Hybrid Thermoreversible Gels from Covalent Polymers and Organogels

Abstract

This paper reports on experiments intended for investigating the feasibility of preparing hybrid thermoreversible gels from covalent polymers and noncovalent self-assembling pi-conjugated molecules. The formation and the degree of dispersion of these hybrid gels have been studied with polystyrenes of various tacticities and oligo(p-phenylenevinylene) molecules (OPV) in different nonpolar organic solvents. Detailed investigations of the systems have been carried out by DSC, SAXS, and AFM. It is shown that no liquid-liquid phase separation is involved, indicating that the systems are highly compatible, and that the growth of one type of gel does not interfere with the other. These studies reveal that the resultant hybrid gels are composed of the intermingled fibrillar architectures of both gels.

The Solvent in Physical Gelation: Polymers Versus Organogelators

“…[ 17 ] We have also reported recently that cis -decalin and trans -decalin enantiomers have affected of the size of the fi brils, particularly on their cross-section. [ 18 ] Also, we have shown the dramatic effect of the solvent on consistent with the degree of solvation, which is higher in cis -than in trans -decalin.…”

Percutaneous Penetration Enhancers Chemical Methods in Penetration Enhancement

“…21.2 ). It is essential to determine the gelation temperature of the LOs containing drugs as it serves as a guide for recommending storage conditions for drug-loaded medicated LOs (Díaz et al 2008 ;Dasgupta et al 2009 ;Guenet 2006 The gelation temperature varies depending on the solvent system used when preparing LOs.…”

Lecithin Organogels in Enhancing Skin Delivery of Drugs

“…The gelation temperature can be determined visibly. It is essential to determine the gelation temperature of the LOs containing drugs as it serves as a guide for recommending storage conditions for drug-loaded medicated LOs (Díaz et al 2008 ;Dasgupta et al 2009 ;Guenet 2006 ).…”