title: Growth Kinetics of Polyelectrolyte Complexes Formed from Oppositely-Charged Homopolymers Studied by Time-Resolved Ultra-Small-Angle X-ray Scattering.
abstract: We have monitored the kinetic process of polyelectrolyte complex formation between sodium polyacrylate (SPA) and polyallylamine hydrochrolide (PAH) in aqueous NaCl solution by time-resolved ultra-small-angle X-ray scattering (TR-USAXS) combined with rapid mixing. SPA and PAH with different NaCl concentrations from 0 to 1 M were rapidly mixed in equimolar concentration of the monomer units using a stopped-flow apparatus with a dead time of about 2.5 ms. Within the dead time, percolated aggregate-like structures were observed suggesting that the initially formed small charge neutral aggregates further assembled to form higher order agglomerates. The early stage time evolution of the molar mass of the global structure in the presence of NaCl was found to be comparable to the Brownian-coagulation rate.
authors.affiliation: ESRF-The European Synchrotron, 71 Avenue des Martyrs, F-38043 Grenoble, France.|Department of Macromolecular Science, Osaka University , 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan.
authors.forename: Rintaro
authors.identifier: http://orcid.org/0000-0003-2168-9436
authors.initials: R
authors.lastname: Takahashi
authors.affiliation: ESRF-The European Synchrotron, 71 Avenue des Martyrs, F-38043 Grenoble, France.
authors.forename: Theyencheri
authors.initials: T
authors.lastname: Narayanan
authors.affiliation: Department of Macromolecular Science, Osaka University , 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan.
authors.forename: Takahiro
authors.identifier: http://orcid.org/0000-0002-8213-7531
authors.initials: T
authors.lastname: Sato