2014/04/09 by Aditi Chakrabarti, Manoj K. Chaudhury
Chemistry · Engineering · Materials Science · Physics and Astronomy · #Chemical engineering #Chemistry #Composite material #Engineering #Lubrication #Materials science #Nanotechnology #Pickering emulsions and particle stabilization #Polymer Surface Interaction Studies #Soft materials #Surface Modification and Superhydrophobicity #cond-mat.soft
paper · pdf · doi:10.1021/la5007988
published as Langmuir 2014, 30, 4684 to 4693
openalex publication_date 2014/04/09 · arxiv created 2014/06/05 · arxiv updated 2014/06/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the interaction of small hydrophobic particles on the surface of an ultrasoft elastic gel, in which a small amount of elasticity of the medium balances the weights of the particles. The excess energy of the surface of the deformed gel causes them to attract as is the case with the generic capillary interactions of particles on a liquid surface. The variation of the gravitational potential energies of the particles resulting from their descents in the gel coupled with the superposition principle of Nicolson allow a fair estimation of the distance dependent attractive energy of the particles. This energy follows a modified Bessel function of the second kind with a characteristic elastocapillary decay length that decreases with the elasticity of the medium. An interesting finding of this study is that the particles on the gel move toward each other as if the system possesses a negative diffusivity that is inversely proportional to friction. This study illustrates how the capillary interaction of particles is modified by the elasticity of the medium, which is expected to have important implications in the surface force driven self-assembly of particles. In particular, this study points out that the range and the strength of the capillary interaction can be tuned in by appropriate choices of the elasticity of the support and the interfacial tension of the surrounding medium. Manipulation of the particle interactions is exemplified in such fascinating mimicry of the biological processes as the tubulation and phagocytic engulfment and in the assembly of particles that can be used to study nucleation and clustering phenomena in well-controlled settings.