Swelling of, colloids

Kratz, K., T. HeUweg, et al. (2000). Influence of charge density on the swelling of colloidal poly(N-isopropylacrylantide-co-acrylic acid) microgels. Colloids and Surfaces A Physicochemical and Engineering Aspects 170(2-3) 137-149. 

Tauer, K., Kaspar, H., Antonietti, M., Equilibrium swelling of colloidal polymeric particle with water-insoluble organic solvents. Colloid Polym. 5c/., 278, 814-820 (2000). 

Class of colloidal substances prepared from plants. Composed of complex carbohydrates and organic acids that swell in water. Also, a number of natural resins are gums. 

Clay films cast from a pure aqueous colloid appear to form a regular array of microplatelets, thin films of which show selective cation exchange, e.g. segregation of Ru(bipy)i from Na" and methylviologen dication and even partial separation of the enantiomers of Co bipy)3 Thicker films (approx. 3 pm) can be supported by the addition of polyvinyl alcohol additive also aids swelling of the... 

As distinct from the gelling properties of certain natural gums, usually exhibited by structural rigidity, viscosity is a thickening of the aqueous portion of a system by means of particle water absorption, and swelling of the colloid. From a practical angle, it manifests itself by the phenomena of thickening and reduced flow characteristics. 

P/P0), the colloidal crystal film exhibited an additional increase in the response sensitivity likely due to the swelling of the core of the core/shell submicron particles. This effect was more pronounced upon exposure to toluene. 

Polyelectrolytes provide excellent stabilisation of colloidal dispersions when attached to particle surfaces as there is both a steric and electrostatic contribution, i.e. the particles are electrosterically stabilised. In addition the origin of the electrostatic interactions is displaced away from the particle surface and the origin of the van der Waals attraction, reinforcing the stability. Kaolinite stabilised by poly(acrylic acid) is a combination that would be typical of a paper-coating clay system. Acrylic acid or methacrylic acid is often copolymerised into the latex particles used in cement sytems giving particles which swell considerably in water. Figure 3.23 illustrates a viscosity curve for a copoly(styrene-... 

The solvation of a sphere swells its volume above the dry volume, which is presumably what is used to evaluate . Therefore whatever factor describes the increase in particle volume due to solvation is absorbed into [rj]. This is easily seen as follows. Suppose the mass of colloidal solute in a solution is converted to the volume of unsolvated material using the dry density. In this way, mass/volume units are converted to volume/volume units, which we label dry since the unsolvated density was used in evaluating this quantity. If the solvation is uniform throughout the particle —as would be the case for, say, aqueous proteins —then the solvated particle exceeds the unsolvated particle in volume by the factor [1 + (m,, b/m2)(p2/ Pi)] as shown by Equation (2.38). Recall that in this expression, muh is the mass of bound solvent, m2 is the mass of the solute particle, and p, is the density of solvent or solute, as appropriate. Still assuming dry has been used to evaluate [17], we see... 

This difference is probably associated with the chain expansion and/or contraction relative to the interface between the blocks within the particular morphology. In analogy to solid inorganic materials whose solubility increases under external pressure and to colloid systems where the capillary pressure leads to an increase in the solubility (Ostwald ripening effect), one would intuitively expect larger swelling of... 

M. Manciu, E. Ruckenstein On possible microscopic origins of the swelling of neutral lipid bilayers induced by simple salts JOURNAL OF COLLOID AND INTERFACE SCIENCE 309 (2007) 56-67. 

A. Loxley and B. Vincent, Equilibrium and kinetic aspects of the pH swelling of poly(vinylpyridine) latex particles, Colloid Polymer Sci. 275, 1108-1114 (1997). 

This is an account of my own research work and conclusions in the field. I do not wish to slight other workers, and I have paid homage to the pioneers in the study of both clay swelling and colloid stability. I hope that this book will contribute significantly to the understanding of these subjects. 

Solubility, as well as the possibly related phenomenon of swelling, depends on the H bonding character of the solvent (or swelling agent). Indeed, the effect is not limited to proteins but also occurs for gelatin, cellulose, wood (1495), nylons, and probably for clays and other colloidal systems as well. Lloyd and co-workers discuss solubility and swelling of protein fibers (1250) (see, in fact, that entire discussion on swelling, 1252). 

Fig. 22 (A) Schematic illustration of Valrelease tablet, a swelling-activated drug-delivery system, and the hydration-induced formation of colloid gel barrier. (B) Comparison in the gastric residence profile between Valrelease with the conventional Valium capsule. (From Ref. l)...

Acute hypersensitivity reactions have been reported with the first infusion of pegylated liposomal doxorubicin (14,15). The symptoms included flushing, shortness of breath, facial swelling, headache, chills, back pain, tightness in the chest and throat, and hypotension. Similar reactions have been reported after the intravenous administration of colloid imaging agents and unloaded liposomes. 

Saponite occurs as a white to off-white, dull powder composed of fine-grained crystals of colloidal size. The material is greasy or soapy to the touch and swells on the addition of water. 

Ugelstad, J., Mork, P. C., Kaggemd, K. H., Ellingsen, T., Berge, A. Swelling of oligomer-polymer particles. New methods of preparation of emulsions and polymer dispersions, Adv. Colloid Interface Sci., 1980, 13, 101-140. 

Loxley, A. Vincent, B. Equilibrium and kinetic aspects of the pH-dependent swelling of poly (2-vinylpyridine-co-styrene) microgels. Colloid Polym. Sci. 1997, 275 (12), 1108-1114. 

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