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Your search keyword '"Zbaida, David"' showing total 23 results
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23 results on '"Zbaida, David"'

22. Surface functionalization of WS2 fullerene-like nanoparticles.

Author

Shahar C, Zbaida D, Rapoport L, Cohen H, Bendikov T, Tannous J, Dassenoy F, and Tenne R

Abstract

WS(2) belongs to a family of layered metal dichalcogenide compounds that are known to form cylindrical (inorganic nanotubes-INT) and polyhedral nanostructures--onion or nested fullerene-like (IF) particles. The outermost layers of these IF nanoparticles can be peeled under shear stress, thus IF nanoparticles have been studied for their use as solid lubricants. However, the IF nanoparticles tend to agglomerate, presumably because of surface structural defects induced by elastic strain and curvature, a fact that has a deleterious effect on their tribological properties. In the present work, chemical modification of the IF-WS(2) surface with alkyl-silane molecules is reported. The surface-modified IF nanoparticles display improved dispersion in oil-based suspensions. The alkyl-silane coating reduces the IF-WS(2) nanoparticles' tendency to agglomerate and consequently improves the long-term tribological behavior of oil formulated with the IF additive.

Published
2010
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23. Synthetic mimic of selective transport through the nuclear pore complex.

Author

Caspi Y, Zbaida D, Cohen H, and Elbaum M

Subjects
Biomimetic Materials chemistry, DNA chemistry, Biomimetic Materials chemical synthesis, Biomimetic Materials metabolism, Nuclear Pore metabolism
Abstract

The nuclear pore complex is a large protein channel present universally in eukaryotic cells. It generates an essential macromolecular separation between the nucleus and cytoplasm. The transport mechanism relies on recognition of molecular cargos by receptor proteins, and on specific interaction between the receptors and the pores. We present a chemical mimic of this "receptor-mediated" transport using modified nanoporous membrane filters, polyisopropylacrylamide as the carrier molecule, or receptor, and single-stranded DNA as the cargo. We show that a complex of ssDNA and polyisopropylacrylamide diffuses faster through the modified pores than does the bare ssDNA, in spite of the larger size of the complex. The mobile polymer thus acts as a soluble receptor to usher a macromolecular cargo specifically through the pores.

Published
2008
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