Skip to main content

"Tempera" and "Oil": rheology and microstructures of paints

Event Label
Lecture (German)
Organisational Units
Conservation – Restoration
Location Description
Block A, 1. OG
Room A1.3.11
Augasse 2–6
1090 Vienna

Guest seminar with Dr. Patrick Dietemann from the Doerner Institute in Munich.

from 9 am –5 pm

What is "tempera", and what is "oil"? And why are the definitions so different in different centuries and languages? In the last two decades, modern colloid chemistry has made fundamental progress, and it turns out that central aspects of our idea of what a tempera is according to today's definition fundamentally contradict colloid chemical principles.
Also, from the point of view of rheology (the study of the flow behavior of matter), our use of language to describe paints contradicts basic laws of physics. In order to correctly describe the properties of paints on the basis of colloidal chemistry, new models are necessary, which fortunately already exist and only need to be applied. So the complex behavior of paints can be described very well, but one must also accept the complexity, which is suddenly named concretely.

The seminar will include an introduction to colloid chemistry and rheology, as well as a detailed discussion of what physical quantities and aspects need to be considered when describing the flow properties of paints. It will be shown that the properties of paints with egg, oil and pigments do not depend on their chemical composition but on their microstructure.