Blob scattering

As shown by Pedersen and Svaneborg, the scattering from the swollen PEO polymer chains in the corona (the blob scattering), can be written as [74,80,81,86] ... 

Thereby, (j) is the volume fraction of polymer in solution (as aggregates), Vc is the fraction of the crystallizable segment in the polymer, R is the lateral dimension of the lamellae (discs) and D x) denotes the Dawson function. The second term in Eq.5 arises from the polymeric structure of the brush (the "blob" scattering). P(Q) is the form factor of the density profile perpendicular to the lamellae surface including the contrast factors of the core and the brush parts and the density profiles of the polymer volume fraction. The form factor of an infinitely large plate of the thickness d considering a simple rectangular density profile is... 

Partial scattering function for fluctuation or blob scattering... 

Scattering from Polymer Brushes - Blob Scattering... 

Therefore Sbb. Sbc, and Sec are the experimentally obtained partial scattering fimctions and Sbb(Q) is the partial scattering function for fluctuation or blob scattering. Equation 36 assmnes an experiment under brush contrast. 

Equation (22) has been confirmed by a variety of techniques including neutron scattering, dynamic light scattering, and osmotic pressured measurements [23]. As concentration increases the concentration blob decreases in size until the Kuhn length is reached and the coil displays concentrated or melt Gaussian structure. The coil accommodates concentrations between the overlap and concentrated through adjustment of the concentration blob size. 

Finally, momentum defines a length scale r 1 jq% and evaluating scattering functions for large momenta, i.e. looking for correlations deep inside a blob, we should choose... 

Chatterjee310 have proposed to take the upper limit to be 1.6 keV, which is the energy of an electron below which elastic scattering becomes efficient. According to Magee and Chatterjee, a blob can be considered as an ellipsoid. 

Diffusion coefficient from dynamic light scattering for dilute polystyrene solutions in the good solvent toluene (open circles). The lines show the limiting power laws with slopes expected by Eq. (8.23) (i/=ij2 inside the thermal blob and i/ = 0.588 at higher molar--------... 

The experimental form factor P( ) shown in Fig. 12a can be expressed as P q) = [bcFc q,rc) + bsFs q,rc,R )], where bc,bs are the contrast factors for the core (c) and shell (5) with core radius and overall micelle radius R, whereas Fc q), F q) aiQ the scattering amplitudes of the core and shell, respectively. Under core contrast conditions (Z s 0), the expected first minimum for the compact sphere at high q values falls outside the ("/-range, whereas under shell contrast conditions the power-law behavior arising from blob (swollen PEO shell) scattering is observed. Hence, the dual colloid-polymer character of the particle is clearly reflected in Fig. 12a. 

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