Molecular engineering to fabricate Li+-enriched multi-stimuli responsive conducting metallogels

Abstract

The development of multi-stimuli responsive soft materials has attracted substantial interest in the scientific community due to their wide applications in the field of soft robotics, bioelectronics, soft sensors and actuators. Metallogels are 3D dimensional nanostructure materials as well as an emerging subclass of the supramolecular gels. Metallogels, engineered through metal-ligand coordination have attracted substantial research interest owing to their unique and fascinating properties. Metallogelation promoted by at least presence of one metal ion, which triggers the self-assembly in gelator by virtue of metal-ligand coordination and several dynamic noncovalent interactions. Moreover, the presence of metal ions in gels is a straightforward way to integrate the specific properties of metals in organic matrix such as conductivity, color, rheological behavior, optical, magnetism, catalytic and redox activities etc. Conductive metallogels will be at the heart of the next generations smart materials with the wide range of applications ranging from energy storage materials to optoelectronic devices. Particularly, conductance property in the metallogel originate due to the mobility of incorporated metal ions in the gel matrix. In spite of metallogels being very versatile for the development of multi-stimuli responsive soft materials, their utilization towards this application has been rarely reported. Since metallogels are very sophisticated systems, it has been observed that synthesizing new metallogels for targeted application is not an easy task due to lack of expertise in engineering of gelator molecules which could further interact with metal ions and form metallogels. In present thesis we adopted molecular engineering strategy to synthesis new symmetrical hydrazones based LMWG gelator molecules by modification of functional group and change of linkers in parent TAS gelator molecule to achieve the specific targets (i) D-(+)-Glucose responsive metallogel to metallogel transformation achieved with modification functional boronic group. (ii) Thixotropic, shear thing properties were achieved with modification of linker with flexible aliphatic chain (C4) and removal of functional group in gelator A and obtained gelator is B. (iii) To study the effect of alkali size on gelation and conductance were achieved with modification of Linker with benzene ring. (iv) Conductance property achieved by incorporation of alkali ions (LiOH, NaOH, KOH, CsOH) All this new era covered in present thesis.