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Preparation of microspherical granules from aerosilogels

The way of spray drying in overheated water steam

Journal of Thermal Analysis and Calorimetry
Authors: Jadwiga Skubiszewska-Zięba and V. Sydorchuk

Abstract  

The influence of the conditions of aerosil dispersion spray drying process in the medium of overheated water steam on the formation of microspheric granules and their porous structure was studied. Water and ammonium solutions as aerosil particles dispersing agents and water steam and air as heat carriers were used. It was stated that the effects of spray drying depend on the kind of dispersing medium and on the conditions of atmosphere and temperature at which drying and forming of aerosilogel granules takes place.

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Abstract  

This study explores the calorimetric analysis of an aligned nano-colloidal aerosil dispersed octyl-cyanobiphenyl gel. This system was prepared by solvent dispersion method (SDM). Heating scans were performed at different heating rates from 20 to 1 K min−1 using DSC. Aligned samples follow Arrhenius behavior and showed a temperature shift in SmA-N and N-I transitions towards lower temperature. These samples show a decreased activated kinetics and an interesting relationship with their enthalpy. This behavior can be explained in terms of surface and molecular interaction between aerosil nano-particles and 8CB molecules and produced strain in the system.

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, Vivapharm-JRS) (JRS Pharma, Weissenborn, Germany), microcrystalline cellulose (MCC, Vivapur-JRS) (JRS Pharma, Weissenborn, Germany), magnesium stearate (Peter Greven Industries, Venlo, The Netherlands) and Aerosil 200 (Evonik Degussa GmbH, Frankfurt am Main

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in SBA-15 (and MCM-41) type hexagonally structured molecular sieves as such or functionalized to bind HRP amino acid residues in comparison with the 2D immobilization onto aerosil A380. Guest–host interactions were pursued by spectrometry and thermal

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Abstract  

The effect of mineral fillers such as Ultrasil VN-3, Ze−O−Sil P-45, Aerosil 200, Frantex 8, Kaolin and precipitated calcium carbonate on the thermal properties sulphur vulcanizates ofcis-1,4-polyisoprene were studied by means of thermal analysis. It was found that the addition of a mineral filler did not change the nature of the thermal processes in isoprene vulcanizates essentially, but it distinctly affected the positions of the peaks recorded in the DTA curves. The mineral fillers affected the temperatures and rates of degradation and destruction of polyisoprene cross-linked with sulphur. The presence of a mineral filler brought about a decrease in the flammability ofcis-1,4-polyisoprene sulphur vulcanizates.

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Abstract  

The kinetics of the interaction between lithium carbonate and silica with various degrees of dispersion was investigated by TG and DTA methods. It was found that the utilization of pyrogenic silica with a specific surface area of about 300 m2g-1 instead of aerosil with one of 175 m2g-1 leads to an increase of the reaction rate between lithium carbonate and silica, which depends on the formation and growth of lithium orthosilicate crystals in the first stage, and is conditioned by the diffusion of lithium and oxygen ions through the lithium orthosilicate layer formed at temperatures above 800 K. This supposition is supported by the kinetic analysis results obtained with the use of the different models. The optimal regime of heating is recommended.

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Surface characterization of various silicas

A tentative correlation between the energies of adsorption sites and the different biological activities

Journal of Thermal Analysis and Calorimetry
Authors: V. Bolis, B. Fubini, and G. Venturello

In order to correlate the biological activity of silica to its surface properties, the analysis of surface sites on three kinds of silicas of different origins and textures has been performed by adsorption calorimetry.

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, Iannacchione , GS 2003 X-ray I. Smectic ordering in liquid-crystal–aerosil dispersions . Scatt Phys Rev E 67 : 011708-1 – 011708–13 . 8. Iannacchione , GS , Garland , CW , Mang , JT

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Journal of Thermal Analysis and Calorimetry
Authors: V. Sydorchuk, W. Janusz, S. Khalameida, E. Skwarek, J. Skubiszewska-Zięba, R. Leboda, and V. Zazhigalov

prepared deposited samples (specific surface area and porosity, surface structure, and electrokinetics) is another task of the presented study. Experimental Reagents Fumed silica (aerosils A50 and A380) and

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of activated kinetics of the nematic and smectic phase transitions in an aligned nano-colloidal liquid crystal? Aerosil gel . J Therm Anal Calorim 93 : 899 – 906 10.1007/s10973-007-8583-9 . 9

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