Characterizing nanoparticle interactions: Linking models to experiments

2019-11-08 07:31:38

potential behavior pair interactions potentials

责任者: Ramakrishnan, S.;Zukoski, C.F. 单位: Dept. of Chem. Eng., Illinois Univ., Urbana, IL, USA 来源出处: Journal of Chemical Physics(J. Chem. Phys. (USA)),2000/07/15,113(3):1237-48 摘要: Self-assembly of nanoparticles involves manipulating particle interactions such that attractions are on the order of the average thermal energy in the system. If the self-assembly is to result in an ordered packing, an understanding of their phase behavior is necessary. Here we test the ability of simple pair potentials to characterize the interactions and phase behavior of silico tungstic acid (STA), a 1.2 nm particle. The strength of interaction is controlled by dispersing STA in different background salt concentrations. The experimental variables used in characterizing the interactions are the osmotic compressibility (dΠ/dρ), the second virial coefficient (B2), relative solution viscosity (η/ηc), and the solubility (ρσ3)sat. Various techniques are then developed to extract the parameters of square well, the adhesive hard sphere (AHS), and the Yukawa pair potentials that best describe the experimental data. The AHS model describes the solution thermodynamic behavior only where the system is weakly attractive but, as would be expected, fails when long range repulsions or nonmonotonic pair potentials become important. Model free representations are presented which offer the opportunity to extract pair potential parameters 关键词: compressibility;equations of state;nanostructured materials;self-assembly;solubility;viscosity;nanoparticle interactions;self-assembly;characterisation;manipulation;average thermal energy;ordered packing;pair potentials;phase behavior;silico tungstic acid;interactions;osmotic compressibility;second virial coefficient;relative solution viscosity;square well;adhesive hard sphere potential;Yukawa pair potential;solution thermodynamic behavior;weakly attractive system;long range repulsions;nonmonotonic pair potentials;model free representations;pair potential parameters