Julie A. Kornfield

Julia A. Kornfield

2017 Bingham Medalist

California Institute of Technology

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It is indeed a pleasure to profile Julia Kornfield (Julie), the recipient of the 2017 Bingham Medal of The Society of Rheology. Julie stands apart as one of my very strongest PhD students and her impressive record of accomplishment at Caltech has further established her as a leading rheologist, worldwide.

Julie Kornfield received her bachelors in chemistry from California Institute of Technology in 1983, her M.S. in chemical engineering also from Caltech, and her PhD in chemical engineering from Stanford University in 1988. After Stanford, she did postdoctoral work with Hans Spiess at the Max Planck Institute for Polymer Research. She started on the faculty at Caltech in 1990, rising to the rank of full professor. She has made considerable contributions in the field of polymer physics and rheology over the course of her career, as I outline below.

Kornfield left graduate school with an enviable collection of papers in the area of rheo-optics applied to problems in polymer melts. In the late 1980s, there was great interest in the reptation dynamics of bimodal molecular weight distributions in polymer melts and, in collaboration with Dale Pearson, Kornfield’s experiments advanced our knowledge in that area. Another collaboration with Masao Doi introduced the concept of nematic ordering in melts.

Upon joining Caltech, Kornfield devised new optical rheometric methods – now beautifully mated with mechanical rheometry. What is astonishing, however, is her mastery of an array of sophisticated microstructural methods (2D nmr, x-ray and neutron scattering, EPR, infrared spectroscopy …) that have been judiciously selected for their ability to reveal precise mechanisms that are at the heart of particular problems. Armed with this arsenal of molecular-level probes, she has investigated the problems of flow-induced crystallization of polymer melts, flow-induced orientational transitions in block copolymers, polymer liquid crystals, and chains with complex architectures. In each case, she was able to recognize new phenomena that consequently led to different ways of thinking about their dynamic responses.

Kornfield’s work on miscible blends led to the important introduction of “self-concentration” that rectified the observation that the components within these mixtures cooperate to adjust their local occupancy volumes to produce unique thermo-rheological behavior. Her 1997 paper in Science reporting on flow-induced alignment of block copolymers identified the mechanism of nanostructural reorientation that gives rise to the coexistence of differently oriented states within the material. Her work on flow-induced crystallization has been applauded as among the finest in this important area of polymer processing. She is the corresponding author on a 2007 Science paper with Japanese collaborators that established that a broad portion of the molecular weight distribution participates in the formation of the “shish” portion of fibrillar crystallites. More recently, Kornfield has turned attention to the influence of chain architecture on viscoelasticity. With Greg McKenna, Kornfield has investigated the dynamics of rings, “wedges”, and branched chains. These topological structures were selected to bring out distinctive relaxation responses that are able to test chain dynamics and glassy behavior.

There are two bodies of recent work that bring out Kornfield’s inventive side. These are her participation and leadership in the development of light-adjustable intraocular lenses and the design of a completely new class of megasupramolecules with the proven promise of delivering anti-misting behavior to jet fuels. Both of these important advances display several aspects of Kornfield’s scientific personality. She has dogged determination and she is able to translate fundamental understanding in rheology towards impactful applications. The former invention improves human health and the latter development can save lives.

Following implantation, intraocular lenses can undergo unwanted and uncontrolled displacement and reorientation. The unfortunate result is that patients, although relieved of cataracts, can have diminished eyesight quality. Kornfield and her colleagues devised a pliable silicone polymer material that can undergo prescribed shape changes after implantation with the application of light. Importantly, the design was guided by a rheological model based on the photo-induced deformational response of the polymer. This patented invention has garnered considerable attention in the ophthalmology community.

Those of us who have investigated the extensional behavior of dilute polymer solutions may recall the excitement in the 1980s surrounding “anti-misting” additives where small amounts of high molecular weight polymer can effectively arrest the breakup of jet fuel into an explosive vapor cloud. However, following a flurry of research activity into this problem, work n this problem faded following a spectacular “failed” demonstration of the technology and the considerable problem of designing additives that did not promptly degrade in the complex flows of pumps and filters. Kornfield has solved this problem by designing, largely from the ground-up, a new class of polymer chains. These new polymers have the high molecular weight needed to resist jet break up and the generation of tiny and explosive fuel droplets. Yet, these chains, if hydrodynamically degraded, have the means of healing themselves through the sticky monomer units that make up their central strands. This work was published in Science in 2015 and has received worldwide acclaim.

There is no better ambassador of the science of rheology (or science in general, for that matter) than Julie Kornfield. Her infectious enthusiasm and positive nature motivate those around her and the results are evidenced by important advances in our field and demonstrations of how rheology can be applied to solve technological problems. We are most fortunate to have Julie Kornfield as a member of our community and we congratulate her on a well-deserved Bingham Medal.