Supramolecular gels: Functions and uses

Abstract

In recent years there has been immense interest in studying gels derived from low molecular mass gelators (supramolecular, or simply molecular gels). The motivation for this is not only to understand the fundamental aggregate structures in the gels at different length scales, but also to explore their potential for futuristic technological applications. Gels have been made sensitive to external stimuli like light and chemical entities by incorporating a spectroscopically active or a receptor unit as part of the gelator molecule. This makes them suitable for applications such as sensing and actuating. The diversity of gel structural architectures has allowed them to be utilized as templates to prepare novel inorganic superstructures for possible applications in catalysis and separation. Gels derived from liquid crystals (anisotropy gels) that can act as dynamically functional materials have been prepared, for example, for (re-writable) information recording. Supramolecular gels can be important in controlled release applications, in oil recovery, for gelling cryogenic fuels etc. They can also serve as media for a range of applications. This tutorial review highlights some of the instructive work done by various groups to develop smart and functional gels, and covers a wide spectrum of scientific interest ranging from medicine to materials science.

Dual Stimuli-Responsive Supramolecular Hydrogel Based on Hybrid Inclusion Complex (HIC)

“…3 Such hydrogels as "smart" soft materials have been found promising in bioapplications 4,5 because they could sense environmental changes and self-induce structural transformations. [6][7][8][9][10][11][12] In the past couple of years, introducing reversible noncovalent bonds as crosslinkers made significant contributions to the research of environmental responsive behavior of hydrogels, especially for redox 13 and pH changes. 14 Obviously, more stimuli responses would generate more flexibility to further applications of the hydrogels.…”

Using gel morphology to control pore shape

“…[1][2][3] These gels adopt a number of nanoscopic morphologies including fibrous, helical, ribbon-like, tubular, lamellar and vesicular structures. [4][5][6] As well as finding applications in their own right 3,7,8 such frameworks have been used as scaffolds to template the formation of rigid, nanostructured 25 materials. The soft structure of the gels can be 'fixed' in a variety of ways, for example by depositing an inorganic material on the inner or outer surface of the template, or by using LMWGs which can themselves be polymerised to give a rigid structure.…”

Controlling supramolecular polymerization through multicomponent self‐assembly

“…Strategies to control the size and shape of nano-and micrometer size objects that rely on selective solvent techniques in the self-assembly of block copolymers will not be discussed here. [60][61][62][63][64][65][66][67][68][69][70][71][72][73] Supramolecular multicomponent gels, [74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89] or orthogonal self-assembly, [90][91][92][93][94][95][96][97] self-sorting [98][99][100][101][102][103][104] and chiral amplification strategies 105 in multicomponent supramolecular polymers will not be covered in detail, and the interested reader is referred to the recent literature and review articles.…”