Friday, July 24, 2020

NanoEngineer earns Dissertation Year Fellowship

Jacobs School of Engineering nanoengineering PhD student Qiaowan Chang has been awarded a Dissertation Year Fellowship funded by the Marye Anne Fox Endowed Fellowship Fund. This fellowship is awarded to students who demonstrate highly distinguished academic records, and provides recipients with a $22,000 stipend for their dissertation year, plus tuition and fees.

Qiaowan Chang
We spoke with Chang about her research, her accomplishments at UC San Diego, and her future goals.

Q: How did it feel to receive this award?
A: I feel very excited and lucky to receive this award. It's not only a recognition of my current research, but also encouragement for my future work. And thanks to my supervisor, Professor Zheng Chen, for the instruction, the help during my PhD studies, and for offering lots of opportunities to collaborate with other groups.

Q: Tell us about the research you’ve been conducting in Professor Zheng Chen's lab.
A: My research is mainly focused on designing electrocatalysts at atomic scale through fundamental understanding of their elementary processes in several key electrocatalytic applications and reactions, including decentralized hydrogen peroxide (H2O2) production (2-electron oxygen reduction reaction), direct liquid fuel cells (ethanol oxidation reaction), and carbon dioxide (CO2) conversion (carbon dioxide reduction reaction).

Q:  What are some of the applications of your research?
A: For the decentralized hydrogen peroxide (H2O2) production (2-electron oxygen reduction reaction), H2O2 is one of the most useful chemicals across the entire chemical industry. For the traditional production method, the transportation and storage of H2O2 are unresolved problems due to its chemical instability. Only a dilute H2O2 solution is needed for most applications. For example, 3% H2O2 solution is used as the disinfectant to fight the COVID-19 virus. My research is to develop a green and user-friendly method to produce H2O2 on-site from the two-electron oxygen reduction reaction.

For the direct ethanol fuel cells (ethanol oxidation reaction), it could be used in electric vehicles. In direct ethanol fuel cells, ethanol is oxidized by oxygen to generate electricity. Ethanol is a green and sustainable fuel that can be produced from agriculture feedstocks. Thus, direct ethanol fuel cells are environmentally-friendly techniques for powering vehicles.

For the carbon dioxide (CO2) conversion (carbon dioxide reduction reaction), electrochemical technology could reutilize and convert CO2 to other important chemicals to mitigate climate change and ocean acidification caused by the increased CO2 level. 

Q: Tell us about your dissertation topic.
A: My dissertation topic is to explore novel strategies to design electrocatalysts at atomic scale through fundamental understanding of their elementary processes in the above applications and reactions. The key to make such electrochemical reactions happen is the electrocatalysts. The thesis mainly discusses several strategies, including to tune the local chemical coordination between atomic catalyst clusters (metal) and their support materials (defect carbons) using a composite approach to achieve the synergistic effect of “1+1>2” (that is, Pd clusters deposited on the oxidized carbon nanotubes) for decentralized hydrogen peroxide (H2O2) production (2-electron oxygen reduction reaction), and to control the morphology and structure of the electrocatalyst (that is, the core-shell cubic-shaped electrocatalysts: 10 nm of platinum (Pt) nanocubes as a core and a ~0.2 nm thick of iridium (Ir) layer as a shell) in direct ethanol fuel cells (DEFCs).

Q: What are your future goals once you earn your PhD?
A: I will do a postdoc first to finish my remaining projects. Then, I will try to pursue a faculty position in academia, or a researcher/scientist position in industry.

Thursday, July 23, 2020

Using nanotechnology for more targeted, safer pesticide delivery

Nanoengineers at UC San Diego will develop more targeted ways to apply pesticides to food crops using plant virus nanocarriers, thanks to a $490,000 grant from the Department of Agriculture’s National Institute of Food and Agriculture. This could lead to a reduction in the amount of pesticide used, and therefore less chemical accumulation from pesticides in our food, drinking water and environment.

Engineers are using a plant virus as a nanocarrier
for more targeted pesticide delivery to protect crops
like tomatoes from root-eating nematodes. 
Pesticides are used extensively in food production to ensure crop health and yield. While these toxic chemicals can keep bugs, weeds, parasites, fungi and rodents from damaging crops, they also accumulate in the environment, in the crops themselves, and even in drinking water supplies, leading to adverse health effects for humans.

Nanoengineers led by Professor Nicole Steinmetz at the Jacobs School of Engineering plan to use a plant virus as a nanocarrier to more precisely deliver pesticide payloads when and where needed, resulting in less pesticide required, and less bioaccumulation. The team will study and use the tobacco mild green mosaic virus (TMGMV), which they’ve previously shown can carry cargo down to 30 centimeters below the soil surface, much deeper than traditional synthetic nanoparticles which travel 8 to 12 centimeters deep.

Their first target for these nanoparticles is a type of roundworm called a nematode, which eats plant roots, destroying the plant in the process. By being able to deliver the pesticide deeper into the plant’s root system, the researchers believe their plant virus nanoparticles will be more effective in stopping nematodes than synthetic pesticide delivery particles.

“In this project we focus on pesticides to target roundworms that infect the roots of crops, using our plant virus nanotechnology,” said Steinmetz.  “More specifically we will produce a library of nanoparticles derived from harmless plant viruses to answer how size, shape, and materials properties affect the nanocarriers interactions with soil and plants. Understanding these fundamental questions is expected to make an impact on next-generation pesticides, literally attacking the problem at its roots.”

Since plant viruses like TMGMV can be engineered to a custom size and certain physical properties, the researchers will study the effectiveness of plant virus nanocarriers of different sizes, shapes, and surface chemistries.  They’ll create a library of nanomaterials derived from TMGMV, detailing the nanocarriers’ pesticide delivery efficacy.

“We’ve seen that in medicine, changing the shape of a nanoparticle delivering a specific drug can lead to advantages such as enhanced diffusion and tissue penetration,” Steinmetz said. “We hypothesize that this is true for pesticide delivery as well, and will investigate the effect of nanocarrier size and shape on pesticide application effectiveness.”

The tobacco mild green mosaic virus is non-infectious to most plants, but the researchers will also create inactivation protocols to ensure it’s safe to use with any desired plant.  The virus is non-infectious in humans.

Steinmetz will collaborate with researchers Erin Rosskopf and Jason Hong at the USDA Agricultural Research Service, who will test candidate materials on nematode-infested crops.

Tuesday, July 21, 2020

Comic-Con@Home features UC San Diego scientists

Saura Naderi, outreach director at the Halıcıoğlu Data
Science Institute
Comic-Con 2020 may look a little different this year, coming to you from the comfort of your own home. The annual San Diego comic and pop culture convention is going virtual due to COVID-19, but the good news is more than 350 panels will be available for free online, no waiting overnight in line required.

Comic-Con@Home will feature seven UC San Diego speakers during the five-day virtual event running from July 22 to July 26.

Tune in on Thursday, July 23 from 3-4pm for The Science of Back to the Future, where the creative teams from "Back to the Future" and "Transformers" talk to local scientists about how they came up with their vision for each storyline and how science would play a part in these movies. UC San Diego panelists include engineer and roboticist Saura Naderi, the outreach director at the Halıcıoğlu Data Science Institute and an alumna of the Jacobs School of Engineering.

Marine biologist Ben Frable will speak on
the More Science in Your Fiction panel.
Up next is The League of Extraordinary Scientists and Engineers: More Science in Your Fiction on Thursday, July 23 from 6-7pm. Scientists and engineers will discuss how both comic books and science fiction push them to dive deeper into the unknown. UC San Diego panelists include Ben Frable, a marine biologist at Scripps Institution of Oceanography, and Angela Zoumplis, an extremophile explorer at Scripps Institution of Oceanography.

You can catch Sinless, Fearless, Ruthless - A look at science and social science in a YA sci-fi book Friday, July 25 at 4pm. Learn about the social sciences and the idea of morality behind Eye of the Beholder by author Sarah Tarkoff. UC San Diego panelists include Samantha Russman, a PhD student at the Jacobs School of Engineering.

Cognitive Science Professor Virgina De Sa
The Fleet Science Center Celebrates: Agents of S.H.I.E.L.D. - The Stories and Science of Androids, Space Travel and Aliens will air on Saturday, July 25 from 3-4pm. Celebrate the seven seasons of Marvel's Agents of S.H.I.E.L.D. and hear executive producers, actors, and writers discuss how accurate the science in the series was with local scientists. UC San Diego panelists include Virginia De Sa, a professor in the Cognitive Science Department and associate director of the Halıcıoğlu Data Science Institute ; Troy Sandberg, a bioengineering PhD alumnus; and Melissa Miller, a scientist and science writer at the Scripps Institution of Oceanography. 

To learn more about Comic-Con 2020 events, visit their website.