Effect of the Addition of Si and Alkali Metal on the Viscosity and Molecular Behavior of Water Glass

Si와 알칼리 금속의 첨가에 따른 물유리의 점도 및 분자결합구조 특성변화

  • Received : 2017.12.04
  • Accepted : 2017.12.24
  • Published : 2018.02.10


In this study, the mixing characteristics of water glass and additives (Si, alkali metal), which are one of the main raw materials of silicate based binder used in the production of molds during casting process, were examined. Molecular structures of water glass, additives and mixtures were analyzed FT-IR and viscosity measurements and their correlation were compared. The addition of Si source to the water glass accelerated the Si networking in the material and increased the viscosity. When the alkali metal was added, the viscosity of the water glass decreased by suppressing the Si networking of the water glass. Viscosities of the water glass and lithium silicate (LS) mixtures increased when the content of LS was less than 20 wt% and gradually decreased when the content was more than 20 wt%. By adding KOH to the water glass, the viscosity could be lowered and it could be used effectively to mix with colloidal silica (CS) or potassium methyl siliconate (PMS).


water glass;FT-IR;viscosity;alkali metals;silicon (Si)


  1. T. Steinhauser, Method for producing core preforms and recycling core sand for a foundry, US Patent 6,371,194 (2001).
  2. W. Martin, Mold or blank, molding material mixture for casting, and method for the production thereof, WO Patent 2007-104469 (2007).
  3. C. K. Johnson, K. T. Tse, L. S. Zaretskiy, and B. E. Algar, Binder for cores and molds, US Patent 6,299,677 (2001).
  4. L. Xia, Y. Zhang, and J. Huang, A New Compound Phosphate Heat-cured Foundry Binder, Adv. Mater. Res., 97-101, 979-982 (2010).
  5. Y. A. Owusu, Physical-chemistry study of sodium silicate as a foundry sand binder, Adv. Colloid Interface Sci., 18, 57-91 (1982).
  6. J. Nordstrom, A. Sundblom, G. V. Jensen, J. S. Pedersen, A. Palmqvist, and A. Matic, Silica/alkali ratio dependence of the microscopic structure of sodium silicate solutions, J. Colloid Interface Sci., 397, 9-17 (2013).
  7. Y. Ryu and M. S. Lee, Infrared spectra and thermal properties of sodium silicate solutions, Korean J. Metals Mater., 56(1), 72-78 (2018).
  8. F. Liebau, Structural Chemistry of Silicates: Structure, Bonding, and Classification, Springer-Verlag, Berlin, Germany (1985).
  9. T. T. Trinh, A. P. J. Jansen, and R. A. van Santen, Mechanism of oligomerization reactions of silica, J. Phys. Chem., 110, 23099-23106 (2006).
  10. W. S. McDonald and D. W. J. Cruickshank, A Reinvestigation of the structure of sodium metasilicate, $Na_2SiO_3$, Acta Cryst., 22, 37-43 (1967).
  11. R. A. van Santen and D. L. Vogel, Lattice dynamics of zeolites, Adv. Solid-State Chem., 1, 151-224 (1989).
  12. A. S. Tenney and J. Wong, Vibrational spectra of vapor deposited binary borosilicate glasses, J. Chem. Phys., 56, 5516-5523 (1972).
  13. T. Fuss, A. Mogus-Milankovic, C. S. Ray, C. E. Lesher, R. Youngman, and D. E. Day, Ex situ XRD, TEM, IR, Raman and NMR spectroscopy of crystallization of lithium disilicate glass at high pressure, J. Noncryst. Solids, 352, 4101-4111 (2006).
  14. Q. W. Chen, X. G. Li, Y. H. Zhang, and Y. T. Qian, Ferroelectric properties of porous silicon, Adv. Mater., 25, 134-137 (2002).
  15. M. M. Mahmoud, D. C. Folz, C. T. A. Suchicital, and David E. Clark, Crystallization of lithium disilicate glass using microwave processing, J. Am. Ceram. Soc., 95, 579-585 (2012).
  16. S. Zhang, X. Zhang, and W. Shang, Chemical investigation of potassium methyl siliconate as deacidification and strengthening agent for preservation of aged papers, Chin. J. Polym. Sci., 33(12), 1672-1682 (2015).


Supported by : 산업통상자원부, 한국생산기술연구원