Article
Engineering, Mechanical
Weiyan Yu, Jian Liu, Yi Yang, Jingcheng Hao, Lu Xu
Summary: We created an organohydrogel lubricant with effective anti-freezing, anti-volatile and anti-corrosive performances using a ternary mixture of colloidal silica nanoparticles, glycerol, and water. The hydrogel could achieve a very low coefficient of friction at room temperature and maintain its lubricity even at -80 degrees C. The lubrication mechanism involved the formation of a physically protective film and the rolling and repairing actions of silica particles in synergy with the presence of glycerol.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Chemistry, Physical
Shuangjian Li, Chuangyong Yu, Chunming Deng, Jun Liu, Xi Tan, Wei Zeng
Summary: A robust self-lubricating ceramic coating was fabricated by in-situ synthesis of carbon and thermal spray technology process. The composite coating exhibited superior mechanical properties and significantly reduced coefficient of friction and wear rate.
APPLIED SURFACE SCIENCE
(2022)
Article
Engineering, Mechanical
Bairun Chen, Lisha Liu, Chunli Zhang, Shengmao Zhang, Yujuan Zhang, Pingyu Zhang
Summary: The SiO2-PIL hybrid showed excellent antiwear ability and load-carrying capacity at high temperatures due to the synergistic effects of nanosilica and ionic liquid during sliding. A protective tribofilm with a sandwich structure of phosphate and amorphous carbon as the outer layer and silica nanoparticles as the interlayer was formed on the worn surface.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Geology
Hyun Na Kim, Byung-Dal So, Min Sik Kim, Kee Sung Han, Sol Bi Oh
Summary: This study reveals the essential role of dolomite decarbonation in weakening carbonate faults, as well as the influence of low crystalline ultrafine fault gouge on decarbonation and slip behavior. Experimental results show a significant contribution of mechanical decarbonation at low temperatures, and a decrease in the onset temperature of thermal decarbonation.
Article
Materials Science, Multidisciplinary
Qilong Zhou, Lisong Dong, Jian Wu, Yijun Shi, Xin Feng, Xiaohua Lu, Jiahua Zhu, Liwen Mu
Summary: By designing a special formula, two functional ionic gels with excellent lubrication, thermal conductivity, and self-healing ability were successfully prepared to meet various industrial demands, showing great application prospects.
ACS APPLIED POLYMER MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Atul Jyoti, Rakesh Kr Singh, Nishant Kumar, Abhay Kr Aman, Manoranjan Kar
Summary: Amorphous nanosilica was prepared from rice husk using a cost-effective and environmentally friendly method, and a magnetic nanocomposite was successfully prepared from amorphous nanosilica, ferrites, and PVDF using injection molding equipment. Various analyses showed the characteristics of the materials, indicating their potential application in technological fields. The study suggested that the prepared nanosilica materials can be utilized for technological applications.
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
(2021)
Article
Construction & Building Technology
Zhigang Zhang, Zhipeng Li, Jialuo He, Xianming Shi
Summary: The addition of nanosilica can improve the self-healing performance of high-strength engineered cementitious composite (ECC) by densifying the matrix and strengthening the bond between fibers and the matrix. The nano-modified mixtures exhibit enhanced mechanical properties, reduced crack widths, and facilitate the autogenous self-healing process of ECC.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Materials Science, Ceramics
Nikolai V. Priezjev
Summary: This study investigates the effect of small-amplitude periodic shear on annealing of a shear band in binary glasses through molecular dynamics simulations. The results show that increasing strain amplitude leads to glasses being relocated to deeper potential energy levels, and mechanical tests demonstrate an increase in shear modulus and yield stress with loading at strain amplitudes close to the yield strain.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2021)
Article
Chemistry, Physical
Yuxi Lu, Seiya Watanabe, Shinya Sasaki, Sergei Glavatskih
Summary: We compared the lubricating performance of two non-halogenated ionic liquids (ILs) with a common cation but different anions in steel/steel and steel/DLC contacts. The results showed that both ILs exhibited better lubricating performance than PAO oils of similar viscosity, with phosphonium bis(oxalato)borate IL demonstrating excellent lubricity. This study demonstrates the potential for controlling lubrication properties by tuning the functional groups of the anion structure and the chemical reactivity of ILs with lubricated surfaces.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Engineering, Biomedical
Anna Gilpin, Yuze Zeng, Jiaul Hoque, Ji Hyun Ryu, Yong Yang, Stefan Zauscher, William Eward, Shyni Varghese
Summary: The modification of hyaluronic acid (HA) to exhibit self-healing properties improves lubrication, enhances free radical scavenging, and attenuates enzymatic degradation. In vivo, self-healing HA shows improved retention despite its low molecular weight, and mitigates cartilage degeneration in rodents with anterior cruciate ligament injury. This study demonstrates how incorporating functional properties such as self-healing can enhance the capabilities of biolubricants.
ADVANCED HEALTHCARE MATERIALS
(2021)
Article
Chemistry, Applied
Rui Yang, Zipeng Zeng, Zhen Peng, Jiafang Xie, Yiyin Huang, Yaobing Wang
Summary: The study introduces an amorphous urchin-like Cu@nanosilica hybrid as an efficient electrocatalyst for CO2 reduction with high Faradic efficiency and stability. Mechanistic study reveals that the amorphous Cu/Cu+ dispersion in the catalyst enhances CO2 adsorption and activation, promoting efficient production of C2+ products while suppressing hydrogen evolution.
JOURNAL OF ENERGY CHEMISTRY
(2021)
Review
Chemistry, Multidisciplinary
Yu Zhao, Hui Mei, Peng Chang, Chao Chen, Laifei Cheng, Konstantinos G. Dassios
Summary: The rapid development of 3D printing technology has provided great opportunities for designing various multiscale lubrication structures. Recent research has focused on constructing multifunctional 3D structures with refined dimensions, from micronanoscale to macroscale, to approach superlubricity. Emphasis is placed on the design, lubrication performance, material requirements, merits, drawbacks, and applications of various 3D printing techniques for structural lubrication.
Article
Chemistry, Multidisciplinary
Beibei Yang, Jiayu Dong, Haifeng Bian, Haimin Lu, Duan Bin, Shaochun Tang, Yaqiong Song, Hongbin Lu
Summary: In this study, a self-healing epoxy coating was prepared by loading expired cefalexin into mesoporous silica nanomaterials (MSNs) for corrosion protection of 304 stainless steel (304SS). The cefalexin@MSNs enhanced the corrosion resistance of the coating, providing a self-healing long-duration corrosion protection for 304SS.
Article
Geochemistry & Geophysics
John D. D. Bedford, Takehiro Hirose, Yohei Hamada
Summary: Fault strength recovery (healing) after earthquakes plays a crucial role in controlling future earthquake recurrence, but the rates and mechanisms of fault healing are not well understood. Through high-velocity friction experiments, we found that granite and gabbro fault gouges recover their strength rapidly after dynamic weakening at seismic slip rates. The healing rates are much faster than those observed in slow slip experiments. The enhanced healing is attributed to thermally activated chemical bonding at frictional contacts in the gouge.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Physics, Fluids & Plasmas
Antoine Parrenin, Rinse W. Liefferink, Daniel Bonn
Summary: The study focuses on reducing friction by using the Leidenfrost effect to form a gas lubricating layer, with the main challenge being to keep the gas inside the contact area. Experimental results show that the substrate temperature and pressure strongly affect friction, with very low friction reached only under specific conditions.
Article
Geochemistry & Geophysics
Vladimir Lyakhovsky, Ivan Panteleev, Eyal Shalev, John Browning, Thomas M. Mitchell, David Healy, Philip G. Meredith
Summary: Crustal rocks undergo repeated cycles of stress and can develop highly anisotropic crack distributions. However, the influence of variations in principal stresses on the evolution of anisotropic crack distributions is not well understood. This study presents a newly developed model that considers both anisotropic damage and porosity evolution, and demonstrates a reasonable fit to experimental data.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Li-Wei Kuo, Chien-Cheng Hung, Haibing Li, Stefano Aretusini, Jianye Chen, Giulio Di Toro, Elena Spagnuolo, Fabio Di Felice, Huan Wang, Jialiang Si, Hwo-Shuenn Sheu
Summary: The 2008 Wenchuan earthquake caused surface ruptures along the Longmenshan fault belt, with the Yingxiu-Beichuan fault and the Guanxian-Anxian faults being the most affected. Frictional experiments were conducted on the gouge materials from the Guanxian-Anxian faults, revealing that wet gouges have lower friction coefficients compared to those under room humidity conditions. Additionally, the gouges exhibited enhanced velocity-strengthening behavior at intermediate velocities, indicating a potential barrier to slip acceleration during fault propagation.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geosciences, Multidisciplinary
Lucia Andreuttiova, James Hollingsworth, Pieter Vermeesch, Thomas M. Mitchell, Eric Bergman
Summary: Near-field surface displacement measurements allow us to quantify the on- and off-fault proportion of earthquake-related deformation. This study takes advantage of high-resolution historical aerial stereo-imagery to measure three-dimensional displacement using correlation of the orthorectified pre- and post-earthquake image mosaics. The results reveal new strike-slip ruptures possibly associated with the aftershocks.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Review
Astronomy & Astrophysics
Massimo Cocco, Stefano Aretusini, Chiara Cornelio, Stefan B. Nielsen, Elena Spagnuolo, Elisa Tinti, Giulio Di Toro
Summary: Large seismogenic faults have fault cores surrounded by damage zones. Earthquakes are caused by rupture propagation and slip within fault cores, dissipating elastic strain energy. Understanding energy partitioning is crucial for explaining fault dynamic weakening and rupture processes. Fracture energy from various studies is reviewed, showing that fracture energy scales with fault slip. Material-dependent fracture energies are important at the microscale but negligible at the macroscale on natural faults.
ANNUAL REVIEW OF EARTH AND PLANETARY SCIENCES
(2023)
Article
Geochemistry & Geophysics
Ashley Stanton-Yonge, Thomas M. Mitchell, Philip G. Meredith
Summary: Fluid flow through the brittle crust is controlled by fracture networks. Fracture intersections have been observed to enhance fluid flow, but the extent of their impact on permeability has not been quantified yet. In this study, we characterized the hydro-mechanical properties of intersections in Seljadalur Basalt by generating orthogonal fractures and measuring their permeability. We found that intersecting fractures have higher permeability and lower compressibility compared to independent fractures. Our results suggest that fracture intersections are critical in maintaining permeability at depth.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
E. M. Conrad, N. Tisato, B. M. Carpenter, G. Di Toro
Summary: This study investigates the effects of frictional melt formation on the coseismic and interseismic strength of faults using a new energy-controlled rotary shear machine. The experiments reveal that the presence of melts modulates different stages of earthquakes and faulting. Monitoring acoustic emissions and vibrational waves during slip events can provide valuable insights into the underlying physical processes and help improve our understanding of earthquakes.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Francesco Lazari, Angela Castagna, Stefan Nielsen, Ashley Griffith, Giorgio Pennacchioni, Rodrigo Gomila, Phil Resor, Chiara Cornelio, Giulio Di Toro
Summary: The frictional power per unit area Q played a crucial role in controlling earthquake rupture nucleation, propagation, and arrest. However, determining Q using geophysical methods is challenging. In this study, we estimated Q dissipated on a fault patch exhumed from 7-9 km depth by combining theoretical models, experimental data, and geological constraints. Our findings suggest that the grain-scale roughness of the boundary between frictional melt and host rock decreases with increasing Q. The estimated Q values range from 4-60 MW m-2, which are at the lower end of previous estimates.(c) 2023 Elsevier B.V. All rights reserved.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geology
H. Wang, H. B. Li, G. Di Toro, L. -w. Kuo, E. Spagnuolo, S. Aretusini, J. L. Si, S. -r. Song
Summary: Frictional melting occurred at shallow depths during the 2008 Wenchuan earthquake in China, instead of thermal pressurization. Rock friction experiments showed that fluid-rich fault gouges can generate pseudotachylytes under conditions expected for seismic slip. This suggests that seismic slip can be accommodated by multiple faults during large earthquakes.
Article
Multidisciplinary Sciences
Lu Yao, Shengli Ma, Giulio Di Toro
Summary: This paper presents experimental evidence of thermal pressurization (TP) weakening of seismic faults and suggests that TP processes could be significantly promoted by wear-induced sealing during earthquakes, even for relatively permeable faults.
NATURE COMMUNICATIONS
(2023)
Article
Geochemistry & Geophysics
G. Magnarini, S. Aretusini, T. M. Mitchell, G. Pennacchioni, G. Di Toro, H. H. Schmitt
Summary: The Light Mantle landslide is a hypermobile landslide on the Moon. The origin of its hypermobility remains undetermined, as the proposed mechanisms are difficult to prove due to lack of theoretical and experimental support and scarcity of field data. Friction experiments under vacuum show that localized dynamic friction weakening does not occur in lunar analog anorthosite-bearing gouges, suggesting other fluidization-related mechanisms may have contributed to the initiation of the landslide. Microstructural observations in the experiments and core samples will provide insights into the emplacement processes of the landslide.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Article
Multidisciplinary Sciences
Wei Feng, Lu Yao, Chiara Cornelio, Rodrigo Gomila, Shengli Ma, Chaoqun Yang, Luigi Germinario, Claudio Mazzoli, Giulio Di Toro
Summary: Earthquakes often occur along faults where there is hot and pressurized water. Experimental studies show that the physical state of water (liquid, vapor, or supercritical) has an impact on the frictional resistance of faults. In this study, friction in gabbro faults with water in different states (vapor, liquid, and supercritical) was examined, and it was found that the friction behavior differs depending on the state of the water. The findings suggest that the formation of weak minerals, chemical bonding properties of water, and hydrodynamic lubrication could explain the weakening behavior of faults.
NATURE COMMUNICATIONS
(2023)
Article
Geochemistry & Geophysics
G. Magnarini, P. M. Grindrod, T. M. Mitchell
Summary: The South Massif and Taurus-Littrow valley provide valuable insights into recent geological processes on the Moon. The presence of overlapping landslide deposits and boulder falls suggests ongoing instability on the northeast slope of the South Massif. The discovery of a young lobate scarp and thrust fault implies seismic activity as a trigger for surface changes and mass-wasting events in the region. This study enhances our understanding of slope deformation on the South Massif beyond the younger landslide deposit.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2023)
Article
Geochemistry & Geophysics
Bobby Elsigood, Nicolas Brantut, Philip G. Meredith, David Healy, Thomas M. Mitchell, Frans M. Aben
Summary: This study measured the poroelastic properties of cracked granite under triaxial conditions and found that increasing differential stress led to the development of elastic transverse isotropy and anisotropy in Skempton's coefficients.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
