Premium
Highly accurate photopyroelectric measurement of thermal diffusivity of vegetable oils
Author(s) -
Dadarlat Dorin,
Neamtu Camelia,
Streza Mihaela,
Socaciu Carmen,
Bele Constantin,
Dulf Francisc
Publication year - 2009
Publication title -
european journal of lipid science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.614
H-Index - 94
eISSN - 1438-9312
pISSN - 1438-7697
DOI - 10.1002/ejlt.200800076
Subject(s) - thermal diffusivity , sunflower oil , sunflower , thermal , materials science , analytical chemistry (journal) , chemistry , thermodynamics , chromatography , mathematics , combinatorics , biochemistry , physics
High‐accuracy photopyroelectric measurements, in the thermal‐wave‐resonator‐cavity configuration, were performed in order to measure the thermal diffusivity of some vegetable oils. The high resolution (relative error ±0.5%) of the above method allows for the detection of small changes in the values of this dynamic thermal parameter. The accuracy of the results is mainly due to the possibility to precisely control the variation (30‐nm step) of sample thickness, a proper selection of the range of the thickness scan (2 µ m < L m < 4 µ m ˜ 5 µ m ), and an iterative procedure of data analysis. A correlation between thermal diffusivity and the fatty acid composition (obtained via gas chromatography) is suggested for some fresh (sunflower, hemp, flax, and soybean) oils and for hemp oil exposed to a microwave field: Thermal diffusivity appears to be determined by the overall content of polyunsaturated fatty acids.