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    Characterization of poly(vinyl chloride) powder produced by emulsion polymerization
    (Springer, 2010) Savrik, Sevdiye Atakul; Balkose, Devrim; Ulutan, Sevgi; Ulku, Semra
    The effect of emulsion process formulation ingredients on the morphology, structure, and properties of polyvinyl chloride (PVC) powder has been considered in this study. PVC powder was extracted with ethanol and films were obtained by solvent casting from tetrahydrofurane. Characterization of powders, films, and ethanol extract was performed through FTIR spectroscopy, DSC, AFM, SEM, EDX analysis, methylene blue, and nitrogen adsorption. PVC powder was composed of spheres of a large particle size range from 10 nm to 20 mu m as shown by SEM. The specific surface area of the PVC powder was determined as 16 and 12 m(2) g(-1) from methylene blue adsorption at 25 A degrees C and from N-2 adsorption at -196 A degrees C, respectively. AFM indicated the surface roughness of the films obtained by pressing the particles was 25.9 nm. Density of PVC powder was determined by helium pycnometry as 1.39 g cm(-3). FTIR spectroscopy indicated that it contained carbonyl and carboxylate groups belonging to additives such as surface active agents, plasticizers, and antioxidants used in production of PVC. These additives were 1.6% in mass of PVC as determined by ethanol extraction. EDX analysis showed PVC particles surfaces were coated with carbon-rich materials. The coatings had plasticizer effect since, glass transition temperature was lower than 25 A degrees C for PVC powder and it was 80 A degrees C for ethanol extracted powders as found by using differential scanning calorimetry. These additives from polymerization process made PVC powder more thermally stable as understood from Metrom PVC thermomat tests as well.
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    Flexible PVC-Silica Composites as an Adsorptive Material for Water Soluble Dyes
    (Sage Publications Ltd, 2013) Ulutan, Sevgi; Yetgin, Senem; Balkose, Devrim
    Methylene Blue (MB) adsorption studies were performed on flexible Polyvinyl Chloride/Silica composites which were obtained by using plastisol-plastigel technology. Change of MB concentration in aqueous phase as the adsorption process advanced was followed by using visible spectroscopy. The diffusion of MB through the composites exhibited non-Fickian behavior with a diffusivity of 10(-11) m(2)s(-1). Making use of such PVC-silica composite sheets as column packing, the packing time will be reduced and the surface available for diffusion will be increased.
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    Flexible PVC-Silica Composites as an Adsorptive Material for Water Soluble Dyes
    (Sage Publications Ltd, 2013) Ulutan, Sevgi; Yetgin, Senem; Balkose, Devrim
    Methylene Blue (MB) adsorption studies were performed on flexible Polyvinyl Chloride/Silica composites which were obtained by using plastisol-plastigel technology. Change of MB concentration in aqueous phase as the adsorption process advanced was followed by using visible spectroscopy. The diffusion of MB through the composites exhibited non-Fickian behavior with a diffusivity of 10(-11) m(2)s(-1). Making use of such PVC-silica composite sheets as column packing, the packing time will be reduced and the surface available for diffusion will be increased.
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    Methylene Blue Adsorption From Aqueous Solutions to Flexible Poly(vinyl chloride) Silica Composites
    (Wiley, 2015) Yetgin, Senem; Ulutan, Sevgi; Balkose, Devrim
    Methylene blue (MB) adsorption studies were performed with poly(vinyl chloride)-(dioctyl phthalate)silica composites, which were obtained by using plastisol-plastigel technology. The films were flexible, having elastic modulus of 1.0-1.5 GPa. Diminishing MB concentration in the aqueous phase was followed as the adsorption process advanced by using visible spectroscopy. Contributions of the individual components of the composites to adsorption were also investigated. Although the MB adsorption capacity was extensively high for silica, it was moderate for the composite, most likely owing to the occlusion of pores of silica by plasticizer to some extent. The improvement of MB adsorption capacity of the composites as the silica ratio increased was explicitly deduced from the optical microscopy photographs. The diffusion coefficients of MB through the composites were 5 x 10(-1)3, 6 x 10(-13), and 3 x 10(-13) m(2) s(-1) with regression coefficients of 0.73, 0.89, and 0.88 for 0, 2, and 16% silica-containing composites, respectively. Because of the slow diffusion of MB in poly(vinyl chloride)-silica composites, using them as dynamic column adsorbent was not practical. However, these versatile plastics can be used as plastic labels, colored clothing, leather substitutes, antimicrobial medical devices, and laser printable surfaces. (C) 2014 Society of Plastics Engineers
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    Methylene Blue Adsorption From Aqueous Solutions to Flexible Poly(vinyl chloride) Silica Composites
    (Wiley, 2015) Yetgin, Senem; Ulutan, Sevgi; Balkose, Devrim
    Methylene blue (MB) adsorption studies were performed with poly(vinyl chloride)-(dioctyl phthalate)silica composites, which were obtained by using plastisol-plastigel technology. The films were flexible, having elastic modulus of 1.0-1.5 GPa. Diminishing MB concentration in the aqueous phase was followed as the adsorption process advanced by using visible spectroscopy. Contributions of the individual components of the composites to adsorption were also investigated. Although the MB adsorption capacity was extensively high for silica, it was moderate for the composite, most likely owing to the occlusion of pores of silica by plasticizer to some extent. The improvement of MB adsorption capacity of the composites as the silica ratio increased was explicitly deduced from the optical microscopy photographs. The diffusion coefficients of MB through the composites were 5 x 10(-1)3, 6 x 10(-13), and 3 x 10(-13) m(2) s(-1) with regression coefficients of 0.73, 0.89, and 0.88 for 0, 2, and 16% silica-containing composites, respectively. Because of the slow diffusion of MB in poly(vinyl chloride)-silica composites, using them as dynamic column adsorbent was not practical. However, these versatile plastics can be used as plastic labels, colored clothing, leather substitutes, antimicrobial medical devices, and laser printable surfaces. (C) 2014 Society of Plastics Engineers
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    Methylene Blue Adsorption From Aqueous Solutions to Flexible Poly(vinyl chloride) Silica Composites
    (Wiley, 2015) Yetgin, Senem; Ulutan, Sevgi; Balkose, Devrim
    Methylene blue (MB) adsorption studies were performed with poly(vinyl chloride)-(dioctyl phthalate)silica composites, which were obtained by using plastisol-plastigel technology. The films were flexible, having elastic modulus of 1.0-1.5 GPa. Diminishing MB concentration in the aqueous phase was followed as the adsorption process advanced by using visible spectroscopy. Contributions of the individual components of the composites to adsorption were also investigated. Although the MB adsorption capacity was extensively high for silica, it was moderate for the composite, most likely owing to the occlusion of pores of silica by plasticizer to some extent. The improvement of MB adsorption capacity of the composites as the silica ratio increased was explicitly deduced from the optical microscopy photographs. The diffusion coefficients of MB through the composites were 5 x 10(-1)3, 6 x 10(-13), and 3 x 10(-13) m(2) s(-1) with regression coefficients of 0.73, 0.89, and 0.88 for 0, 2, and 16% silica-containing composites, respectively. Because of the slow diffusion of MB in poly(vinyl chloride)-silica composites, using them as dynamic column adsorbent was not practical. However, these versatile plastics can be used as plastic labels, colored clothing, leather substitutes, antimicrobial medical devices, and laser printable surfaces. (C) 2014 Society of Plastics Engineers
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    Use, Preparation, and Characterization of Copper-Containing Silica Gel
    (Amer Chemical Soc, 2020) Ulutan, Sevgi; Demir, A. Pinar Tuzun; Balkose, Devrim
    The preparation and characterization of humidity-indicating silica gel containing copper sulfate were aimed at in the present study. the equilibrium and kinetics of Cu(II) sorption were investigated by contacting 200-1600 mg dm(-3) Cu ion-containing solutions with silica hydrogel slabs having 10% silica. the diffusion coefficient of Cu(II) in silica hydrogel was determined to be on the order of 10(-10) m(2) s(-1). X-ray diffraction indicated that the gels contained mainly CuSO4 center dot 3H(2)O, CuSO4 center dot H2O, and small amounts of CuSO4 and CuSiO3 center dot 2H(2)O. the silica gel with Cu(II) can be used as a humidity indicator since its color changes from light blue to dark blue upon moisture adsorption.