Northwestern University

Jan
11
Thu 8:45 AM

ChBE Seminar Series, Dr. Zachariah Page

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When: Thursday, January 11, 2018
8:45 AM - 10:00 AM  

Where: Technological Institute, L361, 2145 Sheridan Road, Evanston, IL 60208 map it

Audience: - Faculty/Staff - Student - Post Docs/Docs - Graduate Students

Contact: Cody Jarrett   847.467.4824

Group: McCormick-Chemical and Biological Engineering

Category: Academic

Description:

Zachariah Page

Title:
Synthesis of Soft Materials for Energy Harvesting and Conservation

Electronically active polymers are valuable components of organic solar cells and light emitting diodes due to their (opto)electronic properties, processability, and mechanical flexibility. This talk will showcase the development of two new synthetic polymer-based platforms for: 1) high performance organic solar cells using hydrophilic conjugated materials, and 2) solution processable light emitting diodes composed of emissive surface-bound pixels. In the first topic, interactions between pendent dipoles of conjugated polymer zwitterions and metal surfaces are tailored to dramatically improve light-to-electricity conversion. The second portion of this talk focuses on the use of multipurpose phosphorescent compounds that initially serve as photocatalysts to facilitate polymer growth from a surface, and subsequently act as dopants to enhance light output for low-energy displays. Each of these platforms pave the way for next-generation energy harvesting and conservation through tailored polymer chemistry to address various technical challenges in the area of soft materials for electronics.

Bio:

Zachariah Page was born in Rochester, NY, and obtained his B.S. in chemistry at Juniata College in 2010. During his senior year, he spent three months abroad at the University of Cambridge, UK, working on the synthesis of novel conjugated polyelectrolytes under the advisement of Prof. Wilhelm Huck. Zak then carried out his Ph.D. studies in the laboratories of Prof. Todd Emrick at the University of Massachusetts, Amherst, where his doctoral research focused on the synthesis and characterization of novel conjugated polymer zwitterions, and their integration into organic solar cells. In 2015, he began his postdoctoral research with Prof. Craig J. Hawker at the University of California Santa Barbara, studying photochemical transformations in the areas of organic electronics and 3D printing.

 

Jan
18
Thu 8:45 AM

ChBE Seminar Series, Dr. Xiaoguang Wang

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When: Thursday, January 18, 2018
8:45 AM - 10:00 AM  

Where: Technological Institute, L361, 2145 Sheridan Road, Evanston, IL 60208 map it

Audience: - Faculty/Staff - Student - Post Docs/Docs - Graduate Students

Contact: Cody Jarrett   847.467.4824

Group: McCormick-Chemical and Biological Engineering

Category: Academic

Description:

Xiaoguang Wang

Title:
Are Imperfections in Materials Useful?

Imperfections in materials, such as point defects (vacancies), line defects (dislocations) and surface defects (grain boundaries in polycrystalline structure), often cause detrimental effect on the macroscopic properties of the materials (e.g., mechanical, electrical or optical). This presentation will describe how imperfect structures in liquid crystalline soft matter can be leveraged to design and synthesize materials with unusual function and structure. The first part of the presentation will reveal that topological defects in liquid crystals can form the basis of a versatile class of three-dimensional, dynamic and reconfigurable templates for directing molecular self-assembly in a manner strongly analogous to other classes of macromolecular templates. The second part will move to design and synthesis of a polycrystalline liquid crystalline elastomer, demonstrating how the introduction of grain boundaries can yield a rich palette of stimuli-dependent shape changes. In particular, complex, non-monotonic responses will be demonstrated for the first time. Overall, this presentation will address fundamental challenges and potential applications of imperfect designs of soft matter using liquid crystallinity.

Bio:
Dr. Xiaoguang (William) Wang received a BS and MS in Chemical Engineering from Zhejiang University in Hangzhou, China. In 2011, he joined the group of Prof. Nicholas L. Abbott in the Department of Chemical and Biological Engineering at University of Wisconsin-Madison. After he received a PhD in 2016, he joined the group of Prof. Joanna Aizenberg as a postdoctoral fellow in the John A. Paulson School of Engineering and Applied Sciences at Harvard University. His research interests revolve around soft matter, including polymers, surfaces, liquid crystals, and self-assembly.

 

 

Jan
25
Thu 8:45 AM

ChBE Seminar Series

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When: Thursday, January 25, 2018
8:45 AM - 10:00 AM  

Where: Technological Institute, L361, 2145 Sheridan Road, Evanston, IL 60208 map it

Audience: - Faculty/Staff - Student - Post Docs/Docs - Graduate Students

Contact: Cody Jarrett   847.467.4824

Group: McCormick-Chemical and Biological Engineering

Category: Academic

Description:

TBA

Title:
TBA

 

Bio:

TBA

 

Feb
1
Thu 8:45 AM

ChBE Seminar Series. Dr. Matthew Gebbie

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When: Thursday, February 1, 2018
8:45 AM - 10:00 AM  

Where: Technological Institute, L361, 2145 Sheridan Road, Evanston, IL 60208 map it

Audience: - Faculty/Staff - Student - Post Docs/Docs - Graduate Students

Contact: Cody Jarrett   847.467.4824

Group: McCormick-Chemical and Biological Engineering

Category: Academic

Description:

Matthew Gebbie

Title:
Tuning Electrostatic Forces in Ionic Liquids and Mapping the Nucleation Landscape of Diamond

Molecular forces are fundamental to wide-ranging challenges, from increasing ion transport efficiency in electrolytes, to combating protein aggregation in neurodegenerative diseases. In this seminar, I will present two examples of systematically varying molecular forces to investigate foundational theories in complex interfaces. I will first discuss using nanoscale force measurements to determine the origin of energy storage in ionic liquid-electrode interfaces. Ionic liquids show promise as nontoxic electrolytes, but higher conductivities are needed for applications. While ionic liquids were initially hypothesized to have extremely high free ion densities, we discovered that greater than 99.99% of the ions in ionic liquids behave as neutral pairs. From these results, we propose a new way of envisioning concentrated electrolytes to guide the design of high performance ionic liquids and energy electrolytes.

I will then present an approach for directly measuring the sub-critical nucleation energy landscape of diamond, a previously inaccessible regime in a core physical process. Diamond exhibits potential for biological imaging and quantum sensing. However, inconsistencies surround prior models of diamond nucleation, hindering the synthesis of high quality diamond for molecular sensing. By measuring relative nucleation probabilities from atomically-defined diamond templates, diamondoids, we find that critical nuclei are 26 carbon atom clusters composed solely of surface atoms, with a nucleation barrier that is four orders of magnitude smaller than classical estimates. Our results answer key questions regarding diamond synthesis and support non-classical concepts for nucleation and growth through multi-step intermediates.

 

Bio:
Matthew Gebbie received his Ph.D. in Materials from UC Santa Barbara in 2016, where he was a 2011–2015 Science and Engineering Fellow in the NSF Center for Nanotechnology in Society. With guidance from Prof. Jacob Israelachvili, Matthew led research that substantially progressed a molecular level, mechanistic understanding of how electrostatic correlations govern the properties of ionic liquids and underwater peptide-based adhesives. Currently, Matthew is a GLAM Postdoctoral Fellow at Stanford University, where he works with Prof. Nicholas Melosh to tackle fundamental problems in diamond nanomaterials to enable single molecule, fluorescence-based electromagnetic sensing and advanced biological imaging.

Feb
8
Thu 8:45 AM

ChBE Seminar Series, Dr. Michele L. Sarazen

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When: Thursday, February 8, 2018
8:45 AM - 10:00 AM  

Where: Technological Institute, L361, 2145 Sheridan Road, Evanston, IL 60208 map it

Audience: - Faculty/Staff - Student - Post Docs/Docs - Graduate Students

Contact: Cody Jarrett   847.467.4824

Group: McCormick-Chemical and Biological Engineering

Co-Sponsor(s):
ISEN private

Category: Academic

Description:

Michele L. Sarazen

Title:
Kinetic, Spectroscopic, and Theoretical Investigations
of Light Hydrocarbon Reactions in Porous Catalytic Materials

The optimization and potential industrial application of porous catalysts requires understanding how properties of these materials affect their reactivity and selectivity and how to control these properties via advanced synthesis strategies. Porous crystalline materials, such as zeolites or metal organic frameworks (MOFs), represent a large and diverse pool of heterogeneous catalysts and catalyst supports. Thorough mechanistic investigations that employ characterization of material properties, active-site identification, kinetic and isotopic studies, and computational modeling are needed to elucidate how structure directs function for any reaction or application. Advances in catalysis science and active site engineering are vital to sustainably meet our growing demands for energy and chemicals.

Here, this strategy is employed to investigate the reactions of light hydrocarbons in various porous catalysts. Light alkenes and alkanes can be sourced from conventional (petroleum), renewable (biomass), and emerging (shale gas) feedstocks; their selective and efficient conversion to transportation fuels and/or molecular building blocks for valuable polymers and chemicals is a major target of heterogeneous catalysis research. The coupling of alkenes and incorporation of alkanes into alkene mixtures is catalyzed by protons in the form of solid Brønsted acids such as zeolites. How the local environment (confinement) of these protons, varied by changes in zeolite framework, as well as their acid strength influences the relative stability of precursors and transition states will be discussed. Further, the use of metal sites, either in physical mixture with solid acids or as monofunctional MOF-derived metal nanoparticles on carbon supports, was also investigated for the dehydrogenation of alkanes to alkenes. These studies combine catalytic material design and synthesis with kinetic analysis and density functional theory to develop the general and unifying concepts underlying how these catalysts work to convert abundant feedstocks into value-added fuels and chemicals.

Bio:

Dr. Michele L. Sarazen is currently a postdoctoral fellow at the Georgia Institute of Technology, working with Professor Christopher W. Jones. Her current research is the synthesis of aminopolymers for application in CO2 capture sorbents as well as metal organic framework mediated synthesis of catalysts for propane dehydrogenation. She obtained a B.S. in Chemical Engineering from the Pennsylvania State University and a Ph.D. in Chemical Engineering from the University of California, Berkeley. Her Ph.D. research, working with Professor Enrique Iglesia, focused on a molecular understanding of alkene and alkane chain growth on solid acid catalysts. Her work was recognized with the Heinz Heinemann Prize for graduate research in catalysis from UC Berkeley’s College of Chemistry and the National Science Foundation GRFP.