Sample controlled thermal analysis

During the outgassing, the residual pressure was maintained at 3 x 10 mbar while the sample temperature was slowly raised to 400 C and held at this level for 16 hours (i.e. the procedure used in Sample Controlled Thermal Analysis). The gas pressures were measured with the aid of three calibrated gauges over the ranges of 0 - 1 mbar, 0-10 mbar and 0 -1000 mbar. Fixed incremental doses of gas were introduced to construct the initial part of the isotherm and thermal transpiration corrections were applied. In the region of very low pressures it was found necessary to allow several hours for each point to attain equilibrium. 

Calcination. Only low concentrations of the surfactants are required such that the concentrations are well below the critical micelle concentration (rather than 25% in mass usually observed in other synthesis routes). Hence calcination may well be a viable process for the large scale preparation of these materials. Sample controlled Thermal Analysis has been used to study the highly controlled pyrolysis of the mesophase including the mechanism of the extraction of the template. 

The thermal extraction (calcination) of cetyltrimethyl ammonium bromide, which is one of the surfactant templates, from a pure silica mesophase to form MCM41 has been studied using SCTA (Sample Controlled Thermal Analysis) by the Marseilles Group. 

Sorenson, O.T. Rouquerol, J. Sample Controlled Thermal Analysis Kluwer Amsterdam, 2003. 

Parkes, G.M.B. Barnes, P.A. Charsley, E.L. New concepts in sample controlled thermal analysis resolution in the time and temperature domains. Anal. Chem. 1999, 71, 2482-2487. 

Sorensen, O.T. and Rouquerol, J. (eds) (2003). Sample Controlled Thermal Analysis Origin, Goals, Multiple Forms, Applications and Future. Kluwer Academic Publishen. 

Sample Controlled Thermal Analysis (SCTA) was carried out under a constant residual pressure of 5.10 mbar on a home-made apparatus [20]. The totality of the evolved gases was analyzed in situ via a mass spectrometer (VG Quadrupoles) with a maximum detection of m/z = 100. 

Sorensen OT, Rouquerol J (2003) (eds) Sample-controlled thermal analysis. Kluwer Academic, Dordrecht... 

Figure 1. Principles of temperature-Controlled (or conventional) thermal analysis (left) and of sample-controlled thermal analysis (right), from [14].

This definition is more complicated than the first one and, in reality, although proposed to the ICTAC membership, was never officially endorsed by the ICTAC Council. It still does not embrace the case of sample-controlled thermal analysis, although SCTA is referred to in that 1991 booklet, in the form of controlled rate thermal analysis (CRTA). 

J. Rouquerol and O.Toft Sorensen, in O.Toft Sorensen and J. Rouquerol (Eds), Sample Controlled Thermal Analysis origin, goals, multiple forms, applications and future, Kluwer, Dordrecht/Boston/London, 2003, pp. 8-15. 

Potential applications of thermal analysis and calorimetry to quality control is not limited in any way to those discussed in this chapter. Once some physical or chemical characteristic of a material or process is known and can be examined and/or characterized by these techniques, it is only the imagination that limits the possibilities for quality control applications. Both traditional techniques (DSC, TG, DMA, isothermal calorimetry, etc.) and non-traditional techniques (temperature modeling, etc.) have been shown to have potential uses for quality control. With the introduction of many new techniques (fast scanning DSC, sample controlled thermal analysis (SCTA), modulated and other temperature programmed techniques, etc.), many more new opportunities will arise for providing quality control tools. 

Sprensen OT, Rouquerol J, eds (2003) Sample-controlled Thermal Analysis (SCTA) Orign, Goals, Multiple Forms, Applications, and Future. Kluwer, Amsterdam. 

Over the last decade, it has been internationally accepted that the generic title for TA techniques whereby the heating rate is controlled using a feedback loop as some function of the rate of reaction or the chemical or physical process under study should be sample controlled thermal analysis (SCTA) and this title now embraces Q-TG, CRTA, SIA, and dynamic rate thermal analysis. 

Charsley EL, Rooney JJ, Hill JO, et al. (2003) Development and applications of a preparative scale sample controlled thermal analysis system. Journal of Thermal Analysis and Calorimetry IT. 1091. 

Sorenson OT and Rouquerol J (2003) Sample Controlled Thermal Analysis. Amsterdam Kluwer. 

Prior to each adsorption experiment, the sample was outgassed using Sample Controlled Thermal Analysis (SCTA) [27] which consisted of heating the sample xmder a constant residual vacuum pressure up to a final temperature of 450°C with specific conditions previously reported in detail [13]. 

J.M. Criado in the book O.T. Sorensen, J. Rouquerol (edts.) Sample Controlled Thermal Analysis Kluwer, Dordrecht 2004 and plenary lecture Sample controlled thermal analysis and kinetics at the ICTAC 13 published in J. Thermal Anal. Calor. 80(2005)27... 

O.T. Sorensen, J. Rouquerol (edts.) Sample Controlled Thermal Analysis Kluwer, Dordrecht 2004... 

Criado Jose Maria (1942-) Spain, chem., heterogeneous catalysis, co-inventor of sample controlled thermal analysis Czarnecki Jerzy ( 9 il-), polish born US chem.., focused on large TG samples and... 

Rong-zu Hu (1938-) Chin, chem., thermodynamics of energetic materials, kinetics of exothermic decompositions Rouquerol Jean ( 1937-) Fr. chem., microcalorimetry, adsorption, co-inventor of sample controlled thermal analysis Rowland Henry Augustus (1848—1901) Amer. phys., gave mechanical equivalent of heat and of the ohm, studied magnetic action due to electric convection (book Elements of Physics 1900)... 

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