Small-Angle Neutron Scattering Study of Poly(oxyethylene)-block-poly(oxypropylene)-block-poly(oxyethylene) in Aqueous Solutions

1993 ◽  
Vol 58 (10) ◽  
pp. 2428-2436 ◽  
Author(s):  
Herman Pospíšil ◽  
Josef Pleštil ◽  
Zdeněk Tuzar

Solutions of a triblock copolymer, poly(oxyethylene)-block-poly(oxypropylene)-block-poly(oxyethylene) (POE-POP-POE), in deuterated water were studied by small-angle neutron scattering (SANS) in the temperature range from 20 to 45 °C. Radius of gyration, molecular weight, second virial coefficient for both unimers and micelles, critical micelle concentration and unimer concentration were determined from the scattering data. Under assumption of the spherical core/shell micellar model structural parameters were estimated. Degree of swelling of the micellar core was evaluated from the mean-square fluctuation of scattering density.

1986 ◽  
Vol 79 ◽  
Author(s):  
L. B. Shih ◽  
M. H. Luccas ◽  
S. H. Chen ◽  
T. L. Lin

AbstractWe present an asymototic analysis of small angle neutron scattering data of a comb-shaped charged copolymer, poly (1-octadecene-co-maleic anhydride), in D20. It is shown that at full ionization, the coRolymer self-asso iate to form cylindrical shape micelles with a radius 26Å and length 101 Å. The number of repeating units per micelle is calculated to be 200 and the hydration number 15 per repeating unit. The dimension of the cylinder remains approximately constant over the concentration range studied.


1994 ◽  
Vol 359 ◽  
Author(s):  
K.A. Affholter ◽  
G.J. Bunick ◽  
J.M. Desimone ◽  
M.O. Hunt ◽  
Y.Z. Menceloglu ◽  
...  

ABSTRACTSmall-angle neutron scattering (SANS) can structurally characterize fullerenes1in solvents with strong SANS contrast (e.g. CS2). Deuterated solvents (e.g. toluene-d8) have a high scattering length density (SLD), which is close to that of C60and C70moieties. Hence, there is virtually no SANS contrast with the solvent and these particles are practically “invisible” in such media. On the other hand, the negative scattering length of hydrogen means that the SLD of H1-containing materials is much lower, so they have strong contrast with toluene-d8. Thus, SANS makes it possible to study the size and shapes of modified buckyballs such as the polymer-substituted fullerenes, or flagellenes2. These consist of C60cores to which 1-4 polystyrene chains (with a molecular weight, MW ≃ 2000) are attached. The extrapolated cross section at zero angle of scatter [dΣ/dΩ(0)]s is a function of the number of pendant chains, so SANS can be used to assess the number of “arms” which are covalently attached to the fullerene “sphere”. Close agreement (± 4%) between the measured and calculated values of dΣ/dΩ(0) along with independent estimates of the radius of gyration (Rg) and second virial coefficient (A2) for a calibration linear polystyrene sample serves as a cross check on the validity of this methodology.


2003 ◽  
Vol 36 (1) ◽  
pp. 117-124 ◽  
Author(s):  
Timofei Krouglov ◽  
Ignatz M. de Schepper ◽  
Wim G. Bouwman ◽  
M. Theo Rekveldt

Spin-echo small-angle neutron scattering (SESANS) is a novel real-space scattering technique. SESANS measures a correlation-like functionG(Z), the meaning of which was unknown until now. Here a direct real-space interpretation ofG(Z) through the particle scattering density and pair correlation function is given. One-dimensional and two-dimensional SESANS are compared. The case of non-interacting particles is considered in detail with an explicit geometrical interpretation. General methods for the calculation of structural parameters, such as the total scattering length and the radius of gyration, are developed. Analytical expressions ofG(Z) for non-interacting solid spheres, hollow spheres and Gaussian coils are derived. The case of solid spheres is compared with experimental data.


2011 ◽  
Vol 44 (5) ◽  
pp. 1120-1122 ◽  
Author(s):  
Dazhi Liu ◽  
Kunlun Hong ◽  
Carrie Y. Gao ◽  
Yuri Melnichenko ◽  
Ken Littrell ◽  
...  

Initial experimental results are reported from the extendedQ-range small-angle neutron scattering (EQ-SANS) diffractometer at the Spallation Neutron Source at Oak Ridge National Laboratory (ORNL). A generation-8 polyamidoamine dendrimer was measured and the conformation parameters (radius of gyration, thickness of the soft shelletc.) extracted by model fitting to the scattering data. The results are compared with data collected at the general-purpose small-angle neutron scattering (GP-SANS) beamline at the High-Flux Isotopic Reactor at ORNL and show that EQ-SANS is ready for scientific studies for the small-angle neutron scattering community.


Langmuir ◽  
1999 ◽  
Vol 15 (2) ◽  
pp. 293-296 ◽  
Author(s):  
Hideki Matsuoka ◽  
Takashi Ikeda ◽  
Hitoshi Yamaoka ◽  
Mitsuhiro Hashimoto ◽  
Toshio Takahashi ◽  
...  

2017 ◽  
Vol 3 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Gilles E. Möhl ◽  
Ezzeldin Metwalli ◽  
Renaud Bouchet ◽  
Trang N. T. Phan ◽  
Robert Cubitt ◽  
...  

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