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A palladium-catalyzed asymmetric chloroenolate allylation with vinyl benzoxazinanones under mild reaction conditions has been developed, affording a series of optically active 3,3-disubstituted oxindoles exhibiting a chloro-group and a linear aryl amino side chain in good yields with up to 96% ee. Versatile functional group tolerance on the benzene ring has been demonstrated, and the utility of this method was probed by a scale-up synthesis and highlighted by product derivatizations.

Lightweight polymeric foam is highly attractive as thermal insulation materials for energy-saving buildings but is plagued by its inherent flammability. Fire-retardant coatings are suggested as an effective means to solve this problem. However, most of the existing fire-retardant coatings suffer from poor interfacial adhesion to polymeric foam during use. In nature, snails and tree frogs exhibit strong adhesion to a variety of surfaces by interfacial hydrogen-bonding and mechanical interlocking, respectively. Inspired by their adhesion mechanisms, we herein rationally design fire-retardant polymeric coatings with phase-separated micro/nanostructures viaa facile radical copolymerization of hydroxyethyl acrylate (HEA) and sodium vinylsulfonate (VS). The resultant waterborne poly(VS-co-HEA) copolymers exhibit strong interfacial adhesion to rigid polyurethane (PU) foam and other substrates, better than most of the current adhesives because of the combination of interfacial hydrogen-bonding and mechanical interlocking. Besides a superhydrophobic feature, the poly(VS-co-HEA)-coated PU foam can self-extinguish a flame, exhibiting a desired V-0 rating during vertical burning and low heat and smoke release due to its high charring capability, which is superior to its previous counterparts. Moreover, the foam thermal insulation is well-preserved and agrees well with theoretical calculations. This work offers a facile biomimetic strategy for creating advanced adhesive fire-retardant polymeric coatings for many flammable substrates.

I. INTRODUCTION The monetary aggregates and money demand in China have received increasing attention in recent years (see, for example, Peebles, 1984; Chow, 1987; Feltenstein and Farhadian, 1987; Portes and [...]

The development of hydrogel–organogel bilayer films has greatly promoted the application of asymmetric structures in bionics, biointegrated electronics, and other basic industries. However, the ability to bond the hydrogel and organogel tightly remains a significant challenge. Herein, we propose a simple one-pot method for the fabrication of multiresponsive hydrogel–organogel bilayer films, consisting of a hydrophobic poly(butyl acrylate) (polyBA) layer, a salt-/thermo-responsive poly(3-(1-(4-vinylbenzyl)-1H-imidazol-3-ium-3-yl)propane-1-sulfonat) (polyVBIPS) layer, and interfacially distributed vinyl-functionalized nanoparticles. The presence of functionalized nanoparticles leads to strong adhesion between the hydrogel and organogel via copolymerization between the hydrogel and organogel precursors. Since the hydrophobic organogels and hydrophilic hydrogels exhibit independent swelling–shrinking behaviors, the resultant bilayer films undergo rapid, large-amplitude, reversible, and repeatable bidirectional bending under various external stimuli, such as temperature, salt solutions, and organic solvents. The excellent multiresponsive bending behaviors were further demonstrated in biomimetic manipulators which show excellent “capture–transport–release” complex mechanical motions. Additionally, on the basis of the salt response of polyVBIPS, a conceptual hydrogel–organogel bilayer pipe has been designed for the removal of oil/seawater pollution. Overall, this work provides a new strategy for enhancing interfacial strength in immiscible binary systems. A new hydrogel–organogel bilayer film has been developed with great potential for use in the applications of soft robots and sewage treatment systems.

B-N-doped graphene (B-N-G) was designed as a novel carrier for Pd nanoparticles (NPs) and it was used as the electrocatalyst for ethanol oxidation in alkaline medium. B and N species were introduced onto the graphene surface by the process of B and N sequentially incorporation. According to XPS results, most of B and N atoms are bonded with C atoms separately, which could increase the spin density and activate the neighboring carbon atoms, and further cause strong interaction between Pd and substrates. So, Pd/B-N-G catalyst presents most metallic Pd content and least Pd2+ content, as well as decreased Pd-3d binding energy. TEM results showed that Pd NPs dispersed most uniformly with an average size of 2.9 nm on Pd/B-N-G. Electrochemical evaluation showed that Pd/B-N-G catalyst exhibited much improved catalytic performance and poisoning tolerance for ethanol oxidation in alkaline medium as compared to those of Pd/B-G, Pd/N-G and Pd/G. B-N-G carrier promoted the high dispersion of Pd NPs due to the coexisting active sites introduced by B-N codoping, which improved the utilization efficiency of Pd. Furthermore, the enhanced electronic effects between Pd particles and the support caused by B-N codoping, may cause synergistic effects and thereby eventually improve the catalytic performance.