When submerged under water, polyelectrolyte brush surfaces become highly oil‐repellent. This is due to the ability of the charged moieties on the polymer backbone to retain strong hydration shells. Despite their technological relevance, there is no rational design principle for optimizing the oil‐repellent performance of hydrophilic polyelectrolyte brushes. Using droplet probe atomic force microscopy, the interaction forces between an oil droplet and different polyelectrolyte brushes are measured. It is shown that surfaces are most repellent when there are repulsive electric double‐layer forces that can stabilize a continuous water film beneath the oil droplet. Once a stable hydration layer forms, the oil‐repellent performance is not affected by the polymer brush characteristics, such as its thickness and swelling ratio.

A modular facile route has been developed to synthesize functionalized 2,5-di(thiophen-2-yl)-1-H-arylpyrroles from readily available starting materials. These units are compatible with various polymerization conditions and are versatile building blocks for conjugated polymers. The polymers show high thermal stability and solubility in a number of solvents. Characterization of the polymers reveals a correlation between molecular packing, controllable by polymer design, and charge carrier mobility.

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Significance:The authors report one-shot annulative π-extension (APEX) reactions that occur at the K-region (convex armchair edge) of polycyclic aromatic hydrocarbons, using the PdMe 4 (SbF 6 ) 2 / o-chloranil catalytic system and silicon-bridged aromatics as π-extending agents. Comment:The protocol is applicable to multiple APEX and sequential APEX reactions, providing convenient and rapid access to various nanographene structures. This method is complimentary to traditional two-step nanographene syntheses. DCE 80 °C, 2 h + o-chloranil (2.0 equiv) Pd(MeCN) 4 (SbF 6 ) 2 (5 mol%) O O Cl Cl Cl Cl Si Me Me 10 examples, 25-89% yield H H R R R R Selected examples:t-Bu t-Bu CF 3 89% yield t-Bu t-Bu OMe 57% yield 51% yield t-Bu t-Bu 83% yield t-Bu t-Bu t-Bu t-Bu 69% yield SYNFACTS Contributors: G e o r g T h i e m e V e r l a g S t u t t g a r t · N e w Y o r k