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Your search keyword '"Sokolov, Alexei P."' showing total 124 results
Start Over Author "Sokolov, Alexei P." Publisher american chemical society
124 results on '"Sokolov, Alexei P."'

31. Addition of Short Polymer Chains Mechanically Reinforces Glassy Poly(2-vinylpyridine)–Silica Nanoparticle Nanocomposites.

Author

Bocharova, Vera, Genix, Anne-Caroline, Carrillo, Jan-Michael Y., Kumar, Rajeev, Carroll, Bobby, Erwin, Andrew, Voylov, Dmitry, Kisliuk, Alexander, Wang, Yangyang, Sumpter, Bobby G., and Sokolov, Alexei P.

Abstract

The addition of hard fillers to a polymer matrix is a well-known process for achieving mechanical reinforcement. With a decrease in the size of the fillers, the contribution from polymer–particle nanometer-sized interfaces becomes significant, and these interfaces affect the mechanical performance of polymer nanocomposites (PNCs) beyond the limits established for conventional composites. However, the molecular mechanisms underlying the improvement in the mechanical performance of glassy PNCs remain unresolved, necessitating a deeper understanding of the structure–property relationships in these intrinsically heterogeneous systems. In this effort, by using Brillouin light scattering (BLS) and dynamic mechanical analysis (DMA), we demonstrated that adding shorter chains to a PNC prepared with high molecular weight polymers significantly improved the mechanical properties of the PNC in the glassy state. The strongest enhancement of mechanical properties occurred at an optimum concentration of short chains. This is in contrast to the behavior of the glass transition temperature of PNCs which shows a monotonic decrease with an increase in the concentration of shorter chains. Using experimental data and coarse-grained molecular dynamics (MD) simulations, we have identified the molecular mechanism leading to the observed nonmonotonic changes in mechanical reinforcement. This mechanism includes changes in the nanoscale organization at the interface combined with chain stretching amplified by the addition of the short chains. Overall, our approach paves a simple and cost-effective pathway to fabricating glassy PNCs with significantly improved mechanical properties that will fill various practical needs. [ABSTRACT FROM AUTHOR]

Published
2020
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32. Wrapping of single-walled carbon nanotubes by a [pie]-conjugated polymer: the role of polymer conformation-controlled size selectivity

Author

Wenhui Yi, Malkovskiy, Andrey, Qinghui Chu, Sokolov, Alexei P., Colon, Marisabel Lebron, Meador, Michael, and Yi Pang

Subjects
Fluorescence -- Evaluation, Nanotubes -- Structure, Nanotubes -- Electric properties, Nanotubes -- Chemical properties, Polymers -- Chemical properties, Polymers -- Electric properties, Polymers -- Spectra, Raman spectroscopy -- Usage, Chemicals, plastics and rubber industries
Published
2008

33. Dynamic transition in tRNA is solvent induced

Author

Caliskan, Gokhan, Briber, Robert M., Thirumalai, D., Garcia-Sakai, Victoria, Woodson, Sarah A., and Sokolov, Alexei P.

Subjects
Transfer RNA -- Research, Neutrons -- Scattering, Neutrons -- Analysis, Chemistry
Abstract

The dynamics of tRNA are measured by using neutron scattering to assess if a universal mechanism drives the dynamical transition in biomolecules. The result supports the idea that unfreezing the translation of solvent molecules is the main cause of the dynamic transition in biomolecules and also indicates that the rotation of methyl groups is not the main cause of the dynamic transition.

Published
2006

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