Article
Physics, Multidisciplinary
L. B. Fletcher, J. Vorberger, W. Schumaker, C. Ruyer, S. Goede, E. Galtier, U. Zastrau, E. P. Alves, S. D. Baalrud, R. A. Baggott, B. Barbrel, Z. Chen, T. Doeppner, M. Gauthier, E. Granados, J. B. Kim, D. Kraus, H. J. Lee, M. J. MacDonald, R. Mishra, A. Pelka, A. Ravasio, C. Roedel, A. R. Fry, R. Redmer, F. Fiuza, D. O. Gericke, S. H. Glenzer
Summary: Angularly resolved X-ray scattering measurements were used to determine the equilibration of electron and ion temperatures in warm dense matter regime. The experiment demonstrated that the energy transfer between electrons and ions is faster than predicted by classical models.
FRONTIERS IN PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Adam Czajka, Steven P. Armes
Summary: The study investigated the aqueous emulsion polymerization of TFEMA using persulfate initiation and monitored the particle size evolution using SAXS and DLS. Well-defined spherical latexes were formed under different conditions, with significant differences observed between surfactant-free and SDS formulations. Comparable polymerization kinetics were observed for in situ SAXS experiments and laboratory-scale syntheses.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Acoustics
Maximilian Mattern, Alexander von Reppert, Steffen Peer Zeuschner, Marc Herzog, Jan-Etienne Pudell, Matias Bargheer
Summary: This review discusses the use of picosecond ultrasonics experiments with ultrashort hard x-ray probe pulses to measure the transient strain response of laser-excited nanoscopic structures. The method provides direct, layer-specific, and quantitative information on the strain response for structures with few-nm thickness. The presented experimental cases include challenging materials that require alternative techniques to traditional all-optical methods.
Article
Physics, Multidisciplinary
Can B. Uzundal, Sasawat Jamnuch, Emma Berger, Clarisse Woodahl, Paul Manset, Yasuyuki Hirata, Toshihide Sumi, Angelique Amado, Hisazumi Akai, Yuya Kubota, Shigeki Owada, Kensuke Tono, Makina Yabashi, John W. Freeland, Craig P. Schwartz, Walter S. Drisdell, Iwao Matsuda, Tod A. Pascal, Alfred Zong, Michael Zuerch
Summary: Second harmonic generation (SHG) spectroscopy is commonly used to investigate surface chemistry, interfacial chemistry, and symmetry properties in solids, but the complexity of novel materials makes interpretation of experiments difficult. Polarization-resolved extreme ultraviolet (XUV-SHG) spectroscopy demonstrates element-specific angular anisotropy investigations for the first time, paving the way for future angle and time-resolved XUV-SHG studies with elemental specificity in condensed matter systems.
PHYSICAL REVIEW LETTERS
(2021)
Article
Biochemistry & Molecular Biology
Alexander W. Mauney, Uma M. Muthurajan, Karolin Luger, Lois Pollack
Summary: Nucleosomes in eukaryotic cells are organized into higher order structures for genome compaction, and understanding their organization is crucial in studying DNA storage efficiency. Arrays of linked nucleosomes serve as models for understanding how DNA and protein properties affect their arrangement, while important questions remain regarding the effects of histone proteins and other chromatin-associated protein partners on nucleosome spacing.
NUCLEIC ACIDS RESEARCH
(2021)
Article
Chemistry, Multidisciplinary
Heemin Lee, Je Young Ahn, Sae Hwan Chun, Do Hyung Cho, Daeho Sung, Chulho Jung, Jaeyong Shin, Junha Hwang, Sung Soo Ha, Hoyoung Jang, Byeong-Gwan Cho, Sunam Kim, Jaeku Park, Daewoong Nam, Intae Eom, Ji Hoon Shim, Do Young Noh, Yungok Ihm, Changyong Song
Summary: Photoinduced nonequilibrium phase transitions have sparked interest in the dynamic interactions between electrons and crystalline ions. Through experiments and simulations, this study reveals the impact of photoexcitation and bonding orbitals on lattice stability.
Article
Multidisciplinary Sciences
Megan L. Shelby, Andrew Wildman, Dugan Hayes, Michael W. Mara, Patrick J. Lestrange, Marco Cammarata, Lodovico Balducci, Maxim Artamonov, Henrik T. Lemke, Diling Zhu, Tamar Seideman, Brian M. Hoffman, Xiaosong Li, Lin X. Chen
Summary: The study focused on ultrafast structural dynamics during the photodissociation of carbon monoxide from iron(II)-heme in bovine myoglobin. Experimental and computational results revealed insights into the interplay between nuclear and electronic structural dynamics. Additionally, the observation of protein quake caused by CO dissociation provides important implications for understanding gas transport and protein deligation processes.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Physics, Multidisciplinary
Craig P. Schwartz, Sumana L. Raj, Sasawat Jamnuch, Chris J. Hull, Paolo Miotti, Royce K. Lam, Dennis Nordlund, Can B. Uzundal, Chaitanya Das Pemmaraju, Riccardo Mincigrucci, Laura Foglia, Alberto Simoncig, Marcello Coreno, Claudio Masciovecchio, Luca Giannessi, Luca Poletto, Emiliano Principi, Michael Zuerch, Tod A. Pascal, Walter S. Drisdell, Richard J. Saykally
Summary: Charge transport processes at interfaces play a crucial role in many processes. Here, the first soft x-ray second harmonic generation (SXR SHG) interfacial spectrum of a buried interface (boron-Parylene N) is reported. SXR SHG shows distinct spectral features that are not observed in x-ray absorption spectra, demonstrating its extraordinary interfacial sensitivity. Comparing to electronic structure calculations indicates a boron-organic separation distance of 1.9 angstrom, with changes of less than 1 angstrom resulting in easily detectable SXR SHG spectral shifts (ca. hundreds of milli-electron volts).
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Krissia Zawadzki, Alberto Nocera, Adrian E. Feiguin
Summary: This study addresses the lack of theoretical understanding of the scattering cross-section in experiments with new light sources that provide unprecedented resolution in X-ray experiments. Traditional numerical techniques are limited in the case of strongly correlated electron systems, and a new alternative approach is proposed in this work. By solving the time-dependent Schrodinger equation in the time domain, the authors present a faithful simulation of scattering processes in actual experiments, including photons and core electrons. The proposed method can yield the full time and momentum resolved Resonant Inelastic X-Ray Scattering (RIXS) spectrum of strongly interacting many-body systems.
Article
Chemistry, Medicinal
Reagan J. Meredith, Luke Sernau, Anthony S. Serianni
Summary: This paper presents a hybrid experimental-computational method for determining conformational equilibria of molecules in solution. The method utilizes redundant NMR spin-spin coupling constants, DFT calculations, and circular statistics, implemented through the MA'AT analysis algorithm. The paper discusses the key components of a computer program that applies this algorithm and presents the results of testing and evaluating the method.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2022)
Article
Multidisciplinary Sciences
Martin A. Schroer, Siawosch Schewa, Andrey Yu Gruzinov, Christian Roennau, Janine Mia Lahey-Rudolph, Clement E. Blanchet, Till Zickmantel, Young-Hwa Song, Dmitri Svergun, Manfred Roessle
Summary: Despite developing a setup combining THz-irradiation with SAXS for studying biological macromolecules, no clear experimental proof was found for structural changes in biological particles in solution induced by THz radiation.
SCIENTIFIC REPORTS
(2021)
Article
Physics, Multidisciplinary
Peco Myint, Karl F. Ludwig, Lutz Wiegart, Yugang Zhang, Andrei Fluerasu, Xiaozhi Zhang, Randall L. Headrick
Summary: In investigating the self-organized ion-beam nanopatterning of silicon using coherent x-ray scattering, a relationship similar to de Gennes narrowing is discovered. However, unlike the classic phenomenon, the dynamic surface exhibits a wide range of behaviors with compressed exponential relaxation at lengths corresponding to the dominant structural motif. This behavior is attributed to the morphological persistence of the self-organized surface ripple patterns.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Florian A. Jung, Maximilian Schart, Lukas Buehrend, Elisabeth Meidinger, Jia-Jhen Kang, Bart-Jan Niebuur, Sina Ariaee, Dmitry S. Molodenskiy, Dorthe Posselt, Heinz Amenitsch, Constantinos Tsitsilianis, Christine M. Papadakis
Summary: Multiblock copolymers with charged blocks exhibit different self-assembly behavior in solutions and thin films, depending on the degree of ionization of the blocks. In solutions, the solubility of the P2VP block and the flexibility of the PDMAEMA block influence structure formation; while in thin films, the segregation strength is crucial for structure formation.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Engineering, Environmental
Yeonsoo Park, Christos D. Malliakas, Qing Zhou, April Z. Gu, Ludmilla Aristilde
Summary: This study investigated the interaction of physiologically relevant metal cations with polyphosphate complexes in polyphosphate-accumulating organisms (PAOs), revealing that Magnesium (Mg) and Potassium (K) have a significant impact on the stability of the complexes. Molecular dynamics simulations showed that Mg-polyphosphate complexes were the most stable, while K-polyphosphate complexes were the least stable, suggesting a role in polyphosphate bioavailability. This research provides insights into the mechanistic role of metal complexation in the phosphorus cycling traits of PAOs in engineered and natural systems.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Lea Ress, Pavel Maly, Jann B. Landgraf, Dominik Lindorfer, Michael Hofer, Joshua Selby, Christoph Lambert, Thomas Renger, Tobias Brixner
Summary: This article presents the experimental and theoretical foundations for femtosecond time-resolved circular dichroism (TRCD) spectroscopy of excitonic systems. A new experimental setup, with a polarization grating as the key element, is introduced to generate circularly polarized pulses for TRCD experiments. By applying a specific chopping scheme, left and right circular polarizations can be switched, and transient absorption (TA) and TRCD spectra can be detected simultaneously. Experiments on a squaraine polymer are performed to investigate excitonic dynamics, and a general theory for TRCD experiments of excitonically coupled systems is developed and applied to describe the experimental data.
Article
Multidisciplinary Sciences
Eun Hyuk Choi, Jong Goo Kim, Jungmin Kim, Hosung Ki, Yunbeom Lee, Seonggon Lee, Kihwan Yoon, Joonghan Kim, Jeongho Kim, Hyotcherl Ihee
Summary: Roaming reaction is a reaction pathway that yields products in the long-range potential region, explaining the unimolecular dissociation and isomerization of various molecules. This study investigates the structural dynamics during a roaming-mediated isomerization process, visualizing atomic movements following frustrated bond fission.
NATURE COMMUNICATIONS
(2021)
Article
Engineering, Environmental
Seung Ho Yook, Ho Young Kim, Seok Jun Kim, Seungjoo Choi, Taehyun Kwon, Handong Cho, Jun Myung Kim, Ki Ro Yoon, Sunhee Jo, So Young Lee, Hyoung-Juhn Kim, Hae Jung Son, Keun Hwa Chae, Jeongho Kim, Kwan Young Lee, Jin Young Kim
Summary: This study investigates the effect of chemically durable mesoporous silica shell on the antioxidation efficiency of CeOx nanomaterials. It is found that the mSiO2 shell can enhance the antioxidation efficiency of CeOx by facilitating dispersion of nanoparticles and increasing the ratio of highly active Ce(III) states. Proton exchange membranes based on CeOx/mSiO2 also exhibit lower degradation rate and excellent durability in energy conversion devices.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Marjorie Ladd-Parada, Katrin Amann-Winkel, Kyung Hwan Kim, Alexander Spah, Fivos Perakis, Harshad Pathak, Cheolhee Yang, Daniel Mariedahl, Tobias Eklund, Thomas J. Lane, Seonju You, Sangmin Jeong, Matthew Weston, Jae Hyuk Lee, Intae Eom, Minseok Kim, Jaeku Park, Sae Hwan Chun, Anders Nilsson
Summary: Using time-resolved wide-angle X-ray scattering, this study investigated the early stages of crystallization of supercooled water. It was found that the crystallizing phase is stacking disordered ice, with a small portion of hexagonal ice also observed. The final crystalline fraction in low-density amorphous ice was considerably lower than that in high-density amorphous ice.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Nanoscience & Nanotechnology
Hyunhong Kim, Seung Ho Yook, Ho Young Kim, Yonghoon Choi, Yeongsu Lim, Yujin Hwang, Jeongho Kim, Kwan Young Lee, Seung Soon Jang, Jongnam Park, Jin Young Kim
Summary: This study reports on the surface-engineered cerium oxide nanoparticles (CNPs) that enhance the antioxidant properties and durability of polymer electrolyte membrane fuel cells (PEMFCs). The researchers also found that negatively charged CNPs with sulfonic acid groups as the surface modifier showed the highest compatibility with the polymer electrolyte membrane, resulting in improved stability and performance of the fuel cell.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Multidisciplinary Sciences
Sang Jin Lee, Tae Wu Kim, Jong Goo Kim, Cheolhee Yang, So Ri Yun, Changin Kim, Zhong Ren, Indika Kumarapperuma, Jane Kuk, Keith Moffat, Xiaojing Yang, Hyotcherl Ihee
Summary: This study investigates the light-induced structural transitions of bacteriophytochromes in a liquid solution phase using time-resolved x-ray solution scattering. It reveals the kinetic analysis of the structural species and provides mechanistic insights into how these photoreceptors transmit structural signals and regulate downstream biological responses.
Article
Chemistry, Physical
Dawoon Jang, Seungjoo Choi, Suyeon Lee, Tae-Woo Lee, Seong-Ju Hwang, Hyungjun Kim, Jeongho Kim, Sungjin Park, Nam Hee Kwon, Kyung Yeon Jang
Summary: This study presents a water-assisted method to enhance the photocatalytic activities of carbon nitride by controlling intraplanar structures associated with H bonds and amine bridges.
APPLIED CATALYSIS B-ENVIRONMENT AND ENERGY
(2022)
Article
Chemistry, Multidisciplinary
Suyeon Lee, Eun Young Shin, Dawoon Jang, Seungjoo Choi, Hyeju Park, Jeongho Kim, Sungjin Park
Summary: Degradation of organic pollutants is an important research area to solve environmental issues. Metal-free carbon nitride (C3N4) materials have a great potential as cost-effective and environment-friendly photocatalysts for this purpose. In this study, mesoporous C3N4 materials were developed through self-assembly and showed excellent photocatalytic activities for degrading rhodamine B under visible light irradiation. These materials exhibited higher surface areas, better adsorption ability of visible light, and longer lifetimes of the photoexcited electrons compared to common C3N4 samples, which contribute to their outstanding photocatalytic performance.
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
(2022)
Article
Multidisciplinary Sciences
Katrin Amann-Winkel, Kyung Hwan Kim, Nicolas Giovambattista, Marjorie Ladd-Parada, Alexander Spaeh, Fivos Perakis, Harshad Pathak, Cheolhee Yang, Tobias Eklund, Thomas J. Lane, Seonju You, Sangmin Jeong, Jae Hyuk Lee, Intae Eom, Minseok Kim, Jaeku Park, Sae Hwan Chun, Peter H. Poole, Anders Nilsson
Summary: Recent experiments have provided evidence for a liquid-liquid phase transition (LLPT) in supercooled water, which can explain the anomalous properties of liquid water and amorphous ice. By subjecting low-density amorphous (LDA) ice to ultrafast heating, researchers observed the coexistence of high-density and low-density liquid phases, and confirmed the LLPT using femtosecond x-ray laser pulses.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
In Seok Yang, You Jin Park, Yujin Hwang, Hoi Chang Yang, Jeongho Kim, Wan In Lee
Summary: Li-doped CuSCN films act as hole-transporting materials in perovskite solar cells, showing improved crystallinity and hole mobility. The addition of a small amount of PCPDTBT further enhances the performance and stability of the solar cells.
Article
Chemistry, Physical
Key Young Oang, Sungjun Park, Jiwon Moon, Eunji Park, Hyun Kyung Lee, Tokushi Sato, Shunsuke Nozawa, Shin-ichi Adachi, Joonghan Kim, Jeongho Kim, Jeong-Hun Sohn, Hyotcherl Ihee
Summary: Time-resolved X-ray liquidography (TRXL) is a powerful technique for studying the structural dynamics of small molecules and macromolecules in liquid solutions. However, it has limited sensitivity for small molecules containing light atoms only, making the signal from solvent molecules dominate. This study presents an alternative approach using solvent temperature change to detect the dynamics of photoinduced reactions, allowing the identification of intermediates and reaction pathways in small molecules without heavy atoms.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Hirohito Ogasawara, Han Wang, Jorgen Gladh, Alessandro Gallo, Ralph Page, Johannes Voss, Alan Luntz, Elias Diesen, Frank Abild-Pedersen, Anders Nilsson, Markus Soldemo, Marc Zajac, Andrew Attar, Michelle E. Chen, Sang Wan Cho, Abhishek Katoch, Ki-Jeong Kim, Kyung Hwan Kim, Minseok Kim, Soonnam Kwon, Sang Han Park, Henrique Ribeiro, Sami Sainio, Hsin-Yi Wang, Cheolhee Yang, Tony Heinz
Summary: We conducted optical pumping and x-ray absorption spectroscopy experiments on a graphene monolayer adsorbed on copper using a free electron laser. Our analysis suggests that the excitation of graphene is primarily due to indirect excitation from hot electron-hole pairs created in the copper. However, once the excitation occurs in graphene, its decay follows a similar path as in previous studies of graphene adsorbed on semiconductors, involving rapid excitation of strongly coupled optical phonons and eventual thermalization. The lifetime of the hot electron-hole pairs in copper likely influences the lifetime of the electronic excitation in graphene.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Chemistry, Physical
Yu-Na Kim, Ju-Hee Jo, Jeongho Kim, Hui-Seon Kim, Wan In Lee
Summary: Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is commonly used as a dopant in 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluor-ene (spiro-MeOTAD), but it results in poor thermal stability. Recently, zinc(II) bis(trifluoromethanesulfonyl)imide (Zn(TFSI)2) has been proposed as a potential replacement for LiTFSI. This study explores the use of Zn(TFSI)2 as a dopant for spiro-MeOTAD to investigate the thermal stability of perovskite solar cells (PSCs).
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Sangmin Jeong, Eunji Park, Joonghan Kim, Kyung Hwan Kim
Summary: By conducting nonadiabatic molecular dynamics simulations, we investigated the photoisomerization dynamics of 1,2-dihydro-1,2-azaborine and identified three different reaction pathways. Our results confirmed that the photoisomerization of azaborine follows the energetically favored pathway, predominantly forming the Dewar isomer, which is consistent with experimental observations.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Hosung Ki, Tae Wu Kim, Jiwon Moon, Jungmin Kim, Yunbeom Lee, Jun Heo, Kyung Hwan Kim, Qingyu Kong, Dmitry Khakhulin, Gemma Newby, Joonghan Kim, Jeongho Kim, Michael Wulff, Hyotcherl Ihee
Summary: The photoactivation mechanism of Os-3(CO)(12) at 400 nm was investigated using time-resolved X-ray liquidography, revealing two pathways: vibrational relaxation following internal conversion and ligand dissociation to form Os-3(CO)(11) with a ligand vacancy.
CHEMICAL COMMUNICATIONS
(2022)
