Dynamic light scattering polydispersity

Dynamic light scattering Polydispersity and oligomeric state... 

DWS addresses dynamic light scattering in the multiple scattering concentration range. Pine et. al. [326] describe the theory for the technique and it has been applied to the determination of mean size and polydispersity [327,328]. The method has also been used for on-line measurement of concentrated suspensions [329]. 

Anticipating further discussions on micro-emulsions, planned for volume V, it is noted that k, or k, or the combination (2kj -i- k ) can also be obtained using scattering techniques or, preferably, combinations thereof. For instance, neutron spin echo spectroscopy (NSES) can be combined with small-angle neutron scattering (SANS) or with dynamic light scattering. Alternatively, 2k + k can be obtained from the polydispersity of the micro-emulsion and then a second type of... 

Size the liposomes by extrusion to an average size of 150 nm and a polydispersity index below 0.2 (see Note 1). Size distribution should be checked with dynamic light scattering. 

Pusey PN, Fijnaut HM, Vrij A. Mode amplitudes in dynamic light scattering by concentrated liquid suspensions of polydisperse hard spheres. J Chem Phys 1982 77 4270-4281. 

Dynamic light scattering. Dynamic light scattering measurements provide the electric field correlation function g(q, t), which can be expressed for a polydisperse system of particles as (see [90,91])... 

With regard to the polydispersity these quantities show a behavior opposite to that of the scattering functions. While the curves of Pz(q) become flatter with rising polydispersity, the angular dependence of Rl , p(q) increases (see [80]). Therefore the combination of static and dynamic light scattering provides reliable information about the polydispersity of the systems under study. Additional information on the polydispersity comes from the second cumulant and the inverse Laplace transform. 

Figure 3.2.6). Narrowly dispersed polystyrene (synthesized by atom transfer radical polymerization [polydispersity < 1.1]) was end fnnctionized with a phosphonate moiety that binds strongly to titanium oxide. The combination of narrowly dispersed titanium oxide and narrowly dispersed phosponate-terminated polystyrene generates a narrowly dispersed core-shell architecture as measured by dynamic light scattering, which can be spun into dielectric films. The covalent coating of polystyrene around titanium oxide is helpful at preventing aggregation of the nanoparticles in organic dispersion and in thin films.

Dynamic light scattering allows measurement of the translational diffusion coefficient A of particles. For noninteracting particles, the first-order autocorrelation function g r) is directly proportional to A- Polydisperse systems are analyzed using the method of cumulants, in which a distribution of exponential terms C(r) is assumed ... 

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