Graphene sheets offer extraordinary electronic, thermal and mechanical properties and are expected to find a variety of applications. A prerequisite for exploiting most proposed applications for graphene is the availability of processable graphene sheets in large quantities. The direct dispersion of hydrophobic graphite or graphene sheets in water without the assistance of dispersing agents has generally been considered to be an insurmountable challenge. Here we report that chemically converted graphene sheets obtained from graphite can readily form stable aqueous colloids through electrostatic stabilization. This discovery has enabled us to develop a facile approach to large-scale production of aqueous graphene dispersions without the need for polymeric or surfactant stabilizers. Our findings make it possible to process graphene materials using low-cost solution processing techniques, opening up enormous opportunities to use this unique carbon nanostructure for many technological applications.

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Processable aqueous dispersions of graphene nanosheets

Nanodiamonds have excellent mechanical and optical properties, high surface areas and tunable surface structures. They are also non-toxic, which makes them well suited to biomedical applications. Here we review the synthesis, structure, properties, surface chemistry and phase transformations of individual nanodiamonds and clusters of nanodiamonds. In particular we discuss the rational control of the mechanical, chemical, electronic and optical properties of nanodiamonds through surface doping, interior doping and the introduction of functional groups. These little gems have a wide range of potential applications in tribology, drug delivery, bioimaging and tissue engineering, and also as protein mimics and a filler material for nanocomposites.

The properties and applications of nanodiamonds

Additive manufacturing (AM) alias 3D printing translates computer-aided design (CAD) virtual 3D models into physical objects. By digital slicing of CAD, 3D scan, or tomography data, AM builds objects layer by layer without the need for molds or machining. AM enables decentralized fabrication of customized objects on demand by exploiting digital information storage and retrieval via the Internet. The ongoing transition from rapid prototyping to rapid manufacturing prompts new challenges for mechanical engineers and materials scientists alike. Because polymers are by far the most utilized class of materials for AM, this Review focuses on polymer processing and the development of polymers and advanced polymer systems specifically for AM. AM techniques covered include vat photopolymerization (stereolithography), powder bed fusion (SLS), material and binder jetting (inkjet and aerosol 3D printing), sheet lamination (LOM), extrusion (FDM, 3D dispensing, 3D fiber deposition, and 3D plotting), and 3D bioprinting....

Polymers for 3D Printing and Customized Additive Manufacturing

Acenes have long been the subject of intense study because of the unique electronic properties associated with their pi-bond topology. Recent reports of impressive semiconductor properties of larger homologues have reinvigorated research in this field, leading to new methods for their synthesis, functionalization, and purification, as well as for fabricating organic electronic components. Studies performed on high-purity acene single crystals revealed their intrinsic electronic properties and provide useful benchmarks for thin film device research. New approaches to add functionality were developed to improve the processability of these materials in solution. These new functionalization strategies have recently allowed the synthesis of acenes larger than pentacene, which have hitherto been largely unavailable and poorly studied, as well as investigation of their associated structure/property relationships.

The larger acenes: versatile organic semiconductors.

Recent progress in processing and properties of ZnO

Mushrooms have been valued as edible and medicinal resources, and antitumor substances have been identified in many mushroom species. Polysaccharides are the best known and most potent mushroom-derived substances with antitumor and immunomodulating properties. Although the isolation process, structural characterization and antitumor activity of mushroom polysaccharides have been extensively investigated in the past three decades, the relationship between the antitumor activity and the chemical composition as well as the high order structure of their active components is still not well established. These studies are still in progress in many laboratories, and the role of polysaccharides as antitumor agent is especially under intense debate. The purpose of the present review is to summarize the available information, and to reflect the current status of this research area with a view for future direction.

Qi Wang

Papers

Antitumor polysaccharides from mushrooms: a review on their isolation process, structural characteristics and antitumor activity

Properties, and Applications

Heat induced gelling properties of soy protein isolates prepared from different defatted soybean flours

A soy protein-polysaccharides Maillard reaction product enhanced the physical stability of oil-in-water emulsions containing citral

A review of isolation process, structural characteristics, and bioactivities of water-soluble polysaccharides from Dendrobium plants