C. Austen Angell left legacy of exploration

By

Skip Derra

C. (Charles) Austen Angell took what was ubiquitous and made it appear exotic. A good part of his career was devoted to exploring the properties of one of the most abundant substances on Earth — water — and transforming our understanding of it into a strangely beautiful compound capable of extraordinary properties.

Water is present before all of us but it was Angell, through his inquisitiveness, that provided foundational insights into its true nature. 

Angell, a world-renowned Regents Professor of chemistry who plumbed into the behaviors and physical properties of glass-forming liquids, died on March 12 after fighting cancer for the past 17 years. 

Angell, commonly referred to as “Austen,” leaves behind a trail of seminal research into liquids and glasses, but he also pioneered topics in the geochemical, biophysical and battery electrolyte spaces. He was devoted to studying substances in their most peculiar forms and was particularly proud of his long list of collaborators, students, protégés and friends.

Angell had been an active faculty member of ASU since 1989. He celebrated his life’s work, accomplishments and the many relationships he maintained with fellow scientists, faculty, students, and staff until his passing. When well-wishers poured upon him toward the end, Angell was overwhelmed, commenting that the attention made him “feel like a sultan.”

“I am very sorry that you are not well,” wrote Pablo Debenedetti, a long-time colleague and dean of research at Princeton University. “As a scientist, you have been an inspiration, a hero, and a venerated teacher. But, more importantly, I treasure you as a human being and as a friend.”

“Austen was an extremely collegial and highly influential scientist, an intellectual giant and scientific hero to many of us, in addition to being just an incredibly warm and wonderful human being,” added Ian Gould, the interim director of the School of Molecular Sciences.

Born in 1933, Angell’s inquisitiveness was sparked by his father’s tinkering. He remembered his father in Canberra, Australia, casting parts from scrap aircraft aluminum saying the molten material “got me interested in hot liquids at an early age.” Angell spent a career working on those liquids, focusing his intense inquisitiveness on them for nearly 70 years. 

He was relentless in trying to understand how certain substances changed their properties, how they behaved when put under extreme physical conditions. A favorite target was water, which, despite being an incredibly common substance on our planet, remains rather poorly understood, exhibiting rich complexity when properly scrutinized. It is the only natural substance found in all three states — solid, liquid and gas — within the range of naturally occurring temperatures on Earth. It is a substance everyone has intimate knowledge and appreciation of, but for Austen Angell it held secrets he wanted to unlock.

In the hands of Angell, water was pushed to extreme physical limits in order to study its peculiar properties. He stretched it and compressed it, heated it and then super-cooled it, reporting new measured physical quantities and observed physical properties along the way. Much of the work focused on the phase transitions of water, those imperceptibly short periods of time when massive reordering happens at the molecular level. One recent set of experiments proved that water could transition from one liquid state to another liquid state with a lower density due to a different arrangement of hydrogen-bonded molecules moving to stronger bonding, making it a more viscous liquid. All of this happens in the split instant before it crystallizes into ice. 

The work proved a liquid-liquid phase transition that had only been predicted in computer simulations of water models. 

“The domain between this crystallization temperature and the much lower temperature at which glassy water (formed by the deposition of water molecules from the vapor) crystallizes during heating has been known as a ‘no man’s land,” Angell said at the time of the discovery. “We found a way to pull aside the crystallization curtain just enough to see what happens behind — or more correctly, below — it.”

It was with that tenacity and intellectual rigor that Angell carried out his work, which resulted in more than 520 publications, many of which provided novel insights into liquids and glasses that have been highly cited among his peers. Four separate scientific societies gave him their internationally contested awards — the American Ceramic Society Morey award in 1989, the American Chemical Society Hildebrand award in 2004, the Materials Research Society Turnbull award in 2006 and the Electrochemical Society Bredig award 2010. 

Angell was elected chair of three different prestigious Gordon Conferences. He was especially proud of an “outstanding reviewer” award, given to him by the American Physical Society in 2009 and was honored as the University College London's Bragg lecturer in 2015. More recently, he was honored with the Otto Schott Research Award (2018) and the Gothenburg Lise Meitner Award from the Gothenburg (Sweden) Physics Centre (2019).

In addition, Angell left an indelible influence on a wide range of students, graduate students and postdoctorates, numbering in the hundreds, and he left a deep impression on countless visiting professors he hosted over the years.

Water plays such an essential role in life that everyone recognizes it. But it was Angell’s unique insight and understanding of the substance that exposed its fundamental nature as marked by his discoveries, which will echo across the universe.