Chemically and Physically Induced (Reversible) Gelation of Organic Liquids by Monomeric and Polymeric Gelators

Abstract

The properties of several types of organogels that can undergo a chemical transition during gelation or while in the gel phase are described. The transitions can be physically induced by light or chemically triggered by the addition of an acid or a neutral molecule such as CO2 or CS2. In some cases, the gelation properties of the new species formed are markedly different from those of the precursors. The link between molecular structure and the nature of the gel networks as well as results obtained from the multidisciplinary tools used to study them are discussed.

Functional π-Gelators and Their Applications

“…It indicates the inability to undergo photopolymerization due to the slight difference in the optimum arrangement of the diacetylene moieties for polymerization. Weiss et al have reported the gelation and polymerization of 10,12-pentacosadiynoic acid derived amides 99a – c , ester 100 and the chiral amidoester 101 (Figure ). , Photopolymerization and subsequent heating led to significant changes in the absorption spectrum and also change of the visible color from blue to red …”

Poly(acrylic acid–sodium styrene sulfonate) organogels: Preparation, characterization, and alcohol superabsorbency

“…Physical gelation is a thermoreversible process in which a phase transition from solid to liquid happens by heating. Heat obstructs solvent–polymer interactions, for example, hydrogen bonding 3. Chemical polymeric organogels may be composed of a linear or crosslinked structure, which can dissolve or swell in organic solvents, respectively.…”

Studies on Gelling Characteristics of N‐Tertiary Butyl Acrylamide–Acrylic Acid Copolymer

“…2,3 There are some reports on polymeric network organogels prepared through solution polymerization when cross-linking also takes place in situ. [2][3][4][5] Recently, some research works have been published on the preparation of cross-linked polymeric organogels. 4,5 Kabiri et al prepared super alcogels based on three constituents namely 2-Acrylamido-2-methylpropane sulfonic acid, poly(ethylene glycol) macromer, and acrylic acid (AAc).…”

“…Much research has been published on physical organic gels, particularly based on the low molecular weight materials . There are some reports on polymeric network organogels prepared through solution polymerization when cross‐linking also takes place in situ . Recently, some research works have been published on the preparation of cross‐linked polymeric organogels .…”