Armand de Waele (1887–1966) was a British chemist, noted for his contributions to rheology, and after whom the Ostwald-de Waele relationship for non-Newtonian fluids is named.
de Waele was born in Islington, London, in 1887, the son of a Belgian father and French mother. He held dual nationality until the age of 21, when he chose to be a British rather than Belgian. He obtained a BSc from the Regent Street Polytechnic then worked in the paint and linoleum industries. In 1914 he married a Frenchwoman with whom he had two sons John and Peter, and the same year was conscripted into the Royal Flying Corps.
After the First World War he joined Gestetner as Chief Research Chemist, where he remained till 1957 when he retired. During this period he published 30 papers on rheology and patents on duplicating as well as a book. He was a Fellow of the Royal Institute of Chemistry and of the Institute of Physics.
-  R.S. Morrell, A. de Waele (1920) Rubber, Resins, Paints and Varnishes (Van Nostrand)
- A. de Waele Journal of the Oil & Colour Chemists Association (1923) 6, pp33–69 "Viscometry and Plastometry"
- US Patent 1744755 (1930) Stencil sheet for use in duplicating
- US Patent 1828766 (1931) Production of stencil sheets for use in duplicating
- US Patent 1819078 (1931) Stencil sheet for use in duplicating typewritten or manuscript documents, drawings and the like
- US Patent 1910005 (1933) Vulcanized or sulphurized oil composition
-  Journal of the Society of Cosmetic Chemists (1956) 7, 4, pp336–346 "Introduction to the Rheology of Disperse Systems"
- ^ Ostwald called it the de Waele-Ostwald equation: Kolloid Zeitschrift (1929) 47 (2) 176-187
- ^ a b Chemistry and Industry, May 13, 1967, page 777 Obituary; Armand de Waele (1887-1966)
- ^ A. de Waele, F.R.I.C., F.Inst.P., (1956) Journal of the Society of Cosmetic Chemists, 7 (4) p336