Facile and controlled synthesis of silica sol nanospheres through a modified sol-gel process

Abstract

An effective and reproducible preparation of silica sol nanospheres via a modified sol-gel process has been described. Monodisperse and stable silica sol nanospheres with uniformsize were successfully obtained through the optimized synthesis in which the mixture of tetraethyl orthosilicate (TEOS) and ethanol was followed by the addition of water and ammonium hydroxide (NH₃) separately, and the size of silica sol spheres was strictly controlled in the range of 25–119 nm with a narrow size distribution by fine adjustment of several reaction parameters. Results showed that in the presence of low concentration of TEOS, spheres size rose first and reached maximum when H₂O concentration was up to 66 g/L. However, the diameter of silica sol spheres decreased above 66 g/L of H₂O concentration. Furthermore, it was also found that the size and size distribution of silica sol nanospheres were affected by NH₃ concentration. As NH₃ concentration increased from 15 to 35 g/L, the diameter declined from 83 to 64 nm. Nevertheless, higher NH₃ concentration would result in relatively broad size distribution, and gelation occurred when NH₃ concentration reached 44 g/L. In addition, the effect of the different feed rates of NH₃ on the size growth of silica sol nanospheres was also discussed.

Keywords

sol-gel process / optimized synthesis / silica sol / nanospheres

References

[1] Jokinen M, Peltola T, Veittola S, . Adjustable Biodegradation for Ceramic Fibers Derived from Silica Sols[J]. J. Eur. Ceram. Soc., 2000, 20(11): 1 739-1 748.

[2] Lidén E, Karlsson S, Tokarz B Silica Sols as Refractory Fibre Binders[J]. J. Eur. Ceram. Soc., 2001, 21(6): 795-808.

[3] Li J Z, Lu G X Reaction Performance of Partial Oxidation of Methane over Ni/SiO₂ Catalysts using Monodisperse Silica Sol as Supporting Precursor[J]. Appl. Catal., A, 2004, 273(1–2): 163-170.

[4] Kesmez Burunkaya E, Kiraz N, . Effect of Acid, Water and Alcohol Ratios on Sol-Gel Preparation of Antireflective Amorphous SiO₂ Coatings[J]. J. Non-Cryst. Solids, 2011, 357(16–17): 3 130-3 135.

[5] Stöber W, Fink A Controlled Growth of Monodisperse Silica Spheres in the Micron Size Range [J]. J. Colloid Interface Sci., 1968, 26(1): 62-69.

[6] Bogush G H, Zukoski C F Studies of the Kinetics of the Precipitation of Uniform Silica Particles through the Hydrolysis and Condensation of Silicon Alkoxides [J]. J. Colloid Interface Sci., 1991, 142(1): 1-18.

[7] Rao K, Elhami K, Kodaki T, . A Novel Method for Synthesis of Silica Nanoparticles[J]. J. Colloid Interface Sci., 2005, 289(1): 125-131.

[8] Park S K, Kim K D, Kim H T Preparation of Silica Nanospheres: Determination of the Optimal Synthesis Conditions for Small and Uniform Spheres [J]. Colloids and Surf. A, 2002, 197(1–3): 7-17.

[9] Wang W, Gu B Self-Assembly of Two- and Three-Dimensional Particle Arrays by Manipulating the Hydrophobicity of Silica Nanospheres[J]. J. Phys. Chem. B, 2005, 109(47): 22 175-22 180.

[10] Kim K S, Kim J K, Kim W S Influence of Reaction Conditions on Sol-Gel Preparation Process Producing Silicon Oxide Particles[J]. Ceram. Int., 2002, 28(2): 187-194.

[11] Kim K D, Kim H T Formation of Silica Nanoparticles by Hydrolysis of TEOS using a Mixed Semi-Bach/Bach Method[J]. J. Sol-gel Sci. Thchnol., 2002, 25(3): 183-189.

[12] Wang X D, Shen Z X, Sang T, . Preparation of Spherical Silica Particles by Stöber Process with High Concentration of Tetra-Ethyl-Orthosilicate[J]. J. Colloid Interface Sci., 2010, 341(1): 23-29.

[13] Wang H C, Wu C Y, Chung C C, . Analysis of Parameters and Interaction between Parameters in Preparation of Uniform Silicon Dioxide Nanoparticles using Response Surface Methodology[J]. Ind. Eng. Chem. Res., 2006, 45(24): 8 043-8 048.

[14] Watanabe R, Yokoi T, Kobayashi E, . Extension of Size of Monodisperse Silica Nanospheres and Their Well-Ordered Assembly[J]. J. Colloid Interface Sci., 2011, 360(1): 1-7.

[15] Li J, Chen L X, Zhang Z M, . Synthesis and Size Control of Monodisperse Silica Sol Nanospheres via a Modified Stöber Method [J]. Adv. Mate. Res., 2012, 560–561: 462-468.

[16] Yoo J W, Yun D S, Kim H J Influence of Reaction Parameters on Size and Shape of Silica Nanoparticles[J]. J. Nanosci. Nanotechnol., 2006, 6(11): 3 343-3 346.

[17] Vasconcelos Daniela C L, Campos W R, Vasconcelos V Influence of Process Parameters on the Morphological Evolution and Fractal Dimension of Sol-Gel Silica Sol Particles[J]. Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process., 2002, 334(1–2): 53-58.

[18] Chang S, Lee M, Kim W Preparation of Large Monodispersed Spherical Silica Particles using Seed Particle Growth[J]. J. Colloid Interface Sci., 2005, 286(2): 536-542.

[19] Green D, Lin J S, Lam Y F Size, Volume Fraction, and Nucleation of Stöber Silica Nanoparticles[J]. J. Colloid Interface Sci., 2003, 266(2): 346-358.

[20] Rahman I A, Vejayakumaran P, Sipaut C S, . An Optimized Sol-Gel Synthesis of Stable Primary Equivalent Silica Particles[J]. Colloids Surf., A, 2007, 294(1–3): 102-110.

[21] Oh C, Shim S B, Lee Y G, . Effects of the Concentrations of Precursor and Catalyst on the Formation of Monodisperse Silica Particles in Sol-Gel Reaction[J]. Mater. Res. Bull., 2011, 46(11): 2 064-2 069.

[22] Rahman I A, Vejayakumaran P, Sipaut C, . Effect of Anion Electrolytes on the Formation of Silica Nanoparticles via the Sol-Gel Process[J]. Ceram. Int., 2006, 32(6): 691-699.

[23] Kesmez Kiraz N, Burunkaya E, . Effect of Amine Catalysts on Preparation of Nanometric SiO₂ Particles and Antireflective Films via Sol-Gel Method[J]. J. Sol-Gel Sci. Technol., 2010, 56(2): 167-176.