How nanoparticle science is advancing | Interview with Dr. George Schatz

00:22Nanoscience

Jed Macosko: Hi, I’m Dr. Jed Macosko at AcademicInfluence.com and Wake Forest University. And today we have a special guest visiting us from Northwestern University outside of Chicago. And this is Professor Schatz. So we’re glad to have you on this show, Professor Schatz. It’s good to see you.

George Schatz: Thank you very much. Yes, I’m pleased to have a chance to talk to you.

Jed: Great. Well, we’d love to know a little bit more about your current research. You have a lot of grad students, post-docs, maybe some undergrads working for you.

And what is it all going towards? What projects are you most excited about?

George: Yeah. So my research over the last…I’ve been a faculty member for 45 years, but I always say, especially in the last 20 years or so, that’s still a long time, we got very interested in nanoscience. So that’s been the highlight of that, of what I’ve been involved with.

Of course, I do theoretical chemistry and computational work and things like that. But it’s easy to look at the program of research that I’m involved with and say that what I’m doing is using the basic tools that I have available for me in terms of computational chemistry and theory. And we’re applying them to problems that relate to the nanoscience field in the broadest way and sort of many different directions.

And so, yeah, I mean, we got involved initially in understanding just what nanoparticles are all about. Okay, strictly the silver and gold nanoparticles and other metal particles that they have unique size-dependent optical quantities.

So optical quantities kind of got pushed on us early on as being an interesting area of field, and we’ve worked very hard on a lot of different directions of that topic over the years. But we also do things related to structures of, not only the nanoparticles, but also the molecules that you put on to the nanoparticles. The interaction of molecules and nanoparticles is a very interesting topic. It can go on many directions that include biological molecules like DNA interacting with nanoparticles and peptides. And so, yeah, this is…

We’ve covered a lot of different topics. And, yeah, I always say, it’s like, “How many projects do I have going on right now? Like 20. Okay.” Yeah, but to me, they’re all exciting projects where we’re trying to learn in many cases about properties of molecules, nanoparticles, optical properties, and sometimes other properties, particularly structure and thermodynamics, that are often cases where it’s just we can use computational tools to study and understand these things and provide important insights that are crucial for understanding experiments and for making applications in a wide set of directions.

03:32Finding molecules to replace the fullerenes

Jed: Very Cool. Well, yesterday we spoke with Nobel Prize winner, Bob Curl, who lamented the fact that C60, the fullerenes, never really found an application. “Junior never grew up and got a job” is how he described it. But it already sounds like you’re hinting at applications.

Can you share some of the exciting applications of some of the research that you and your students have done?

George: Oh, sure, yeah. Actually the fullerenes have…Once in a while, we’ve played around with the fullerenes. And I know about Curl. He’s a terrific guy, absolutely. And the fullerenes did find a somewhat unique application in terms of a field that we have worked in the area of organic photovoltaics, and so on.

Although it turns out, the funny thing about it is that it was like…For a while, there was a fullerene that ended up being the best possible molecule to use for organic photovoltaics. But then, of course, everybody said, “Oh well, yeah, but that’s…Don’t really wanna do that long-term.” And so a research area that we’ve worked on in the last few years has been finding molecules that can replace the fullerenes in organic photovoltaics, and so that’s, yeah, so that’s been an interesting topic.

And the photovoltaics topics is, I think a good area that we’re…I mean, I don’t think with us just having been, necessarily, the leading edge players of that field, but we certainly have been involved in it, and it’s been exciting to watch it. And so that has been a field that has evolved quite a lot over the years.

Yeah, where we kind of got more involved is, it had to do again with these metal nanoparticles, the silver and gold particles, and understanding how you can use them for various applications. Of course, that’s kind of an older topic in some respects. I mean, people were already making topics…I mean, Michael Faraday studied the properties of gold nanoparticles for about a year in the 1850s.

And, yeah, so, it’s an older topic. But at the same time, in some respects, it has a very, sort of modern version of what’s going on that began with the discovery of all the tools for nanoscience that we all use, the scanning tunneling microscopes and things like that.

And in addition, there were a bunch of exciting spectroscopic tools that came along that went beyond what Michael Faraday was doing that were discovered starting in the 1970s.

And so that for me was a big deal because of the fact that there was a technique called surface-enhanced Raman spectroscopy that was discovered here at Northwestern by one of my colleagues in the 1970s. And so that proved to provide lots of interesting challenges for doing theory and computation.

And then there’s directions and applications of the gold particles and silver particles, and so on, that have gone in many different directions, particularly having do with how to attach molecules to these particles and then use the particles for assessing applications.

And then there’s been exciting work done here that has had to do with attaching DNA to gold particles, and then using that combination of things, both for assessing applications and more recently for medical therapeutics, which was a surprise that that could actually be done.

And so this is the work of another colleague, a guy named Chad Mirkin , he’s a very exciting person. And then…Yeah, then there’s other biological applications. One of my other colleagues, a guy named Sam Stupp, has done some very exciting work in which he’s figured out how to make peptide-based materials that form nanofibers.

And so it turns out those have both therapeutic and applications in making structures of various types that where fibers have useful mechanical and also biological applications.

Jed: Very cool.

George: So it’s like…It just goes on and on in terms of where you can find exciting science to get involved with.

08:14Gold particles

Jed: That is really exciting stuff. So it’s nice how you talk about a lot of your fellow chemists and colleagues at Northwestern. Definitely, it’s nice just to see that you’re promoting other people’s stuff too.

But when you walk into a seminar room to give a little talk about what you and your group have done, what applications do you mainly like to focus on on those first few slides? Things that have made it into the everyday public sensing or therapeutics or whatnot?

George: Yeah. So, well, the sensing and therapeutics has been one that we’ve talked about, that for us it was…That’s more in the past. There were fundamental discoveries that were done about 10 years ago that sort of established what was possible in that direction, so I haven’t been pushing that so much.

But another thing that actually was discovered 10 years ago, but which had a more recent life of its own, had to do with understanding, again, so these gold particles, it turns out you could make arrays of gold particles. And they had some exciting properties, optical properties, and where you can combine together the excitation of gold particles with light, in combination with the properties of the arrays, where you have a diffraction that’s possible, things like that.

And so that combination of two things, the excitation in individual particles and the diffraction, ends up leading to optical properties that went in directions that I never could have predicted.

But it was one of these things where we discovered all this stuff initially on the computer, and then it was like, “Oh,” and at the time there were really no experiments which showed the effects that we thought were interesting.

But eventually people got doing those experiments. Initially, I was told that isn’t gonna work. But later on they did the experiment, showed the interesting optical effects, and now it turns out that sort of morphed into a way to make lasers.

And so we all had to become experts in the laser area, that has to do with these optical properties and then coupling those into either laser dies, or into things like semiconductor nanoparticles that can lase. And so that combination of things ended up being an area that has been a very active field in the last seven or eight years.

Jed: Wow.

George: And so, yeah. So that’s [10:45] ____.

Jed: Did that particular project point to something that would be something consumers could use with some sort of interesting optical properties?

I know it’s not gonna give us a cloak of invisibility like Harry Potter…

George: No. [laughter]

Jed: But maybe it would give us some kind of display or…

George: So unusual optical properties, right. Again, at this point, it still hasn’t translated itself into practical lasers that somebody’s gonna use in the grocery store, but it could. They’re…It’s always a matter of just…The laser business is one where the applications are all about who’s got the best…The best and the cheapest, and all that kinda stuff.

And…So yeah, there’s always the issues about is that…Can it go in that direction? Maybe there’s applications in the communications business, that’s an area that we’re exciting right now, having to do with just understanding…

There’s an area called Quantum Science that has kinda emerged in the last few years that has to do with things like secure communications, so it could be that that’s gonna end up being where more of where the applications will come.

There’s optical devices, photonic devices that have already appeared to a certain extent, but which could evolve…Okay, get rid of the electron circuits in your devices and have them all evolve, just beams of light that are being transmitted within your device, things that like that.

12:21Whats next?

Jed: Wow, that would be incredible. Well, it’s really exciting to hear the kinds of things that you’re already doing in your lab. Are there any things that you still wanna accomplish? You have a lot of career left ahead of you, so are there things on the horizon that you wanna talk about?

George: Well, we got involved in some areas that were non-traditional, at least for me and my group, but which I think are exciting. We’re involved in a center right now that’s trying to solve the problem of…The fact that right now we all have these wonderful cell phones that we love, and so on.

They’re full of materials that are things like lanthanides, which are sometimes called rare earths. They’re not that rare, but nevertheless it turns out it’s an environmental catastrophe to both extract them in mining, and also throwing them away into garbage dumps is a terrible thing, and so you’d like to recycle all these guys. But the recycling…The chemistry isn’t known, basically, for the most part, for recycling of lanthanides, or it just doesn’t work very efficiently right now.

So I’m involved in a group of people, one of whom is my colleague Fraser Stoddart , he’s the famous guy, that where we’re really trying to figure out how to design new chemistries, new molecules that will enable us to capture these metals.

It could be gold, it could be things like cerium or neodymium or whatever, so that we can effectively recycle them and get them out of the garage dump business.

14:08Sign off

Jed: Oh, wow. Well, that would be great. We just spoke with the guy yesterday who started the Green Chemistry project at the EPA back in the 1980s, and he would be very proud of you for figuring all this out. And yet another example of how we as humans can take better care of the things that we’ve been entrusted with so…That’s awesome. Well, thank you so much for sharing all these great things with us today, it’s just been such a delight to speak with you, Professor Schatz, and we really appreciate you taking the time.

George: Happy to do it. Thank you very much.