Plenary Abstracts

Electrochemical Carbon Conversion for a Fossil-Free Future
Jason Cooper , Twelve

Twelve is the carbon transformation™ company eliminating emissions from everyday products and corporate supply chains by converting CO2 into the chemicals, materials, and fuels that make up our modern world. The process of carbon electrolysis uses just water and renewable energy as inputs to transform CO2 emissions into thousands of products, from apparel to jet fuel. This talk will discuss the development of CO2 electrolyzers for the production of CO and syngas, which are subsequently converted into sustainable aviation fuel (SAF), heavy marine fuel, and polymers. The Molecular Foundry at LBNL has been a key partner in the development of Twelve’s CO2 electrolysis technology, from Twelve’s early days as part of the LBNL Cyclotron Road program through the present. This talk will highlight how this partnership has enabled the development of scalable CO2 electrolyzers for a fossil-free future.

One Dimensional Wormhole Corrosion in Metals
Yang Yang , Penn State

Corrosion is a ubiquitous failure mode of materials. Often, the progression of localized corrosion is accompanied by the evolution of porosity in materials previously reported to be either three-dimensional or two-dimensional. However, using new tools and analysis techniques, we have realized that a more localized form of corrosion, which we call 1D wormhole corrosion, has previously been miscategorized in some situations. Using electron tomography, we show multiple examples of this 1D and percolating morphology. To understand the origin of this mechanism in a Ni-Cr alloy corroded by molten salt, we combined energy-filtered four-dimensional scanning transmission electron microscopy and ab initio density functional theory calculations to develop a vacancy mapping method with nanometer-resolution, identifying a remarkably high vacancy concentration in the diffusion-induced grain boundary migration zone, up to 100 times the equilibrium value at the melting point. Deciphering the origins of 1D corrosion is an important step towards designing structural materials with enhanced corrosion resistance.

Electronic Structure Calculations of Donor/Acceptor Materials for Thermally Activated Delayed Fluorescent Devices
Seyhan Salman , Clark Atlanta University

The active layers in organic electronic devices usually consist of blends containing two or more molecular and/or polymeric components. For instance, in organic solar cells and organic light-emitting diodes (OLEDs) based on thermally activated delayed fluorescence (TADF) exciplexes, two components present are an electron-donor and an electron-acceptor material where their lowest intra-molecular and inter-molecular excitations generally display a strong charge-transfer (CT) character. The challenge for theory is the accurate determination of the electronic processes that take place in the organic electronic devices which requires a quantum mechanical methodology that can adequately describe both the intra-molecular and inter-molecular excited states in the active layers. Density Functional Theory (DFT) is a cost-effective and reliable method for the evaluation of the electronic states of the multicomponent organic molecular materials. However, DFT is highly sensitive to the choice of the functional for a satisfactory description of the CT states. In this talk, we will present the DFT calculations by means of a screened version of range-separated-hybrid (RSH) functional for the description of the excited states of organic donor/acceptor compounds used as active layer emitters in TADF OLEDs. We will show that the screened RSH functionals along with the optimally-tuned range separation parameter provide the most satisfactory description of the CT states and can be used to derive the microscopic parameters that control the radiative and non-radiative transitions in donor/acceptor compounds.

User Town Hall

Boyce Chang
Iowa State University

Developing micro- and nano-fluidic integrated circuits and sensors to increase our understanding of the self-assembly and energy-transfer processes that underpin single and multicellular life.
Aeron Hammack , Berkeley Lab

Structure, folding and flexibility of co-transcriptional RNA origami
Jianfang Liu , Berkeley Lab

RNA origami is a method for designing RNA nanostructures that can self-assemble through co-transcriptional folding with applications in nanomedicine and synthetic biology. However, the dynamic folding processes are challenging to study because current structure determination methods heavily rely on averaging. Here we combined two reconstruction methods of cryogenic electron microscopy: conventional single-particle analysis (SPA) and in-house developed individual-particle electron tomography (IPET), to study RNA origami 6-helix bundle with a clasp helix (6HBC) that undergoes slow maturation from a “young” to “mature” conformation. SPA allowed sorting and reconstruction of the two major conformations to sub-nanometer resolution. Further IPET enabled us to observe individual RNA helices and tertiary structures without averaging. Statistical analysis of 120 tertiary structures confirms the two main conformations and suggests a possible folding pathway driven by helix-helix compaction. Studies of the full conformational landscape reveal both trapped states, misfolded states, intermediate states, and fully compacted states. The study provides novel insight into RNA folding pathways and paves the way for future studies of the energy landscape of molecular machines and self-assembly processes. Additionally, we applied IPET to reconstruct a multidomain satellite-shaped RNA origami, revealing the flexibility of its domains.

Observations of spin-momentum locked surface states in amorphous Bi2Se3
Paul Corbae , UC Santa Barbara

Crystalline symmetries have played a central role in the identification and understanding of quantum materials. The use of symmetry indicators and band representations have enabled a classification scheme for crystalline topological materials, leading to large scale topological materials discovery. Amorphous materials lie beyond this classification due to the lack of long-range structural order. In this talk I will discuss how amorphous materials can have topological properties in the solid state. I will present results for amorphous Bi2Se3 where spin- and angle-resolved photoemission spectroscopy data is consistent with a dispersive two-dimensional surface state that crosses the bulk gap with an antisymmetric spin texture. The observation of spin-momentum locked surface states in amorphous materials opens a new avenue to characterize amorphous matter, and triggers the search for an overlooked subset of quantum materials outside of current classification schemes, as a novel route to develop promising scalable quantum devices.

Bioorthogonal chemistry, the journey from basic science to commercial translation

Carolyn Bertozzi
Stanford University

Bioorthogonal chemical reactions are designed to neither interact nor interfere with biological systems. We originally invented these chemistries for applications in biological research, disease diagnostics and drug development, but their use has been extended to fields as diverse as plant biology and materials science. This presentation will provide an historical account of the field’s development and current directions in the area of clinical translation.