Chain Colloid

Stearns, R.S., Oppenheimer, H., Simon, E., Harkins, W.D. (1947) Solubilization by solutions of long chain colloidal electrolytes. J. Chem. Phys. 15, 496-507. 

Solutions of soaps and other long-chain Colloidal electrolytes. The surface tension of soaps has been very extensively studied,1 but for the most part the results in the literature are discordant far beyond the usual error of measurement of surface tension. In general the surface tension diminishes rapidly with increasing concentration, reaching a steady, or nearly steady, low value after a certain concentration is reached this concentration is naturally lower the longer the hydrocarbon chain. The variation between the results obtained by different experimenters, and even by the same experimenter under different conditions, may... 

Stability of isolated liquid films soap films foams. Pure liquids rarely, if ever, foam, but most solutions of capillary active substances do so to a greater or less extent, and long-chain colloidal electrolytes, particularly the soaps, have an almost miraculous power of rendering liquid films stable. Dewar1 has maintained soap films unbroken for over a year (one for three years ), with due precautions against evaporation, mechanical and thermal shocks, and absorption of carbon dioxide. 

Solutions of soaps and other long-chain colloidal electrolytes... 

Higuchi M, Minoura N, Kinoshita T. 1995b. Photo responsive behavior of a monolayer composed of an azobenzene containing polypeptide in the main chain. Colloid Pol Sci 273(11) 1022 1027. 

Stoll, S. and Buffle, J. (1998). Computer simulation of flocculation processes the roles of chain conformation and chain/colloid concentration ratio in the aggregate stmctures. J. Colloid Interface Sci., 205,290-300. 

Steams, R.S., H. Oppenheimer, E. Simon, and W.D. Harkins. Solrrbilization by Solutiorrs of Long-Chain Colloidal Electrolytes, J. Chem. Phys., 15(7) 496-507 (1947). 

Matrab, T., Chancolon, ]., L hermite, M.M, Rouzaud, J.-N., Deniau, G., Boudou, J.P, Chehimi, M.M., and Delamar, M. (2006) Atom transfer radical polymerization (ATRP) initiated by aryl diazonium salts a new route for surfiice modification of multiwalled carbon nanotubes by tethered polymers chains. Colloid. Surf., A, 287 (1-3), 217-221. 

Hibiya, K., Tsuneda, S. and Hirata, A. 2000. Formation and characteristics of nitrifying biofllm on a membrane modified with positively-charged polymer chains. Colloids and Surfaces B Biointerfaces, 18,105-112. 

Soft paraffin behaves rheologically as a gel (plastic). In a physical sense it is described as a colloidal system (hydrocarbon gel) of long chains colloidally dispersed in shorter chains. 

BroveUi, D., Caseri, W.R., and Hahner, G. (1999) Self-assembled monolayers of alkylammonitun ions on mica Direct determination of the orientation of the alkyl chains. /. Colloids Intetface Sci., 216, 418-423. 

Nakahara H and Fukuda K 1983 Orientation of chromophores in monolayers and multilayers of azobenzene derivatives with long alkyl chains J. Colloid Interface Sol. 93 530-9... 

In many colloidal systems, both in practice and in model studies, soluble polymers are used to control the particle interactions and the suspension stability. Here we distinguish tliree scenarios interactions between particles bearing a grafted polymer layer, forces due to the presence of non-adsorbing polymers in solution, and finally the interactions due to adsorbing polymer chains. Although these cases are discussed separately here, in practice more than one mechanism may be in operation for a given sample. 

The first case concerns particles with polymer chains attached to their surfaces. This can be done using chemically (end-)grafted chains, as is often done in the study of model colloids. Alternatively, a block copolymer can be used, of which one of the blocks (the anchor group) adsorbs strongly to the particles. The polymer chains may vary from short alkane chains to high molecular weight polymers (see also section C2.6.2). The interactions between such... 

The second case involves non-adsorbing polymer chains in solution. It was realized by Asakura aird Oosawa (AO) [50] aird separately by Vrij [51] tlrat tlrese chains will give rise to air effective attraction between colloidal particles. This is kirowir as depletion attraction (see figure C2.6.4. We will summarize tire AO tlreory to explain tlris. 

In section C2.6.4.3 it was shown how tlie addition of non-adsorbing polymer chains induces a depletion attraction between colloidal particles. If sufficient polymer is added, tliese attractions can be strong enough to induce a phase separation of tire colloidal particles. An early application of tliis was tire creaming of mbber latex [93]. 

A typical recipe for batch emulsion polymerization is shown in Table 13. A reaction time of 7—8 h at 30°C is requited for 95—98% conversion. A latex is produced with an average particle diameter of 100—150 nm. Other modifying ingredients may be present, eg, other colloidal protective agents such as gelatin or carboxymethylcellulose, initiator activators such as redox types, chelates, plasticizers, stabilizers, and chain-transfer agents. 

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