Ronald Harry Ottewill, who died from cancer on 4 June 2008 in Wickham, UK, was a colloid scientist with unusually broad vision and great energy. He played an important role in the development of soft condensed matter as a distinct subdiscipline of physics.

Ron was born on 8 February 1927 in Southall, a suburb of London. He attended local schools and developed an interest in science; he also excelled at cricket and middle-distance running. In 1948 he received a BSc in chemistry, with subsidiary physics, from London University’s Queen Mary College, where he also earned a PhD, supervised by D. C. Jones, in 1952. His thesis was on the adsorption of hydrocarbon vapors on surfaces. In 1952 Ron joined the department of colloid science at Cambridge University. There, working on antigen-antibody reactions supervised by Paley Johnson, he completed a second PhD in 1955. That work initiated a lifelong interest in light scattering and electron microscopy. He stayed in Cambridge for 12 years and developed broad interests in colloid science. In 1964 Ron moved to the chemistry department at Bristol University; he became a professor in 1971 and remained at Bristol for the rest of his career.

Ron’s initial task at Bristol was to set up a one-year MSc program in colloid science. He ran it successfully for many years; the program had some 250 graduates, many of whom rose to senior positions in academia and industry. Ron was an inspiring teacher who continued to give about 60 lectures a year even when he was heavily distracted by other activities.

In 1964 physical chemistry research at Bristol was centered on surface science. Ron established a colloid group that quickly became world renowned. At that time a main focus of colloid science was understanding the principles underlying the stability of colloidal particles, particularly charged particles, in dilute suspension. For that purpose, Ron developed various well-characterized “model” systems, first basing them on silver iodide and later using colloidal polystyrene. In the 1970s he was one of the first colloid scientists to recognize the challenges posed by concentrated suspensions. Light-scattering experiments with one of us (Pusey) demonstrated the strong influence of interparticle interactions on both the structure and the dynamics of the suspension.

In the late 1970s, Ron and John White, then director of the Institut Laue-Langevin (ILL) in Grenoble, France, pioneered the use of neutron scattering in the study of colloid structure and interactions. That became one of Ron’s main interests for the rest of his career. He was very “hands on” and frequently traveled to Grenoble, where he could be found in the instrument halls late at night. The fact that soft matter now commands a large fraction of the beam time at the ILL and other neutron facilities owes much to Ron’s early insights.

The synthesis of colloidal particles, particularly with a narrow distribution of size, is a skilled activity beyond the scope of many physicists. Ron and his group were generous in providing samples for others to use. His poly(methyl methacrylate) particles, developed with Imperial Chemical Industries’ (ICI) paints division, became the standard “hard sphere” model colloid, now used by many physicists. The particles were used by William Russel, Paul Chaikin, and David Weitz in their study of colloidal crystallization on the space shuttle and the International Space Station.

Ron also was heavily involved in administration and the promotion of colloid science. At Bristol he served terms as chairman of the school of chemistry and dean of science. He was instrumental in setting up the UK Polymer Colloids Forum, which recently established a medal in his name, and the colloid and interface science group of the Royal Society of Chemistry. Ron chaired committees of the ILL and the UK Science and Engineering Research Council. He was also an active member of the “colloid mafia,” which for many years ran the Gordon Conference on Polymer Colloids. Throughout his career Ron was in demand as a consultant for industrial companies such as Procter & Gamble, Exxon Corp, ICI, and BP, whose scientists appreciated his remarkable ability to provide quick, practical solutions to almost any problem.

Although he liked to be in charge, Ron was not particularly well organized. His office, with every surface piled high with books and papers, was a standing joke among colleagues and students. But once you got inside—frequently after waiting in line—and found a vantage point from which to see him through the piles, Ron appeared to have all the time in the world and could unerringly find obscure papers relating to experiments done years earlier.

Ron will be sorely missed, especially for his open mind, his keenness to help, and his encyclopedic knowledge.

Ronald Harry Ottewill