Microcalorimetiy

Another thermal analysis method available for catalyst characterization is microcalorimetiy, which is based on the measurement of the heat generated or consumed when a gas adsorbs and reacts on the surface of a solid [66-68], This information can be used, for instance, to determine the relative stability among different phases of a solid [69], Microcalorimetiy is also applicable in the measurement of the strengths and distribution of acidic or basic sites as well as for the characterization of metal-based catalysts [66-68], For instance, Figure 1.10 presents microcalorimetry data for ammonia adsorption on H-ZSM-5 and H-mordenite zeolites [70], clearly illustrating the differences in both acid strength (indicated by the different initial adsorption heats) and total number of acidic sites (measured by the total ammonia uptake) between the two catalysts. 

Heat-Flow Microcalorimetiy and Its Applications to Heterogeneous Catalysis P. C. Gravelle... 

Using different probe molecules such as ammonia and sulfiir dioxide, the acid-base properties of the samples were determined by adsorption microcalorimetiy. 

Flow adsorption calorimetry is recognized as an important method to study adsorption/desorption phenomena at solid-fluid interfaces. According to a review by Groszek [37], flow adsorption microcalorimetiy is now developed to a point where it provides accurate and reliable adsorption and desorption data for events occurring at the solid-liquid or gas-solid interface over a wide range of temperatures, pressures and solution concentrations. 

PRI Principi, T., Goh, C.C.E., Liu, R.C.W., and Wimiik, F.M., Solution properties of hydrophobically modified copolymers of A-isopropylaciylamide and A/-glycineacryl-amide A study by microcalorimetiy and fluorescence spectroscopy. Macromolecules, 33, 2958, 2000. 

MA3 Maron, S.H. and Filisko, F., Use of microcalorimetiy for deteimination of order in polymers, na/. Calorimetry, Proc.Amer. Chem. Soc. Symp., 155,153,1968. 

Harsted, B. S. Thomsen, E. S. Excess enthalpies from flow microcalorimetiy. 2. Excess enthalpies for carbon tetrachloride + n-hexane, -I- n-heptane, -1- n-octane, -r n-hexadecane, 4- isooctane, and -r neopentane, and of octamethyltetrasiloxane -1- isooctane and -I- cyclohexane J. Chem. Thermodyn. 1974,6, 557-563... 

Microcalorimetiy and HPLC were used to study the thermodynamics of hydrolysis of a range of disaccharides with enzymes. Data obtained indicated that additivity can be applied to the prediction of the thermodynamics of the processes. ... 

However, in an attempt to gain further insight on these processes, we proceeded with the thermodynamics associated with the interactions of the cyclic tetramer and amines in benzonitrile and in nitrobenzene at the standard temperature. For these purposes, titration microcalorimetiy was the technique used since inconsistent data were obtained by the use of classical macrocalorimetry mainly due... 

Keywords— Muscle Eneigetics, Cardiac Trabeculae Cameae, Microcalorimetiy. 

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