This article addresses some established protocols for characterizing thermoplastics and whether they are homogeneous resins, alloyed, or blended compositions or highly modified thermoplastic composites. It begins with a discussion on characterizing mechanical, rheological, and thermal properties of polymer. This is followed by a section describing molecular weight determination using viscosity measurements. Next, the article discusses the use of cone and plate and parallel plate geometries in melt rheology. It then reviews the processes involved in the analysis of thermoplastic resins by chromatography. Finally, the article covers three operations of thermoanalysis, namely differential scanning calorimetry, thermogravimetric analysis, and thermomechanical testing.

This article is dedicated to gas chromatography (GC), covering the chromatographic method and primary components of a modern GC apparatus. The components include the carrier gas cylinder, flow controller and pressure regulator, sample inlet and injection port, column oven, and detector. Common GC detectors are the thermal conductivity cell detector, flame ionization detector, electron capture detector, sulfur chemiluminescence detector, and nitrogen-phosphorus detector.

This article briefly describes the capabilities of gas chromatography/mass spectrometry, which is used to qualitatively and quantitatively determine organic (and some inorganic) compound purity and stability and to identify components in a mixture. The discussion covers in more detail gas chromatography/mass spectrometry (GC/MS) instrumentation, interpreting mass spectra, GC/MS methodology, and GC/MS advances. Sample preparation, which is very important in GC/MS to avoid erroneous data and to minimize maintenance and troubleshooting of the instrument, is also discussed. Further, the article highlights the state of the art in the MS detector technology.

This article describes high-performance liquid chromatography and ultra-high-performance liquid chromatography that are used to separate and quantify the chemical components in any sample that can be dissolved in a liquid. This includes pharmaceutical drugs, medicinal plant extracts, food constituents, flavors, fragrances, industrial chemicals, pesticides, and pollutants. Readers are introduced to the most commonly employed mode, reverse-phase chromatography, with examples and an exclusive focus on commercially available instruments and consumables. The discussion covers the various processes involved in liquid chromatography, including assessing a separation of sample components, adjusting the mobile phase, choosing the stationary phase, optimizing a separation, preparing real samples, and analyzing complex samples.

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.

This article provides an overview of common analytical tools used as part of the process of providing practical information regarding the causes of a coating problem or failure. The common analytical tools include Fourier transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy-energy dispersive X-ray spectroscopy, chromatography, and electrochemical impedance spectroscopy. Test cabinets and standard test environments for laboratory analysis are reviewed. The article describes non-standard simulation testing and case studies of simulated environments for coating failure analysis.

The atmosphere within a furnace chamber is a basic factor in achieving the desired chemical reactions with metals during heat treating. This article presents the fundamentals of heat treating atmospheres, and describes two groups of atmosphere control, namely, furnace atmosphere control and supply atmosphere control. The two basic types of atmospheric supply systems are generated atmospheres and nitrogen-base atmospheres. The article provides a brief overview of the gas reactions associated with oxidation and carbon control to ensure either carburization, or to prevent decarburization. It demonstrates how the carbon potential control is achieved by controlling water vapor concentration, carbon dioxide concentration, or oxygen partial pressure. The article also describes the various devices and analyzers used to monitor sampled gas from furnace atmospheres, namely, chromatographs, oxygen probes, Orsat analyzers, infrared analyzers, dewpoint analyzers, and hot-wire analyzers. Finally, it discusses the advantages, disadvantages, and limitations of these analyzers.

This article focuses on epoxy because this resin category has widespread use and because it is tested using quality control measures typical of most resin systems. It explains that a typical resin system will consist of one or more epoxy resins, a curing agent, and a catalyst to control the rate of reaction. The article describes the component material tests, mixed resin system tests, and prepreg tests for the resin system. These tests include high-performance liquid chromatography, infrared spectroscopy, and gel permeation chromatography. The article contains a table that lists typical resin and prepreg property tests.

The primary goal of single-crystal x-ray diffraction is to determine crystal structure and the arrangement of atoms in a unit cell. This article discusses the diffraction of light through line gratings and explains the significance of crystal symmetry, space groups, and diffraction intensities. It also addresses phase and crystallographic analysis along with related challenges, and presents several application examples highlighting various experimental techniques.

This article provides an introduction to x-ray spectrometry, and discusses the role of electromagnetic radiation, x-ray emission, and x-ray absorption. It focuses on the instrumentation of wavelength-dispersive x-ray spectrometers, and energy dispersive x-ray spectrometers (EDS) that comprise x-ray tubes, the analyzing system, and detectors. The fundamentals of EDS operation are described. The article also provides useful information on preparation of various samples, explaining the qualitative and quantitative analyses of EDS. It reviews the applications of the x-ray spectrometry.

The diffraction pattern of any material contains structural and chemical property information that can be extracted using radial distribution function analysis. This article provides an introduction to the technique and presents several examples highlighting various ways in which it can be used. It begins with a discussion on the principles of diffraction and scattering and the effectiveness of x-ray, neutron, and electron energy sources for different types of measurements. It provides information on data collection and reduction and explains how to create atomic distribution plots from intensity and scattering angle data. The article also presents application parameters for defining short distances and background intensity and describes a procedure for generating pair distribution functions.

This article is a compilation of definitions of terms related to materials characterization techniques.

Electron probe microanalysis (EPMA) makes it possible to combine structural and compositional analysis in one operation. This article describes the basic concepts of microanalysis and the processing of EPMA that involves the measurement of the characteristic X-rays emitted from a microscopic part of a solid specimen bombarded by a beam of accelerated electrons. It provides information on the various aspects of energy-dispersive spectrometry (EDS) and wavelength-dispersive spectrometry (WDS), and elucidates the qualitative analysis of the major constituents of EDS and WDS. The article includes information on the analog and digital compositional mapping of elemental distribution, and describes the strengths and weaknesses of WDS and EDS spectrometers in X-ray mapping. It also outlines the application of EPMA for solving various problems in materials science.

Low-energy ion-scattering spectroscopy (LEISS) is used extensively to analyze solid surfaces. The LEISS process relies on binary elastic collisions between an incident ion beam and the atoms in a sample to obtain information on the surface atoms. The velocity of the scattered ions is used to determine the mass of the atoms that are struck. This article introduces LEISS and its principles. It describes the use of LEISS spectra in qualitative and quantitative analyses, and reviews the instrumentation and applications of LEISS.

This article provides a detailed account of the principles, instrumentation,and applications of x-ray photoelectron spectroscopy (XPS), a technique used for elemental and compositional analysis of surfaces and thin films. It reviews the nomenclature of energy states and sensitivity of electrons at the surface that are capable of producing peaks in XPS. Additionally, it presents information on the instrumentation and the preparation and mounting of samples for XPS analysis. The article explains qualitative analysis, namely, measuring of shifts in the binding energy of core electrons, multiplet splitting, and the Auger parameter; and quantitative analysis such as depth analysis carried out using XPS. It also discusses the applications of XPS with examples.

Particle-induced x-ray emission (PIXE) is one of several quantitative analyses based on characteristic x-rays. This article provides a detailed account on the principles of PIXE, discussing the data-reduction codes used to identify, integrate, and reduce x-ray peaks into elemental concentrations. It provides information on the calibration of PIXE analysis, which is mostly performed using gravimetric standards to avoid serious absorption, refluorescence, or ion energy change corrections. A comparative study on PIXE and x-ray fluorescence is also included. Finally, the article discusses the applications of PIXE in three areas, namely, atmospheric physics and chemistry, external proton milliprobes and historical analysis, and PIXE microprobes.

This article provides an introduction to extended x-ray absorption fine structure (EXAFS). It describes the fundamentals of EXAFS with an emphasis on the physical mechanism, the single-scattering approximation, and multiple-scattering effects. The article discusses the use of synchrotron radiation as the x-ray source for EXAFS experiments. It also describes the typical EXAFS data analysis of pure nickel at 90 K, and explains the near-edge structure analysis of vanadium. The article presents a discussion on the unique features and applications of EXAFS.

Crystallographic texture measurement and analysis is an important tool for correlating material properties with microstructural features. This article describes the general approach to quantifying crystallographic texture, namely, the collection of statistical data from grain measurements and subsequent analysis based on Euler plots (i.e., pole figures), orientation distribution functions, and stereographic projections. Using detailed illustrations and examples, it explains the significance of preferred crystallographic orientations and their influence on properties and material behavior. The article also discusses sample selection and preparation as well as the challenges and limitations of various methods.