Article
Chemistry, Physical
Xiaoyuan Wang, Hanhan Yang, Zhenmei Yu, Zengtao Zhang, Yong Chen
Summary: Graphene-based laminar membranes have excellent ion sieving properties, but their selectivity for monovalent ions is still low compared to natural ion channels. In this study, a new strategy is proposed to mimic biological K+ channels using graphene laminar membranes composed of 2D angstrom-scale channels, supporting a simple model of a semi-biomembrane at the oil/water interface. It is found that K+ has a stronger preference over Na+ and Li+ for transfer across the graphene laminar membrane-supported water/1,2-dichloroethane interface within the same potential window (-0.1-0.6 V), although the monovalent ion selectivity of the graphene laminar membrane in aqueous solution is still low (K+/Na+~1.11 and K+/Li+~1.35). Furthermore, the voltammetric responses of NH4+ at the graphene laminar membrane-supported water/1,2-dichloroethane interface show that NH4+ can also pass through biological K+ channels due to similar hydration-free energies and cation-pi interactions. The observed K+ selective voltammetric responses are discussed and found to be consistent with the energy balance of cationic partial-dehydration (energetic costs) and cation-pi interaction (energetic gains) involved in biological K+ channels.
Article
Chemistry, Physical
Michio Niwano, Teng Ma, Kazuki Iwata, Daisuke Tadaki, Hideaki Yamamoto, Yasuo Kimura, Ayumi Hirano-Iwata
Summary: The interfacial layer structure of bulk nanobubbles was determined, revealing the presence of three-, four-, and five-membered ring clusters of water molecules. It was hypothesized that a specific interfacial layer with a hydrogen bond network stabilizes the nanobubbles. The hardness of the interfacial layer was found to be dependent on the encapsulated gas species.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Multidisciplinary Sciences
Go Yumoto, Fumiya Sekiguchi, Ruito Hashimoto, Tomoya Nakamura, Atsushi Wakamiya, Yoshihiko Kanemitsu
Summary: Monitoring of spin dynamics in two-dimensional semiconductors reveals the emergence of a halo-like spatial profile and ultrafast expansion of spin-polarized exciton population at room temperature in halide perovskites. This is attributed to the long exciton spin relaxation times and exciton-exciton interactions, which allow for density-dependent nonlinear relaxation and rapid transport of exciton spins.
Article
Chemistry, Multidisciplinary
Jaehyung Yu, Ce Liang, Myungjae Lee, Soumik Das, Andrew Ye, Fauzia Mujid, Preeti K. Poddar, Baorui Cheng, Nicholas L. Abbott, Jiwoong Park
Summary: This study reports a method for the fabrication and dynamical imaging of freely floating MoS2 solids on water, minimizing extrinsic interactions between the solid and water. By introducing photoswitchable surfactants, spatial and temporal control of the floating MoS2 is achieved, demonstrating a variety of reversible shape changes in two-dimensional mechanical systems.
Article
Construction & Building Technology
Jingwei Ying, Zhijun Jiang, Jianzhuang Xiao
Summary: The synergistic effect of incorporating three-dimensional graphene (3DG) and silica fume (SF) into hardened cement paste has been investigated in this study. The results showed a significant improvement in the microstructure, mechanical properties, and high-density C-S-H content of the cement paste, as well as a decrease in chloride concentration and diffusivity, which will benefit the promotion and application of cement-based materials in coastal concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Chemistry, Physical
Zhen Zeng, Tianyou Wang, Rui Chen, Mengshan Suo, Kai Sun, Panagiotis E. Theodorakis, Zhizhao Che
Summary: This study investigates the formation mechanism of multidirectional partitioned square icing patterns using molecular dynamics simulations. The researchers propose square icing parameters to distinguish partitioned patterns from homogeneous patterns and liquid water. It is found that the number of graphene monolayers influences the formation of partitioned patterns, with greater energetically favorable conditions for confinement between multiple graphene sheets. The interaction between layers of water molecules is identified as another dominant factor. The study also explores the conversion from partitioned structures to homogeneous square patterns by manipulating pressure and temperature.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Julian Hniopek, Josefine Meurer, Stefan Zechel, Michael Schmitt, Martin D. Hager, Juergen Popp
Summary: Stimuli-responsive polymers can switch specific physical properties in response to a change of the environmental conditions, making them useful for applications requiring adaptive materials. A straightforward method using Raman micro-spectroscopy and 2DCOS analysis is presented to study the response behavior of reversible polymers on a molecular level with molecular sensitivity and spatial as well as temporal resolution. This label-free and non-invasive approach allows for the investigation of macroscopic properties alongside the molecular response of the polymer to external stimuli.
Article
Crystallography
Hai Huang, Xiaoting Yuan, Xiaoxin Ge, Qing Peng
Summary: This study investigates the effects of intrinsic and irradiation-induced defects in graphene on the displacement damage and He diffusion in Ni-graphene nanocomposites. The results show that the presence of intrinsic defects significantly affects the Ni lattice structure near the Ni-graphene interface. The irradiation-induced defects, on the other hand, do not decrease the ability of the interface to trap He atoms/clusters and may even improve it.
Article
Materials Science, Multidisciplinary
Daniil S. Antonenko, Eslam Khalaf, Pavel M. Ostrovsky, Mikhail A. Skvortsov
Summary: A one-dimensional boundary of a two-dimensional topological superconductor can host topologically protected chiral modes. By combining two superconductors with different topological indices, only a given number of channels (m) can be topologically protected while others are subject to Anderson localization. We study the transport properties of such quantum wires and calculate various statistics, including the average conductance, variance, third cumulant, and average shot noise power. The presence of topologically protected modes results in the appearance of a topological Wess-Zumino-Witten term in the action of the sigma model, leading to additional eigenstates of the transfer-matrix Hamiltonian.
Article
Physics, Fluids & Plasmas
Tu Vu-Minh, Anh Dao-Hong, Phuong Bui-Bich, Nam Nguyen-Tran-Thanh, Cuong Tran-Manh, Linh Tran-Phan-Thuy, Hien Doan-Thi, Hoang Luc-Huy, Hai Pham-Van
Summary: We propose a simulation strategy for assembling Janus nanoparticles in oil-in-water emulsion droplets by evaporation based on dissipative particle dynamics. Our method reproduces all observed cluster configurations and investigates the kinetic process of cluster formation. We observe a structural transition from spherical packings to minimal second-moment configurations, with the critical volume of the transition being a cubic function of the number of particles, N. Our approach allows anticipation of higher-order clusters, overcoming the limitations of standard methods. Similarly to small N values, all final clusters in the range of 16-39 have unique configurations.
Article
Chemistry, Multidisciplinary
Jiahao Chen, Yingtian Xu, Yang Liu, Heng Liu, He Zhang, Liang Jin, Linlin Shi, Yunping Lan, Yonggang Zou, Jie Fan
Summary: This study successfully synthesized a 2D conjugated metal-organic framework and graphene stacked vertical heterostructure. Theoretical simulations and experimental characterizations showed that the charge transfer rate and nonlinear optical properties of this structure were significantly enhanced, demonstrating its potential in the field of ultrafast photonics.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Physics, Multidisciplinary
Shuanhu Wang, Hui Zhang, Jine Zhang, Shuqin Li, Dianbing Luo, Jianyuan Wang, Kexin Jin, Jirong Sun
Summary: In this study, the circular photogalvanic effect (CPGE) in oxide two-dimensional electron gases (2DEGs) is reported for the first time. Selectively excited spin polarized electrons from the in-gap states of SrTiO3 are converted into electric current via the mechanism of spin-momentum locking arising from Rashba spin-orbit coupling. Furthermore, the CPGE can be effectively modified by the density and distribution of oxygen vacancies, providing an effective approach to generate and manipulate spin polarized current in oxide spintronics.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Hana Yoon, Mehdi Rezaee, Yeong A. Lee, Kanghoon Yim, Rizcky Tamarany, Chan-Woo Lee, Valerie S. McGraw, Takashi Taniguchi, Kenji Watanabe, Philip Kim, Chung-Yul Yoo, D. Kwabena Bediako
Summary: In this study, the energetics and dynamics of chloroaluminate ion intercalation in a rechargeable aluminum-ion battery were investigated. The results demonstrate that engineering ion transport can lead to significant improvements in battery performance.
Article
Chemistry, Multidisciplinary
Hexiang Wang, Jin-Ho Choi
Summary: This study investigates hydrogen adsorption on vertical heterostructures of graphene and electride. The results reveal that heterostructure formation can activate graphene for hydrogen-evolution reactions, providing an innovative and promising strategy for hydrogen production.
Article
Chemistry, Physical
Luca Camilli, Daniele Capista, Massimo Tomellini, Jianbo Sun, Patrick Zeller, Matteo Amati, Luca Gregoratti, Luca Lozzi, Maurizio Passacantando
Summary: We investigate the oxidation mechanism of GeAs and find that a Ge-rich ultrathin oxide film is formed on the surface while As leaves upon oxidation. A theoretical model suggests that the activation energy for As oxidation is almost twice that for Ge at room temperature.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)