Ion-specific ice provides a facile approach for reducing ice friction.

Hypothesis: Ice friction plays a crucial role in both basic study and practical use. Various strategies for controlling ice friction have been developed. However, one unsolved puzzle regarding ice friction is the effect of ion-ice interplay on its tribological properties.

Friction Reduction Achieved by Ultraviolet Illumination on TiO Surface.

Controlling friction by light field is a low-cost, low-energy, non-polluting method. By applying ultraviolet light on the surface of photosensitive materials, the properties of the friction pairs or lubricant can be influenced, thus achieving the purpose of reducing friction. In this study, TiO, an inorganic photosensitive material, was selected to investigate the modulating effect of light fields on friction lubrication when using polyalphaolefin (PAO) base oil as a lubricant, and the modulation law of light fields on the friction lubrication behavior was investigated under different loads (1-8 N), different speeds (20-380 mm/s), and different viscosities (10.

Hydration layer structure modulates superlubrication by trivalent La electrolytes.

Water-based lubricants provide lubrication of rubbing surfaces in many technical, biological, and physiological applications. The structure of hydrated ion layers adsorbed on solid surfaces that determine the lubricating properties of aqueous lubricants is thought to be invariable in hydration lubrication. However, we prove that the ion surface coverage dictates the roughness of the hydration layer and its lubricating properties, especially under subnanometer confinement.

Significantly Affected Lubrication Behavior of Silicone Oil Lubricated SiN/Glass Contact after Cleaning with Different Solvents.

Conventional methyl silicone oils have poor lubricating properties in boundary lubrication regions, particularly for ceramic/oxide point contact lubrication. In this study, the residues of various organic solvents on the surfaces of SiN spheres/glass disks were used to determine their effect on the lubricating properties of silicone oil 200. The minute ethanol residues significantly enhanced the antifriction and antiwear properties of silicone oil.

Enhanced dewaterability of sludge by Fe(II)-sludge biochar activate persulfate.

Sludge biochar supported Fe(II) (Fe(II)-SBC) was successfully prepared using waste activated sludge as peroxydisulfate (PDS) activator to condition sludge for deep dewatering. The experimental results showed that Fe(II)-SBC with FeO on it could effectively active PDS to produce and . The radicals could destroy the structure of sludge cells and extracellular polymeric substance (EPS), transformed the hydrophilic and tightly bound EPS into soluble-EPS, degrade partial proteins and polysaccharides and released bound water.

High-Temperature Superlubricity Realized with Chlorinated-Phenyl and Methyl-Terminated Silicone Oil and Hydrogen-Ion Running-in.

Ceramic friction pairs lubricated with chlorinated-phenyl and methyl-terminated silicone oil (CPSO) systems have potential applications in the aerospace industry. In this study, the effects of the running-in process and temperature on the lubricating performance of CPSO were investigated. The superlubricity of SiN/sapphire lubricated with CPSO was realized at >190 °C after H-ion running-in.

Homogeneous interfacial water structure favors realizing a low-friction coefficient state.

Hypothesis: The use of water to reduce friction has always played a significant role in a wide range of areas ranging from biology to engineering. Many efforts have been made to extensively investigate the water behavior between two contacted surfaces, but its role in water-based friction remains incompletely understood.

Experiments: Herein, we utilize the sum-frequency generation (SFG) spectroscopy to identify interfacial water structures upon adjusting the wettability of titanium dioxide (TiO) and silicon surfaces.

Imaging dynamic three-dimensional traction stresses.

Traction stress between contact objects is ubiquitous and crucial for various physical, biological, and engineering processes such as momentum transfer, tactile perception, and mechanical reliability. Newly developed techniques including electronic skin or traction force microscopy enable traction stress measurement. However, measuring the three-dimensional distribution during a dynamic process remains challenging.

Intermolecular hydrogen bond ruptured by graphite with different lamellar number.

Intermolecular hydrogen bonds are formed through the electrostatic attraction between the hydrogen nucleus on a strong polar bond and high electronegative atom with an unshared pair of electrons and a partial negative charge. It affects the physical and chemical properties of substances. Based on this, we presented a physical method to modulate intermolecular hydrogen bonds for not changing the physical-chemical properties of materials.

Surface wettability effect on aqueous lubrication: Van der Waals and hydration force competition induced adhesive friction.

Hypothesis: Wettability effect has long been a concern in various aqueous lubrication systems including biological and industrial applications. The wettability may affect lubrication performance by changing interfacial viscosity or hydration force. The key point to reveal the mechanism is to design an ideal experimental system to exclude other bulk factors other than surface wettability.

Effects of Abrasive Particles on Liquid Superlubricity and Mechanisms for Their Removal.

Liquid superlubricity results in a near-frictionless lubrication state, which can greatly reduce friction and wear under aqueous conditions. However, during the running-in process, a large number of abrasive particles are generated, and because these may lead to a breakdown in superlubricity performance, they should be effectively removed. In this paper, the morphology, size, and composition of abrasive particles were verified using scanning electron microscopy with energy-dispersive X-ray spectroscopy, and their influence on liquid superlubricity was explored through friction tests.

Micro-Nano Hierarchical Structure Enhanced Strong Wet Friction Surface Inspired by Tree Frogs.

Superior wet attachment and friction performance without the need of special external or preloaded normal force, similar to the tree frog's toe pad, is highly essential for biomedical engineering, wearable flexible electronics, etc. Although various pillar surfaces are proposed to enhance wet adhesion or friction, their mechanisms remain on micropillar arrays to extrude interfacial liquid via an external force. Here, two-level micropillar arrays with nanocavities on top are discovered on the toe pads of a tree frog, and they exhibit strong boundary friction ≈20 times higher than dry and wet friction without the need of a special external or preloaded normal force.

sp. nov., an endogenous actinomycete isolated from .

A novel endogenous actinobacteria strain, designated TRM 66187, was isolated from sampled at Alar, Xinjiang, Northwest PR China, and characterized using a polyphasic taxonomic approach. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain TRM 66187 with the genus . The whole-cell sugar pattern of TRM 66187 consisted of galactose, glucose and ribose.

sp. nov., an endogenous actinomycete isolated from .

A novel actinomycete, designated strain TRM 66233, was isolated from L. collected from the Xinjiang Uygur Autonomous Region of China and characterized using a polyphasic taxonomic approach. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain TRM 66233 with the genus .

Negative friction coefficient in microscale graphite/mica layered heterojunctions.

The friction of a solid contact typically shows a positive dependence on normal load according to classic friction laws. A few exceptions were recently observed for nanoscale single-asperity contacts. Here, we report the experimental observation of negative friction coefficient in microscale monocrystalline heterojunctions at different temperatures.

Extreme-Pressure Superlubricity of Polymer Solution Enhanced with Hydrated Salt Ions.

The development of new routes or materials to realize superlubricity under high contact pressure can result in energy-saving and reduction of emissions. In this study, superlubricity (μ = 0.0017) under extreme pressure (717 MPa, more than twice the previously reported liquid superlubricity) between the frictional pair of SiN/sapphire was achieved by prerunning-in with a HPO (HP) solution followed by lubrication with an aqueous solution consisting of poly(vinyl alcohol) (PVA) and sodium chloride (NaCl).

Macroscale Light-Controlled Lubrication Enabled by Introducing Diarylethene Molecules in a Nanoconfinement.

Reversible friction regulation is of long-standing great interest in the fields of both industry and scientific research, so some materials and theories have been developed aiming to solve this problem. Light-sensitive materials are promising because of the easy controllable switching of the properties and structures. Here, a reversible light-controlled macrolubrication was realized by regulating the performance of nanoscale light-sensitive molecules adsorbed on contact surfaces.

Tribo-Induced Near-Infrared Light Emission between Metal and Quartz.

Triboluminescence (TL) refers to the luminescence phenomenon at the material surface under the action of pressure or shear. This fascinating phenomenon can directly convert mechanical energy into light emission without the need for other auxiliary components; therefore, it attracts more and more researchers to conduct research in different wavelength ranges, such as X-ray, ultraviolet, visible light, and terahertz. However, there have been few reports on the study of the near-infrared (NIR) range, which is very important in the integrity of the triboluminescence research.

On Lubrication States after a Running-In Process in Aqueous Lubrication.

Recently, many studies have reported the ultralow friction coefficient of sliding friction between rigid solid surfaces in aqueous lubrication. A running-in process that goes through high-friction and friction-decreasing regions to a stable ultralow friction region is often required. However, the role of the friction-decreasing region is often ascribed to tribofilm formation in which complexity hindered the quantitative description of the running-in process and the prediction of its subsequent lubrication state.

Big data analysis for evaluating bioinvasion risk.

Background: Global maritime trade plays an important role in the modern transportation industry. It brings significant economic profit along with bioinvasion risk. Species translocate and establish in a non-native area through ballast water and biofouling.

Expressions for the evaporation of sessile liquid droplets incorporating the evaporative cooling effect.

The evaporation along the surface of pinned, sessile droplets is investigated numerically by using the combined field approach. In the present model, the evaporative cooling at the droplet surface which leads to a reduction in the evaporation is taken into account. Simple, yet accurate analytical expressions for the local evaporation flux and for the total evaporation rate of sessile droplets are obtained.

Triboluminescence dominated by crystallographic orientation.

Triboluminescence (TL) is an optical phenomenon that has a long and varied history with broad applications, such as damage detection, X-ray source, and mass health monitoring sensor. So far, the properties and mechanisms of TL remain not completely understood. The TL properties emitted during the sliding contact between Al2O3 and SiO2 surfaces were studied along different crystallographic orientations.

Frictional Dissipation Pathways Mediated by Hydrated Alkali Metal Ions.

Frictional energy dissipation between sliding solid surfaces in aqueous media may proceed by different pathways. Using a surface force balance (SFB), we have examined systematically how such dissipation is mediated by the series of hydrated cations M(+) = Li(+), Na(+), and K(+) that are trapped between two atomically smooth, negatively charged, mica surfaces sliding across the ionic solutions over many orders of magnitude loading. By working at local contact pressures up to ca.

Worst-Case Cooperative Jamming for Secure Communications in CIoT Networks.

The Internet of Things (IoT) is a significant branch of the ongoing advances in the Internet and mobile communications. The use of a large number of IoT devices makes the spectrum scarcity problem even more serious. The usable spectrum resources are almost entirely occupied, and thus, the increasing radio access demands of IoT devices cannot be met.