Structural properties of polymer-brush-grafted gold nanoparticles at the oil–water interface: insights from coarse-grained simulations

Abstract

In this work, the structural properties of amphiphilic polymer-brush-grafted gold nanoparticles (AuNPs) at the oil-water interface were investigated by coarse-grained simulations. The effects of grafting architecture (diblock, mixed and Janus brush-grafted AuNPs) and hydrophilicity of polymer brushes are discussed. Simulation results indicate that functionalized AuNPs present abundant morphologies including typical core-shell, Janus-type, jellyfish-like, etc., in a water or oil-water solvent environment. It is found that hydrophobic/weak hydrophilic polymer-brush-grafted AuNPs have better phase transfer performance, especially for AuNPs modified with hydrophobic chains as outer blocks and weak hydrophilic chains as inner blocks. This kind of AuNP can cross the interface region and move into the oil phase completely. For hydrophobic/strong hydrophilic polymer-brush-grafted AuNPs, they are trapped in the interface region instead of moving into any phase. The mechanism of phase transfer is ascribed to the flexibility and mobility of outer blocks. Besides, we study the desorption energy by PMF analysis. The results demonstrate that Janus brush-grafted AuNPs show the highest interfacial stability and activity, which can be further strengthened by increasing the hydrophilicity of grafted polymer brushes. This work will promote the industrial applications of polymer-brush-grafted NPs such as phase transfer catalysis and Pickering emulsion catalysis.

Colloidal capsules: nano- and microcapsules with colloidal particle shells

“…Significant research interest is dedicated to the study and advancement of the adsorption and desorption of colloidal particles at fluid interfaces. However, the elucidation of the full details of this field would go well beyond the scope of this review, as why we would like to redirect the interested reader to the books by Binks 75 and Ngai et al 79 (which both include detailed mathematical descriptions) and recent research studies, [80][81][82][83][84][85][86][87][88][89][90][91] novel measurement techniques, [92][93][94][95] and recent reviews [96][97][98][99][100][101][102][103][104][105] for further information.…”

The Martini Model in Materials Science

“…Another area where Martini polymers have been used extensively is to study polymer behavior at surfaces and interfaces. Studies have targeted for example polymer conformations at oil/organic solvent–water interfaces, [ 95–97 ] surface water interfaces, [ 64,98 ] or even water/air interfaces. [ 32,55 ] Polymer behavior at interfaces is interesting in many applications among others for coatings or glues.…”

“…Martini parameters are available for a wide variety of nanoparticles including fullerenes, [ 67–69 ] carbon nanotubes, [ 70–73 ] and gold [ 79,80,155 ] among others. Apart from their importance to modeling organic electronics, which are the subject of the next section, they have been used to simulate polymer nanoparticle composites, [ 78,80,95,96,155–165 ] self‐assembly of nanoparticles, [ 79,166–168 ] and solution processing of nanoparticles. [ 76,77,85,86 ]…”

“…Within the Martini framework, in particular gold nanoparticles have received a lot of attention. [ 80,95,96,162,164,169,170 ] For example, Dong and Zhou have studied the solvent behavior of differently composed PEO‐ b ‐PS block copolymers attached to gold nanoparticles. They found varying the composition of the block copolymer leads to a variety of different morphologies.…”

Interface and Interphase in Polymer Nanocomposites with Bare and Core-Shell Gold Nanoparticles

“…Besides experiments [56][57][58][59][60][61][62][63][64], molecular simulations have been used to study the properties of polymer-based complex materials [65][66][67][68][69][70][71], including atomistic molecular dynamics (MD) [3,[72][73][74][75][76], dynamic Monte Carlo simulations (MCMD) [77][78][79], self-consistent field theory (SCFT) and density functional theory (DFT) [80], dissipative particle dynamics (DPD) [81], coarse-grained (CG) MD simulations [82][83][84][85] and stochastic dynamics simulations [86].…”