Adhesion of Nanoparticles

Abstract

We have developed a new model of nanoparticle adhesion which explicitly takes into account the change in the nanoparticle surface energy. Using combination of the molecular dynamics simulations and theoretical calculations we have showed that the deformation of the adsorbed nanoparticles is a function of the dimensionless parameter beta proportional, variant gamma(p)(GR(p))(-2/3)W(-1/3), where G is the particle shear modulus, R(p) is the initial particle radius, gamma(p) is the polymer interfacial energy, and W is the particle work of adhesion. In the case of small values of the parameter beta < 0.1, which is usually the case for strongly cross-linked large nanoparticles, the particle deformation can be described in the framework of the classical Johnson, Kendall, and Roberts (JKR) theory. However, we observed a significant deviation from the classical JKR theory in the case of the weakly cross-linked nanoparticles that experience large shape deformations upon particle adhesion. In this case the interfacial energy of the nanoparticle plays an important role controlling nanoparticle deformation. Our model of the nanoparticle adhesion is in a very good agreement with the simulation results and provides a new universal scaling relationship for nanoparticle deformation as a function of the system parameters.

Surface tension and contact with soft elastic solids

“…Thus, we expect a capillary regime for R ( maxðL; L ffiffiffiffiffiffiffiffiffiffiffiffiffiffi Ç sv =W p Þ. This is similar to the scaling found for theoretical predictions of nanoparticle adhesion on hard surfaces 44 . For Ç sv ¼ 30 mN m À 1 (ref.…”

“…A simple energy argument, modified from Carrillo et al 44 explains the transition from capillary to elastic regimes. Breaking Contact radius  Young's modulus versus bead radius  Young's modulus.…”

Elastocapillarity: Surface Tension and the Mechanics of Soft Solids

“…As ω → ∞, this pull-off force can be reduced by more than 30% [98]. Useful, semi-analytical expressions [98] and scaling laws [19,97,99] relating force to indentation can be found in recent work and some results are provided in the Supplementary Information.…”

Solid capillarity: when and how does surface tension deform soft solids?

“…In the limit of small contacts on soft substrates, theoretical analyses suggest that the JKR theory will be replaced by the Young-Dupré condition with the soft substrate in the place of the wetting liquid [43][44][45][46]. Recently, a JKR-YD crossover was observed using silicone gels [44,47] at a length scale around 10 µm.…”