Mücahit UĞUR

Investigation of Fractal Dimension Change in Synthesized CaSO4 Using PSSS

Generally, commercial product of calcium sulfate anhydrous (CaSO4) is synthesized burning gypsum in kiln, in the process that the water is removed from gypsum crystallized by mixing CaCl2 and Na2SO4 in aqueous medium. It is possible to change gypsum properties by changing the parameters during crystallization. Also, the differentiation in the structures of the synthesized product can be possible with using additives during the crystallization. The changes in properties of these synthetically produced materials may be investigated instrumentally. This study examines change of surface fractal dimensions (Df) of synthesized CaSO4 anhydrate instrumentally. CaSO4.2H2O was synthesized by chemical precipitation method in the presence Poly(Sodium 4-Styrene Sulphonate) and measured N2-physisorption measurements after burning. Fractal dimensions were determined using single N2-adsorption/desorption isotherms method. For Fractal dimension calculations, the Frenkel–Halsey–Hill (FHH) and the Neimark–Kiselev (NK) methods were used. Taguchi method has been used in evaluation of experimental design for optimization of Df values.

Keywords:

Crystallization Df value,

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1 Rasband, S. N. "Fractal Dimension." Ch. 4 in Chaotic Dynamics of Nonlinear Systems. New York: Wiley, pp. 71-83, 1990.
2 Gori, U and M. Mari (2001) The correlation between the fractal dimension and internal friction angle of different granular materials, Soils and Foundations, 41, 3-4,17-23
3 Pfeifer P., and Avnir D., (1983) Chemistry in noninteger dimensions between two and three. I. Fractal theory of heterogeneous surfaces. The Journal of Chemical Physics, 79, 3558.
4 Pfeifer, P., Farin, D., and Avnir D., (1983) Chemistry in noninteger dimensions between two and three. II. Fractal surfaces of adsorbents. The Journal of Chemical Physics, 79, 3566.
5 Dobrescu, G., Berger, D., Papa, F., Ionescu, N.I., Rusu M. (2003) Fractal analysis of micrographs and adsorption isotherms of La1-xSrxCoO3 samples. Journal of Optoelectronics and Advanced Materials, 5, 5, 1433-1437
6 Khalilia, N.R., Pana, M., Sand, G., (2000) Determination of fractal dimensions of solid carbons from gas and liquid phase adsorption isotherms, Carbon 38, 573–588.
7 Lowell S., Shields J.E., Thomas M.A., Thommes M. (2004) Characterization of Porous Solids and Powders: Surface Area, Pore Size and Density. Particle Technology Series, vol 16. Springer.
8 Amjad, Z. and Demadis K.D. (2015) Mineral Scales and Deposits Scientific and Technological Approaches. Elsevier.
9 Doğan, Ö., Akyol, E. and Öner, M. (2004), Polyelectrolytes inhibition effect on crystallization of gypsum. Cryst. Res. Technol., 39: 1108-1114