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A series of four hydrophobically modified, diphenylazo-based organic salts have been prepared and characterized. To achieve this a C(x) (x = 4, 6, 8, or 10) hydrocarbon chain was inserted between the diphenylazo moiety and the quaternary ammonium headgroup of the salt. The absorption of each of the four modified organic salts into anionic microgel particles of poly(N-isopropylacrylamide-co-acrylic acid) has been studied at pH 8. In addition, the hydrodynamic diameters and electrophoretic mobilities of the microgel particles have been studied as a function of the organic salt concentration, also at pH 8. In addition to the electrostatic attraction between the quaternary ammonium head groups of the organic salts and the anionic groups within the microgel particles, hydrophobic association between the chains of the organic salts within the microgel particles plays a role, with this effect increasing strongly from x=4 to 10. Desorption of the x=4 and 6 organic salts occurs readily on changing, in situ, the pH from 8 to 2.5 (and thereby eliminating the electrostatic interaction) but is only partially achieved for the x=8 and 10 organic salts. Indeed, for the x=10 organic salt, only about 80% of the organic salt is desorbed upon dilution of the microgel particles into a large excess of water.

A surfactant featuring a polymerizable pyrrole head group (dodecyl-dimethyl-(2-pyrrol-1-yl-ethyl)-ammonium bromide, DDPABr) was synthesized. The thermotropic behavior of the surfactant was investigated by differential scanning calorimetry (DSC) and X-ray scattering techniques, with small-angle X-ray scattering (SAXS) analysis revealing a highly ordered lamellar bilayer structure. After full characterization, DDPABr was used in the preparation of mesostructured SiO2 nanocomposite thin films via evaporation-induced self-assembly (EISA). Resulting thin SiO2-DDPABr films were studied by 1D and 2D small-angle X-ray scattering (SAXS) techniques, indicating a lamellar nanocomposite structure. Suitable theoretical SAXS models were applied to fit the experimental 1D SAXS data. The surfactant could be chemically polymerized within the lamellar domains.

The copolyaddition of α-ω-dienes with disulfides and unsaturated surfmers within the organized architecture of polyelectrolyte−surfactant complexes is presented. The influence of monomer swelling and polymerization on the phase morphology of the host was investigated by small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). SAXS shows that the specific monomer systems allow unusually high monomer swelling (and corresponding polymer content of hydrophobic monomer) under preservation of the order on the nanoscale. This is supported by the TEM measurements where long-range ordered lamellar arrays with a repeat period of up to 4.8 nm were identified. This corresponds to a swelling of the lamellar phase, with preservation of long-range order, and an increase in the d-spacing as compared to the original complex, of more than 150%.

The structure and phase behavior of a class of multiple negatively charged azo-dyes complexed with a homologous series of cationic surfactants were examined by differential scanning calorimetry, diverse microscopy techniques, and small- and wide-angle X-ray scattering. It turned out that the resulting dye−surfactant complexes do form highly organized supramolecular architectures, which are crystalline/liquid crystalline in nature. The phase structure and the onset of thermal phase transitions depend both on the substitution pattern of the dye scaffold as well as on the sterical demands and volume fractions of the surfactant tails. This class of materials also shows a number of interesting physicochemical properties, namely, liquid crystalline phases with pronounced optical anisotropy.

Polymerization of hydrophobic monomers, such as the difunctional monomer m-diisopropenylbenzene, within mesoscopically structured polyelectrolyte−surfactant complexes as hosts, leads to the formation of unconventionally shaped polymeric particles. The influence of the presence of monomers and guest polymers on the phase morphology of the host is investigated by small-angle X-ray scattering (SAXS) and dynamic mechanical analysis (DMA). SAXS shows that these new stable hosts can hold up to 17% guest polymer before phase disruption is encountered. These findings are supported by changes in the mechanical properties as determined by DMA. Transmission electron microscopy (TEM) investigations show that colloidal copies of the same length scale as the deformable host are formed. The shapes of the mesostructures are dictated by the phase morphology of the structure-directing host to produce nanosized wires, cigars and fibrillar bent shapes, as revealed by TEM.