Nanocrystalline ZnZr4(PO4)6 ceramics as an efficient catalyst have been used for the preparation of methyl 6-amino-5-cyano-4-aryl-2,4-dihydropyrano[2,3-c]pyrazole-3-carboxylates by the four component reaction of dimethylacetylenedicarboxylate, hydrazinehydrate, malononitrile and aromatic aldehydes in water at room temperature. In this research Nano-ZnZr4(PO4)6 coordinate with the active groups(...

1 Instituto de Cerámica y Vidrio, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain, 2 Microdevices for Photonics Laboratory (MIP-LAB), Istituto di Fisica Applicata “Nello Carrara”, Consiglio Nazionale delle Ricerche (CNR), Sesto Fiorentino, Italy, 3 Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Roma, Italy, 4 Instituto de Catálisis y Petroleoquímica, Co...

background: an increase in surface roughness of ceramics may decrease strength and affect the clinical success of ceramic restorations. however, little is known about the effect of acidic agents on ceramic restorations. the aim of this study was to evaluate the surface roughness of dental ceramics after being immersed in acidic agents.     methods: eighty-three ceramic disk specimens (12.0 mm i...

For the first time a novel oxygen reduction catalyst with a 3D platinized graphene/nano-ceramic sandwiched architecture is successfully prepared by an unusual method. Herein the specific gravity of graphene nanosheets (GNS) is tailored by platinizing graphene in advance to shorten the difference in the specific gravity between carbon and SiC materials, and then nano-SiC is well intercalated int...

Technology of active glass-ceramics (GC) is an important part of luminescent materials engineering. The classic method to obtain GC is based on annealing of parent glass in proper temperature and different time periods. Generally, only the bulk materials are investigated as a starting host for further applications. However, the effect of an additional heat-treatment process on emission and stru...

Theoretical analysis and Computer simulations have proven to be cost-effective and powerful tools in scientific studies of materials, particularly at nano-scale where synthesis of nano-structures, interpretation of their observed character and exploration of new structures are not always straight forward. We present here fundamental principles of techniques used today for computational simulati...

Reducing mass without sacrificing mechanical integrity and performance is a critical goal in a vast range of applications. Introducing a controlled amount of porosity in a strong and dense material (hence fabricating a cellular solid) is an obvious avenue to weight reduction. The mechanical effectiveness of this strategy, though, depends strongly on the architecture of the resulting cellular ma...

INTRODUCTION Alumina ceramics have long been of technological importance. However, their brittleness limits their potential for use in structural applications. Traditional approaches proposed to improve the strength and reliability of ceramics include: decrease flaw size, improve fracture toughness and flaw insensitivity, and decrease applied stresses. Polymers on the other hand, although weak,...

In the context of the modern world, the term ceramics suggests a very versatile group of materials capable of being designed to have particular physical and chemical properties and to fulfil a wide range of functions, functions that traditionally have often been fulfilled by other types of material.1 While suitably designed ceramics may hold the key to overcoming many of humankind’s future tech...

Calcium phosphate based glasses with different concentrations of TiO2 (0 to 2.5 mol%) were prepared and their corresponding glass-ceramics were obtained by controlled heat treatments. The amorphous nature of glasses and the presence of crystalline phases in glass-ceramics were studied through XRD studies. Density, molar volume, ultrasonic velocities, attenuation, elastic constants and microhard...