Synthesis of Nanosized Silica and Silver-Doped Silica Nanoparticles for Heat Transfer Fluids Applications

Abstract:

The nanosized silica (SiO₂) with the size less than 100 nm have successfully been prepared by hydrolysis and condensation of tetraethyl orthosilicate (TEOS) via a modified Stöber method at room temperature. The experiment was conducted by controlling the amount of the catalyst used, i.e., ammonium hydroxide (NH₄OH). The morphology observation of the synthesized silica nanoparticles was conducted by using a transmission electron microscope (TEM). It was found that the size of the silica depending on the amount of the catalyst used, with homogenous size ranging from 10 to 360 nm. The doping of silver nanoparticles was done by mixing the synthesized silica with the silver ions (Ag⁺) solutions. Then the sample was annealed for 75 min which results in the nucleation of the silver nanoparticles less than 20 nm onto the silica surfaces, depending on the temperature used.

• Periodical: Key Engineering Materials (Volume 660)
• Pages: 155-160
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.660.155
• Online since: August 2015
• Authors: Norsuria Mahmed*, Mohd Mustafa Al Bakri Abdullah, Andrei Victor Sandu, Petrică Vizureanu, Simo Pekka Hannula
• Keywords: Silica, Silver, Stöber Method, Transmission Electron Microscope

References

[1] V. Trisaksri, S. Wongwises. Critical view of heat transfer characteristics of nanofluids. Renew. Sust. Energ. Rev. 11 (2007) 512–523.

DOI: 10.1016/j.rser.2005.01.010

[2] C. J. Geankoplis. Transport Process and Separation Process Principles, fourth ed., Prentice Hall, USA, (2014).

[3] S. Lee, S.U.S. Choi, S. Li, J.A. Eastman. Measuring thermal conductivity of fluids containing oxide nanoparticles. ASME J. Heat Transfer. 121 (1999) 280–289.

DOI: 10.1115/1.2825978

[4] H. Xie, J. Wang, T. Xi, Y. Liu, F. Ai, Q. Wu. Thermal conductivity enhancement of suspensions containing nanosized alumina particles. J. Appl. Phys. 91 (2002) 4568–4572.

DOI: 10.1063/1.1454184

[5] P. Keblinski, S.R. Phillpot, S.U.S. Choi, J. A. Eastman. Mechanisms of heat flow in suspensions of nano-sized particles (nanofluids). Int. J. Heat Mass Transfer. 45 (2002) 855–863.

DOI: 10.1016/s0017-9310(01)00175-2

[6] Y. Xuan, Q. Li. Heat transfer enhancement of nanofluids. Int. J Heat Fluid Flow. 21 (2000) 58–64.

DOI: 10.1016/s0142-727x(99)00067-3

[7] Stöber, W., Fink, A. & Bohn, E. (1968) Controlled growth of monodisperse silica spheres in the micron size range. J. Colloid Inter. Sci. 26 (1), 62–69.

DOI: 10.1016/0021-9797(68)90272-5

[8] N. Mahmed, H. Jiang, O. Heczko, O. Söderberg, S-P. Hannula. Influence of different synthesis approach on doping behavior of silver nanoparticles onto the iron oxide-silica coreshell surfaces. J. Nanopart. Res. 14 (2012) 987.

DOI: 10.1007/s11051-012-0987-1

[9] I.A.M. ibrahim, A.A.F. Zikry, M.A. Sharaf. Preparation of spherical silica nanoparticles: Stöber silica. J. Am. Sci. 11 (2010) 985–989.

[10] T. Matsoukas, E. Gulari. Dynamics of growth of silica particles from ammonia-catalyzed hydrolysis of tetra-ethyl-orthosilicate. J. Colloid Int. Sci. 124 (1987) 252–261.

DOI: 10.1016/0021-9797(88)90346-3