The Materials Research Society’s (MRS) David Turnbull Lectureship Award recognizes the career of a scientist who has made outstanding contributions to understanding materials phenomena and properties through research, writing, and lecturing, as exemplified by the late David Turnbull of Harvard University. This year, Jacob Klein, Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, Israel, has been selected to give the 2015 Turnbull Lectureship. Klein is cited “for discoveries which transformed our understanding of soft matter and interfaces, through sustained research, inspirational lecturing, and academic leadership.” He will be presented with the award at the 2015 MRS Fall Meeting in Boston.
Klein has made landmark discoveries in polymer physics, in the understanding and control of surface forces, and in elucidating friction and lubrication in aqueous systems. He first studied polymer dynamics, and subsequently, the properties of polymer interfaces, surfaces, and wetting effects. In parallel, Klein focused on the behavior of confined simple and complex fluids, and on forces between surfaces, including steric interactions, nanotribology, and biological lubrication. His work is characterized by studying nature as directly as possible at a microscopic level, often developing, for this purpose, novel experimental approaches and designing state-of-the-art experimental approaches (including infrared microdensitometry and nuclear reaction analysis for polymer dynamics studies, and uniquely sensitive self-designed surface force balances for studying steric forces, confinement effects, and nanotribology). Klein has recently been expanding his basic studies to the biomedical area, with potential impact for alleviation of widespread lubrication-related diseases, such as osteoarthritis.
Klein’s major achievements include the first experimental demonstration of reptation (Nature 1978) (snake-like motion of entangled polymers), using a novel, self-designed diffusion-measuring technique (Nature 1975, Nature 1977), together with the theoretical analysis of the onset of reptation and the idea of tube renewal. His findings—extended over the following decade by further discoveries on dynamics of entangled polymers (Nature 1983, Nature 1986, Science 1990)—firmly underpinned our molecular understanding of the rheology of entangled polymers. An additional major achievement was to first measure molecular attraction and repulsion mediated by polymers at surfaces (Nature 1980, 1982, 1984, 1988)—years before the advent of atomic force microscopy. Such forces underlie the steric stabilization of colloidal dispersions in myriad natural and synthetic systems. These findings became classic textbook material and played a major role in underpinning the modern understanding of dynamics of entangled polymers and of polymers at surfaces. More recent achievements by Klein include the discovery of confinement-induced phase transitions in liquids (Science 1995); the remarkable entropy-based lubrication that can be achieved by polymer brushes (Nature 1991, Nature 1994); and in particular, the discovery of the hydration lubrication effect (Nature 2001, Science 2002, Nature 2003, Nature 2006, Science 2009a), which underlies most lubrication processes in biology. Although these achievements are of a very basic nature, the effects they relate to are important in a much wider context of materials science, from the rheology of polymer melts and properties of colloidal dispersions, to tertiary oil recovery, and to more efficient tissue engineering and biomedical devices, such as prosthetic implants (Science 2009b).
Some 70 graduate students and postdocs received their training at Klein’s labs (at the University of Cambridge, the Weizmann Institute, and the University of Oxford), of whom 26 are currently in tenured faculty positions in leading universities in Israel, Europe, China, and North America, including several who have achieved their own high level of distinction. In Israel, he was one of the pioneers in soft matter research, establishing (in the early 1980s) the first seminar and lecture series in soft matter and interfacial phenomena, and was later a founder of the Department of Materials and Interfaces at the Weizmann Institute. His awards include the Tribology Gold Medal (2012), the Royal Society of Chemistry Soft Matter and Biophysics Prize (2011), the Israel Chemical Society Prize (2010), and the American Physical Society High Polymer Physics Prize (1995). He is a Fellow of the Royal Society of Chemistry, the Institute of Physics (UK), the American Physical Society, and the European Academy.
