This article introduces the structure, tribological properties, advantages, and applications of ionic liquids (ILs) as lubricating media. It discusses the mechanisms of IL lubrication for different contacts. The advances in studies focusing on tribological properties of a wide range of ILs are reviewed. The article concludes with the challenges that limit the applications of ILs in tribology engineering.

This article provides a brief introduction to lubrication as a method to reduce friction between two surfaces. It discusses the surface characteristics of parts and explores how lubrication helps separate two contacting surfaces and thereby decreases the coefficient of friction. The article details the classifications of lubrication regimes, namely, boundary, mixed, hydrodynamic, and elastohydrodynamic lubrications. It discusses the various types of lubricant materials and additives, including liquid lubricants, solid lubricants, gaseous lubricants, greases, green lubricants, and nanomaterials. The article also reviews the properties of lubricants. It describes the tribological evaluation of lubricants, including stribeck test, four-ball test, block-on-ring test, pin-in-vee test, and reciprocating motion test.

Strategies for the lubrication of mechanical systems operating in extreme environments must exclude the liquid lubricants and greases and rely on alternative methods of lubrication, such as gases and solids. This article provides a survey of some of the more effective alternative methods of lubrication. It provides a discussion on the solid materials that have been most commonly used as lubricants: carbon-base materials, transition metal dichalcogenides, polymers, and soft metals.

Potentiometric membrane electrodes are electrochemical devices that can be used to quantify numerous ionic and nonionic species. This class of electrochemical sensors can be divided into ion-selective and gas-sensing membrane electrodes. The first half of this article mainly focuses on the subclasses, the membrane potential, electrode selectivity limitations and the methods of analysis of the ion-selective membrane electrodes. These methods of analysis include the use of calibration curves, addition techniques, subtraction techniques, and titration. The second half outlines gas sensing membrane electrodes, and discusses important elements that must be considered in addition to the potentiometric membrane electrode to ensure proper electrode response. These elements are reference electrodes, temperature controls, recording of the potential with respect to time, electrode storages, and sample pretreatment. The article also explains the applications of the potentiometric membrane electrodes with the aid of an example.

This article introduces the fundamental concepts and the essential components of liquid chromatography (LC). It discusses the different modes of LC, such as liquid-solid chromatography, liquid-liquid chromatography, bonded-phase chromatograph, normal-phase chromatography, reversed-phase chromatography, ion-exchange chromatography, ion-pair chromatography, and size-exclusion chromatography. The article also includes a discussion on the qualitative and quantitative analyses and the applications of LC.

This article provides a discussion on the fundamentals of corrosion thermodynamics. The discussion focuses on electrochemical reactions, molten salt corrosion thermodynamics, and geochemical modeling.

This article reviews the fundamental relationships between microstructure and mechanical properties for major classes of nonmetallic engineering materials: metals, ceramics and glasses, intermetallic compounds, polymers, and composites. It details the structures of inorganic crystalline solids, inorganic noncrystalline solids, and polymers. The article describes the various strengthening mechanisms of crystalline solids, namely, work hardening, solid-solution hardening, particle/precipitation hardening, and grain size hardening. Deformation and strengthening of composite materials, polymers, and glasses are reviewed. The article concludes with information on the two important aspects of the mechanical behavior of any class of engineering material: fatigue response and fracture resistance.

This article discusses the attempts made by the industry to create sensing approaches for modeling a process, part, and chemistry and kinetics. It reviews microwave curing of thick-section composites and the resin cure sensors that are used for resin cure monitoring. These include dielectric cure sensors, fiberoptics-based resin cure sensors, ultrasonics-based resin cure sensors, and dosimetry-based resin cure sensors. The article provides information on the resin cure control flow sensing, flow modeling, flow mapping, and resin flow. It addresses some practical issues in sensing resin cure and flow.

Molten salts, in contrast to aqueous solutions in which an electrolyte (acid, base, salt) is dissolved in a molecular solvent, are essentially completely ionic. This article begins with an overview of the thermodynamics of cells and classification of electrodes for molten salts: reference electrodes and indicator electrodes. It explains that corrosion in molten salts can be caused by the solubility of the metal in the salt, particularly if the metal dissolves in its own chloride. The article describes the factors that affect the corrosion of titanium, namely, the titanium chloride content of the magnesium chloride melt, magnesium or sodium content, and oxygen content of the product. It concludes with a discussion on the oxygen activity in the titanium metal product.

This article focuses on the relationships among material properties and material structure. It summarizes the fundamental characteristics of metals, ceramics, and polymers. The article provides information on the crystal structure, the atomic coordination, and crystalline defects. It discusses the relevance of the properties to design. The article describes the common means for increasing low-temperature strength and presents an example that shows structure-property relationships in nickel-base superalloys for high-temperature applications. The relationships of microstructure with low-temperature fracture, high-temperature fracture, and fatigue failure are also discussed.

This article presents an overview of the science and engineering of materials along with suitable definitions, descriptions, and examples for better understanding for corrosionists with limited field knowledge. It begins with a detailed description of various categories of engineering materials and moves into the discussion of physical properties of materials, such as the phases, strength, conductivity, and wear. The article describes the methods used in the fabrication of engineering materials and summarizes the materials and their properties in a tabular form. The article concludes with information on material design, materials applications, and materials failure analysis.

Ion chromatography (IC) is an analytical technique that uses columns packed with ion exchange resins to separate ions in aqueous solutions and dynamically elute them to a detector. This article provides information on the different modes of detection, namely, eluent-suppressed conductivity detection, single-column ion chromatography with conductivity detection, ion chromatography with spectrophotometric detection, and amperometric electrochemical detection. It describes the modes of separation techniques in IC and reversed-phase IC. The article discusses the detection capabilities of IC, the procedures for preparing solid and liquid samples, as well as the applications of IC.

This article presents a detailed account of ion chromatography (IC). It begins by describing the principles of common separation modes in IC. This is followed by a section on the different modes of detection, namely suppressed conductivity detection, nonsuppressed conductivity detection, spectrophotometric detection, and electrochemical detection. Various separation modes in IC are then described. The article further provides information on various eluents species, analyte range, and sample preparation techniques in IC. It ends by providing information on the instrumentation and applications and future directions of IC.

Microvalve jetting, with its advantages of low cost, ease of operation, high printing speed, and ability to process living cells with high viability, has been primarily used for fabricating high-throughput drug-screening models, in vitro cellular structures for fundamental cell biology research, and cell-laden structures for regenerating tissues or organs in the human body after disease or trauma. This article provides an overview of microvalve jetting of biomaterials, including operational parameters. The jetting technologies covered are inkjet printing, microvalve jetting, and laser-assisted jetting. The parameters covered include nozzle size (nozzle inner diameter), pneumatic pressure, valve-opening time, and printing speed of microvalve jetting. Subsequently, the article discusses biomaterials for microvalve jetting in terms of biomaterial definition, required properties for a suitable biomaterial, currently used biomaterials, and cells and cellular structures. Additionally, applications of microvalve jetting in biomedical engineering are presented, which include cellular and RNA analysis, high-throughput drug screening, and tissue engineering.

Electrode potential is a key parameter in the thermodynamic and kinetic processes that drive aqueous corrosion. This article discusses the complexities associated with measuring electrode potential and explains where and how to use reference electrodes to improve measurement accuracy. It describes a three-electrode approach that compensates for measurement error stemming from nonequilibrium conditions. It also examines electrode materials and behaviors and offers insights on selection and operating conditions.

Electropolishing is an electrochemical process that involves anodic dissolution of a metal specimen (anode electrode) in an electrolytic cell. This article reviews the two-electrode and three-electrode systems for electropolishing. It presents the equations of anodic reactions and the selection criteria of electrolyte for electropolishing. The article also describes the mechanism of electropolishing and the effect of electropolishing on properties of metals.

This article focuses on the principles and applications of X-ray photoelectron spectroscopy (XPS) for the analysis of elemental and chemical composition. The discussion covers the nomenclature, instruments, and specimen preparation process of XPS. Some of the factors pertinent to the calibration of materials for accurate measurements using XPS are provided, along with some aspects of the accuracy in quantitative analysis by XPS. In addition, the article presents examples of how XPS data can be used to solve problems with surface interactions.

This article provides information on various forms of corrosion that occur in electronic packaging. Portable consumer electronic hardware which is subjected to humidity exposures is prone to condensed moisture and liquid damage. The article discusses two other corrosion-related phenomena that are found only in electronics, namely, electrochemical migration (ECM) and conductive anodic filament formation (CAF). It describes the corrosion that takes place in metals such as copper, tin, and tin-lead alloys, which are commonly used in electronic packaging. The article also discusses the corrosion of the components used in electronic assemblies.