Characterisation of Materials

It is a wise precaution to ensure that all material can be checked against a known internal company standard. These may be a simple test such as melting point but where blends of materials are purchased such a test is not useful. A good, almost universal, test method, that yields a quantitative result, is produced using differential thermal analysis. With careful selection of the temperature profile it is often possible to measure moisture content, detect phase changes and the ratio of various components. 

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The characterisation of materials is a central necessity of modern materials science. Effectively, it signifies making precise distinctions between different specimens of what is nominally the same material. The concept covers qualitative and quantitative analysis of chemical composition and its variation between phases the examination of the spatial distribution of grains, phases and of minor constituents the crystal structures present and the extent, nature and distribution of structural imperfections (including the stereological analysis outlined in Chapter 5). 

Lifshin, E. (1986) Investigation and characterisation of materials, in Encyclopedia of Materials Science and Engineering, vol. 3, ed. Bever, M.B. (Pergamon Press, Oxford) p. 2389. 

Acknowledgements. The authors thank the Division of Food Chemistry, Department of Food Science and Technology, Wageningen Agricultural University, The Netherlands, for the possibility of carrying-out the characterisation of materials. 

H. Hutter, Ch. Brunner, St. Nikolov, Ch. Mittermayer and M. Grasserbauer, Imaging surface spectroscopy for two- and three-dimensional characterisation of materials, Fresenius J. Anal. Chem., 355(5-6), 1996, 585-590. 

Neutron activation is not a widely used method (Fig. 17.8). Some of its applications include characterisation of materials (e.g. high purity metals, semiconductors), the study of the distribution of chemical elements within fossils, ultra-trace analysis in archaeology and geology, and the study of volcanoes. 

This review article describes progress made in scanning force microscopy of polymers during the last 5 years including fundamental principles of SFM and recent developments in instrumentation relevant to polymer systems. It focuses on the analytical capabilities of SFM techniques in areas of research where they give the most unique and valuable information not accessible by other methods. These include (i) quantitative characterisation of material properties and structure manipulation on the nanometer scale, and (ii) visualisation and probing of single macromolecules. 

Impedance spectroscopy is a valuable addition to the range of techniques for the electrical characterisation of materials and components, especially where interfaces (e.g. metallic electrode/cathode or anode materials) are involved. This is particularly so in the case of batteries and fuel cells, the subjects of the most intensive research and development stimulated by the need to develop power sources which reduce dependence on fossil fuels and their damage to the environment (see Section 4.5.1). 

The LCBLs identified issues surrounding the characterisation of materials for treatment and disposal. 

Thermoanalytical instruments allow the study of chemical and physical changes that occur with temperature, allowing the characterisation of materials and an understanding of their thermal events. 

The use of luminescent ions as a probe does nut belong to the field of industrial application of luminescent materials, but should be considered as an application in the field of research and characterisation of materials. The basic idea is that the luminescence properties of an ion tell us something about the ion itself and also about its surroundings in the host lattice. The dangerous side of this use of luminescence, a side which is often overlooked, is that only luminescent ions can be monitored. However, it may well be that the material contains the specific ion but that it does not or only partly luminesce under the given circumstances. It is therefore important to know whether the ion has really been excited or not, and whether all ions show emission or not. 

The introduction and development of Micro-Thermal Analysis are described and discussed by Duncan Price in Chapter 3. The atomic force microscope (AFM) forms the basis of both scanning thermal microscopy (SThM) and instruments for performing localised thermal analysis. The principles and operation of these techniques, which exploit the abilities of a thermal probe to act both as a very small heater and as a thermometer, in the surface characterisation of materials are described in detail. The... 

A new NMR method for the characterisation of materials at different length scales has been proposed by Alonso and Massiot. It combines a selection of H- C pairs by a through-bond polarisation transfer and exploration of larger... 

Characterisation of Materials. Parts 1 2in Material Science and Technology, E. Lifshin Ed., VCH Weinheim (1992). 

UV/Vis/NIR spectroscopy may be employed directly for the characterisation of materials formed or deposited on electrode surfaces. 

S.B. Sharma, M.P.F. Sutcliffe, and S.H. Chang, Characterisation of material properties for draping of dry woven composite material. Compos. A 34,1167-1175 (2003). 

V.F.F. Barbosa, K.J.D. MacKenzie, C. Thaumaturgo, Synthesis and characterisation of materials based on inorganic polymers of alumina and silica sodium polysialate polymers, Int. J. Inorg. Mater. 2 (2000) 309-317. 

Adsorbent materials have been characterized and tested using a range of techniques. Characterisation of materials has focused on deteiming the physical and chemical properties of the sold sorbent materials. This has heen conducted using a range of techniques, for example, elemental analysis, power x-ray diffraction (XRD), diffuse reflectance infrared Fourier transform spectra (DRIFTS), textural properties have been determined by BET N2 adsorption analysis. Thermogravimetric analysis (TGA) has been used to determine the thermal stability of the materials as well as measure CO2 adsorption capacity and cyclic capacity [14]. 

FT-IR spectroscopy is becoming a techniqne of choice for the analysis and characterisation of materials. It provides a unique fingerprint of the sample, which can lead to a positive identification within minutes. In the past, the problem was how to handle the sample and whether there was sufficient sample to obtain an adequate spectrum. As early as 1949 it was appreciated that one solntion was to ntilise the handling and viewing capabilities of a microscope, i.e., FT-IR microscopy. 

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