skip to main content
Idioma:

Fast scanning power compensated differential scanning nano-calorimeter: 1. The device

Zhuravlev, E. ; Schick, C.

Thermochimica acta, 2010-06, Vol.505 (1), p.1-13 [Periódico revisado por pares]

Oxford: Elsevier B.V

Texto completo disponível

Citações Citado por
  • Título:
    Fast scanning power compensated differential scanning nano-calorimeter: 1. The device
  • Autor: Zhuravlev, E. ; Schick, C.
  • Assuntos: Calibration ; Calorimetry ; Chemistry ; Crystallization ; Devices ; Differential power compensation ; Exact sciences and technology ; Fast scanning nano-calorimetry ; General and physical chemistry ; Mathematical analysis ; Metals ; Nanostructure ; Physical chemistry of induced reactions (with radiations, particles and ultrasonics) ; Scanning ; Sensors ; Specific heat ; Temperature calibration
  • É parte de: Thermochimica acta, 2010-06, Vol.505 (1), p.1-13
  • Notas: ObjectType-Article-2
    SourceType-Scholarly Journals-1
    ObjectType-Feature-1
    content type line 23
  • Descrição: Fast scanning calorimetry becomes more and more important because an increasing number of materials are created or used far from thermodynamic equilibrium. Fast scanning, especially on cooling, allows for the in situ investigation of structure formation, which is of particular interest in a wide range of materials like polymers, metals, and pharmaceuticals to name a few. Freestanding silicon nitride membranes are commonly used as low addenda heat capacity fast scanning calorimetric sensors. A differential setup based on commercially available sensors is described. To enhance performance of the device a new asymmetric power compensation scheme was developed. The hardware realization of the scheme and calculation of differential power are presented in the first part of this paper. The fast analog amplifiers allow calorimetric measurements up to 100,000 K/s. The lower limit is defined by the sensitivity of the device and is 1 K/s for sharp melting or crystallization events in metals and ca. 100 K/s for broad transitions in polymers. Another limiting factor is accuracy of sample temperature measurement. A strong dependency of temperature on sample placement on the sensor is observed; even reproducibility is within ±1 K. For finite sample thicknesses the commonly observed thermal lag must be considered too. Uncertainty of the temperature measurement based on previous thermopile calibration is in the order of ±10 K. A significant improvement is possible by adding a small particle of a temperature calibration standard, e.g. indium or tin, on top of the sample under investigation. Then uncertainty is about ±3 K. The second part of the paper describes sample heat capacity determination and an example to demonstrate the performance of the device.
  • Editor: Oxford: Elsevier B.V
  • Idioma: Inglês;Holandês
Links
Voltar para lista de resultados
Ir para página anteriorAnterior Resultado  6 AvançarIr para próxima página

  • Realização: ABCD-USP USP   Logos de Redes Sociais: Freepik

Buscando em bases de dados remotas. Favor aguardar.