scholarly journals Hollow Nano Silica: Synthesis, Characterization and Applications

10.5772/33547 ◽  
2012 ◽  
Author(s):  
N. Venkatathri
Keyword(s):  
2020 ◽  
Vol 12 (24) ◽  
pp. 10646
Author(s):  
Evidence Akhayere ◽  
Ashok Vaseashta ◽  
Doga Kavaz

Water contamination by petroleum and its byproducts presents a major challenge worldwide. It is critical that sustainable treatment methods be employed for the removal of such contaminants from polluted water. For this investigation, magnetic nano silica (M-NS) was synthesized using agricultural waste from barley husk using a two-step process that is environmentally friendly and uses green chemistry synthesis. The barley husk waste was used as a precursor for the synthesis of nano-silica following a low energy and sustainable method of acid reflux and heat treatment. Nano-silica was then used for the synthesis of M-NS, with the addition of a magnetic solution of Fe3O4 nanoparticles. The magnetic nano-silica particles were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), Zeta potential analysis (ZETA) and X-Ray Diffraction (XRD). Magnetic nano-silica particles were observed to have an average diameter of 162 nm and appeared to be hydrophobic, with a large surface area of ~120 m2/gm. Due to these characteristics, magnetic nano-silica was used as an adsorbent for the removal of petrol contaminants from water. The experimental procedure showed that only 0.6 gm. of M-NS was used on 40 mg/L concentration of petroleum and the experiments recorded a high uptake efficiency of 85%. The sorption was shown to be an effective process since a high amount of petroleum was removed. The study further demonstrates that as the amount of sorbent is increased, the sorption capacity also increases until an equilibrium is reached. The results of this study establish that synthesis of M-NS, using environmentally sustainable processes, has the required characteristics to serve as sorbent for petroleum and its byproducts from contaminated water, thus enhancing environmental sustainability.


2021 ◽  
pp. 103338
Author(s):  
Behnam Behnia ◽  
Hossein Safardoust-Hojaghan ◽  
Omid Amiri ◽  
Masoud Salavati-Niasari ◽  
Ali Aali Anvari

Author(s):  
Jia Lu ◽  
Xiaohou Shao ◽  
Chao Yin ◽  
Xinyu Mao ◽  
Long Wang ◽  
...  

GIS Business ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 158-165 ◽  
Author(s):  
Dr. Sarvesh PS Rajput

This study reported that the addition of nano-silica enhances the mechanical characteristics of concrete as its compressive, flexural and tensile split strengths are increased. As a comparison mixture to equate it along with nano-modified concrete, ordinary samples of Portland cement (OPC) have been utilized. Herein, upto 6.0 percent of OPC has been substituted by nanosilica. In fact, the introduction of nanosilica improves mechanical and microstructural characteristics of concrete by significantly (28 to 35%). The finding therefore, indicated that partly replacing OPC with up to 5 percent nanosilica increases the mechanical and microstructural properties cured up to ninety days as opposed to the standard OPC mix.


2020 ◽  
Vol 9 (1) ◽  
pp. 303-322 ◽  
Author(s):  
Zhifang Zhao ◽  
Tianqi Qi ◽  
Wei Zhou ◽  
David Hui ◽  
Cong Xiao ◽  
...  

AbstractThe behavior of cement-based materials is manipulated by chemical and physical processes at the nanolevel. Therefore, the application of nanomaterials in civil engineering to develop nano-modified cement-based materials is a promising research. In recent decades, a large number of researchers have tried to improve the properties of cement-based materials by employing various nanomaterials and to characterize the mechanism of nano-strengthening. In this study, the state of the art progress of nano-modified cement-based materials is systematically reviewed and summarized. First, this study reviews the basic properties and dispersion methods of nanomaterials commonly used in cement-based materials, including carbon nanotubes, carbon nanofibers, graphene, graphene oxide, nano-silica, nano-calcium carbonate, nano-calcium silicate hydrate, etc. Then the research progress on nano-engineered cementitious composites is reviewed from the view of accelerating cement hydration, reinforcing mechanical properties, and improving durability. In addition, the market and applications of nanomaterials for cement-based materials are briefly discussed, and the cost is creatively summarized through market survey. Finally, this study also summarizes the existing problems in current research and provides future perspectives accordingly.


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