Wetting Of Nanoparticles/Polymer Surfaces:Theory And Experiment

Polymer materials have been widely used in modern society. The wettingability of polymer materials will seriously influence the reliability and durability of polymer. Nanoparticles/polymer composites offer an effective method to solve this problem. It is also necessary to have a complete understanding of these heterogeneous surfaces as well as the theories capable of predicting such properties. In this work, the wettability of nanoparticles/polymer composites was investigated with theory and experiment, including the influence of surface structure, interactions between different sites and different fluids.Firstly, the oleophobicity of pure and F-POSS decorated polyvinylidene fluoride (PVDF) and polymethyl methacrylate (PMMA) films were investigated using a three-dimensional density functional theory approach. The role of nanoparticle size and coverage, as well as the chemical features of F-POSS and polymer film, on the wetting behavior of diiodomethane droplet was integrated to the remaining ratio of surface potential to quantitatively characterize the corner effect. It has proven that, based strictly on the universal force field parameters, the theoretical predicted contact angles are in general agreement with the available experiment data.Secondly, a simple coating technology was applied to generate the superhydrophobic styrene-butadiene rubber (SBR). Silica nanoparticles were covalently bonded with y-methacryloxy propyl trimethoxysilane (y-MPTMS), which was employed to improve coating durability through the thiol-ene click reaction with SBR matrix. The contact angles of water droplets on the net and modified surfaces were then measured. On the other hand, the application of a three-dimensional density functional theory approaches to predict the wetting contact angles. It has shown that the chemical composition, chain conformation, and micro/nanostructure have different contributions to the hydrophobic behaviors. The theoretically predicted contact angles have been partly validated by their experimental counterparts.Finally, a new three-dimensional dynamic density functional theory model was proposed based on the Smoluchowski equation of motion for obtaining insight into the fundamental factors that control ice nucleation, where the density functional was systematically constructed with the fundamental measure theory and the direct correlation function from atomic interactions. It can provide the required molecular resolution with the potential to yield structural insights, dynamics, and estimates of thermodynamic quantities.