Water-miscible liquids

Poly(vinyl chloride) is commercially available in the form of aqueous colloidal dispersions (latices). They are the uncoagulated products of emulsion polymerisation process and are used to coat or impregnate textiles and paper. The individual particles are somewhat less than 1 p,m in diameter. The latex may be coagulated by concentrated acids, polyvalent cations and by dehydration with water-miscible liquids. 

Toxic products may be produced care must be exercised after use in confined spaces. Special foam required for water-miscible liquids. 

M. Fagnoni, A. Profumo, D. Merli, D. Dondi, P. Mustarelli, E. Quartarone, Water-miscible liquid multiwalled carbon nanotubes, Advanced Materials, vol. 21, pp. 1761-1765, 2009. 

Groundwater, liquid, and solid matrices Direct injection of head-space gas (EPA method 5020) or purge-and-trap preconcentration and thermal desorption (EPA method 5030) GC/HSD (EPA method 8010) 0.5 pg/L (ppb, w/v) for groundwater, 0.5 pg/g (ppm, w/w) for low-level soil, 500 pg/L (ppb, w/v) for water-miscible liquid waste, 1,250 pg/g (ppm, w/w) for soil, sludge, and non-water-miscible waste Water 0.93C -0.39 where C = true concentration in pg/L. EPA1986a... 

AFFF is suitable for subsurface injection into tanks containing ordinary hydrocarbons it is not suitable for subsurface injection into storage tanks containing water-miscible liquids or polar solvents, or for oil with a viscosity of 2000 or more Saybolt Standard Units (SSU). 

NOTE CHB, container handling building WIL, water-immiscible liquid WIS, water-insoluble solid WML, water-miscible liquid and WSS, water-soluble solid. 

An important function of animal skin is to act as a barrier to prevent water loss and entry of foreign materials. In man and other mammals this barrier property is conferred by the outermost layer known as the stratum corneum. Although it is composed essentially of a few layers of cells which undergo extensive keratinization as they are forced upward from the dermis layer, the barrier properties of this stratum corneum layer far exceed those of keratin. The eflBciency of stratum comeum as a barrier depends on the presence in it of lipoidal material. This eflBciency (I) is severely impaired if the stratum corneum is treated with combinations of polar, water miscible liquids such as methanol and water immiscible lipophilic solvents such as hexane or chloroform. 

The large groups of liquids that can be encapsulated into Softgels fall into one of two categories water-miscible liquids and water-immiscible liquids. ... 

Water-miscible liquids include polyethylene glycols (PEG) and non-ionic surfactants, such as the poly-sorbates. Low molecular weight grades of PEG (e.g., PEG 400) are used most commonly as they remain liquid at ambient temperatures. Small amounts (up to 5-10%) of other water-miscible liquids, such as propylene glycol, ethanol, and glycerin, can also be used. 

The three 1,3-azoles, imidazole, thiazole and oxazole, are aU very stable compounds that do not autoxidise. Oxazole and thiazole are water-miscible liquids with pyridine-like odours. Imidazole, which is a solid at room temperature, and 1-methylimidazole are also water soluble, but are odourless. They boil at much higher temperatures (256 °C and 199 °C) than oxazole (69 °C) and thiazole (117 °C) this can be attributed to stronger dipolar association resulting from the very marked permanent charge separation in imidazoles (the dipole moment of imidazole is 5.6 D cf. oxazole, 1.4 D thiazole, 1.6 D) and for imidazole itself, in addition, extensive intermolecular hydrogen bonding. The dihydro- and tetrahydro-1,3-azoles are named imidazoline/imidazolidine, thiazoline/thiazolidine and oxazoline/oxazolidine. 

Methyloxirane (propylene oxide) is a colourless, water-miscible liquid, bp 35°C. It is produced commercially from propene and tert-hMtyX hydroperoxide in the presence of molybdenum acetylacetonate [8]. 

An important quantity in this regards is the interfacial tension between the two liquids. Freitas et al. (1997) compiled a comprehensive list of yws values for the surface tension between water and immiscible Uquids S mostly at 20 °C or exceptionally at temperatures between 19 and 26 °C. Representative values are shown in Table 4.1. The larger the mutual solubility of water with the liquid S the smaller is the interfacial tension, until it vanishes, of course, for water-miscible liquids. Tri-ethylamine is a case in point, since at 20 °C with yws = 0.1 mN m it is just 2 °C above the upper consolute temperature. 

A related subject is the interfacial potential between water (W) and the liquid S, where the latter could be either miscible or immiscible with water. In the first case the individual surface potentials between W and air (A), Ax, and between S and air, A X, are measured or estimated and the difference is taken A x = A x - A x. In the latter case direct measurements of the interfacial potential (at zero charge) between the mutually saturated W(S) and S(W) are possible. Koczorowski et al. (1989) presented values for many liquids S of both kinds, and these are compared with values for some water-miscible liquids obtained by other authors in Table 4.2. It should be noted that for the mutually immiscible pair water/nitrobenzene the interfacial potential, 0.105 0.20 V (Koczorowski and Zagorska 1983), is considerable lower than that estimated for the neat liquids, 0.24 V. 

The aqueous phase may contain, apart from water, water-miscible liquids as humectants, co-solvents or penetration enhancers. The aqueous phase has to be preserved. If substances are dispersed in the aqueous phase they are considered part of the solid phase (see Sect. 12.5.1). For the substances reference is made to appropriate sections of Chap. 23 Raw materials. Just some functional details are mentioned here. 

Ttie quantities of medicines, foodstuffs and cosmetics, containing not more than 50 percent hy volume of water-miscible liquids and with the remainder of the solutions not being flammable, in retail sales uses are unlimited when packaged in individual containers not exceeding 4 liters. 

Oxetane, a colorless, water-miscible liquid of bp 48 ° C, is obtained in 40% yield by heating I q I... 

Pyridine, mp —42°C, bp 115 °C, is a colorless, water-miscible liquid of an amine-like odor. Pyridine is poisonous, and inhalation of its vapor causes damage to the nervous system. It is a weak base (pfQ, = 5.20, cf. aliphatic amine pfQ, 10, aniline pfQ, = 4.58). Pyridine, as well as picolines and lutidines, are constituents of coal-tar and bone-oil. 

Prior to addition to water, the powder is wetted with a water-miscible liquid such as alcohol, glycol, or glycerol that will not cause the CMC to swell. Two to three parts of liquid per part of CMC should be sufficient... 

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