Alcohol-Mediated Resistance-Switching Behavior in Metal-Organic Framework-Based Electronic Devices.

Metal-organic frameworks (MOFs) have drawn increasing attentions as promising candidates for functional devices. Herein, we present MOF films in constructing memory devices with alcohol mediated resistance switching property, where the resistance state is controlled by applying alcohol vapors to achieve multilevel information storage. The ordered packing mode and the hydrogen bonding system of the guest molecules adsorbed in MOF crystals are shown to be the reason for the alcohol mediated electrical switching. This chemically mediated memory device can be a candidate in achieving environment-responsive devices and exhibits potential applications in wearable information storage systems.

Self-assembled metal-organic frameworks crystals for chemical vapor sensing.

A 3D metal-organic frameworks (MOFs) crystals film is obtained via Langmuir-Blodgett technique and used as a photonic sensor for chemical vapor detection. The MOFs crystals film exhibits both acute responses towards various chemical vapors and high controllability in terms of peak intensity and position. The method represents a general, facile and flexible strategy for the fabrication of MOFs-based photonic sensors.

Self-Healing Microcapsule-Thickened Oil Barrier Coatings.

Low-viscosity oils could potentially act as self-healing barrier coatings because they can readily flow and reconnect to heal minor damage. For the same reason, however, they typically do not form stable coatings on metal surfaces. Increasing viscosity helps to stabilize the oil coating, but it also slows down the healing process. Here, we report a strategy for creating highly stable oil coatings on metal surfaces without sacrificing their remarkable self-healing properties. Low-viscosity oil films can be immobilized on metal surfaces using lightweight microcapsules as thickeners, which form a dynamic network to prevent the creep of the coating. When the coating is scratched, oil around the opening can rapidly flow to cover the exposed area, reconnecting the particle network. Use of these coatings as anticorrosion barriers is demonstrated. The coatings can be easily applied on metal surfaces, including those with complex geometries, both in air or under water, and remain stable even in turbulent water. They can protect metal in corrosive environments for extended periods of time and can self-heal repeatedly when scratched at the same spot. Such a strategy may offer effective mitigation of the dangerous localized corrosion aggravated by minor imperfections or damage in protective coatings, which are typically hard to prevent or detect, but can drastically degrade metal properties.

Ultrathin MnO(2) nanoflakes as efficient catalysts for oxygen reduction reaction.

Free-standing, ultrathin manganese dioxide nanoflakes were synthesized by cationic surfactant controlled reduction of KMnO4. MnO2 nanoflakes showed a much higher mass activity than other manganese based oxides as well as B and N doped nano carbons. The approach here demonstrates a facile chemical route towards efficient manganese dioxide catalysts.

In situ synthesis of large-area single sub-10 nm nanoparticle arrays by polymer pen lithography.

In order to take advantage of the unique properties of nanoparticles in integrated devices, it is desirable to position monodispersed nanoparticles on substrates with controlled placement. Herein, we utilize small molecules such as ethylene glycol (EG) or glycerol to facilitate the delivery of nanoparticle precursors to the substrates in the polymer pen lithography (PPL) process. Subsequently, large-area ordered single nanoparticle arrays, including sub-10 nm Ag nanoparticle, 30 nm Au nanoparticle and 80 nm Fe2O3 nanoparticle arrays have been synthesized in situ with controllable sizes and pitches.

Controlled incorporation of nanoparticles in metal-organic framework hybrid thin films.

A facile encapsulation strategy was reported for preparing nanoparticles/metal-organic framework hybrid thin films which exhibit both the active (catalytic, magnetic, and optical) properties derived from the NPs and the size-selectivity originating from the well-defined microporous structure of the MOF thin films.

A family of metal-organic frameworks exhibiting size-selective catalysis with encapsulated noble-metal nanoparticles.

The encapsulation of noble-metal nanoparticles (NPs) in metal-organic frameworks (MOFs) with carboxylic acid ligands, the most extensive branch of the MOF family, gives NP/MOF composites that exhibit excellent shape-selective catalytic performance in olefin hydrogenation, aqueous reaction in the reduction of 4-nitrophenol, and faster molecular diffusion in CO oxidation. The strategy of using functionalized cavities of MOFs as hosts for different metal NPs looks promising for the development of high-performance heterogeneous catalysts.