Physical properties and characterisation

the various stimuli used to trigger responses from peptide surfaces wiU be discussed. Emphasis is placed on addressing possible issues that are particular to the peptide material or the biological environment in which the stimulus may be used. Subsequently, various techniques and strategies to analyse both the surface and the material response will be presented. 

From the previous sections of this chapter, it becomes evident that, despite the early stages of research on peptide-based responsive surfaces, the diversity of stimuli that are being used match those of other responsive materials. Here, these stimuli will be shortly discussed with respect to their benefits and limitations when used with peptide materials. 

For stimulus-responsive peptides, temperature has thus far exclusively been used to induce phase transitions of ELP (Hyun et al., 2004 Nath Chilkoti, 2003). As with other temperature-responsive biomaterials such as peptide-modified pNIPAM-based polymers (Ebara et al., 2004), the transition temperature has to be close to the physiological temperature if the material is to be used in conjunction with a living system in which the denaturing of naturally occurring proteins becomes an issue. 

Changes in the solution pH are typically used to elicit a change in the conformation of a peptide. As the formation of secondary structmes in peptides strongly depends on the charge of ionisable amino acid residues (e.g., lysine and glutamic acid), a change in 

Switchable and Responsive Surfaces and Materials for Biomedical Applications 

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Physical Properties and Characterisation of Small Gold Particles... 

A transition element containing an incomplete d subshell has many interesting properties and its oxides form a series of compounds with various unique electronic properties. They have a variety of applications such as catalysis, photocatalysis, sensors and electrode materials because of their catalytic, optical and electronic properties. Recently, many attempts have been made to combine these chemical and physical properties and ordered porous properties in order to create novel functional materials. In this chapter, we summarise the synthetic procedures, structural characterisation and applications of ordered porous crystalline transition metal oxides. 

Two-dimensional (2D) nanocrystals are now recognised as a new form of matter with unusual physical properties and a number of potential exciting applications. Recent developments in the field of two-dimensional nanocrystals such as the chemical modification of graphene and the isolation of monolayers of molybdenum disulfide and boron nitride are reviewed. The different techniques that have been employed to prepare the materials such as mechanical and solution exfoliation, and chemical vapour deposition are discussed briefly. The techniques employed to characterise these 2D materials are described and their properties discussed. Potential engineering applications of 2D materials in fields such as nanocomposites and catalysis are then described. 

This paper reports on the synthesis, characterisation, and applications of novel flame retardant dibromostyrene-based latexes. They are copolymers of dibromostyrene with butadiene, alkyl acrylates and methacrylates, vinyl acetate, styrene and unsaturated carboxylic acids, which form a wide variety of flame retardant latexes via an emulsion polymerisation technique. Choice of monomer or monomer blend is based upon the final glass transition temperature of the copolymer desired. Other criteria include desired physical properties and chemical resistance. Dibromostyrene-based butadiene and acryUc latexes are shown to possess the desired physical properties for use in coatings, adhesives and sealants, and the bromine content of the latexes has enabled the material to pass six different flammability requirements for the end uses such as textile backcoating, latex-based paint, contact adhesive, latex sealant, nonwoven binder, and carpet backing. 18 refs. 

As described above, the basic catalyst characterisation involves two main steps the investigation on the porous nature of the catalyst support (physical properties) and on the properties of the active sites that are dispersed on the support surface (see Table 1). 

The feldspar minerals have similar physical properties and often occur as prismatic or tabular crystals in igneous rocks, or as more anhedral grains in metamorphic and sedimentary rocks. They are colourless when fresh but are more commonly white due to incipient alteration impurities or inclusions result in coloured varieties, with green-brown alkali feldspars found in some metamorphic rocks, and orthoclase commonly found as pink. The surfaces of feldspar crystals are often iridescent due to twinning on a microscopic scale, with labradorite characterised by blue surface iridescence. Feldspars readily alter under hydrothermal action or chemical weathering to form members of the clay minerals group (. v.). Sodium-rich feldspars commonly decompose to form montmorillonite, in the presence of limited water, or to kaolinite with excess water alkali feldspars typically form illite or kaolinite sub-group (qq.v.) clay minerals (Deer et al, 1992 Rutley, 1988). 

The new material science opened by the discovery of the electrical conductivity [1/2] and optical non linearities of polyconjugated organic polymers is a classical example of the need of an interdisciplinary approach to the study of their physical properties and shows the importance played by the experimental physical sciences in the characterisation of the materials and in the understanding of the phenomena. 

Chakactkrisation of Unsaturatkd Aliphatic Hydrocarbons Unlike the saturated hydrocarbons, unsaturated aliphatic hydrocarbons are soluble in concentrated sulphuric acid and exhibit characteristic reactions with dUute potassium permanganate solution and with bromine. Nevertheless, no satisfactory derivatives have yet been developed for these hydrocarbons, and their characterisation must therefore be based upon a determination of their physical properties (boiling point, density and refractive index). The physical properties of a number of selected unsaturated hydrocarbons are collected in Table 111,11. 

The low reactivity of aliphatic ethers renders the problem of the preparation of suitable crystalline derivatives a somewhat difficult one. Increased importance is therefore attached to the physical properties (boding point, density and refractive index) as a means for providing preliminary information. There are, however, two reactions based upon the cleavage of the ethers which are useful for characterisation. 

J. P. Ibar and co-workers, in Polymer Characterisation Physical Property, Spectroscopic, and Chromatographic Methods, American Chemical Society, Washington, D.C., 1990, p. 167. 

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