The width of the interface between two immiscible polymers, deuterated polystyrene and poly(methyl methacrylate), has been measured using neutron reflectivity as a function of the thickness of the deuterated polystyrene layer. A logarithmic dependence of interface width on film thickness is observed, characteristic of an interface broadened by thermal induced capillary waves, whose spectrum is cut off by dispersive interactions across the polymer layer. Reasonable agreement is obtained with the results of self-consistent field theory when suitably modified to account for capillary waves, resolving a longstanding discrepancy between theory and experiment. [S0031-9007(97)03096-2]

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The detonation nanodiamond is a versatile low‐cost nanomaterial with tunable properties and surface chemistry. In this work, it is shown how the application of nanodiamond (ND) can greatly increase the performance of electrochemically active polymers, such as polyaniline (PANI). Symmetric supercapacitors containing PANI‐ND nanocomposite electrodes with 3–28 wt% ND show dramatically improved cycle stability and higher capacitance retention at fast sweep rate than pure PANI electrodes. Contrary to other PANI‐carbon nanocomposites, specific capacitance of the selected PANI electrodes with embedded ND increases after 10 000 galvanostatic cycles and reaches 640 F g−1, when measured in a symmetric two‐electrode configuration with 1 M H2SO4 electrolyte. The demonstrated specific capacitance is 3–4 times higher than that of the activated carbons and more than 15 times higher than that of ND and onion‐like carbon (OLC).

The dewetting of thin films of end-functionalized polymers, ω- and α,ω-barium sulfonato polystyrenes, on a silicon substrate has been investigated as a function of initial film thickness, molecular weight, and functionality of the chains. The lower molecular weight monofunctional chains are found to dewet the substrate analogously to normal polystyrene but display an anomalous flow behavior at the surface. Moreover, after dewetting, the entire silicon surface still remains covered by a monolayer of monofunctional chains. The monolayer consists of a polymer brush of densely packed tethered chains, adsorbed via their ionic end groups. The dense packing and special conformations of the chains in the brush prevent interpenetration with other polymer chains, and the unadsorbed macromolecules dewet the brush. When the molecular weight of the monofunctional chains is increased, entanglements between the adsorbed polymer brush and the unadsorbed chains can occur and the dewetting process is retarded. Thin films of the difunctional chains do not dewet regardless of the molecular weight of the chains. The difference between mono- and difunctional materials is attributed to ionic aggregation, which is responsible for thermoreversible cross-linking and stabilization of thicker films by interaction of aggregates with dangling ends. It is suggested to use high molecular weight end-functionalized chains as polymeric additives to retard thin polymer film dewetting.