Four MRL students awarded PPG Graduate Research Assistantships

Written by Lauren Laws

Kenyi Choy Hernandez, Sanghyun Jeon, Jr Wen (Brian) Lin, and Sayantani Sur have been awared PPG Materials Research Laboratory Graduate Research Assistantships to pursue cutting-edge research broadly related to the areas of interest to PPG. 

PPG and the PPG Foundation aim to protect and beautify the world. In their partnership with Illinois, the company and foundation supports diverse students preparing for in-demand careers that will shape global innovation and cutting-edge technologies in areas such as polymer science and engineering, chemical engineering, materials science and synthetic organic chemistry. This fellowship enables graduate students focused on organic and inorganic coating within the Materials Research Laboratry. 

Jr Wen (Brian) Lin, PhD Student, Materials Science and Engineering

“Battery technology is playing an indispensable role in the push for global decarbonization. Owing to their high energy density, Li-ion batteries (LIBs) are now found in a wide range of applications, spanning from grid-scale energy storage and electric vehicles (EV) to consumer electronics. While already successful, there remains considerable demands for LIBs with even higher energy densities and better cycle lives. In that regard, the development of next-generation cathode active materials (CAMs) is necessary. And for that purpose, it is important to be able to characterize and understand the electrode degradation mechanisms at the nanoscale. The application of atom probe tomography

(APT) is key in that it simultaneously provides sub-nanometer, three-dimensional (3-D) resolution and equal chemical sensitivity at the ppm level for most elements. However, the Li migration and preferential evaporation under the intense electric field that cause detected Li excess, which is a phenomenon that has been termed “in situ delithiation”, possess as significant obstacles to wide APT application for battery materials. Regarding that, extensive research has been dedicated to understanding its origin, but the role that crystallographic orientation and anisotropic transport properties play in it has yet been discussed. Thus, my research focuses on utilizing electrodeposited, dense cathodes with well-controlled textures to study the effect of anisotropic transport properties on APT analysis. With the knowledge that we learn, I hope to pave the way for the broader range of APT applications in the battery space, as well as to aid in the development of better design strategies for next-gen CAM.”

Professor Paul Braun, Advisor

“I have had the good fortune to serve as Jr Wen (Brian) Lin’s PhD advisor since he joined the Department of Materials Science and Engineering. The strength of his scholarship and the overlap between his research interests and the interests of PPG makes him an outstanding recipient of a PPG-MRL Graduate Research Assistantship.”

Sanghyun Jeon, Graduate Student, Materials Science and Engineering

"My project aims to develop a fundamental understanding and control of functional materials' assembly down to the nanoscopic and even molecular scale of relevance to solution coating and printing.  With advances in functional polymer synthesis and printing techniques, it has been essential in various industrial applications. In particular, polymer coatings are an important step in fabricating products. I am interested in printable conductive polymers with high conductivity, transparency, and flexibility promise broad applications in thermoelectric, bioelectronics, transparent conductors, electrochromic, and so on. Specifically, the redox-active conjugated polymer, which is an emerging frontier of this field, is my main interest of study, and which shows great promise by showing excellent chemical doping efficiency and processability. I am working on analyzing the effect of processing steps such as printing parameters, solubility, etc on structures of fabricated films, and eventually, link them to their optical and electrical properties to map PSP properties."

Associate Professor Ying Diao, Advisor

“Sanghyun has been a very versatile and productive student. His past experience in the semiconductor industry helps provide him a unique prospective.  I am excited that he is being recognized with the prestigious MRL-PPG fellowship.” 

Sayantani Sur, PhD Student, Chemistry

"Zeolites are a class of aluminosilicate-based porous materials that can be used as an extended ligand  for binding transition metals to develop robust heterogeneous catalysts. Such transition metal sites often show unusual reactivity due to their unique geometric and electronic structure inside the zeolite framework. My research focuses on leveraging the reactivity of these transition metal sites in zeolites to activate some of the most infamous greenhouse gases, CO₂ and N₂O, to convert them into less harmful and/or more useful products and understanding the mechanistic details of these processes. Currently, I am exploring the reactivity of Cu(I) sites in different zeolites towards oxygen atom transfer reactions with these target molecules. A primary goal is to understand how the Cu(I) speciation in zeolite impacts the reactivity and how this speciation can be modulated through new synthetic strategies to generate more of the active precursor sites (over other spectator sites) which will react with the targeted molecules. An important aspect of the projects involves the use of site-selective spectroscopy to study the precursor, active site and reactive intermediates to understand the mechanistic details of these processes which enables targeted synthetic tuning for designing a more efficient material."

Assistant Professor Benjamin Snyder, Advisor

“I am so grateful that Sayantani took a leap of faith and decided to join my brand new lab. This speaks to her scientific bravery - she is not afraid of taking on difficult questions - and a strong innate curiosity. Working with Sayantani, I have come to appreciate her bright intellect and the high level of rigor she brings to her work on metal-containing zeolites as heterogeneous catalysts for small molecule activation. I expect she will change the way we think about these materials as her work progresses, and I am thrilled that Sayantani is gaining some well-deserved recognition through this generous award from PPG.”

Kenyi Choy Hernandez, PhD Student, Materials Science and Engineering

"During 3D printing, Marangoni flow arises in the liquid state when the surface tension gradient, , couples the temperature gradient. In the context of additive manufacturing, the desired scenario is for the Marangoni coefficient, , to be positive, since this will result in an inward radial flow in melt pools, ensuring deeper melt pools that promote bonding between layers. A negative coupling sign would promote radially outward flow, leading to wider but shallower pools and promoting lack-of-fusion porosity. Surface active elements can lead to a positive Marangoni coefficient, by segregating to the liquid surface and reducing its surface tension in a specific temperature range. Due to a natural tendency to phase segregate and decompose during solidification, immiscible alloy systems present a novel research opportunity, which has not been exploited yet. Previous studies on nonequilibrium immiscible alloys such as Cu-Ag, showed that during sliding wear, this microstructure can self-organize into alternating Cu-rich and Ag-rich nanolayers from initial spherical precipitates, resulting in a reduction of wear rates by a factor up to 20. It is proposed here to design and evaluate immiscible alloys that combine a positive Marangoni coefficient to print adherent coatings and self-organization of the microstructure at the nanoscale during sliding wear to improve wear resistance. Through a combination of computational and experimental tools, this will facilitate an optimal production of durable and wear-resistant metallic coatings."

Professor Pascal Bellon, Advisor

"It has been a great pleasure to mentor Kenyi. He has a broad range of research interests and a remarkable ability to learn complex techniques, both experimental and computational ones, from atom probe tomography for the characterization of phase and microstructure evolution in 3D printed materials, to molecular dynamics simulations for the screening and selection of alloys with surface active elements that promote inward Marangoni flows. This PPG fellowship will provide Kenyi with the opportunity to apply these concepts and techniques to the design and evaluation of 3D printed alloys with high wear resistance."