Small angle neutron scattering measurements

Small angle neutron scattering measurements were carried out with the PACE diffractometer at the Laboratoire Leon Brillouin, (CE Saclay, France). The q range observed was 3.4 lO" to 0.2 A l. Samples were prepared in deuterated instead of ordinary water to achieve a suitable value for the neutron contrast factor. 

In t-DVB/S copolymerization, Antonietti and Rosenauer isolated microgels slightly below the macrogelation point [221]. Using small angle neutron scattering measurements they demonstrated that these microgels exhibit fractal behavior, i.e. they are self-similar like the critically branched structures formed close to the sol-gel transition. 

Hammermann, M., Brun, N., Klenin, K.V., May, R., Toth, K., and Langowski, J. (1998) Salt-dependent DNA superhelix diameter studied by small angle neutron scattering measurements and Monte Carlo simulations. Biophys. J. 75, 3057-3063. 

Maranzano, B. J. and Wagner, N. J. 2002. Flow-small angle neutron scattering measurements of colloidal dispersion microstructure evolution through the shear-thickening transition. J. Chem. Phys. 117 10291-10302. 

We can exploit mixtures of per-deuterated and per-hydrogenated polymers in small-angle neutron scattering measurements to reveal information on the configuration of individual chains as well as assemblies of chains in the case of phase separating blends, block copolymers, and other inhomo-... 

Small-Angle Neutron Scattering. Measurements were made as described previously (10, II) using a multidetector instrument installed in the PLUTO reactor at Harwell and also with the Dll instrument at the Institut Laue-Langevin, Grenoble, France. 

Small angle neutron scattering measurements of the anisotropy of the main chain conformation of a side-on sidechain LCE under a mechanical stress are described in the isotropic and in the nematic phase [45]. It is found that a weak anisotropy of the main chain conformation exists only in the nematic phase and for sufficiently high values of the elongation. 

As a test of the revised theory, further experiments were conducted [Zhao et al., 2005] on nematic solutions of a SCLCP. ER measurements indicated, via application of the Brochard hydrodynamic model, a slightly prolate conformation, R /R = 1.17 0.02, consistent with small-angle neutron scattering measurements, which indicated, that= 1.12 0.06. Observations of the shear stress transient response of a homeotropic monodomain indicated that at a concentration between 0.01 and 0.02 g/mL, the solution exhibited a transition from director-aligning to director-tumbling behavior. The latter result is inconsistent with the original Brochard model [see Eq. (1.94)], which predicts such a transition (i.e., Sas > 0) only for a polymer with an oblate shape but agrees with the modified theory [Eq. (1.96)]. 

The formation of micelles and the special ordered structure were identified by small-angle neutron scattering measurements in collaboration with Professor M. Shibayama of the University of Tokyo. 

To test this prediction of the crossover from mean-field to Ising-t5q)e behavior, very precise small-angle neutron scattering measurements were completed on blends of deuterated polystyrene (d-PS) and poly(vinyl methyl ether) (PVME) at the critical concentration for a series of temperatures as the one-phase mixture approaches the temperature of phase separation (ie, the critical point Tc in Fig. 7) (61). The data were analyzed by fitting the measured I (q) to the random phase approximation to estimate l(g=0) for each temperature, where the temperature is controlled to 0.01 K... 

The structure factor is proportional to the scattering intensity in small angle x-ray scattering or small angle neutron scattering measurements. It has a maximum occurring at x = 3.873, which corresponds to a wavenumber... 

The information about these systems obtained from diamagnetic and viscosity measurements [79], birefringence [72], [74], small angle neutron scattering measurements [73], nuclear magnetic resonance and relaxation [80], and scanning electron microscopy [81], patched together, led to a consistent picture about the polymer structure on all scales. 

Small angle neutron scattering measurements were made on samples with DO. When ILO is replaced by DO, the lower phase boundary changes slightly from ui/s = 1.0 to ui/s 0.95. The neutron scattering cross section can in the dilute case be written as... 

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