Felix Sebba was the son of Isadore Sebba, a Cape Town businessman, and his wife Ernestine Carmel. He received his early education at the South African College School and continued his studies at the University of Cape Town, graduating as Bachelor of Science (BSc, 1933), Master of Science in chemistry (MSc, 1934) and Doctor of Philosophy (PhD, 1937). His doctoral research dealt with the chemistry of the elements gallium and germanium. Aided by an 1851 Exhibition Science Research Scholarship he spent two years at Imperial College, London, working on monolayers [with a thickness of only one molecule], followed by a year at the Colloid Science Research Laboratory at the University of Cambridge. He was awarded the Diploma in Industrial Chemistry by Imperial College in 1940. Returning to South Africa that same year, shortly after the outbreak of World War I (1939-1945), he served in the South African Air Force until 1943 and then as senior technical officer at the Royal Aircraft Establishment Laboratory at Farnborough, England, until the end of the war.
Returning to the University of Cape Town in 1946 Sebba was appointed as lecturer in physical chemistry and later as senior lecturer. He continued his research on gallium and germanium and on monolayers, and later also on heterogeneous catalysis. He was elected a Fellow of the Royal Institute of Chemistry and of the [British] Chemical Society, and became a member of the Society of Chemical Industry, the Royal Society of South Africa, and several other professional societies. In 1952 he spent a sabbatical year as a Visiting Fellow at the Frick Chemical Laboratory, University of Princeton, in the United States. He was appointed as professor of physical and inorganic chemistry at the University of the Witwatersrand in 1957 and became head of the Department of Chemistry in 1965. In 1979 he moved to the United States to take up a teaching post at the Virginia Polytechnic Institute and State University in Blacksburg, Virginia, where he continued his research and teaching.
Sebba's work covered a wide range of topics in chemistry and was reported on in over 100 publications, but his main interest was in surface chemistry. One of his most important contributions was his work on ion flotation, which culminated in his book Ion flotation (1962), though the distinction between this form of flotation and precipitate flotation remained controversial (Rice 1989). He was a physical chemist of considerable excellence, an "ideas man" characterised by enthusiasm and width of vision, rather than a skilled experimenter. Much of his theoretical and experimental work was directed at the solution of practical problems and resulted in some patents. For example, his work on monolayers included attempts to reduce the evaporation of water from reservoirs and to remove oil slicks from the sea. His discovery of bi-liquid foams eventually led to a new colloid system, the semigel, which has many possible applications, for example in the production of safety fuels, tertiary oil recovery, solvent extraction and the removal of contaminants from solution. Much of his work in this field was reported in his last book entitled Foams and biliquid foams - Aphrons (1987).
Sebba was inclined to express himself forcefully and publicly on matters affecting chemistry and chemists. Two undergraduate scholarships in chemistry and chemical engineering were created at Blacksburg in his honour. His hobbies included gardening and polishing semiprecious stones. He died suddenly while visiting his daughter and son-in-law in Manchester, England, a few days after their wedding. He was due to return to Virginia that same day and would have been back at work again within a few days. He was survived by his wife, Margot Ellison, whom he had married in London in 1954.
