Some Thoughts, by Saad Hasan

This week I had an article accepted for publication. Normally not a big deal when you have done it before, but this one was my first without any participation by my PhD advisor. I learned much in my time in his group and we produced some high-impact results, but I knew, when I left grad school, it would be important to cultivate my own thought processes to identify important questions and then design and execute projects to address them.

What this new article represents is the culmination of such a process. I consider it the fulfillment of a small goal, because publishing is only one component of scientific work, and for someone in an industrial role such as I’m targeting, it’s a small component, too. It’s significance is in the confidence that comes from proving to myself, I can fly on my own – conceive the idea, do some feasibility tests, get the right people on board, execute the project itself and finally shepherd the manuscript through the revision process to acceptance.

I’m especially pleased by my student, Eleni, making such a meaningful contribution to this work. She was a newcomer to this field of graphene and dispersions – and full credit to her for learning the measurement techniques that yielded data for one of the article’s figures.

Here I write about my time in Sweden and how it has led me to my present position and thoughts. I start with an account of how it came to be. (That’s actually a picture of Copenhagen, Denmark in the summertime.)

In the fall of my final year, I phone-interviewed for a postdoctoral researcher position in a European project called Nanommune, which was investigating the toxicity and risks of engineered nanoparticles. Professor Maria Strømme’s group at Uppsala University was contributing mesoporous silica to the studies, and the different functionalizations had to be thoroughly characterized, in both dry and dispersed forms, to correlate observed biological effects to the particles’ properties.

Looking back at my notes of the interview, one thing I said was

I got into doing research because I like generating new ideas, understanding why they worked, and want these ideas to change the world for the better. By doing a postdoc like this, then later when I am in an industrial setting, the knowledge of these materials’ health impact as they go in new products would be invaluable.

Do I still believe this today? I’ll answer that before this post is finished.

I was offered the job. Before I made a decision, I visited Uppsala and came back with very positive feelings of the people in Maria’s group and the Uppsala-Stockholm area. What about the work itself? In Part 3 I wrote about the ES&H constraints we faced at Sandia, stemming from a lack of health-risk data on nanomaterials. And now I was being offered a chance to contribute to research in this area? Yes, sign me up!

My first work activity was the annual meeting in Scotland, with presentations from all the different work packages. I hadn’t given much thought to biology in my nanomaterials PhD but I was able to follow the discussions of our collaborators’ in vitro work thanks to the tissue engineering course I took in college along with the lab component in which we did cell experiments, including tagging and imaging them.

My work with silica led me to learn new techniques, sol gel synthesis and surfactant-based templating. The particle analysis was comprehensive, using techniques I was well versed in, such as DLS and zeta potential measurement, and others that I learned as I did, such as BET gas adsorption isotherm for surface area and porosity. Outside of the lab, interactions with my colleagues on the biology side of the project inspired further interest in how materials could be tailored for applications like drug delivery while minimizing adverse side effects.

Another reason that I accepted the Uppsala job was the encouragement of individual research interests. Having worked on carbon nanotubes and graphene oxide dispersions to wrap up my PhD, I was still thinking about carbon. Maria funded my travel for two very useful events: a workshop on nanocomposites in Lund, from which I continued over the Øresund to present my graphene oxide work at the very aptly named Carbonhagen 2010 conference.

The nanocomposites workshop, in particular, helped me see the academia-industry connections centered around carbon nanomaterials (CNMs) and the array of products being invented or optimized using CNMs. What I learned there along with what I’d been reading led to a convergence of thoughts around the idea of developing products based on dispersible graphene.

Around this time, IVA, the Royal Engineering Sciences Academy, put out a call for researchers who were interested in commercializing their work. If you were accepted, you got a pot of money and a mentor experienced in a technology business to accelerate your learning and testing.

I got an awesome mentor. He asked very incisive questions that helped me understand how graphene dispersions could be a platform technology, from which products could be offered as long as they created enough value for the  potential markets I identified. What I learned in this process helped cultivate graphene into my “20% time” project at Uppsala. I reached out to some researchers from the composites workshop who were looking at industrial applications and began to investigate chemical modifications of graphene based on some of the problems they cited with existing graphene products. The new synthesis method I developed in response yielded interesting products containing nitrogen groups, and these were characterized pretty comprehensively: by using AFM again, becoming more proficient at TGA, and teaching myself XPS, to name a few of the techniques. The real payoff was getting data from a collaborator showing my material outperform a commercial graphene product in a composite. (Look for the synthesis paper in a chemistry journal later this year.)

After Nanommune finished, I wanted to continue my work on CNMs. I landed at the University of Pittsburgh with a group who had partnered with Nanommune, and was investigating biodegradation of CNMs. Here I’m investigating the degradation of composites containing CNMs, while exploring nuances in the nitrogen content of doped CNMs through chemical assays. Alongside the experimental work, we’re writing a review article on the biological persistence and interactions of CNMs.

Recall the above question about my comment from the Uppsala interview. I totally embrace it today. Nanomaterials will improve many technologies, and consumers will compel us to prove that the materials don’t harm them. Having come down this path, immersing myself in nano-health-risk studies and gaining a deeper understanding of the challenges in using CNMs commercially, I’ve begun to envision my potential next step. I believe my knowledge can contribute to the development of actual products, not just published papers and patents. I think the following two areas are ones in which my understanding and skills may prove effective:

1. Skincare and cosmetics: (Nano)particles are already employed in this industry. They will have the ability to carry therapeutic agents across cell membranes, or be active themselves inside cells. What new restorative capabilities could they offer? How could they be engineered and then later formulated, with surfactants for example, to have maximum efficacy and minimum toxicity?
2. Industrial materials: composites, coatings, etc. Carbon nanotubes and graphene will be key players in this field. How can they be harnessed in ways that are compatible with existing capital equipment and manufacturing methods?

I’ve explored solutions to these questions and aim to validate them in a commercial setting.

Earlier I wrote about my academic experiences at Hopkins, how they led me to grad school at Vanderbilt, and my first two years there.

Year 3

The excitement of being published for the first time: an article on star polymer thin films with my group mate Suseela, who was the lead on this project. I still feel pride about my contributions, which helped get the paper over the finish line: AFM (all those hours of self-training in Year 2!) to record unique arrangements of the star that were predicted by a theory paper; FTIR (infrared spectroscopy) to detect strain in one of those arrangements; and, a fair amount of editing to impart conciseness and forcefulness to our claims in response to the reviewer comments. More papers would come, as a lead author and in even higher impact-factor journals than Journal of Physical Chemistry B, each with their own thrilling and pride-worthy moments, but this first one said, “You belong.”

My work on quantum dot thin films was picking up steam. Suseela and I wrote a successful proposal for CNMS at Oak Ridge National Lab to study the interface between nanoparticle thin films and the surface on which they were assembled, continuing to probe the question What happens at the interface with the substrate? Around the same time, I’d read about commercial work on these films. One young company, QD Vision, was working to produce quantum dot films for displays. In their method, the film was confined to the particular surface on which it had been carefully assembled (part of QD Vision’s method was a trade secret). What if you could assemble the film and then transfer it to any location you desired? Now we’re possibly onto something. Flexible and curved display screens are a possibility. Extend the question of the interface to consider how to make it weak deliberately, in order to lift off the film and have the film be free-standing and transferable.

I tested an idea that’s typically used in top-down patterning: using a sacrificial layer. Polymers could be dissolved in different solvents than the quantum dots, so the polymer, when situated between the quantum dot film and the substrate, could be dissolved to release the film. In principle, this worked. My first successful sample was barely 1 mm across. This wasn’t ready for publication, in both my and my adviser’s view. The process had to be refined immensely.

Looking back at it now, I realize I effectively staked my PhD career on this technique I’d proposed. I faced a lengthy struggle to make it work well enough to get repeatable, publishable (aka sexy) images. Right around this time I also faced down the challenges of passing my preliminary exam (making me an official PhD candidate). An accumulation of frustrations gave rise to self-doubt. Thoughts of “file paperwork to get the Masters degree and leave” crossed my mind. I decided to stick with it because… well, I really can’t pinpoint any one particular reason. I guess I had just enough belief in myself remaining.

After a fun and relaxing Christmas holiday (I needed it!) I was back to it in January, working through the problems in an exceedingly meticulous fashion. If this period was good for one thing, it’s this: internalizing the ability to methodically sweep a broad parameter space with elevated focus until only the solution remains. Bonus achievement: nailing down the sacrificial layer technique that had frustrated me for weeks and weeks. Work remained to verify things and write it up as an article. These would come but not for several months.

Intermission

My fellowship program had allocated funding for students to do a semester-long internship. I held hopes of going abroad more than anything else, something others had done and have done since.

I went to New Mexico.

My adviser had in mind for me to round out my PhD building and working on an elaborate laser/microscope/microfluidic setup to image small numbers of quantum dots being moved by an electric field. A scientist at Sandia National Lab, and acquaintance of my adviser, was open to sharing his expertise in the microfluidic and imaging areas. So there I went.

New Mexico is stunning. I could see why their license plate reads Land of Enchantment. Aside from work, I learned to ski in New Mexico and developed some excellent friendships that continue today. All considered, I’m glad I went. And at the same time, not going abroad firmly planted the seed of seeking international experience early in my career.

My mentor’s group at Sandia had built an impressive microfluidic device and we were able to do some interesting recordings of dielectrophoretic deposition of quantum dots in it. Now the part that was most challenging about Sandia: bringing quantum dots into his particular lab space. At the time, it was not approved for nanomaterials, and Sandia enforced ES&H regulations quite firmly. I found it puzzling until I realized that these regulations were inclined to err strongly on the side of caution because of a lack of health-risk data on the nanomaterials. This experience would plant another seed that motivated my eventual journey to Sweden.

Years 4 and 5

Back from New Mexico, I resumed work on my sacrificial layer technique. In the spring of year 4, we got it published in Chemical Communications (a record in our group for highest impact-factor at the time), having christened the technique sacrificial layer electrophoretic deposition (SLED). Yes, having an acronym that’s easily pronounced was essential.

In my article, I showed SLED could work on different kinds on nanoparticles (quantum dots, iron oxides). My group mate John was working with carbon nanotubes and he validated the technique for them, as well, producing some very cool looking buckypapers (another way of saying “free-standing carbon nanotube film/mat”). We would end up working together on this, with my focus on the mechanical testing, resulting in a Carbon article around the time I graduated.

The laser/microscope project intended for me vanished when the other professor on the grant decided to take a position in Europe. Vanished… because he owned the laser. My adviser threw out this alternative: graphene. We had a few conversations about it, which can be summed up, “Lots of groups have started working on colloidal forms of graphene. See what you can do with it using electric fields and making free-standing forms of it.” So began my journey with graphene oxide.

The final piece of my thesis was a discovery on controlling the microstructure in graphene oxide films, which we reported to ACS Nano (another group record for impact-factor!) After some relaxing trips to visit friends around the U.S. and wonderful time spent with friends in Nashville, I was off to Sweden.

I’ll elaborate on my Sweden experience in the next post.

Photoshop your data.

I’m saddened to read a story like this one about another scientist:

The university said an anonymous tip led to an investigation that began in 2008. A 60,000-page report — the summary of which is available at http://bit.ly/xkyS4A — resulted, outlining 145 counts of fabrication and falsification of data. Other members of Das’ laboratory may have been involved, and are being investigated, the report continues.

UConn has “declined to accept $890,000 in federal grants awarded to” Das, according to the statement, and has begun dismissal proceedings.

I’m working on a review article about biodegradation of carbon nanomaterials. While looking up papers on fullerenes (buckyballs), I come across one called Gated and Near-Surface Diffusion of Charged Fullerenes in Nanochannels published in 2011. One of the author names catches my eye: Fazle Hussain†.

Sounds familiar. When my dad reminisces about his PhD experience, doesn’t he mention his adviser, Fazle this, Fazle that?

My dad did his PhD at the University of Houston in Mechanical Engineering. I look at the author affiliations…

^† Department of Nanomedicine, Methodist Hospital Research Institute, 6670 Bertner Street, M.S. R2-216, Houston, Texas 77030, United States

Houston, yes, but Nanomedicine? What about the other affiliation…

 Departments of Mechanical Engineering, Physics, and Geosciences, University of Houston, N207 Engineering Building 1, Houston, Texas 77204, United States

And there it is.

I chuckled aloud. Everyone is doing nano these days. And in Fazle’s case, it’s a pretty remarkable transition in research interests to fullerenes (width: ~ 1 nanometer) considering my dad did his PhD on jet noise and acoustics using wind tunnels.

Let’s continue with grad school at Vanderbilt, where I did my PhD in Interdisciplinary Materials Science.

Year 1

Completed core classes in physics, chemistry, and crystallography. Served as a TA for materials lab courses. Performed three 10-week research rotations that functioned as a brief immersion to help first-years select an advisor for the remaining duration of grad school. I selected Prof. James Dickerson, who at the time was interested in the transport properties (like electrical conductivity) of thin films consisting of colloidal quantum dots, a type of nanoparticle. Because quantum dots absorb and emit light at specific wavelengths, I envisioned the big picture as working toward new types of solar cell, lighting, and display devices. The distinguishing feature of this research was that an electric field would be used to deposit the particles out of suspension, allowing for larger scale manufacturing than techniques like spin coating.

The summer after I joined his group, Dickerson gave everyone a copy of the Laws of Herman, which included a line about how grad student scientists in the “good old days” used to build from scratch every instrument they used in their work. So, what was it I did earlier in my rotation with the Dickerson lab? Using a glass slide, teflon strips, wire, screws, and epoxy, I built a reusable electrode holder that enabled rapid exchange of the electrodes. And I used this electrode holder to deposit every single thin film sample I prepared until my final year of grad school. How fitting.

Year 2

More classes, this time on individual topics like Polymer Science and Opto-electronics. At the time, the polymer course simply helped to fulfill my course credit requirements. Not until my third and fourth years did I put that knowledge to practical use, investigating which polymer compositions yielded the most effective sacrificial layers (more on this later).

In the lab, we knew that certain processing protocols for the quantum dot dispersions did not produce good thin films. I became interested in why this was the case. Started asking questions like What happens at the interface with the substrate? At the same time, I was getting into characterization of the films. Ellipsometry is a fairly standard way to extract optical constants like index of refraction. For our films, we had to treat them as a composite of semiconductor (CdSe for example), organic surfactant (aka ligand molecules), and air, but without knowing the exact packing fraction, an accurate composition couldn’t be modeled. Now came learning AFM (atomic force microscopy), where by imaging the surface at the nanometer scale you could calculate surface roughness and estimate packing fractions. I don’t know how many tens of hours I spent in the VINSE clean room doing AFM, figuring out how to get the best measurements out of it. The funny/unexpected thing about all those AFM hours is that it ended up being a minimal component of the ellipsometry work… but later it was crucial to my report on free-standing films and for measurements of sub-nanometer thickness graphene sheets.

Again, I’ll pause and continue to gather my thoughts at a later time. The last three years of grad school to come!

This week the NYT ran an opinion piece titled What is College For? in which a Notre Dame philosophy prof defends the model of a liberal education:

Students, in turn, need to recognize that their college education is above all a matter of opening themselves up to new dimensions of knowledge and understanding.  Teaching is not a matter of (as we too often say) “making a subject (poetry, physics, philosophy) interesting” to students but of students coming to see how such subjects are intrinsically interesting.  It is more a matter of students moving beyond their interests than of teachers fitting their subjects to interests that students already have.

I see the value of this aspect of a college education and wrote similarly about the humanities courses that supplemented my engineering education:

Of course, none of these classes makes you an expert in the given field. Instead, they are tiny windows to new voices and new ways to exercise the mind.

But this question of “What purpose does college serve?” remains. Another excerpt from the NYT piece:

In particular, the university curriculum leaves students disengaged from the material they are supposed to be learning.  They see most of their courses as intrinsically “boring,” of value only if they provide training relevant to future employment…

Unless you attend a trade school, today’s post-high school education does not replicate a real working environment in which to practice first. Solving problem sets for homework vs. solving the problem and getting the product delivered on time. Engineering programs come close with their co-op activities (like BME Design Team). Students in other majors probably need to seek out an internship or two while they’re still in college. And for those of us well past college who want to bring our research talents to a new industry, the key will be to gain an understanding of the specific business problem that a given company wants to solve with the help of our skills – which can seem a vague task since the measure of a “better” product, improved through basic research, depends on many factors including some that are external like what your competitors are doing at a given price point. Further, consider that the cutting edge of science is not always the same thing as the cutting edge of industrial technique. Keeping up with all of these advances means that, really, the education never stops.