Physical gelation of polar aprotic solvents induced by hydrogen bonding modulation of polymeric molecules

Abstract

Poly(aryl ether amide) containing o-nitroanilide forms a physical gel in polar aprotic solvents by solvent-induced change of hydrogen bonding modes, in which hydrogen bonding acceptor solvent molecules break intramolecular hydrogen bonding of o-nitroanilide and induce intermolecular hydrogen bonding.

Synthesis and physical gelation induced by self-assembly of well-defined poly(arylene ether sulfone)s with various numbers of arms

“…It seems that the stability of the gel comes from the effective protection of the hydrogen bonds by surrounded PAES chains which are solvophobic in THF, hence prevents THF molecules from the access to the amide. The suggested mechanism resembles to those proposed for low-molecular weight organogelators 37-41 rather than polymers, [42][43][44][45] which can be understood considering well-defined but rather low molecular weight of the polymers used in this study. Powder X-ray diffraction patterns of the xerogels shown in Fig.…”

Sol–gel synthesis and characterisation of nanoscopic strontium fluoride

“…From polymers and supramolecular chemistry it is known, that hydrogen bonding and van der Waals interactions due to polar solvents are expected to be the key factor of gelation. 20 In our system, gelation has to be considered due to strong hydrogen bonding since the SrF 2 sol particles are obtained in polar protic solvents such as acetic acid and ethanol. Additionally, the SrF 2 particles are highly distorted and coordinatively This journal is © The Royal Society of Chemistry 2014 unsaturated, thus providing polar surface sites for interactions with solvent molecules.…”

Induced Aggregation of Epoxy Polysiloxane Grafted Gelatin by Organic Solvent and Green Application

“…For example, the convenient preparation of gels has been achieved through hydrophobic interactions [48]. A highly stable gel has been prepared by intermolecular hydrogen bonding between polymer chains and solvents [49]. The addition of solvent might lead to PGG aggregation and decreased solubility [50].…”