Chemistry Weekly Seminar - Srikant Singh, PhD Student

Title

Langmuir Monolayers of “Minimal-Linker” Dimeric Surfactants at the Interface

Abstract

Gemini surfactants, the common name for “bis-surfactants”, are more surface-active than conventional single chain surfactants. While a variety of cationic gemini surfactant monolayers have been thoroughly studied in the past, anionic gemini surfactants are less well-known. The objective of my doctoral research is to develop fundamental knowledge about how the chemical structure of amphiphilic molecules affects the properties of their resulting monolayer.

To achieve these goals, I have investigated a series of structurally different anionic dimeric surfactants of the family disodium 2,3-dialkyl-1,2,3,4-butanetetracarboxylates (Figure 1) that have recently been reported in the literature. The seminar will focus on the unique interfacial properties of these compounds that results from having a "minimal-length” spacer (i.e., a single covalent bond joining the two amphiphilic head groups). These minimal linker geminis represent the extreme limit in terms of gemini headgroup compactness, thus making them useful test cases to establish structure-monolayer properties such as crystallographic and micron–scale structure, phase composition, miscibility in binary mixtures with perfluorocarboxylic fatty acids and mechanical rigidity. The research will be presented to highlight our ultimate goal of developing a simple, general structure-monolayer property relationship model for individual and synergistic surfactant systems.

Date:    Friday, December 8

Time:    1:30 pm

Location:    Thorvaldson 159