Learn from mistakes!
As told by Ralph Nuzzo

2022 KAVLI PRIZE IN NANOSCIENCE

MORE ABOUT RALPH G. NUZZO

I believe much of the story of my life follows a plotline that is rather typical for people of my generation. I wish I could say that I was distinguished in some way, blessed with great personal insight or followed a clearly understood path during my life. Nothing could be further from the truth. At many places where decisions were made that would prove critical, luck – good and bad – often had an important say on how events would play out. Here there is an irony in that it is likely the less fortunate outcomes taught me more about things that I deeply value as an adult approaching my seventh decade. Learn from mistakes! Maybe more about that later…

I was born on February 23rd, 1954 in Paterson, New Jersey. It was the time of the post war baby boom and, in relative terms, a period of prosperity for my family. My parents were in their early 40s and thus older than the norm. They had raised most of my siblings during the depression and second world war. They were crushingly poor most of that time and only survived the latter 30s by playing “gigs” at NJ bars (my mom played piano, my father the drums). I used to say that I was raised as an only child in a family of 5 siblings. The second youngest, my brother Roy (who is now an accomplished pediatric orthopedic surgeon), is more than a decade older. My earliest playmate was actually my niece, who is a year older than me. The significance I think is that my parents spent so much energy on my brothers and sister that I tended to drift by the doings in our family in less observed ways. I think that is why I have always been a bit independent/improvisational in the things I do. The Italian immigrant part of our family story was influential in many ways but so too was the zeitgeist of growing up in the chaos that was life in the late 60s and early 70s. Somehow in all this, and with a few missteps I regret, I came to identify myself as being inclined towards science. It was an important decision albeit one I have revisited many times over the years in terms of my long-standing interests in music and history.

A perfect fit
The earliest nudge, though, was “Sputnik”– in my era basically a metaphor for contemporary challenges that could only be addressed via discovery and progress in science. The vintage 50s Sci-Fi movies had a special resonance for me – basic plot, a really big problem requires a scientist to figure out against all odds the solution that saves the day (that vision admittedly grew darker as the years went by when it became more the norm that we might be the source of our own worst problems). Even so, the thought that it might be possible to discover a solution to a big problem was and remains exciting to me. Whatever else was going on in my life, that was a grounding idea that would always bring me back to “earth.” There were many ups and downs and even though I earned good grades in high school, I was more than a bit undisciplined. You might say that with those tumultuous times I formed a perfect fit. And so it was that I went off to university in 1972 (Rutgers College), accepting that I would never be a good enough guitarist to consider music as anything more than a hobby.

“The thought that it might be possible to discover a solution to a big problem was and remains exciting to me.”

First Exposure to Research
In university I came to understand relatively quickly that my education had important gaps, and I think more so than anything else it was a relative weakness in math that led me to pick chemistry rather than physics as a major. I tend not to think in terms of equations and to this day my approach to research is more conceptual/relational, rather than based on ideas expressed mathematically. It was a fortunate choice of a major I think in that I was able to be involved very early as a freshman in laboratory work synthesizing compounds needed by the more senior graduate students for their research.

The undergraduates doing research work then were a superb group, I thought. As my skills and coursework advanced, the efforts focused more on independent projects leading to my first publications. I had discovered in this incremental way first approaches to what would be a lifelong engagement with research. The irony here is that I am quite terrible as a synthetic chemist, but those early experiences were ones that influenced and stuck with me. The lab in those days was a retreat, a place where I could go to think and explore ideas with friends and colleagues. The complexity of the social upheavals of those days was still there in the background (and we did worry about that a lot) but acquired a different perspective in terms of how important it would be to act less based on passion and more via the agency of reason. That was a lesson that helped me as I grew older.

On to MIT
I earned good grades as an undergraduate and was fortunate to gain admission to the graduate program in Chemistry at the Massachusetts Institute of Technology. There I joined the research group of Professor George M. Whitesides, a person I am privileged to share this recognition with. Those were great days in the field of physical organic chemistry. The molecules we would synthesize and study were not ends unto themselves, but rather formed the tools through which we could discover what I would call the “how” of physical phenomena – how things worked, came to have the properties we see, act and transform within the environments of their use. The main body of my thesis described collaborative studies I carried out with another graduate student (Thomas McCarthy) on the mechanisms of a very fundamental organometallic reaction – the so-called beta hydride elimination process. It was a great interaction and affirmed collaboration as being the most effective way to formulate and carry out a program of research. It also has the great virtue of providing the best means I know of to undertake complex interdisciplinary studies to solve important problems confronting society today.

As major as that portion of my thesis was, it turns out that a separate piece of work carried out towards the end of my graduate studies may have been more important in shaping the science that is being recognized by The Kavli Prize. That work concerned itself with studies of the properties of interfaces formed with/by organic materials, notably polymers. These sorts of interfaces are found ubiquitously throughout the natural world and are an essential underpinning of performance in many areas of technology. We focused in these early studies on a few fundamental concepts as guiding directions for the research – to understand how the fundamental molecular interactions occurring at an interface came to determine important properties we can observe macroscopically. Wetting – the shape formed by a drop of water on a surface, for example – and adhesion – why things “stick together as they do” – were particularly interesting. We had great aspirations for the work, ones that generally would far exceed the grasp of what the enabling science at that time would allow. Notable here was the control of how living systems – cellular tissues or organs – recognize, react, and accommodate to the interactions such as might occur with medical devices. The approach we took in this work was to use a generally inert polymeric material (polyethylene) as a sort of blank canvas on which via synthesis we could create broad and selectable sets of molecular modifications from which the underlying structure-property correlations of complex interfacial phenomena could be deduced. It was a work that sought to render the modification of the properties of complex interfaces via rational design as a new paradigm of materials chemistry. I think the most important progress we made in this early work was actually in beginning the important effort of identifying/developing the concepts and toolsets (physical, spectroscopic, etc.) that would be required for interfacial characterization in contexts relevant to the complex systems of interest. It was actually a non-trivial task to usefully define what a functionalized polymer interface was microscopically, for example, given the inherent heterogeneity/multiscale nature of such structures. With this exposure, I began to move towards graduation in 1980 and a life after MIT. Some important issues to work through included finding a job and, most importantly, marrying my wife and life partner Dr. Victoria Nelson.

Bell Laboratories
Finding the job was particularly stressful for me. It was the first time I had to directly confront and take what seemed a door closing stand on the question of what I wanted to do professionally. I didn’t feel I was made of the stuff that was needed for a successful career in academia, and so I began doing the ritual of industrial interviews as they were hosted within the department. It was a vibrant activity, and one that filled us with dread (mostly about doing

“I didn’t feel I was made of the stuff that was needed for a successful career in academia, and so I began doing the ritual of industrial interviews.”

something stupid that would kill an opportunity with a company we were interested in). Some interviewers were known to be tough and probably no company seemed less attainable than did Bell Laboratories, to me the place that was the absolute height of excellence in industrial research. But as the saying goes you can’t catch a fish if you don’t cast a line, so signing up to talk to Ed Chandross (who ultimately became my Department Head at Bell) is what I did with little hope for a positive outcome. I recently spoke to Ed about his memory of that interview. He had forgotten that I had a slight mishap in the NMR lab just before my interview. I had managed to break a finger on my right hand, which made trying to do a chalk talk presentation of my thesis research really difficult. I finished that interview feeling deeply depressed at how bad a train wreck it was trying to write with my left hand while my right hand turned various shades of purple. As it turned out, I don’t think Bell had an iota of interest in beta-hydride elimination or mechanisms of catalysis, but it did like the idea of understanding wetting and adhesion, especially as it might involve interfaces formed with organic materials. I cannot remember if I showed him a demonstration I had worked up in which modestly stretching a hydrophilically modified polyethylene surface caused it to revert to its more expected hydrophobic state. In any event, the interview must have gone better than I thought because I was invited a short time later to an on-site interview in Murray Hill, NJ – tremendously exciting and terrifying all at the same time.

The interview having gone well, and with the offer of a position as a Member of Technical Staff, I moved to NJ with my wife, a baby soon to come, and came to face the first major exemplar of what I call a “Now What?” moment in research. These moments are important to get right. Bell was interested in surfaces and interfaces as formed by complex organic materials, especially as regards to properties of wetting, adhesion, and, from a technology perspective, their durability in use. The idea of control by design was conceptually attractive as a starting point for a plan of work. How to best get at the enabling science that would allow its realization was the important question. This is for me where the story that would become Self-Assembled Monolayers, or SAMs, began.

Many cross currents converged in my thinking. The easiest start would have been to revisit work on polymers as had been explored at MIT (and some studies so directed were part of the work done in 1981). It just didn’t seem to have traction, though. I had given some thought to surface modified electrodes for electrocatalysis. I knew nothing about electrochemistry, but it was a major theme in the literature at that time (important rule for young researchers, be willing to enter new fields). An putative approach that interested me was to use adsorbates inspired by the structures of the surfactant ligands for homogeneous catalysts as I had synthesized some years before with George – polar bifunctional chelating phosphines as an exemplar. It seemed to be a more general idea than those explicit molecules and that specific area of application, though. And maybe in part that closed the loop in my mind related to the mesophases (the assemblies, micelles) surfactants form in aqueous solutions. It might be possible to modify metal surfaces very generally by allowing them to interact with a ligand system for which they have a high affinity – and if sufficiently strong an interaction, allow modification of an interface with a bifunctional reagent containing an orthogonally directed chemical moiety. If, as with micelles, the materials could “assemble” – pack densely and directionally – all the better. The interfaces could express a broad range of physical and compositional properties, with substantial structural organization in the adlayers so formed. Some quick sleuthing for resources and simple trial systems identified gold as a good substrate, one bringing the advantage that it does not form an oxide at its surface and could be manipulated easily for modification by a bifunctional reagent containing what coordination chemists would call a soft ligand system (sulfur was identified as a good choice very early on). That was the core of the idea in a nutshell. Use strong/specific molecular interactions to selectively modify a base substrate material and use the appended functional groups so directed to create new surface and interfacial properties by design. That begat a second “now what” moment (and a critical part of the story). The aspiration for the work was to develop a science that would both make the expressed properties of surfaces and interfaces understandable at a microscopic/molecular (nanoscale—we didn’t have that word yet) level and more importantly to make them manipulatable rationally as such. What sort of data could make this an achievable goal?

I do not recall when I first met Dave Allara – surely by at least early 1981. That he was doing studies of polymer surface chemistry is what I recall hearing about as I explored Murray Hill, so the fit seemed natural. I remember some nice work being done to understand how copper ions leached from a wire led to oxidative failures in its insulation. The phone company was very big into copper wire, so this was an important area of study. We had many discussions, more than I can ever remember or sort out chronologically. What I remember best was how open he was to explore new science and the great depth he was building regarding modes of characterization that would be pivotal in making SAMs the nanoscience foundation they became. One must remember that in 1981, most of the methods we consider routine for use in studies of this type either did not exist or had yet to be demonstrated as being capable of such applications. There was some external criticism, as an example, about the relevance of spectroscopy for the proposed work that actually inspired the presentation of data given in the early SAM papers (e.g., the chain length dependence of a SAM thickness yielding a slope with the dimensions of the methylene group – a true quantitative affirmation). Dave made it all work in my view, and he brought a complimentary physical/analytical depth to the project that complimented the types of contributions I was able to make. And that’s how it was as best as I now remember it – discovery in every direction, with the impacts spreading like an oil film as one bit of progress made possible new, more ambitious follow-on extensions. And most importantly, it was the effective development of quantitative analytical foundations for spectroscopic characterization that made the argument about molecular assembly as an enabling tool for interfacial design very convincing. We had begun the process of extending surface science in this sense towards a new frontier for what would become foundational nanoscience.

At some point in the building of the program at Bell, I reconnected with George. We knew enough at this point to see that the approach we were taking at Bell was going to be very impactful and there were so many potential areas of application to form opportunities for a lifetime of work. For me this was a return to the interests of the earlier polymer surface chemistry effort with George but with twists that made it both more understandable and precise in applications. It was an ideal place to renew collaborations and to realize the promise of the opportunity (next lesson for young research scientists—science is a big universe, one to freely share of its mysteries with people you like working with). George and his students (notable was Colin Bain in the early cohort) had immediate impacts on the range of the questions being asked and answered in the research. The elucidation of the microscopic/molecular structure-property correlations of wetting dynamics and proton transfer at organic surfaces would be one of the first major achievements contributed by this expanding collaborative effort. That those papers continue to be cited at a high rate affirms this view. As it would turn out, we worked very intensively in many collaborations (with a special shout out to Larry Dubois, Paul Laibinis, and Atul Parikh) over the decades that followed to fully build out the story and establish enabled opportunities that had their beginnings in the arc described above. My collaborations with Dave and George, though, were life changing. The work we cobbled together proved out and, in its evolution as an enabling science of nanotechnology, continues to impact materials research in important ways. The control of molecular interactions at the nanoscale (and more recently, their physicochemical dynamics) by design remains a vibrant area of ongoing research and a foundation for applications in nanotechnology that can be generalized beyond assemblies themselves. I think especially of the development by George and his coworkers of soft-lithography, work that brought patterning and fabrication into play by first exploiting assemblies in molecular patterning and then transcending them in enabled forms of fabrication. From here the science of SAMs evolved into the now very sophisticated methods of transfer assembly (pioneered by John Rogers) that exploit viscoelastic dynamics to extend soft patterning methods beyond planar form factors into 3D and with applicability to essentially any class of nanoscale material. It has recently come to pass that even the capability of 3D fabrication may represent an intermediate stage in developments that will make it possible to manipulate materials structures in both spatial and temporal domains (the emerging field of 4D fabrication). Such ideas came to have a major impact on the research I would do after moving to the University of Illinois in 1991.

Fortunate
So that more or less brings me to the present, with many areas of work I have been involved in by necessity not being discussed. But I think it’s important to note that I feel very fortunate to have had a chance to work across a range of interdisciplinary fields over the last 40 years, with more than a little related to SAMs and nanoscience themes. Not all were successful but each of these work efforts had the virtue of teaching me something new.

Growth in a personal context seems so important now. I am old enough that I can be a little “fussier” about the efforts I will get involved in. There also are new responsibilities that will require a discipline that my younger self sorely lacked.

My wife and I continue to enjoy travel and art. Our children and grandchildren are amazing human beings – kind, accomplished and loving. Cooking is a joy for me and an area where there is still so much to learn. Vicky is a great partner to practice this creative art with. And as in 1968, there remain my guitars and amps. I am thinking that, yes definitely, more attention should be given to them if for no other reason than to help keep the blue meanies of our current hard times at bay for just a bit.