Structure and supramolecular assembly in multi-component organogels

Abstract

This thesis reports on the “structure and supramolecular assembly in multi-component organogels”. It guides readers how the aim of this research has been achieved by division of the main question into subgoals in different chapters. This introduction chapter gives a brief overview on the research theme, it is followed by the second chapter extracted from our literature review on “From molecular assembly to gel formation: what is going on behind the scenes of supramolecular gel formation”. This tutorial review discusses three different assembly mechanisms in molecular gels namely: supramolecular polymerization, crystallization, and spinodal decomposition. The second chapter of this thesis is based on the section on the crystallization mechanism from the larger tutorial review paper, since crystallization is found to be the dominant mechanism of gel formation in bisamide systems throughout our research. It provides a general background on molecular gels followed by how crystallization can lead to the order in the gel network. The third chapter elaborates the study of single bisamide gelators in the solid state. It aims at understanding how odd-even spacer length in the chemical structure affects the complementarity of hydrogen bonding which determines the molecular structure and gelator properties. The fourth chapter describes the supramolecular arrangement and rheological properties of single bisamide gels. In the fifth chapter of this thesis, we explain how we developed and validated the DSCN(T) analytical model. This model empowered our research toolkit to quantitatively analyze the experimental data obtained from DSC. This reliable analysis enabled us to understand the phase behavior of bisamide molecules in the solid state (chapter 3), gel state (chapter 4), and binary systems (both solid and gel state in the subsequent chapter). The last chapter (chapter 6) focuses on the ultimate goal of this thesis: to develop design rules to control the supramolecular assembly pattern in the solid and gel state of multi-component systems. In the course of this phase of research, we made an attempt to understand how compound formation/ co-assembly and phase separation/ self-sorting impact the rheological properties of bisamide gels. The summary of this scientific journey is provided at the end of this thesis.