No abstract

No abstract

No abstract

No abstract

No abstract

Highly stable and reproducible molecular-colloidal water solutions of C60 fullerenes (FWS) obtained by transferring fullerenes from an organic solution into an aqueous phase with the help of ultrasonic treatment are investigated by means of small-angle neutron scattering (SANS). A polydispersity in the size of detected particles up to 84 nm is revealed. These particles are slightly anisotropic and have a characteristic size of approximately 70 nm. Along with it, there are some indications that a significant part of fullerenes composes particles with the size of the order of 1 nm. The contrast variation based on mixtures of light and heavy water shows that the mean scattering length density of the particles is close to that of the packed fullerene associates as well as that the characteristic size of possible fluctuations of the scattering length density within the particles does not exceed 2 nm. A smooth surface resulting in the Porod law for the scattering is detected. A number of models discussed in the literature are considered with respect to the SANS data.

Aggregates of nanodiamond particles dispersed in polar liquids (H 2 O and DMSO) upon undergoing a special milling procedure are studied by small-angle neutron scattering at a scale of 1-100 nm. The size and fractal character of the aggregates as well as the structural features of nanodiamond particles (size, surface) are compared for both solutions. The structural difference between liquid dispersions and initial nanodiamond powder is analyzed. The concentration effect is followed within an interval of 0.2-10 wt % to conclude about the interaction of the aggregates. It is shown that the developed structure of the aggregates allows their interpenetration in concentrated solutions. The contrast variation procedure using mixtures of nondeuterated and deuterated solvents is performed to judge the homogeneity of the aggregates and to find out their mean scattering length density. The existence of a nondiamond component in the particles is discussed on the basis of the scattering data.

New model of separated form factors is proposed for the evaluation of small-angle neutron scattering curves from large unilamellar vesicles. The validity of the model was checked by comparison to the model of hollow sphere. The model of separated form factors and hollow sphere model give reasonable agreement in the evaluation of vesicle parameters.Comment: LaTeX: 3 pages, 1 figure, 14 references; submitted to Applied Physics