Ariane Vartanian of Nature Reviews Materials interviewed Gopal Rao, the Chief Editor for Technical Content at the Materials Research Society, about preparations that went into the combined in-person and virtual format of the 2021 MRS Fall Meeting. "We knew that networking was of paramount importance to the in-person attendees’ experience after nearly 2 years without in-person interactions," Rao said; "We wanted to reserve ample time in the programme for attendees to interact. This split schedule also allowed logistically for better organization of the two meeting components, which translated to a better meeting experience for in-person and virtual meeting attendees."
While the 2021 MRS Fall Meeting & Exhibit came to conclusion with the end of The Virtual Experience on December 8th, Meeting content will be available online to registered participants through January 15, 2022. Due to the COVID-19 pandemic, special efforts were made by volunteers and participants to ensure a successful hybrid Meeting!
Our congratulations go to the 2021 MRS Fall Meeting Chairs Markus J. Buehler, Craig Fennie, Marina Leite, Laura Na Liu, and Cengiz S. Ozkan for putting together an excellent technical program along with various special events. MRS would also like to thank all the Symposium Organizers and Session Chairs for their part in the success of this Meeting. A thank you goes to the Exhibitors, Symposium Support, and to the sponsors of the Meeting and of the special events and activities.
Contributors to news on the 2021 MRS Fall Meeting & Exhibit include Meeting Scene reporters Sophia Chen, Andrew Fitzgerald, Jessalyn Low, Chetna Madan, Judy Meiksin, Don Monroe, and Prachi Patel; bloggers Essraa Ahmed, Luigi Angelo Castriotta, and Chenru Duan; and graphic artist Stephanie Gabborin; with newsletter production by Jason Zimmerman.
Thank you for subscribing to the MRS Meeting Scene newsletters. We hope you enjoyed reading them and continue your subscription as we launch into the 2022 MRS Spring Meeting & Exhibit – A Hybrid Event - the conversation already started at #S22MRS! We welcome your comments and feedback.
David Ginley, National Renewable Energy Laboratory
Achieving a Circular Economy
Written by Chetna Madan
The term circular economy is becoming an indispensable concept due to the foundation of redefining growth and remodeling sustainable consumption of finite resources available on the planet. The aim is to design practical pathways to extract and recycle as much as materials of significance along with a re-evaluation of the processes to achieve the same. The key principles of circular economy can be stated as (1) eliminating waste and pollution, (2) re-using finished products and extracted materials, and (3) re-establishing natural systems. As proposed by Dr. Ginley from NREL, the design of materials should be done to attain reusability and self-restoration and with the principle of causing negligible environmental harm. The talk addressed that seemingly renewable energy sources like solar and wind come with associated setbacks of exposing toxic materials to the environment, complete non-recovery of difficult to process elements and incapability to design end-of-life reusability of certain significant components. This is the right time to visualize and practice circular economy as a new pathway to designing, processing, and ultimate recycling of our resources for enabling justified utilization.
Shaun Alia, National Renewable Energy Laboratory
Anode catalyst Layer Durability in Low-Temperature Electrolysis
Written by Chetna Madan
The potential of hydrogen to become the fuel for the future can be foreseen owing to its high energy density and the ability for long-term storage and conversion between electricity and chemical bonds. Till today, the utility of hydrogen in the energy sector, particularly with electrochemical water electrolyzers, lags complete exploration. A thorough investigation of the electrocatalyst chemistry including the degradation mechanism and accelerated stress tests was discussed by Dr. Alia in this talk. It was discovered that significant potential losses due to cycling between open circuit and operating potentials were inevitable and could lead to catalyst dissolution, migration, and interfacial tearing. The impact of components integration into membrane electrode assemblies (MEAs), on catalyst properties and electrolyzer durability, was also considered. The study also concluded that catalysts comprising of less stable elements or sub-stoichiometric oxides are more likely to incur severe performance losses. These observations suggest that an in-depth analysis of catalyst membrane interface is essential to design lasting and reliable electrocatalysts for water electrolysis application.
Sarah Heilshorn, Stanford University
Adaptable, Protein-Engineered Hydrogels for Organoid Culture
Written by Jessalyn Low
Three-dimensional culture matrices are essential to support organoid formation. Commonly used matrices like Matrigel, however, have limited translational potential as it is animal-derived and exhibit low batch-to-batch similarity. In this talk, Heilshorn reports the development of a novel hyaluronan elastin-like protein (HELP) matrix which was demonstrated to support the formation, passaging, and differentiation of patient-derived intestinal organoids. Properties of the HELP matrix such as matrix stiffness, stress relaxation rate, and density of cell-receptor ligands are tunable and can be optimized by studying the interactions between the cells and polymers. In line with this, it is also essential that techniques are developed to probe the cell-matrix interactions. To do so, Heilshorn presents the development of a broadband dynamic light scattering microrheology (DLSµR) technique. DLSµR is advantageous as it can probe stiffness over a wide range of values, and also achieve data over an extended timescale, which allows for a wide range of cellular processes to be studied. Using DLSµR, it was demonstrated that it could capture cell-induced changes in matrix mechanics and allow estimation of dynamic matrix mechanics, highlighting its use in studying living soft matter changes over time.
Paul Janmey, University of Pennsylvania
Biopolymer-Particle Composites Designed to Match the Mechanical Properties of Soft Biological Tissues
Written by Jessalyn Low
Tissues stiffen in compression but not in extension. However, interestingly, the opposite is observed in polymer networks like fibrin and collagen, which soften in compression and stiffen in extension. This behavior of softening upon compression is observed not only extracellularly but also intracellularly, in particular the actin filaments and microtubules. The difference in response to strain between tissues and polymer networks can be attributed to the fact that most tissues are densely packed cells within a matrix. As such, the mechanical properties of the matrix dominate the properties of the tissue, but presence of cellular inclusions alter the mechanical properties of the network. To test this, fibrin networks were polymerized around dextran beads and it was found that the inclusion of packed beads converted fibrin gel from a compression-softening to compression-stiffening behavior. These results imply that polymer network rheology converts to tissue rheology when volume-conserving inclusions become dense enough to limit network strand configurations. Moreover, it was found that single cells also stiffen in compression, which is postulated to be attributed to the intermediate filaments. Unlike other components of the cytoskeleton, namely actin filaments and microtubules which soften upon compression, intermediate filaments stiffen upon compression. This is thought to be because of their higher flexibility, which reduces their ability to buckle.
Susan Rempe, Sandia National Laboratories
Ultra-Thin and Robust Liquid Membrane for CO2 Capture from Gas Mixture
Written by Chetna Madan
The dire effects of ever-increasing CO2 in the atmosphere can be sensed by the unpredictable climate change taking over the planet. The attempts of sequestering CO2 require high energy inputs and costs. An effective approach as developed at Sandia National Laboratories could be using nature-inspired, ultra-thin, and robust enzyme functionalized membranes with pore size selectivity that permits only CO2 molecules separation. The membrane functionalized with metalloenzyme carbonic anhydrase (CA) is comprised of 18-nm thick arrays of 8-nm diameter hydrophilic pores stabilizing water by capillary action. The benefit of functionalizing with CA comes from the catalyzed conversion of CO2 and water into carbonic acid, thus facilitating the capture and release of CO2. The mixed pore chemistry of the membrane is designed strategically to have super hydrophilic surface on the catalytic side while a superhydrophobic surface on the other. With the optimized diffusion constraints and CA concentration within the nanopore array, the super-thin membrane was able to achieve 10 times better CO2 capture as compared to other methods.
Phonnapha Tangthuam, Chulalongkorn University
Anionic Polyelectrolyte Coating as Artificial Solid Electrolyte Interface for Zinc Anode
Written by Chetna Madan
Zinc battery chemistry research is seeing a spike in recent times due to the promising features of excellent stability, high volumetric capacity, cheaper abundance, and economic viability. The high electrode potential of zinc (-0.76 V vs standard hydrogen electrode) makes it suitable to be used with an aqueous neutral or mildly acidic electrolyte. However, the challenges associated with corrosion, hydrogen evolution, and dendritic growth over long-term cycling inhibit its utilization. To address this problem with zinc anode, the researchers have developed an artificial solid electrolyte interface (ASEI) on the surface of zinc anode which regulates the nucleation and distribution of zinc ions for a uniform plating. As described, a zinc-carbon composite anode utilizing ultra-thin layers of carboxymethyl cellulose, an anionic polyelectrolyte, contributed toward dendrite-free zinc plating even at high current density due to fast ion migration. This ASEI is selectively permeable for Zn ions and highly efficient in preventing corrosion as confirmed from its electrochemical behavior.
The MRS Graduate Student Awards are intended to honor and encourage graduate students whose academic achievements and current materials research display a high level of excellence and distinction. In addition to the MRS Graduate Student Gold and Silver Awards, the Arthur Nowick Graduate Student Award, which honors the late Dr. Arthur Nowick and his lifelong commitment to teaching and mentoring students in materials science, will be presented to a GSA finalist who shows particular promise as a future teacher and mentor.