ISSN:
1572-8943
Schlagwort(e):
frequency domain
;
heat-flux calorimeter
;
indium
;
integral analysis
;
melting transition
;
pseudo-isothermal analysis
;
quasi-isothermal measurement
;
reversible melting
;
saw-tooth modulation
;
sinusoidal modulation
;
temperature-modulated calorimetry
;
time-domain
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract Indium was analyzed with both, standard differential scanning calorimetry (DSC) and temperature-modulated DSC (TMDSC) using sinusoidal and saw-tooth modulation. Instrument and sample effects were separated during nucleated, reversible melting and crystallization transitions, and irreversible crystallization with supercooling. The changes in heat flow, time, and sample and reference temperatures were correlated as functions of heating rate, mass, and modulation parameters. The transitions involve three regions of steady state (an initial and a final region before and after melting/crystallization, a region while melting/crystallization is in progress) and one region of approach to steady state (melting peak to final steady state region). Analyses in the time domain show promise when instrument lags, known from DSC, are used for correction of TMDSC. A new method of integral analysis is introduced for quantitative analysis even when irreversible processes occur in addition to reversible transitions. The information was derived from heat-flux calorimeters with control at the heater block or at the reference temperature sensor.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1010190425284
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