Soft Particles

Sheiko SS, Moller M (2001) Hyperbranched Macromolecules Soft Particles with Adjustable Shape and Capability to Persistent Motion. 212 137-175 Shen B (2000) The Biosynthesis of Aromatic Polyketides. 209 1-51 Shinkai S, see James TD (2002) 218 159-200 Shirakawa E, see Hiyama T (2002) 219 61-85 Shogren-Knaak M, see Imperial B (1999) 202 1-38 Sinou D (1999) Metal Catalysis in Water. 206 41-59... 

Ohshima H. Primary Electroviscous Effect in a Dilute Suspension of Soft Particles. Langmuir 2008, 24, 6453-6461. 

It applies specifically to soft spheres and discusses the flocculation in terms of interpenetration of free polymer coils with the polymer sheaths surrounding the particles. Beyond a certain polymer concentration, the interpenetration of two polymer sheaths is easier than the mutual interpenetration of free polymer and attached polymer, resulting in attraction between the soft particles. 

One may wonder to what extent our predictions for hard spheres apply to a system of soft particles in a polymer solution. A definite answer to this question cannot be given at the moment since numerical data for the depletion of free polymer chains in the neighbourhood of a surface with terminally attached chains are not yet available. Some qualitative features for such a system have been discussed using scaling arguments (24). We may expect that the depleted amount of polymer is, at least in some cases, less than near a hard surface, giving rise to weaker attraction. Both the destabilization concentration (J) and the restabilisation concentration (<(> ) could be much lower. Experimental observations support this qualitative conclusion (1-5). 

For some soft particles effective anchoring may require covalent grafting of the incompatible PS blocks to the core polymer. 

Hyperbranched Macromolecules Soft Particles with Adjustable Shape and Persistent Motion Capability... 

The effect of the column diameter on the shapes of elution curves was studied with the use of hard particles (Toyopcarl IIW55F) for gel chromatography [7] and soft particles (Matrix Blue A) for affinity chromatography [8]. The results showed that Hs did not vary for column diameters of 1.0-9.0 cm in the former case, nor for column diameters of 1.65-18.4cm in the latter case. 

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