Phase stability and small-angle neutron scattering (SANS) data show that surfactant-stabilized nanodomains of a typical ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF4]) may be dispersed by the nonionic surfactant Triton-X100 in cyclohexane. Analyses of these SANS data are consistent with the formation of ionic liquid-in-oil microemulsion droplets.

Controlling the order and spatial distribution of self-assembly in multicomponent supramolecular systems could underpin exciting new functional materials, but it is extremely challenging. When a solution of different components self-assembles, the molecules can either coassemble, or self-sort, where a preference for like-like intermolecular interactions results in coexisting, homomolecular assemblies. A challenge is to produce generic and controlled 'one-pot' fabrication methods to form separate ordered assemblies from 'cocktails' of two or more self-assembling species, which might have relatively similar molecular structures and chemistry. Self-sorting in supramolecular gel phases is hence rare. Here we report the first example of the pH-controlled self-sorting of gelators to form self-assembled networks in water. Uniquely, the order of assembly can be predefined. The assembly of each component is preprogrammed by the pK a of the gelator. This pH-programming method will enable higher level, complex structures to be formed that cannot be accessed by simple thermal gelation.

Neutron reflection (NR) and surface tension methods were compared for accessing the equilibrium adsorption isotherm of various ionic surfactants at the air-water interface. Four custom-synthesized anionics were investigated in detail: sodium dihexyl sulfosuccinate (di-C6SS), bis(1H,1H-perfluoro-npentyl)sodium sulfosuccinate (di-CF4), bis(1H,1H,5H-octafluoro-n-pentyl)sodium sulfosuccinate (di-HCF4), and bis(1H,1H,5H-octafluoropentyl)-2-sulfoglutaconate (di-HCF4GLU). Commercial n-alkyltrimethylammonium bromide (Cn-TAB) cationic surfactants with C12, C14, and C16 chain lengths were also studied. The experiments examined the validity of the Gibbs equation, and the prefactor 2, for these seven compounds. Effects of contaminants, trace levels of polyvalent metal ions, and hydrophobic impurities were assessed for the anionics. When added at low levels, tetrasodium ethylenediaminetetraacetate (EDTA) was effective for eliminating effects of metallic impurities, and foam fractionation was used to remove hydrophobic contaminants. The effects of these treatments on the apparent surface excess and procedures for obtaining agreement between the neutronic and tensiometric isotherms are described. Finally, it was confirmed that the Gibbs prefactor of 2 applies for all these 1:1 ionic surfactants.