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Crystalline solids properties

Schemes for classifying surfactants are based upon physical properties or upon functionality. Charge is tire most prevalent physical property used in classifying surfactants. Surfactants are charged or uncharged, ionic or nonionic. Charged surfactants are furtlier classified as to whetlier tire amphipatliic portion is anionic, cationic or zwitterionic. Anotlier physical classification scheme is based upon overall size and molecular weight. Copolymeric nonionic surfactants may reach sizes corresponding to 10 000-20 000 Daltons. Physical state is anotlier important physical property, as surfactants may be obtained as crystalline solids, amoriDhous pastes or liquids under standard conditions. The number of tailgroups in a surfactant has recently become an important parameter. Many surfactants have eitlier one or two hydrocarbon tailgroups, and recent advances in surfactant science include even more complex assemblies [7, 8 and 9]. Schemes for classifying surfactants are based upon physical properties or upon functionality. Charge is tire most prevalent physical property used in classifying surfactants. Surfactants are charged or uncharged, ionic or nonionic. Charged surfactants are furtlier classified as to whetlier tire amphipatliic portion is anionic, cationic or zwitterionic. Anotlier physical classification scheme is based upon overall size and molecular weight. Copolymeric nonionic surfactants may reach sizes corresponding to 10 000-20 000 Daltons. Physical state is anotlier important physical property, as surfactants may be obtained as crystalline solids, amoriDhous pastes or liquids under standard conditions. The number of tailgroups in a surfactant has recently become an important parameter. Many surfactants have eitlier one or two hydrocarbon tailgroups, and recent advances in surfactant science include even more complex assemblies [7, 8 and 9].
Physical properties. All are colourless crystalline solids except formic acid, acetic acid (m.p. 18 when glacial) and lactic acid (m.p. 18°, usually a syrup). Formic acid (b.p. loo ") and acetic acid (b.p. 118 ) are the only members which are readily volatile lactic acid can be distilled only under reduced pressure. Formic and acetic acids have characteristic pungent odours cinnamic acid has a faint, pleasant and characteristic odour. [Pg.347]

Physical Properties All colourless odourless crystalline solids. Acetanilide,CH3CONHCflH5,andbenzanilide,C,H6CONHCeH6 are both sparingly soluble in cold water, but acetanilide has the greater solubility in hot water. [Pg.379]

Physical Properties. Glycine is a colourless crystalline solid soluble in water. Owing to the almost equal opposing effects of the amino and the carboxylic groups. its aqueous solution is almost neutral (actually, slightly acidic to phenolphthalein) and glycine is therefore known as a neutral ampholyte. f It exhibits both acidic and basic properties. [Pg.380]

Physical Properties. Colourless crystalline solid, soluble in boiling water, very sparingly soluble in cold water crystallises 2H2O. The strongly acidic — SO3H group suppresses the normal basic properties of the — NHj group the acid therefore dissolves readily in alkalis, but not in dilute mineral acids. [Pg.384]

Physical Properties. All heavier than, and insoluble in water. All liquids, except iodoform, CHI3, which is a yellow crystalline solid with a characteristic odour. The remainder are colourless liquids when pure ethyl iodide, CjHjI, and iodobenzene, CjHgl, are, however, usually yellow or even brown in colour. Methyl iodide, CH3I, ethyl bromide, CgH Br, ethyl iodide, chloroform, CHCI3, and carbon tetrachloride, CCI4, have sweetish odours, that of chloroform being particularly characteristic. [Pg.390]

Because diastereomers are not mirror images of each other they can have quite different physical and chemical properties For example the (2R 3R) stereoisomer of 3 ammo 2 butanol is a liquid but the (2R 3S) diastereomer is a crystalline solid... [Pg.302]

The physical properties of a typical amino acid such as glycine suggest that it is a very polar substance much more polar than would be expected on the basis of its formula tion as H2NCH2CO2H Glycine is a crystalline solid it does not melt but on being heated It eventually decomposes at 233°C It is very soluble m water but practically insoluble m nonpolar organic solvents These properties are attributed to the fact that the stable form of glycine is a zwittenon, or inner salt... [Pg.1117]

Below Tg the material is hard and rigid with a coefficient of thermal expansion equal to roughly half that of the liquid. With respect to mechanical properties, the glass is closer in behavior to a crystalline solid than to a... [Pg.202]

Anhydrous Hydrogen Chloride. Anhydrous hydrogen chloride is a colorless gas that condenses to a colorless liquid and freezes to a white crystalline solid. The physical and thermodynamic properties of HCl are summarized in Table 2 for selected temperatures and pressures. Figure 1 shows the temperature dependence of some of these properties. [Pg.437]

Cane sugar is generally available ia one of two forms crystalline solid or aqueous solution, and occasionally ia an amorphous or microcrystalline glassy form. Microcrystalline is here defined as crystals too small to show stmcture on x-ray diffraction. The melting poiat of sucrose (anhydrous) is usually stated as 186°C, although, because this property depends on the purity of the sucrose crystal, values up to 192°C have been reported. Sucrose crystallines as an anhydrous, monoclinic crystal, belonging to space group P2 (2). [Pg.13]

Nicotinamide is a colorless, crystalline solid. It is very soluble in water (1 g is soluble in 1 mL of water) and in 95% ethanol (1 g is soluble in 1.5 mL of solvent). The compound is soluble in butanol, amyl alcohol, ethylene glycol, acetone, and chloroform, but is only slightly soluble in ether or benzene. Physical properties are Hsted in Table 1. [Pg.47]

Physicochemical Properties White crystalline solid powder or granular, ion- toxic and odorless ... [Pg.51]

Acrylamide is the most important and the simplest of the acrylic and methacrylic amides. Acrylamide is a colorless crystalline solid. The basic physical properties and solubilities of acrylamide are given in Table I. Acrylamide is a severe neurotoxin and is a cumulative toxicological hazard. [Pg.61]

Electro-optic The liquid crystal plastics exhibit some of the properties of crystalline solids and still flow easily as liquids (Chapter 6). One group of these materials is based on low polymers with strong field interacting side chains. Using these materials, there has developed a field of electro-optic devices whose characteristics can be changed sharply by the application of an electric field. [Pg.229]

Among the polymers which contain clear crystalline phases are poly(eth-ylene) and PTFE. Their properties, however, are very different from those usually associated with crystalline solids in particular, they tend to exhibit... [Pg.42]

When crystals with covalent bonds (e.g., AICI3 or TiCy melt, the melt conductivity remains low (e.g., below 0.1 S/m), which implies that the degree of dissociation of the covalent bonds after melting is low. The covalent crystals also differ from the ionic crystals by their much lower melting points. The differences between these two types of crystal are rather pronounced, whereas there are few crystalline solids with intermediate properties. [Pg.131]

Glasses typically are metastable substances. Like crystalline solids they exhibit macroscopic form stability, but because of their structures and some of their physical properties they must be considered as liquids with a very high viscosity. Their transition to a thermodynamically more stable structure can only be achieved by extensive atomic movements, but atom mobility is severely hindered by cross-linking. [Pg.31]

Molecules having the same composition but different structures are called isomers. The corresponding phenomenon for crystalline solids is called polymorphism. The different structures are the modifications or polymorphic forms. Modifications differ not only in the spatial arrangement of their atoms, but also in their physical and chemical properties. The structural differences may comprise anything from minor variations in the orientation of molecules up to a completely different atomic arrangement. [Pg.31]

The planar representation shown serves, in part, to obscure somewhat the complexity of the structural problem involved. Actually, four stereoisomers are represented by the simple planar representation shown it is not yet known with certainty which is the one corresponding to aldrin. Physically pure aldrin is a white crystalline solid with the properties set forth in Table I. [Pg.176]

Dieldrin, which, when pure, is a white crystalline solid, possesses the physical properties shown in Table III. [Pg.177]

An enormous variety of solvates associated with many different kinds of compounds is reported in the literature. In most cases this aspect of the structure deserved little attention as it had no effect on other properties of the compound under investigation. Suitable examples include a dihydrate of a diphosphabieyclo[3.3.1]nonane derivative 29), benzene and chloroform solvates of crown ether complexes with alkyl-ammonium ions 30 54>, and acetonitrile (Fig. 4) and toluene (Fig. 5) solvates of organo-metallic derivatives of cyclotetraphosphazene 31. In most of these structures the solvent entities are rather loosely held in the lattice (as is reflected in relatively high thermal parameters of the corresponding atoms), and are classified as solvent of crystallization or a space filler 31a). However, if the geometric definition set at the outset is used to describe clathrates as crystalline solids in which guest molecules... [Pg.14]


See other pages where Crystalline solids properties is mentioned: [Pg.401]    [Pg.356]    [Pg.401]    [Pg.356]    [Pg.142]    [Pg.178]    [Pg.1361]    [Pg.2898]    [Pg.748]    [Pg.522]    [Pg.292]    [Pg.210]    [Pg.73]    [Pg.1117]    [Pg.103]    [Pg.193]    [Pg.144]    [Pg.947]    [Pg.95]    [Pg.239]    [Pg.96]    [Pg.59]    [Pg.421]    [Pg.42]    [Pg.217]    [Pg.291]    [Pg.458]    [Pg.463]    [Pg.268]    [Pg.597]   
See also in sourсe #XX -- [ Pg.349 ]

See also in sourсe #XX -- [ Pg.35 , Pg.37 ]

See also in sourсe #XX -- [ Pg.35 , Pg.37 ]




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Solids properties

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