Competition of the connectivity with the local and the global order in polymer melts and crystals

Bernini, S.; Puosi, F.; Barucco, M.

doi:10.1063/1.4828725

Title: Competition of the connectivity with the local and the global order in polymer melts and crystals

Full Record
Other Related Research

Abstract

The competition between the connectivity and the local or global order in model fully flexible chain molecules is investigated by molecular-dynamics simulations. States with both missing (melts) and high (crystal) global order are considered. Local order is characterized within the first coordination shell (FCS) of a tagged monomer and found to be lower than in atomic systems in both melt and crystal. The role played by the bonds linking the tagged monomer to FCS monomers (radial bonds), and the bonds linking two FCS monomers (shell bonds) is investigated. The detailed analysis in terms of Steinhardt's orientation order parameters Q{sub l} (l = 2 − 10) reveals that increasing the number of shell bonds decreases the FCS order in both melt and crystal. Differently, the FCS arrangements organize the radial bonds. Even if the molecular chains are fully flexible, the distribution of the angle formed by adjacent radial bonds exhibits sharp contributions at the characteristic angles θ ≈ 70°, 122°, 180°. The fractions of adjacent radial bonds with θ ≈ 122°, 180° are enhanced by the global order of the crystal, whereas the fraction with 70° ≲ θ ≲ 110° is nearly unaffected by the crystallization. Kink defects, i.e., large lateralmore »« less

Authors:: Bernini, S.; Puosi, F.; Barucco, M.

Publication Date:: Thu Nov 14 00:00:00 EST 2013

OSTI Identifier:: 22251465

Resource Type:: Journal Article

Journal Name:: Journal of Chemical Physics

Additional Journal Information:: Journal Volume: 139; Journal Issue: 18; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606

Country of Publication:: United States

Language:: English

Subject:: 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CRYSTALLIZATION; CRYSTALS; MOLECULAR DYNAMICS METHOD; MONOMERS; ORDER PARAMETERS; POLYMERS; SIMULATION

Citation Formats


                    Bernini, S., Puosi, F., Barucco, M., and Leporini, D., E-mail: dino.leporini@df.unipi.it. Competition of the connectivity with the local and the global order in polymer melts and crystals.  United States: N. p., 2013. 
        Web.  doi:10.1063/1.4828725.

Copy to clipboard


                    Bernini, S., Puosi, F., Barucco, M., & Leporini, D., E-mail: dino.leporini@df.unipi.it. Competition of the connectivity with the local and the global order in polymer melts and crystals.  United States.  https://doi.org/10.1063/1.4828725

Copy to clipboard


                    Bernini, S., Puosi, F., Barucco, M., and Leporini, D., E-mail: dino.leporini@df.unipi.it. 2013.  
        "Competition of the connectivity with the local and the global order in polymer melts and crystals".  United States.  https://doi.org/10.1063/1.4828725.

Copy to clipboard


                    
@article{osti_22251465,

  title        = {Competition of the connectivity with the local and the global order in polymer melts and crystals},

  author       = {Bernini, S. and Puosi, F. and Barucco, M. and Leporini, D., E-mail: dino.leporini@df.unipi.it},

  abstractNote = {The competition between the connectivity and the local or global order in model fully flexible chain molecules is investigated by molecular-dynamics simulations. States with both missing (melts) and high (crystal) global order are considered. Local order is characterized within the first coordination shell (FCS) of a tagged monomer and found to be lower than in atomic systems in both melt and crystal. The role played by the bonds linking the tagged monomer to FCS monomers (radial bonds), and the bonds linking two FCS monomers (shell bonds) is investigated. The detailed analysis in terms of Steinhardt's orientation order parameters Q{sub l} (l = 2 − 10) reveals that increasing the number of shell bonds decreases the FCS order in both melt and crystal. Differently, the FCS arrangements organize the radial bonds. Even if the molecular chains are fully flexible, the distribution of the angle formed by adjacent radial bonds exhibits sharp contributions at the characteristic angles θ ≈ 70°, 122°, 180°. The fractions of adjacent radial bonds with θ ≈ 122°, 180° are enhanced by the global order of the crystal, whereas the fraction with 70° ≲ θ ≲ 110° is nearly unaffected by the crystallization. Kink defects, i.e., large lateral displacements of the chains, are evidenced in the crystalline state.},

  doi          = {10.1063/1.4828725},

  url          = {https://www.osti.gov/biblio/22251465},
  journal      = {Journal of Chemical Physics},

  issn         = {0021-9606},

  number       = 18,

  volume       = 139,

  place        = {United States},

  year         = {Thu Nov 14 00:00:00 EST 2013},

  month        = {Thu Nov 14 00:00:00 EST 2013}

}

Copy to clipboard

Journal Article:

https://doi.org/10.1063/1.4828725

Other availability

Find in Google Scholar

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

Similar records in OSTI.GOV collections:

Pitfalls of molecular replacement: The structure determination of an immunoglobulin light-chain dimer

Journal Article Huang, D; Ainsworth, C; Schiffer, M; ... - Acta Crystallographica

The structure of protein Cle, a human light-chain dimer from the {lambda}III subgroup, was determined using 2.6 {angstrom} data; the R value is 18.4%. The structure was solved, after a false start, by molecular replacement with the {lambda}II/V Mcg protein as a search structure. When the refinement did not proceed beyond an R value of 27%, it was discovered that while the constant domains were in their correct positions in the unit cell, the incorrect variable domains were used for defining the molecule. The correct solution required a rotation of 180{degrees} around the local twofold axis that relates the twomore »« less
https://doi.org/10.1107/S090744499600813X
Molecular dynamics simulations of n-alkane melts confined between solid surfaces

Journal Article Winkler, R; Gerstmair, A; Reineker, P - International Journal of Quantum Chemistry

Molecular dynamics simulations of polyethylene chains (C{sub n}H{sub 2n+2} for n = 13, 16, 28, 60) have been carried out to investigate both equilibrium and dynamic properties of polymer melts confined between flat solid surfaces. The authors observe an oscillatory monomer density in the direction normal to the solid surfaces, which depends on the size of the monomers (i.e., on the volume density of the system). The packing manner of monomer segments, segment orientation, and local conformations of chains are found to be independent of chain length. In addition, preferential interfacial adsorption of chain ends is observed. The chains aremore »« less
https://doi.org/10.1002/qua.560520216
Molecular structure of vapor-deposited amorphous selenium

Journal Article Goldan, Amirhossein; Li, Chen; Pennycook, Stephen; ... - Journal of Applied Physics

The structure of amorphous selenium is clouded with much uncertainty and contradictory results regarding the dominance of polymeric chains versus monomer rings. The analysis of the diffraction radial distribution functions are inconclusive because of the similarities between the crystalline allotropes of selenium in terms of the coordination number, bond length, bond angle, and dihedral angle. Here, we took a much different approach and probed the molecular symmetry of the thermodynamically unstable amorphous state via analysis of structural phase transformations. We verified the structure of the converted metastable and stable crystalline structures using scanning transmission electron microscopy. In addition, given thatmore »« less
Cited by 59
https://doi.org/10.1063/1.4962315

Full Text Available
Structure of the concanavalin A--methyl. cap alpha. -D-mannopyranoside complex at 6-A resolution

Journal Article Hardman, K; Ainsworth, C - Biochemistry; (United States)

The carbohydrate binding site of concanavalin A has been identified in crystals of the concanavalin A-methyl ..cap alpha..-D-mannopyranoside complex and is 35 A from the iodophenol binding site (K. D. Hardman and C. F. Ainsworth (1973), Biochemistry 12, 4442), which has been postulated to be adjacent to the carbohydrate-specific binding site (Edelman et al. (1972), Proc. Natl. Acad. Sci. U.S.A. 69, 2580). The crystals are orthorhombic in space group C222/sub l/ and crystal density measurements indicate a protein mass of four monomers (molecular weight of 104,000) per asymmetric unit. However, the electron density map contains eight monomers/asymmetric unit, revealing latticemore »« less
Crystal structure of a self-assembling lipopeptide detergent at 1.20 Å

Journal Article Ho, Dona; Pomroy, Neil; Cuesta-Seijo, Jose; ... - Proc. Natl. Acad. Sci. USA

Lipopeptide detergents (LPDs) are a new class of amphiphile designed specifically for the structural study of integral membrane proteins. The LPD monomer consists of a 25-residue peptide with fatty acyl chains linked to side chains located at positions 2 and 24 of the peptide. LPDs are designed to form {alpha}-helices that self-assemble into cylindrical micelles, providing a more natural interior acyl chain packing environment relative to traditional detergents. We have determined the crystal structure of LPD-12, an LPD coupled to two dodecanoic acids, to a resolution of 1.20 {angstrom}. The LPD-12 monomers adopt the target conformation and associate into cylindricalmore »« less
https://doi.org/10.1073/pnas.0801941105

Similar Records