跳至主要内容

Influence of Temperature and Water Vapour Pressure on Drying Kinetics and Colloidal Microstructure of Dried Sodium Water Glass

Read  full  paper  at:
http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53263#.VLiDr8nQrzE

ABSTRACT
Industrially produced sodium water glasses were dried in climates with controlled temperature and humidity to transparent amorphous water containing sodium silicate materials. The water glasses had molar SiO2:Na2O ratios of 2.2, 3.3 and 3.9 and were dried up to 84 days at temperatures between 40°C and 95°C and water vapour pressures between 5 and 40 kPa. The materials approached final water concentrations which are equilibrium values and are controlled by the water vapour pressure of the atmosphere and the microstructure of the solids. The microstructure of the dried water glasses was characterized by atomic force microscopy. It has a nanosized substructure built up by the silicate colloids of the educts but deformed by capillary forces. In the final drying equilibrium, the water vapour pressure of the atmosphere in the drying cabinet is equal to the reduced vapour pressure of the capillary system built up by the silicate colloids. Their size scale can be explained by the deformation of colloidal aggregates due to capillary forces.
 
Cite this paper
Roggendorf, H. , Fischer, M. , Roth, R. and Godehardt, R. (2015) Influence of Temperature and Water Vapour Pressure on Drying Kinetics and Colloidal Microstructure of Dried Sodium Water Glass. Advances in Chemical Engineering and Science, 5, 72-82. doi: 10.4236/aces.2015.51008.
 
References
[1]Vail, J.G. (1952) Soluble Silicates—Their Properties and Uses, Vol. 1, Chemistry. Reinhold, New York.
 
[2]Roggendorf, H., Grond, W. and Hurbanic, M. (1996) Structural Characterization of Concentrated Alkaline Silicate Solutions by 29Si-NMR Spectroscopy, FT-IR Spectroscopy, Light Scattering, and Electron Microscopy—Molecules, Colloids, and Dissolution Artefacts. Glass Sci. Technol., 69, 216-231.
 
[3]Iler, R.K. (1979) The Chemistry of Silica. Solubility, Polymerisation, Colloid and Surface Properties, and Biochemistry. Wiley-Interscience Publication, New York.
 
[4]Falcone, J.S. (2005) Silicon Compounds, Anthropogenic Silica and Silicates. In: Kirk-Othmer Encyclopedia of Chemical Technology, Wiley Online Library, New York.
http://dx.doi.org/10.1002/0471238961.1925142006011203.a01.pub2
 
[5]Yoshida, A. (2006) Silica Nucleation, Polymerization, and Growth Preparation of Monodisprsed Sols. In: Bergna, H.E. and Roberts, W.O., Eds., Colloidal Silica: Fundamentals and Applications, Surfactant Science Series 131, 47-56.
 
[6]Iler, R.K. (1982) Colloidal Components in Solutions of Sodium Silicate. In: Falcone, J.S., Ed., Soluble Silicates, ACS Symposium Series, 194, 95-114.
 
[7]Healey, T. (2006) Stability of Aqueous Silica Sols. In: Bergna, H.E. and Roberts, W.O., Eds., Colloidal Silica: Fundamentals and Applications, Surfactant Science Series, 131, 247-252.
 
[8]Bahlmann, E.K.F., Harris, R.K., Metcalfe, K., Rockliffe, J.W. and Smith, E.G. (1997) Silicon-29 NMR Self-Difusion and Chemical-Exchange Studies of Concentrated Sodium Silicate Solutions. Journal of the Chemical Society, Faraday Transactions, 93, 93-98.
http://dx.doi.org/10.1039/a604878a
 
[9]Boschel, D., Janich, M. and Roggendorf, H. (2003) Size Distribution of Colloidal Silica in sodium Silicate Solutions Investigated by Dynamic Light Scattering and Viscosity Measurements. Journal of Colloid and Interface Science, 267, 360-368.
http://dx.doi.org/10.1016/j.jcis.2003.07.016
 
[10]Nordstrom, J., Sundblom, A., Jensen, G.V., Pedersen, J.S., Palmqvist, A. and Matic, A. (2013) Silica/Alkali Ratio Dependence of the Microscopic Structure of Sodium Silicate Solutions. Journal of Colloid and Interface Science, 397, 9- 17.
http://dx.doi.org/10.1016/j.jcis.2013.01.048
 
[11]Tognonvi, M.T., Massiot, D., Lecomte, A. and Rossignol, S. (2010) Identification of Solvated Species Present in Concentrated and Dilute Sodium Silicate Solutions by Combined 29Si NMR and SAXS Studies. Journal of Colloid and Interface Science, 352, 309-315.
http://dx.doi.org/10.1016/j.jcis.2010.09.018
 
[12]Halasz, I., Li, R., Agarwal, M. and Miller, N. (2007) Monitoring the Structure of Water Soluble Silicates. Catalysis Today, 126, 196-202.
http://dx.doi.org/10.1016/j.cattod.2006.09.032
 
[13]Trautz, V., Gartner, F., Korner, H.H., Linke, R., Weber, H. and Wirth, H. (1978) Fire-Protective Materials. Patent No. DE 2703022.
 
[14]Dent Glasser, L.S. and Lee, C.K. (1973) Drying of Sodium Silicate Solutions. Journal of Applied Chemistry and Biotechnology, 21, 127-133.
http://dx.doi.org/10.1002/jctb.5020210502
 
[15]Roggendorf, H. and Boschel, D. (2002) Hydrous Sodium Silicate Glasses Obtained by Drying Sodium Silicate Solutions. Journal of Glass Science and Technology, 75, 103-111.
 
[16]Roggendorf, H., Boschel, D. and Trempler, J. (2001) Structural Evolution of Sodium Silicate Solutions Dried to Amorphous Solids. Journal of Non-Crystalline Solids, 293-295, 752-757.
http://dx.doi.org/10.1016/S0022-3093(01)00785-2
 
[17]Pusey P.N. and Van Megen, W. (1990) The Glass Transition of Hard Spherical Colloids. Berichte der Bunsengesellschaft für physikalische Chemie, 94, 225-229.
http://dx.doi.org/10.1002/bbpc.19900940306
 
[18]Cann, J.Y. and Cheek, D.L. (1925) Relationship between Composition and Boiling Point of Aqueous Solutions of Sodium Silicate. Industrial & Engineering Chemistry, 17, 512-514.
http://dx.doi.org/10.1021/ie50185a031
 
[19]Brinker, C.J. and Scherer, G.W. (1990) Sol-Gel Science. Academic Press, San Diego.
 
[20]Chiang, Y.-M., Birdie III, D.P. and Kingery, W.D. (1997) Physical Ceramics. John Wiley & Sons, New York.
 
[21]Knudsen, M. (1909) Die Gesetze der Molekularstromung und der inneren Reibungsstromung der Gase durch Rohren. Annalen der Physik, 28, 75-130.
http://dx.doi.org/10.1002/andp.19093330106
 
[22]Winston, P.W. and Bates, D.H. (1960) Saturated Solutions for the Control of Humidity in Biological Research. Ecology, 41, 232-237.
http://dx.doi.org/10.2307/1931961
 
[23]Susan, D. (2005) Stereological Analysis of Spherical Particles: Experimental Assessment and Comparison to Laser Diffraction. Metall. Metallurgical and Materials Transactions A, 36, 2481-2492.
http://dx.doi.org/10.1007/s11661-005-0122-3
 
[24]Vargaftik, N.B., Volkov, B.N. and Voljak, L.D. (1983) International Table of the Surface Tension of Water. Journal of Physical and Chemical Reference Data, 12, 817-820.
http://dx.doi.org/10.1063/1.555688
 
[25]Weast, R.C., Ed. (1983) CRC Handbook of Chemistry and Physics. 62nd Edition, CRC Press, Boca Raton.
 
[26]Muster, T.H., Prestidge, C.A. and Hayes, R.A. (2001) Water Adsorption Kinetics and Contact Angles of Silica Particles. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 176, 253-266.
http://dx.doi.org/10.1016/S0927-7757(00)00600-2
 
[27]Washburn, E.W. (1921) The Dynamics of Capillary Flow. Physical Review, 17, 273-283.
http://dx.doi.org/10.1103/PhysRev.17.273                                                                               eww150116lx
标签：

评论

发表评论

此博客中的热门博文

A Comparison of Methods Used to Determine the Oleic/Linoleic Acid Ratio in Cultivated Peanut (Arachis hypogaea L.)

Cultivated peanut ( Arachis hypogaea L.) is an important oil and food crop. It is also a cheap source of protein, a good source of essential vitamins and minerals, and a component of many food products. The fatty acid composition of peanuts has become increasingly important with the realization that oleic acid content significantly affects the development of rancidity. And oil content of peanuts significantly affects flavor and shelf-life. Early generation screening of breeding lines for high oleic acid content greatly increases the efficiency of developing new peanut varieties. The objective of this study was to compare the accuracy of methods used to classify individual peanut seed as high oleic or not high oleic. Three hundred and seventy-four (374) seeds, spanning twenty-three (23) genotypes varying in oil composition (i.e. high oleic (H) or normal/not high oleic (NH) inclusive of all four peanut market-types (runner, Spanish, Valencia and Virginia), were individually tested ...
发表评论
阅读全文

Location Optimization of a Coal Power Plant to Balance Costs against Plant’s Emission Exposure

Fuel and its delivery cost comprise the biggest expense in coal power plant operations. Delivery of electricity from generation to consumers requires investment in power lines and transmission grids. Placing a coal power plant or multiple power plants near dense population centers can lower transmission costs. If a coalmine is nearby, transportation costs can also be reduced. However, emissions from coal plants play a key role in worsening health crises in many countries. And coal upon combustion produces CO 2 , SO 2 , NO x , CO, Metallic and Particle Matter (PM10 & PM2.5). The presence of these chemical compounds in the atmosphere in close vicinity to humans, livestock, and agriculture carries detrimental health consequences. The goal of the research was to develop a methodology to minimize the public’s exposure to harmful emissions from coal power plants while maintaining minimal operational costs related to electric distribution losses and coal logistics. The objective was...
发表评论
阅读全文

Evaluation of the Safety and Efficacy of Continuous Use of a Home-Use High-Frequency Facial Treatment Appliance

At present, many home-use beauty devices are available in the market. In particular, many products developed for facial treatment use light, e.g., a flash lamp or a light-emitting diode (LED). In this study, the safety of 4 weeks’ continuous use of NEWA TM , a high-frequency facial treatment appliance, every alternate day at home was verified, and its efficacy was evaluated in Japanese individuals with healthy skin aged 30 years or older who complained of sagging of the facial skin.  Transepidermal water loss (TEWL), melanin levels, erythema levels, sebum secretion levels, skin color changes and wrinkle improvement in the facial skin were measured before the appliance began to be used (study baseline), at 2 and 4 weeks after it had begun to be used, and at 2 weeks after completion of the 4-week treatment period (6 weeks from the study baseline). In addition, data obtained by subjective evaluation by the subjects themselves on a visual analog scale (VAS) were also analyzed. Fur...
发表评论
阅读全文