Ion channel forming self-assembling systems based on benzenesulfonic acid with unsaturated aliphatic substituents

Abstract

The structure and phase behavior of amphiphilic compound sodium 2,3,4-tri(dodecyl)benzenesulfonate, which is capable of self-assembling and contains methacryloyl groups in aliphatic ends, were studied by X-ray diffraction and differential scanning calorimetry. The initial samples are characterized by an ordered columnar ϕ oh phase, which, during a rise in temperature to 53°C (at the expense of mobility, an increase in mesogenic groups, and a loss of order in their mutual arrangement), transforms into a disordered columnar ϕ h phase. Under the action of irradiation, the cross-linking of benzenesulfonate molecules by methacryloyl groups and the formation of a continuous polymer matrix occur, which leads to a consistency of the column diameter at high temperatures. Cross linking proceeds much more intensively in the area where the disordered columnar phase exists. To analyze the structure of the columnar phase, we used an established technique: the reconstruction of electron density distribution maps in cylindrically symmetric systems from the relation of the intensities of small-angle X-ray reflections. Mutual ordering of benzenesulfonic groups in the area where the ϕ oh phase exists leads to the formation of ordered ion channels; this opens up possibilities to use this material to make ion-selective membranes with controlled conductivity.