title: Structured water in polyelectrolyte dendrimers: understanding small angle neutron scattering results through atomistic simulation.
abstract: Based on atomistic molecular dynamics (MD) simulations, the small angle neutron scattering (SANS) intensity behavior of a single generation-4 polyelectrolyte polyamidoamine starburst dendrimer is investigated at different levels of molecular protonation. The SANS form factor, P(Q), and Debye autocorrelation function, γ(r), are calculated from the equilibrium MD trajectory based on a mathematical approach proposed in this work. The consistency found in comparison against previously published experimental findings (W.-R. Chen, L. Porcar, Y. Liu, P. D. Butler, and L. J. Magid, Macromolecules 40, 5887 (2007)) leads to a link between the neutron scattering experiment and MD computation, and fresh perspectives. The simulations enable scattering calculations of not only the hydrocarbons but also the contribution from the scattering length density fluctuations caused by structured, confined water within the dendrimer. Based on our computational results, we explore the validity of using radius of gyration R(G) for microstructure characterization of a polyelectrolyte dendrimer from the scattering perspective.
authors.affiliation: Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Bin
authors.initials: B
authors.lastname: Wu
authors.forename: Boutheïna
authors.initials: B
authors.lastname: Kerkeni
authors.forename: Takeshi
authors.initials: T
authors.lastname: Egami
authors.forename: Changwoo
authors.initials: C
authors.lastname: Do
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Wang
authors.forename: Lionel
authors.initials: L
authors.lastname: Porcar
authors.forename: Kunlun
authors.initials: K
authors.lastname: Hong
authors.forename: Sean C
authors.initials: SC
authors.lastname: Smith
authors.forename: Emily L
authors.initials: EL
authors.lastname: Liu
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Smith
authors.forename: Wei-Ren
authors.initials: WR
authors.lastname: Chen