Catalytic growth of metallic tungsten whiskers based on the vapor-solid-solid mechanism

Recent Advances in Whiskers: Properties and Clinical Applications in Dentistry

Whiskers are nanoscale, high-strength fibrous crystals with a wide range of potential applications in dentistry owing to their unique mechanical, thermal, electrical, and biological properties. They possess high strength, a high modulus of elasticity and good biocompatibility. Hence, adding these crystals to dental composites as reinforcement can considerably improve the mechanical properties and durability of restorations. Additionally, whiskers are involved in inducing the value-added differentiation of osteoblasts, odontogenic osteocytes, and pulp stem cells, and promoting the regeneration of alveolar bone, periodontal tissue, and pulp tissue. They can also enhance the mucosal barrier function, inhibit the proliferation of tumor cells, control inflammation, and aid in cancer prevention. This review comprehensively summarizes the classification, properties, growth mechanisms and preparation methods of whiskers and focuses on their application in dentistry. Due to their unique physicochemical properties, excellent biological properties, and nanoscale characteristics, whiskers show great potential for application in bone, periodontal, and pulp tissue regeneration. Additionally, they can be used to prevent and treat oral cancer and improve medical devices, thus making them a promising new material in dentistry.

Green synthesis of stable Cu(0) nanoparticles onto reduced graphene oxide nanosheets: a reusable catalyst for the synthesis of symmetrical biaryls from arylboronic acids under base-free conditions

The Cu(0) nanoparticle-rGO composites exhibit excellent catalytic activity for the synthesis of symmetrical biaryls from arylboronic acids under microwave irradiation.

A large-scale fabrication of flower-like submicrometer-sized tungsten whiskers via metal catalysis

Tungsten powder mixed with an appropriate amount of nickel and iron powders is used as raw material to fabricate large-scale tungsten whisker-like structure. The morphology, microstructure and composition of the whisker-like tungsten are observed and tested by scanning electron microscope and FESEM, transmission electron microscopy, X-ray spectroscopy, and X-ray diffraction, respectively. The main component of the tungsten whisker-like structure is tungsten, which has the axial growth along the <100 > direction with large aspect ratio and possesses flower-like structure. Large-scale submicrometer-sized whisker-like tungsten was fabricated via vapor phase deposition approach with the aid of metal catalysts at 800°C by holding for 6 h in the appropriate atmosphere. The growth procedure of flower-like tungsten whisker is probably based on the vapor-liquid-solid mechanism at beginning of the formation of tungsten nuclei, then vapor-solid mechanism is dominant.