Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
권호 표지

Preparation of Mesoporous and Spherical-shaped Silica Particles by Spray Pyrolysis

분무열분해 공정을 이용한 메조기공을 가지는 실리카 구형입자의 제조

  • Baek, Chul-Min (Department of Chemical Engineering, Gongju National University) ;
  • Jung, Kyeong Youl (Department of Chemical Engineering, Gongju National University) ;
  • Park, Kyun Young (Department of Chemical Engineering, Gongju National University) ;
  • Park, Seung Bin (Department of Chemical and Biomolecular Engineering, KAIST) ;
  • Cho, Sung Baek (Korea Institute of Geoscience & Mineral Resources (KIGAM))
  • Received : 2008.05.10
  • Accepted : 2008.07.14
  • Published : 2008.10.31
Download PDF
⟨ Previous Next ⟩

Abstract

Spray pyrolysis was applied to prepare spherical silica particles with mesopores of a regular structure. The physical properties such as surface area, pore size, pore structure, particle size, and morphology were studied by BET, SEM, SAXS, and DLS analysis. At a fixed gas flow rate, the BET surface area changed from 200 to $1,290m^2/g$ as changing the CTAB/TEOS molar ratio from 0.05 to 0.3. At a fixed CTAB/TEOS ratio, the surface area of silica particles was varied from 1,062 to $1,305m^2/g$ with changing the gas flow rate from 10 to 40 l/min. The average pore size measured by BJH desorption was about $21{\sim}23{\AA}$ and not significantly influenced by the CTAB/TEOS ratio and the gas flow rate. Finally, the highest surface area which was $1,305m^2/g$ were obtained when the CTAB/TEOS ratio and the gas flow rate were 0.2 and 20 l/min, respectively. According to SAXS analysis, the prepared silica particles showed a strong peak at $2{\theta}=2.6^{\circ}$ and two minor peaks around $2{\theta}=4.4^{\circ}$ and $5.1^{\circ}$, which are due to regular mesopores of hexagonal structure. The morphology of silica particles prepared were spherical shape and the average particle size was $1.0{\mu}m$.

분무열분해 공정을 이용하여 규칙적인 메조기공을 가지는 실리카 분말을 제조하고 고표면적을 얻기 위한 합성조건을 최적화하였다. 주형제로 이용된 CTAB의 양과 액적들의 반응기 내에서 체류시간을 변화시켜주면서 입자를 제조하고 SEM, BET, SAXS, 그리고 DLS를 통해 분말특성을 조사하였다. 기체 유입속도를 고정하고 CTAB/TEOS 몰비를 0.05에서 0.30으로 변화시킴에 따라 비표면적은 200에서 $1,290m^2/g$으로 변화였다. CTAB/TEOS 몰비를 고정했을 때 입자의 비표면적은 기체의 유입속도에 따라 1,062에서 $1,305m^2/g$ 사이에서 변화되었다. 제조된 입자들의 BJH 탈착에 의한 평균 기공 크기는 $21{\sim}23{\AA}$를 가졌으며, CTAB/TEOS 몰비나 기체 유입속도에 크게 영향을 받지 않았다. 최대 표면적은 CTAB/TEOS 비를 0.2, 기체 유속을 20 l/min으로 했을 때 $1,305m^2/g$를 얻었다. 제조된 실리카 분말은 육방형구조의 규칙적인 기공에 기인한 $2{\theta}=2.6^{\circ}$ 강한 피크와 $2{\theta}=4.4$ 및 $5.1^{\circ}$ 약한 피크를 가지는 것을 SAXS 분석결과로 확인하였다. 제조된 실리카 분말은 구형의 형상을 가졌으며 $1.0{\mu}m$의 평균크기를 가졌다.

Keywords

Acknowledgement

Supported by : 지식경제부

References

  1. Corma, A., "From Microporous to Mesoporous Molecular Sieve Materials and Their Use in Catalysis, " Chem. Rev., 97(6), 2373-2419(1997) https://doi.org/10.1021/cr960406n
  2. Rama Rao G. V., Lopez, G. P., Bravo, J., Pham, H., Datye A. K., Xu, H. and Ward, T. L., "Monodisperse Mesoporous Silica Microspheres Formed by Evaporation-Induced Self Assembly of Surfactant Templates in Aerosols, " Adv. Mater., 14(18), 1301-1304(2002) https://doi.org/10.1002/1521-4095(20020916)14:18<1301::AID-ADMA1301>3.0.CO;2-T
  3. Nooney, R. I., Dhanasekaran, T., Chem, Y., Josephs, R. and Ostafin, A. E., "Synthesis of Nanoscale Mesoporous Silica Spheres With Controlled Particle Size," Chem. Mater., 14(11), 4721-4728(2002) https://doi.org/10.1021/cm0204371
  4. Chung, J.-S., Kim, D.-J., Ahn, W.-S., Ko, J.-H. and Cheong, W.-J., "Synthesis, Characterization, and Applications of Organic-Inorganic Hybrid Mesoporous Silica," Korean J. Chem. Eng., 21(1), 132-139(2004) https://doi.org/10.1007/BF02705391
  5. Roh, H.-S., Chang, J.-S. and Park, S.-E., "Synthesis of Mesoporous Silica in Acidic Condition by Solvent Evaporation Method," Korean J. Chem. Eng., 16(3), 331-337(1999) https://doi.org/10.1007/BF02707121
  6. Lu, Y., Fan, H., Stump, A., Ward, T. L., Rieker, T. and Brinker C. J., "Aerosol-assisted Self-assembly of Mesostructured Spherical Nanoparticles," Nature, 398, 223-226(1999) https://doi.org/10.1038/18410
  7. Mangesh, T. B., Shailendra, B. R., Timothy, L. W. and Abhaya, K. D., "Hexagonal Mesostructure in Powders Produced by Evaporation-Induced Self-Assembly of Aerosols from Aqueous Tetraethoxysilane Solutions," Langmuir, 19(2), 256-264(2003) https://doi.org/10.1021/la020704h
  8. Fan, H., Swol, F. V., Lu, Y. and Brinker, C. J., "Multiphased Assembly of Nanoporous Silica Particles," J. Non-Crystal. Solids, 258(1-3), 71-78(2001)
  9. Hampsey, J. E., Arsenault, S., Hu, Q. and Lu, Y., "One-Step Synthesis of Mesoporous Metal-$SiO_2$ Particles by an Aerosol-Assisted Self-assembly Process," Chem. Mater., 17(9), 2475-2480(2005) https://doi.org/10.1021/cm0487167
  10. Jung, K. Y., Kang, Y. C. and Park, Y.-K., "DMF Effect on the Morphology and the Luminescent Properties of $Y_2O_3:Eu^{3+}$ Red Phosphor Prepared by Spray Pyrolysis," J. Ind. Eng. Chem., 14(2), 224-229(2008) https://doi.org/10.1016/j.jiec.2007.09.011
  11. Jung, K. Y. and Lee, H. W., "Enhanced Luminescent Properties of $Y_3Al_5O_{12}:Tb^{3+},Ce^{3+}$ Phosphor Prepared by Spray Pyrolysis," J. Lumin., 126(2), 469-474(2007) https://doi.org/10.1016/j.jlumin.2006.09.009
  12. Gurav, A., Kodas, T. T., Pluym, T. and Xiong, Y., "Aerosol Processing of Materials," Aerosol Sci. & Tech., 19(4), 411-452(1993) https://doi.org/10.1080/02786829308959650
  13. Ortega, J. and Kodas, T. T., "Control of Particles Morphology During Multicomponent Metal Oxide Poder Generation by Spray Pyrolysis," J. Aerosol Sci., 23(1), 253-256(1992) https://doi.org/10.1016/0021-8502(92)90397-E