title: Microphase separation induced by interfacial segregation of isotropic, spherical nanoparticles.
abstract: In a recent experiment by Chung et al. [Nano Lett. 5, 1878 (2005)] and simulation by Stratford et al. [Science 309, 2198 (2005)] on immiscible blends containing nanoscale particles, it was shown that the phase separation of the two polymers can be prevented as a result of the aggregation of the nanoparticles at the interfaces between the two polymers. Motivated by these studies, we performed large scale systematic simulations, based on the dissipative particle dynamics approach, on immiscible binary (A-B) fluids containing moderate volume fractions of isotropic nanoscale spherical particles N. The nanoparticles preferentially segregate at the interfaces between the two fluids if the pairwise interactions between the three components are such that chi(AB)>/chi(AN)-chi(BN)/. We find that at later times, the average domain size saturates to a value, L approximately R(N)/phi(N), where R(N) and phi(N) are the radius and volume fraction of the nanoparticles, respectively. For small nanoparticles, however, full phase separation is observed.
authors.affiliation: Department of Physics, The University of Memphis, Memphis, Tennessee 38152, USA.
authors.forename: Michael J A
authors.initials: MJ
authors.lastname: Hore
authors.forename: Mohamed
authors.initials: M
authors.lastname: Laradji
mesh_terms: D000327:Adsorption; D001703:Biophysics / Q000379:methods; D002627:Chemistry, Physical / Q000379:methods*; D016000:Cluster Analysis; D003198:Computer Simulation; D015233:Models, Statistical; D008962:Models, Theoretical; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry; D013997:Time Factors
chemical_list: D011108:Polymers