Devices differential scanning calorimetry

For the determination of reaction parameters, as well as for the assessment of thermal safety, several thermokinetic methods have been developed such as differential scanning calorimetry (DSC), differential thermal analysis (DTA), accelerating rate calorimetry (ARC) and reaction calorimetry. Here, the discussion will be restricted to reaction calorimeters which resemble the later production-scale reactors of the corresponding industrial processes (batch or semi-batch reactors). We shall not discuss thermal analysis devices such as DSC or other micro-calorimetric devices which differ significantly from the production-scale reactor. 

Chromophores must be thermally robust enough to withstand temperatures encountered in electric field poling and subsequent processing of chromophore/polymer materials. Chromophore decomposition temperatures can be assessed by techniques such as thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA and DSC measurements on neat chromophore samples in air will tend to yield decomposition temperatures lower than those for the same chromophores in hardened polymer lattices. Typically, to be useful for development of device quality materials, a chromophore must exhibit thermal stability of 250 °C or higher (with thermal stability defined as... 

Acidity modification of the external surface was characterized by differential scanning calorimetry (DSC) after pre-adsorption of 4-methyl quinoline which cannot enter the pore system. For comparison, sample OW-ZSM-5 and sample lOW-ZSM-5 were subjected to DSC measurements without amine pre-adsorption. In each case, after completion of the first DSC run and re-establishment of initial conditions a second run was performed, and the resulting profile was substracted from that of the first run. In this way, device-dependent factors are eliminated. Measurements were performed by means of a SETARAM DSC-92 equipment under 3 1/h air and nitrogen, respectively, and a heating rate of 5 K/min. 

A method utilizing differential scanning calorimetry has been developed for quick and reproducible estimation of the thermal stability of nonlmear optical chromophores under consideration for incorporation into polymers for use in second-order nonlinear optical devices. The mediod which uses sealed glass ampoules has been used to compare a large number of chromophores and has been compared to electric field-induced second harmonic generation methods. 

The energy yield of porous silicon explosive devices was measured using a calorimetric bomb test, resulting in a value of 7.3 kJ/g with calcium perchlorate as oxidizer (Clement et al. 2005). Differential scanning calorimetry techniques were also used to measure the energy output for sodium perchlorate at almost 9 kJ/g (Plummer et al. 2008). The extent of the NaC104 reaction was observed with bomb calorimetry in N2 and O2 atmospheres. Without the supplementary O2 environment, the heat of reaction was measured to be 9.9 1.8 kJ/g, but with supplementary O2, the reaction yielded 27.3 3.2 kJ/g and approached the theoretical value of 33.0 kJ/g for complete Si oxidation (Becker et al. 2010). 

In conclusion, a starchy material is converted into thermoplastic starch (TPS) by melting in closed devices such as heated extruders or other closed devices capable of maintaining temperature, pressure and shear conditions. Starch that has undergone a thermoplastic transformation does not show the typical melting peaks of native starch at specific water content, under differential scanning calorimetry (DSC) analysis in sealed vials, and can be defined as thermoplastic starch. 

Phase diagrams can also be constructed from data obtained by the technique of differential scanning calorimetry (abbreviated DSC). In this technique a sample of the material to be studied is placed in a small pan with a cover, usually made of aluminum, since aluminum has a rather large thermal conductivity. The sample can be as small as 10 mg, which makes the method quite versatile. An identical pan is usually left empty, but could contain a blank substance. Each of the pans is fitted with a temperature-measuring device and an electrical heater. Both of the pans are gradually heated and the amount of electrical energy added to each pan is monitored. 

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