New Knudsen effusion apparatus with simultaneous gravimetric and quartz crystal microbalance mass loss detection

• Tipo: Artigo em Revista Científica Internacional
• Data: 2011

Autores

Luis M N B F Santos (Autor) FCUP; Luis Spencer S S Lima (Autor) Outra; Carlos F R A C Lima (Autor) Outra; Fernao D Magalhaes (Autor) FEUP; Manuel C Torres (Autor) Outra; Bernd Schroeder (Autor) Outra; Manuel A V R Ribeiro da Silva (Autor) FCUP

Revista

Título: Journal of Chemical Thermodynamics

Vol. 43 Nº 2

Páginas: 834-843

ISSN: 0021-9614

Editora: Elsevier

Indexação

ISI Web of Knowledge - 60 Citações

Scopus - 63 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia mecânica

Outras Informações

ID Authenticus: P-002-RAH

DOI: 10.1016/j.jct.2010.12.022

Abstract (EN): A new Knudsen effusion apparatus, enabling simultaneous gravimetric and quartz crystal microbalance mass loss detection, is described. This device allows the measurement of vapour pressures of small sample mass (50 to 100) mg over a wide temperature range (350 to 650) K using very short effusion time intervals. The performance of the apparatus was checked by measuring the vapour pressures of anthracene, benzanthrone, and 1,3,5-triphenylbenzene, between (0.1 and 1) Pa, over temperature intervals of 20 K. The derived standard molar enthalpies of sublimation and vapour pressures are in excellent agreement with the mean of the available literature values and with the recommended values. The new working methodology and design of this apparatus allows the measurement of high quality vapour pressure data due to: accurate temperature measurement and control; improvement in vacuum thermal contact between the effusion cell and the oven metal block; optimisation of the quartz crystal sensor head microbalance position; efficient temperature control of the quartz crystal microbalance head; accurate measurement of the resonance crystal frequency using an impedance circuit analyser methodology.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10