in recent years, using sol-gel procedure for the purpose of laboratory and industrial synthesis of nano-structures, and especially silica nano-particles, has been significantly increased. in this research, silica particles were synthesized by sol-gel procedure and their physical and chemical properties were studied by means of scanning electron microscopy (sem), transmission electron microscopy...

The effects of adding Nano-Silica particles on the compressive strength and water permeability of concrete and its comparison with that of Micro-Silica were investigated in this work. The effect of combination of Nano- silica and Micro-silica were also studied in this work, which resulted in an increase in compressive strength of concrete in comparison with other concrete specimens tested in th...

The effects of adding Nano-Silica particles on the compressive strength and water permeability of concrete and its comparison with that of Micro-Silica were investigated in this work. The effect of combination of Nano- silica and Micro-silica were also studied in this work, which resulted in an increase in compressive strength of concrete in comparison with other concrete specimens tested in th...

in the recent years, rapid growth of the world’s population and overutilization of fresh water resources have caused fresh water shortage crisis in the world. in spite of the agricultural activities in the northern beaches of iran and also severe decrease of the ground water level, it still has not taken any effective measures to desalinate caspian sea water in large scale. in this research, de...

zinc oxide nano-particles with the average diameter of about 25 nm were modified with different mole ratios of trimetoxyvinyl silane (tmvs) and oleic acid, as coupling agents, in order to modify their surface properties and render them more hydrophobic. then, dispersibility of the surface modified nano-particles was examined in some monomers with different levels of hydrophobicity, including me...

In fiber concretes, microcracks in the boundary area between the cement paste and the surface of aggregates or fibers are higher. Natural and artificial pozzolans can be used for reinforcing this area. In this research, the combination of glass fiber, zeolite, and nano silica particles were used in lightweight self-compacting concrete containing scoria. Fiber volume fractions between 0% to 1.5%...

In this paper the influence of two different sizes of silica particles (micro-silica and nano-silica) was studied on mechanical properties of sulfur and sulfur composite. To improve the structural properties, sulfur was plasticized using dicyclopentadiene (DCPD) and methyl styrene (MSt). Plasticized sulfur composite was prepared by melt blending of plasticized sulfur and silica particles. T...

Polyurethane-based micro- and nano-hybrid composites were produced with controlled porosity to be used as obturation materials. In addition to hydroxyapatite (HAp) micro-particles in the composites, two different ceramics particle types were also added: alumina micro-particles and silica nano-particles. Particles of different sizes provide the materials with improved mechanical properties: the ...

In this study a series of epoxy/silica nanocomposites were prepared by using nano silica particles which had different surface modifications. The morphology of the nanocomposite coatings was characterized by scanning electron microscopy SEM. The effects of the hydrophilic and hydrophobic feature of the nano particles on the Tg and anticorrosive properties of nanocomposite coatings were evaluate...