Light- and neutron scattering experiment

However, the structure and composition of microdroplets in which the reaction takes place are not the only parameters controlling polymerisation. We shall see later that particles in the initial microemulsion cannot be considered as independent reactors since interparticle interactions play an important role. Small angle light and neutron scattering experiments have shown that these interactions are attractive [6.20]. There is a clear increase in these attractive interparticle forces as the proportion of acrylamide is raised. In particular, this has two consequences the second virial coefficient of osmotic pressure takes negative values the peak in the structure factor which characterises a hard sphere system is no longer present. 

Saric M, Dietsch H, Schurfcaiberger P (2006) In situ polymerisation as a route towards transparent nanocomposites Time-resolved light and neutron scattering experiments. Colloids Surf A Physicochem Eng Asp 291(1-3) 110-116... 

Sommer, C., Pedersen, J.S., Egelhaaf, S.U., Cannavacciuolo, L., Kohlbrecher, J., Schurtenberger, P. Wortnlike micelles as Equilibrium Polyelectrolytes light and neutron scattering experiments. Langmuir 2002, 18(7), 2495-2505. 

The colloidal properties of anionically prepared poly(styrene-g-ethylene oxide) graft copolymers were studied by Candau et al. in different water/toluene/ alcohol mixtures by light and neutron scattering, NMR, and viscometry [307-309]. Aggregation numbers depend on mixture compositions with the highest values attained for water-rich systems. The micelles formed seem to have a core and shell conformation, with PS cores, in all cases studied. Dialysis experiments showed that the enhanced water-oil solubility was due to preferential solvation of the two segregated components of the copolymers by the solvent mixture and not to one specific solvent entrapment as is the case of classical microemulsions. 

Performing light- or neutron-scattering experiments, we were able to measure on samples prepared below the gel point the exponents x, y and D. 

Spontaneous thermal fluctuations of the density, p r,t), the momentum density, g(r,t), and the energy density, e(r,t), are dynamically coupled, and an analysis of their dynamic correlations in the limit of small wave numbers and frequencies can be used to measure a fluid s transport coefficients. In particular, because it is easily measured in dynamic light scattering. X-ray, and neutron scattering experiments, the Fourier transform of the density-density correlation function - the dynamics structure factor - is one of the most widely used vehicles for probing the dynamic and transport properties of liquids [56]. 

Additional insights into the dynamics and structure of bimodal elastomers have been obtained by dynamic light-scattering experiments [129], neutron scattering experiments [130] and calculations [131], dual cross-linking system experiments [132], non-affine swelling [133], and the computer simulations already mentioned. 

The average DNA helix diameter used in modeling applications such as the ones described here includes the diameter of the atomic-scale B-DNA structure and— approximately—the thickness of the hydration shell and ion layer closest to the double helix [18]. Both for the calculation of the electrostatic potential and the hydrodynamic properties of DNA (i.e., the friction coefficient of the helix for viscous drag) a helix diameter of 2.4 nm describes the chain best [19-22]. The choice of this parameter was supported by the results of chain knotting [23] or catenation [24], as well as light scattering [25] and neutron scattering [26] experiments. 

While rheological measurements are wonderfully quantitative, they are usually poor qualitative probes of fluid structure. This is because in rheological experiments, the structural changes responsible for the measured relaxation behavior remain hidden. Thus, rheometry is often most useful when supplemented by other experimental methods that characterize fluid structure and flow-induced structural changes. Some of the most useful methods are microscopy, light, x-ray, and neutron scattering, and polarimetry. 

While complete ring closure is indicated by mass spectral and NMR analysis, characterization of 5 by X-ray and neutron scattering [133], and by dynamic light scattering experiments [134] suggested this polymer has... 

Polymer conformations are studied by various scattering experiments (light, small-angle X-ray and neutron scattering). These techniques are based on the contrast between the polymer and the surrounding media (solvent in the case of polymer solutions and other polymers in the case of polymer melts or blends). The contrast in light scattering arises from differences in refractive index between polymer and solvent, and the scattered intensity is proportional to the square of the refractive index increment dn/dc [see Eq. (1.86)]. 

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