92168.pdf

272 Emulsions and foams Foam drainage Initially, the liquid films of a foam will be relatively thick and drainage will take plac ...

Emulsions and foams 273 affect the equilibrium film thickness that a balance between the above forces would otherwise determine. ...

274 Emulsions and foams 100 200 Disjoining pressure/Nnrr^ Figure 10.4 Film thickness as a function of disjoining pressure for fi ...

Emulsions and foams 275 required for surfactant molecules to diffuse to this surface region and restore the original surface ten ...

276 Emulsions and foams Antifoaming agents The prevention of foaming and the destruction of existing foams is often a matter of ...

Problems k = 1.3805 x 1(T^23 JK'^1 NA = 6.0225 x lO^moP^1 R = 8.314 3 J K-^1 moP^1 e = 1.602 1 x UP^19 C e 0 = 8.8542 x KP^12 Fn ...

278 Problems equilibrium at 11000 revolutions per minute and at 25°C. The following equilibrium concentrations were measured: Di ...

Problems 279 If bubbles of air 10~^7 m in diameter and no other nuclei are present in water just below the boiling point, by ap ...

280 Problems The c.m.c. of a non-ionic surfactant in water varies with temperature as follows: Temperature/°C 15 20 25 30 40 c ...

Problems 281 The following data refer to the adsorption of nitrogen on 0.92 g of a sample of silica gel at 77 K, p being the pr ...

282 Problems Amount of'N 2 adsorbed (VIVm) 0.4 0.8 1.2 p (90 K)/p (77 K) 14.3 17.4 7.8 Calculate an isosteric enthalpy of adsorp ...

Problems 283 At 20°C the surface tension of benzene is 28.9 mN m"^1 and its molar volume is 89.2 cm^3 mol"^1. Determine the rel ...

284 Problems aqueous solutions at 25°C: (a) 0.1 fflol din"^3 KCl, (6) 0.001 mol dm™^3 KCI, (c) 0.001 mol dm"^3 K 2 SO 4 , (d) 0. ...

Problems 285 constants for the particles and the dispersion medium are 1.6 x 10~^19 J and 0.4 x 10~^19 J, respectively, and the ...

286 Problems used for routine determinations of the relative molecular masses of cellulose acetate samples in this relative mole ...

Answers 17.2 /urn Mr = 17000 (i.e. M = 17.0 kg mol"^1 ) /// 0 =1.11 (which, allowing for hydration, suggests that dissolved myo ...

288 Answers MT = 13000 (suggesting surface dissociation) wA = 2RT (suggesting that hydrogen is dissociated into atoms when chem ...

Answers 289 C (inner part of double layer) = 0.106 F m~^2 6/eo (inner part of double layer) = 4.8 (suggesting orientation of wa ...

References General IUPAC, 'Manual of Symbols and Terminology in Colloid and Surface Chemistry', Pure Appl. Chem., 31, 578 (1972 ...

References 291 MATIJEVIC, E., 'Preparation and characterisation of monodispersed metal hydrous oxide sols', Progr. Colloid Poly ...