Article
Polymer Science
Wei Sun, Xiaojun Liu, Qingrui Song, Kun Liu, Wei Wang, Yunxiang Lu, Jiaxin Ye
Summary: The 10 000x wear resistance improvement of PTFE by a trace amount of nanofillers is heavily researched, with the proposed mechanism involving mechanochemical formation of transfer films rich in carboxylate salts. The role of fillers in wear reduction remains debated, but studies suggest that filler-driven polymer defluorination plays a key role, with filler surface functionality and chelation products influencing wear resistance. Thermal experiments also show sensitivity of mechanochemistry and wear resistance.
Article
Polymer Science
Xuelei Li, Li Zhang, Hu Wang, Yongqing Zhao
Summary: In this study, FEP films were chemically activated using sodium naphthalene solution, resulting in improved surface properties such as decreased contact angle and increased surface energy.
Article
Chemistry, Multidisciplinary
Daniel J. Sheldon, Joseph M. Parr, Mark R. Crimmin
Summary: Perfluoroalkyl substances (PFAS), including the commonly used poly(tetrafluoroethylene) (PTFE), are widespread pollutants in the environment. However, there are limited methods for repurposing PFAS. In this study, a nucleophilic magnesium reagent was found to react with PTFE at room temperature, forming a molecular magnesium fluoride that can be easily separated from the modified polymer. This fluoride can then be used to transfer fluorine atoms to other compounds, demonstrating the potential for harvesting and reusing the atomic fluorine content of PTFE in chemical synthesis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Hongxiang Yu, Xiaolong Liu, Zhiwen Zheng, Dan Qiao, Dapeng Feng, Zhenbin Gong, Guojun Dong
Summary: Graphene is widely used as a lubricating material due to its excellent tribological performance. However, its complex synthesis process leads to environmental pollution and increased production costs. In this study, a simple strategy was developed to construct a sustainable lubricant system by generating graphene in situ, avoiding the complicated synthesis process. The novel lubricant system consists of cyclopropanecarboxylic acid (CPCa) and metal particles (nickel and copper) in base oil, which undergo tribochemical reactions to produce hydrocarbons serving as solid lubricants, and metal particles catalyze the graphitization of hydrocarbons. The friction products can be reused as lubricating additives for base oil, providing better lubrication performance compared to the original lubricant systems, demonstrating their sustainable lubrication ability and potential as recyclable lubricant additives.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
J. Tian, X. Chen, J. Xu, J. Yu, Q. Yu, C. Zhang, L. Ma
Summary: By inducing reactions at the sliding interface between DLCH and MoS2 under high pressure, a composite shear band and a transfer film are formed, resulting in macroscale superlubricity and ultra-mild wear.
MATERIALS TODAY CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Ruiyun Li, Xing Yang, Jun Zhao, Chengtao Yue, Yongfu Wang, Jiangong Li, Ernst Meyer, Junyan Zhang, Yijun Shi
Summary: This study reports a facile way to achieve robust macroscale superlubricity in a vacuum environment by forming graphene/transition-metal dichalcogenide (TMDC) heterostructures on wear-induced rough surfaces. The sandwich structures readily transform into graphene/TMDC heterostructures during running-in stage, and assemble into multipoint flake-like tribofilms to achieve macroscale superlubricity.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Materials Science, Composites
Debashis Puhan, Shaoli Jiang, Janet S. S. Wong
Summary: This study investigated the impact of short carbon fiber fillers on the transfer layers and tribological performance of PEEK and PBP against steel at temperatures up to 300 degrees C. The findings revealed that CF-reinforced PEEK and PBP transfer layers contain CF-related materials, resulting in reduced friction compared to neat PEEK and PBP.
COMPOSITES SCIENCE AND TECHNOLOGY
(2022)
Article
Chemistry, Inorganic & Nuclear
Yan-Li Huang, Lin-Jie Ping, Jie Wu, Yan Yan Li, Xiao-Ping Zhou
Summary: Researchers have developed a new strategy to enhance the stability of zeolitic imidazolate framework (ZIF)-8 by preparing MOFs/poly(tetrafluoroethylene) (PTFE) composites. These composites exhibit improved chemical, pressure, and photostabilities, as well as superhydrophobic properties.
INORGANIC CHEMISTRY
(2022)
Article
Materials Science, Ceramics
Yasuo Takahashi, Masato Tsutaoka, Masakatsu Maeda
Summary: This study aimed to investigate the interfacial reaction between Al/Ti bi-layered films and 4H-SiC with different surface orientations, as well as the preferential growth orientation of Ti3SiC2 crystals. Microstructures were examined using X-ray diffractometry and transmission electron microscopy after depositing Al/Ti bi-layered films on different SiC substrates and annealing them step by step. The results showed that Ti3SiC2 phase grew epitaxially in the [11 (2) over bar0](SiC) orientation on the (0001) surface of 4H-SiC, and the electrical characteristics of p-type 4H-SiC contact films were improved after annealing, particularly for Al/Ti/ (11 (2) over bar0)(4H-SiC).
CERAMICS INTERNATIONAL
(2021)
Article
Chemistry, Multidisciplinary
Shujiao Yang, Xialiang Li, Yifan Li, Yabo Wang, Xiaotong Jin, Lingshuang Qin, Wei Zhang, Rui Cao
Summary: By studying two isomorphous manganese phosphates, the significant effect of proton transfer on water oxidation has been observed, with the hydrogen-bonding network in NH4MnPO4 center dot H2O proven to be the sole reason for its better catalytic activity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Engineering, Chemical
Wei Zhang, Xiaoyu Chen, Seiji Yamashita, Mitsuhiro Kubota, Hideki Kita
Summary: The tribological performance of B4C-SiC ceramics under water lubrication was studied at different water temperatures, revealing that the wear mechanisms are mainly mechanical wear and tribochemical wear. The study also found that the lowest friction coefficients and wear rates were obtained at water temperatures between 40 and 60 degrees C for B4C-SiC/SiC tribopairs. Gradual formation of more SiO2 film on the wear surfaces led to reduced friction coefficient, tribochemical wear, and mechanical wear for B4C-SiC ceramics.
Article
Thermodynamics
Chuang-Yao Zhao, Zhuo-Liang Yao, Di Qi, Wen-Tao Ji, An-Gui Li, Wen-Quan Tao
Summary: Falling film heat transfer is widely used in refrigeration and desalination systems. Numerical simulations show that bundle effect universally exists in falling film tube bundles and is influenced by liquid flow rate, distributor height, tube pitch, and tube bundle arrangement.
APPLIED THERMAL ENGINEERING
(2022)
Article
Engineering, Mechanical
Andreas Gebhard, Bai Cheng Jim
Summary: This study investigates the behavior of transfer films between polymers and metals through experimental analysis of friction and wear of materials. The results show that the extent and stability of transfer film formation have a significant impact on friction and wear, and mixed fiber/solid lubricant grades can reduce this impact.
Article
Materials Science, Multidisciplinary
Qijing Sun, David M. Miskovic, Michael Ferry
Summary: This study investigated the impact of film thickness on the development of ultrastable metallic glasses, showing that controlling thickness can tune the thermophysical and mechanical properties of the material. Structural heterogeneity develops with film buildup, leading to variations in properties as the glass undergoes rejuvenation.
MATERIALS TODAY PHYSICS
(2021)
Article
Energy & Fuels
Xin-Yang Zeng, Jing-Chun Feng, Wei Ke, Jiang Wang, Si Zhang, Yan Xie
Summary: The study explores the effect of hydrate inhibitors on the morphological evolution of hydrate growth, specifically focusing on the growth kinetics of methane-propane hydrate film. The results indicate that the inhibitors play a crucial role in inhibiting hydrate growth, with the hydrate film acting as a mass transfer barrier. The research also highlights the importance of environmental factors, such as subcooling and inhibitor concentration, in determining the growth rate and morphology of the hydrate film. This study provides valuable insights for effectively inhibiting hydrate growth and ensuring multiphase flow in deep sea oil & gas transportation.
Article
Chemistry, Physical
Motohiro Kasuya, Daiki Kubota, Sho Fujii, Kazue Kurihara
Summary: The study utilized the electrochemical surface forces apparatus (EC-SFA) to investigate electrochemical reactions in a nano-space, revealing a sudden current increase at short distances between electrodes in a confined electrolyte solution. This study demonstrated the potential of EC-SFA as a powerful tool for fundamental knowledge and insights into nano-confined electrochemical reactions with implications for sensors and energy devices.
FARADAY DISCUSSIONS
(2022)
Article
Chemistry, Multidisciplinary
Masashi Mizukami, Takuya Yanagimachi, Noboru Ohta, Yuuta Shibuya, Naoto Yagi, Kazue Kurihara
Summary: We have conducted X-ray diffraction measurements and resonance shear measurements to study the structural and viscous changes of OMCTS and n-hexadecane under nanoconfinement. The results indicate that the structural order of OMCTS and n-hexadecane significantly increases under nanoconfinement, especially below 100 nm. The increase in viscosity requires a certain level of ordering.
Article
Materials Science, Multidisciplinary
Minami Oka, Masashi Mizukami, Kazue Kurihara, Satoshi Honda
Summary: Recyclability is crucial for the next generation of materials science towards a sustainable future. In this study, a photoreversible liquid pressure-sensitive adhesive (PSA) was developed by linking hexaarylbiimidazoles (HABIs) with cyclic polydimethylsiloxane (PDMS) chains, providing recyclability to polymeric materials that cannot be readily replaced by degradable polymers.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Chemistry, Physical
Yoshimasa Suzuki, Nobuaki Kunikata, Motohiro Kasuya, Hideshi Maki, Masaki Matsui, Kazue Kurihara, Minoru Mizuhata
Summary: Solution structures at solid-liquid interfaces are crucial in electrochemical reactions. This study investigated the behavior of a mixed solvent at the interface with SiO2 and found a long-range ordered structure. The interfacial structure influenced ionic conduction.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Yang Wang, Jie Qin, Jingxiang Xu, Junhui Sun, Lei Chen, Linmao Qian, Momoji Kubo
Summary: This study investigates the atomic-scale contact area and its correlation with friction force using large-scale atomistic simulations. The results show that different contact definitions lead to non-equivalent contact areas, with only the contact area defined by interatomic distance consistent with the continuum Hertz contact mechanics. Additionally, the contact area defined by interfacial chemical bonds is found to be proportional to the friction force, indicating its dominant role in determining materials' frictional behaviors.
Article
Chemistry, Multidisciplinary
Masanori Iizuka, Masashi Mizukami, Kazue Kurihara
Summary: The viscosity of branched-chain fatty acids confined between mica surfaces was investigated, and it was found that they exhibited better lubricity and preserved fluidlike properties in nanoconfinement. These findings are of great importance for the development of novel high-performance lubricants.
Article
Chemistry, Multidisciplinary
Noriyuki Uchida, Yunosuke Ryu, Yuichiro Takagi, Ken Yoshizawa, Kotono Suzuki, Yasutaka Anraku, Itsuki Ajioka, Naofumi Shimokawa, Masahiro Takagi, Norihisa Hoshino, Tomoyuki Akutagawa, Teruhiko Matsubara, Toshinori Sato, Yuji Higuchi, Hiroaki Ito, Masamune Morita, Takahiro Muraoka
Summary: Biological membranes can be functionalized by membrane-associated protein machinery. A synthetic molecular machine (AzoMEx) with a photoresponsive diazocine core is developed to expand liposomal membranes and encapsulate cargo components through membrane deformation. This molecular approach has the potential for drug delivery and controlling cellular activities.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Takamasa Saito, Masaki Kubo, Takao Tsukada, Eita Shoji, Gota Kikugawa, Donatas Surblys, Momoji Kubo
Summary: Controlling the dispersion state of nanoparticles in a polymer matrix is crucial for the production of polymer nanocomposites. This study used molecular dynamics simulations to investigate the influence of surface coverage, modifier length, and polymer species on the interfacial structure and affinity between surface-modified Al2O3 nanoparticles and polymer melts. The results showed that the interfacial affinity could be improved by adjusting the surface coverage and modifier species.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Hiroaki Ito, Naofumi Shimokawa, Yuji Higuchi
Summary: This study investigates the lateral transport of lipids and self-assembled lipid domains under an applied electric field. The results show that the speed of domain motion is positively correlated with the electric field strength, while the exchange of lipids between the domain and bulk shows no clear correlation with the field strength. The study provides insight into the dynamic responses of lipid domains to electric fields and contributes to the understanding of lateral lipid transportation.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Md. Khalidur Rahman, Takeshi Yamada, Norifumi L. Yamada, Mafumi Hishida, Yuji Higuchi, Hideki Seto
Summary: The dynamics of hydration water in DMPE and DMPC were investigated by QENS and MD simulations, revealing three modes of motion: fast, medium-speed, and slow. The HW dynamics in DMPE differed from that in DMPC, suggesting different hydration states or hydrogen-bonded networks around the headgroups. The activation energy for medium-speed HW in DMPE was also found to be different from free HW in DMPC.
STRUCTURAL DYNAMICS-US
(2023)
Article
Chemistry, Physical
Yuji Higuchi, Klemen Bohinc, Jurij Rescic, Naofumi Shimokawa, Hiroaki Ito
Summary: Revealing the ion distributions on charged phospholipid bilayer membranes during phase separation using coarse-grained molecular dynamics simulations. Cations closely follow negatively charged lipids and undergo rapid redistribution parallel to the lipid bilayer. Comparing simulation results with a modified Poisson-Boltzmann theory suggests the importance of ion-ion interactions in aqueous solution.
Article
Chemistry, Multidisciplinary
Yang Wang, Haoyu Zhao, Chang Liu, Yusuke Ootani, Nobuki Ozawa, Momoji Kubo
Summary: High entropy alloys (HEAs) have excellent potential but are limited by stress corrosion cracking (SCC). This study investigates the effects of high-temperature/pressure water on the tensile behavior and deformation mechanisms of an Fe40Ni40Cr20 alloy. In a vacuum, the alloy forms layered HCP phases due to Shockley partial dislocations. However, in a corrosive environment, an oxide surface layer suppresses the formation of Shockley partial dislocations, leading to FCC-to-BCC phase transition and reduced ductility. This fundamental study contributes to improving HEAs' resistance to SCC in experiments.
Article
Chemistry, Multidisciplinary
Takayuki Ota, Valentina Montagna, Yuji Higuchi, Takashi Kato, Masaru Tanaka, Haritz Sardon, Kazuki Fukushima
Summary: This study investigates the ring-opening reactions of γ-carbonyl-substituted ε-caprolactones and finds that chain propagation hardly occurs, as the propagating species preferentially transform to α-substituted five-membered lactones. This study contributes to understanding the chemistry of ring-opening reactions of substituted lactones for designing functional degradable polymers.
Article
Chemistry, Physical
Yoshimasa Suzuki, Nobuaki Kunikata, Motohiro Kasuya, Hideshi Maki, Masaki Matsui, Kazue Kurihara, Minoru Mizuhata
Summary: The behavior of a mixed solvent of propylene carbonate (PC)-1,2-dimethoxyethane (DME) at the interface with SiO2 was investigated. The interfacial structure affected ionic conduction and could be reduced by adding LiClO4.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Quynh T. N. Phan, Junichi Kawamura, Kazue Kurihara
Summary: This study systematically investigates the molecular mechanism of SEI formation and the effect of the additive VC in LMO cathode material for lithium-ion batteries. The results demonstrate that carbonate solvents and VC spontaneously decompose on the LMO surface to form new compounds, and the electrochemical reaction of VC increases the LiF/MnF2 ratio in the SEI layer.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)