Fall 2018

Karl Johnson and his team discovered a new material that remove carbon dioxide from the air and convert it into useful chemicals

  • By Ke Xu
  • 12 October 2018

Karl Johnson and his team worked with a class of nanomaterials called metal-organic frameworks or “MOFs,” which can be used to take carbon dioxide out of the atmosphere and combine it with hydrogen atoms to convert it into valuable chemicals and fuels.

Their findings were published in the Royal Society of Chemistry (RSC) journal Catalysis Science & Technology. The journal featured their work on its cover, illustrating the process of carbon dioxide and hydrogen molecules entering the MOF and exiting as CH2O2 or formic acid—a chemical precursor to methanol. 

Kenneth Jordan will be honored at the Spring 2019 ACS Meeting with a two-day symposium

  • By Ke Xu
  • 2 October 2018

Kenneth Jordan will be honored for his contributions to Computational and Theoretical Chemistry in a two-day symposium, Electron-Molecule & Molecule-Molecule Interactions. The symposium is co-sponsored by the COMP and PHYS divisions of ACS and will be held during the Spring 2019 ACS meeting in Orlando, FL. The symposium will be for two full days from March 31 to April 1, 2019.

Zachary Ulissi developed a machine learning system to discover new materials for electrocatalysis

  • By Ke Xu
  • 18 September 2018

Zachary Ulissi and his team developed a machine learning system to search through millions of intermetallics to discover new materials for electrocatalysis.

Typically, catalysts are discovered through trial and error coupled with chemical intuition. Now, an automatic machine-learning framework has been developed that can guide itself to fnd intermetallic surfaces with desired catalytic properties.

Through their study, published in Nature Catalysis, they have a list of materials and intermetallic combinations that experimentalists should try, both for hydrogen evolution and carbon dioxide reduction. The experiments will then determine what will make good electrocatalysts for the large scale.

Hrvoje Petek won the 2019 Ahmed Zewail Award in American Chemical Society

  • By Ke Xu
  • 18 September 2018

Hrvoje Petek has won the 2019 Ahmed Zewail Award in Ultrafast Science and Technology of the American Chemical Society.

The award, which has been given yearly since 2005, recognizes outstanding and creative contributions to fundamental discoveries or inventions in ultrafast science  and technology in areas of physics, chemistry, biology, or related fields.

Room-temperature quantum fluids of light

Speaker(s): 
Dr. Stéphane Kéna-Cohen
Dates: 
Monday, October 22, 2018 - 4:00pm

Light-matter interaction is at the heart of most optical processes we are familiar with such as absorption, emission and scattering. These are normally treated by assuming that the incident light does not significantly modify the underlying electronic states of the material it interacts with. The strong coupling regime consists of the extreme case where light-matter interaction is so strong that it must be treated non-pertubatively. Polaritons, the resulting mixed light-matter particles, can be the source of many unique phenomena. We will describe how these quasiparticles can be exploited...

Giannis Mpourmpakis Part of $800K DOE Study Targeting Safer Storage for Nuclear Waste

  • By Ke Xu
  • 4 September 2018

Giannis Mpourmpakis is part of a collaborative research team studying the corrosion behavior of glass containers often used to store nuclear waste. Its goal is to find solutions to reduce or avoid the degeneration of the containers. The U.S. Department of Energy awarded $800,000 to the project, titled “Formation of Zeolites Responsible for Waste Glass Rate Acceleration: An Experimental and Computational Study for Understanding Thermodynamic and Kinetic Processes.” 

Karl Johnson and John Keith unlocked the secrets of Polyisobutylene’s reaction mechanism

  • By Ke Xu
  • 28 August 2018

Karl Johnson and John Keith lead a collaboration between the University of Pittsburgh’s Swanson School of Engineering and Wickliffe, Ohio-based Lubrizol Corporation to unlock the secrets of Polyisobutylene (PIB)’s reaction mechanism.

PIB is a workhorse polymer that is found in a multitude of products, ranging from chewing gum, to tires, to engine oil and gasoline additives. Although commercially produced in large quantities since the 1940s, PIB chemistry was a mystery – scientists weren’t sure how the reaction mechanism that creates the polymer happens at the molecular level, which limited further potential. 

Utilizing the University’s Center for Research Computing to analyze the molecular processes, the Pitt/Lubrizol group found that the assumed reaction mechanism was not correct and that initiation of the reaction requires a “superacid” catalyst. 

The group’s findings were published this month in the journal ACS Catalysis.

Statistical mechanics of the transition to turbulence

Speaker(s): 
Dr. Nigel Goldenfeld
Dates: 
Wednesday, September 26, 2018 - 10:00am

How do fluids become turbulent as their flow velocity is increased? In recent years, careful experiments in pipes and Taylor-Couette systems have revealed that the lifetime of transient turbulent regions in a fluid appears to diverge with flow velocity just before the onset of turbulence, faster than any power law or exponential function. I show how this superexponential scaling of the turbulent lifetime in pipe flow is related to extreme value statistics, which I show is a manifestation of a mapping between transitional turbulence and the statistical mechanics model of directed percolation.  This mapping itself arises from a further surprising and remarkable connection: laminar and turbulent regions in a fluid behave as a predator-prey ecosystem. Such ecosystems are governed by individual fluctuations in the population and being naturally quantized, are solvable by path integral techniques from field theory. I explain the evidence for this mapping, and propose how a unified picture of the transition to turbulence emerges in systems ranging from turbulent convection to magnetohydrodynamics. 

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