Issue 34, 2014

Effect of the position of the urea group in the hydrocarbon tail of fatty acid amphiphiles on the physical gelation of organic liquids

Abstract

To investigate the effect of the position of the urea group in the hydrocarbon tail of an amphiphilic gelator, three positional isomers of 3-N-(n-tetradecylcarbamoyl)aminopropanoic acid (C14NHCO-APA) were designed and synthesized. The gelation behavior of these three amphiphiles in different organic solvents was investigated and compared. The amphiphiles were found to gelate organic solvents employed, but only in presence of H2O. The gelation in all the solvents employed was observed to be thermoreversible, having gel-to-sol transition temperatures (Tgs) above the physiological temperature (37 °C). It was observed that the critical gelation concentration (CGC) of the amphiphiles decreased; that is, gelation ability increased with the increase of spacer length between the –COOH and –NHCONH groups. The results suggested that H-bonding and van der Waals interactions have a major contribution in the gelation process. The morphology of the organogels was studied by XRD spectroscopy and electron microscopy. The amphiphiles were observed to form ribbon-like aggregates of high aspect ratio in organic solvents. The mechanical strength of the gels was studied by rheology. Their gelation abilities, Tgs values and values of yield stress (σy) of the organogels follow a similar trend, indicating that the gel becomes stronger when the urea linkage is in the middle of the hydrocarbon tail of the amphiphile.

Graphical abstract: Effect of the position of the urea group in the hydrocarbon tail of fatty acid amphiphiles on the physical gelation of organic liquids

Article information

Article type
Paper
Submitted
24 Jan 2014
Accepted
21 Mar 2014
First published
24 Mar 2014

RSC Adv., 2014,4, 17521-17525

Effect of the position of the urea group in the hydrocarbon tail of fatty acid amphiphiles on the physical gelation of organic liquids

A. Pal and J. Dey, RSC Adv., 2014, 4, 17521 DOI: 10.1039/C4RA00712C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements