectic solvents. We monitor the ionic conductivity and demonstrate that conductivities for the deep eutectic gels are similar to those of the deep eutectic liquids themselves, indicating that the ionic components do not suffer from immobilisation through interaction with the self-assembled gel nanofibres. Chapter five reports all Experimental details, materials and methods. In summary, this thesis provides insights into a range of different dynamic processes in gels – (i) the formation of gels, (ii) the mobility of the solid-like fibres themselves, and (iii) the mobility/conductivity of ionic species in innovative deep eutectic gels.