Small-angle neutron scattering studies of aqueous solutions of short-chain amphiphiles

Abstract

We present small angle neutron scattering measurements on binary aqueous solutions of some short-chain amphiphiles (diols, triols, glycols and diglycols) at room temperature. The spectra were analysed in terms of the Teubner-Strey phenomenological formula which allows to obtain a measure for the amphiphilicity strength of each system (amphiphilicity factor fa). In some systems, however, other models, valid for micellar solutions, give also a good representation of the spectra. As a result, we find that, independently of the type of hydrophilic group side (oxydrilic or oxirane), these systems cover the entire accessible amphiphilicity scale ( -1 < fa < 1). Some disordered systems (fa > 1) presumably are able to form micelle-like aggregates.

Microstructure and concentration fluctuations in alcohol–Toluene and alcohol-Cyclohexane binary liquids: A small angle neutron scattering study

“…The theory has been later discussed for aqueous solutions of short-chains amphiphilic molecules, including TBA and discussed in the frame of so-called molecular emulsions [6,7,8,9,36]. According to Teubner-Strey approach, the scattering function is expressed as the inverse four-order polynomial in q.…”

Revisiting aqueous-acetone mixtures through the concept of molecular emulsions

“…17 A simplified micro-emulsion is a binary mixture containing only water and surfactant, with large oily tails, which then also plays the role of the oily solute. 18,19 If we stick to such binary mixtures, one may ask what would happen if the oily part gets smaller and smaller. The oil-water domains will be reduced, bringing the large domain-like structure to something that looks very much micro-heterogeneous, in the sense that the smaller domains become indistinguishable from concentration fluctuations.…”

Small-angle neutron scattering study of aqueous solutions of pentanediol and hexanediol

“…This procedure has been followed by D'Arrigo for analysing the scattering curves for diol solutions (D'Arrigo et al, 2000(D'Arrigo et al, , 2003. As the scattering curves for these systems are rather featureless, using model functions with more than four parameters was not always reliable (D'Arrigo et al, 2000).…”

“…In small-angle neutron scattering (SANS) studies of aqueous solutions of several diols and triols by D'Arrigo and co-workers (D'Arrigo et al, 2000(D'Arrigo et al, , 2003, the experimental data were analysed considering various models of interacting micelles. 1,2-Pentanediol and 1,2-hexanediol were suggested to form spherical hydrated micelle-like aggregates with attractive interaction between them.…”