Persistence lengths of stilbene and styrene containing alternating copolymers were measured using small-angle X-ray scattering (SAXS) and size-exclusion chromatography (SEC). For SAXS measurement, a graphical approach and the Sharp and Bloomfield method of analyzing scattering data were both used to quantify the chain stiffness. For SEC measurement, the Bohdanecký linear approximation was applied to determine persistence lengths. The complementary results obtained from SAXS approaches as well as from SEC measurements characterized stilbene copolymers as a class of semirigid polymers with persistence lengths in a range of 2–6 nm. Stilbene copolymers are more rigid than their styrene analogues.

The controlled atom transfer radical polymerization of an ionic liquid, 1-(11-acryloylundecyl)-3-methyl imidazolium bromide (ILBr), from both ends of a telechelic poly(propylene oxide) (PPO) macroinitiator, end-functionalized with bromoisobutyryloyl is reported. The resulting highly water-soluble triblock, poly(ILBr-b-PO-b-ILBr) is multistimuli responsive. This new class of triblocks exhibits classical surface activity in lowering surface tension at the air-water interface and in modifying wetting in waterborne coatings. It also immunizes model colloids against coagulation induced by Debye-Hückel (indifferent electrolyte) electrostatic screening. Further, sol-gel thermoreversibility is unexpectedly found as an additional form of stimuli responsiveness.

Anatase titanium dioxide nanoparticles are derivatized with the polymerizable reagent (3-methacryloxypropyl)trimethoxysilane to provide dispersions in organic solvent. The titania core particles are characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The organic component structures and thickness are elucidated using nuclear magnetic resonance (NMR), quasielastic light scattering (QELS), and size-exclusion chromatography (SEC). Thin, high-refractive-index coatings prepared from the organic dispersions are characterized by atomic force microscopy (AFM). The combination of microscopies, spectroscopy, light scattering, and separation techniques provides unique information on the structure, thickness, morphology, and size distributions of the surface-treated nanoparticles that is difficult to obtain by any single technique. The findings indicate titania platelets with a modal diameter of 9.8 nm and a thickness of approximately 1.5 nm. The particles are coated with a 1.5-1.9 nm thick organic ligand layer, and a substantial population of 2 nm siloxane oligomers is detected. The analytical methodology presented may also be useful for characterizing other anisotropic organic-inorganic nanoparticles and their dispersions.

A stimuli-responsive homopolymer poly(ILBr) is fabricated via a "two-phase" atom transfer radical polymerization (ATRP) process, where ILBr stands for the reactive ionic liquid surfactant, 1-[11-acryloylundecyl]-3-methyl-imidazolium bromide. An extraordinarily wide molecular weight distribution (PDI = 6.0) was obtained by introducing the initiator (4-bromomethyl methyl benzoate) in a heterogeneous two-phase process. The molecular weight distribution of poly(ILBr) was characterized by size-exclusion chromatography (SEC). The resulting homopolymer was found to be surface active and stimuli responsive. Poly(ILBr) films coated on quartz exhibit stimuli-responsive dewetting after ion exchange of Br(-) by PF(6)(-). This dewetting phenomenon can be understood in chain segmental terms as a stimuli-induced structural relaxation and appears to be the first such reported stimuli-responsive polymeric dewetting. Titrating aqueous poly(ILBr) with aqueous bis(2-ethylhexyl)sulfosuccinate induces nanophase separation and results in the condensation of nanoparticles 30-60 nm in diameter.