Merin Jose

Radboud University | RU · Physical Chemistry of Soft Matter

Hypothesis: Microgels are a class of model soft colloids that act like surfactants due to their amphiphilicity and are spontaneously adsorbed to the fluid-air interface. Here, we exploit the surfactant-like characteristics of microgels to generate Marangoni stress-induced fluid flow at the surface of a drop containing soft colloids. This Marangoni...

Evaporation of fluid from a pinned drop placed on solid surface proceeds via constant contact radius (CCR) mode, with a continuous reduction in the contact angle. The reduction of contact angle leads to an imbalance of interfacial tensions at the three-phase contact line. When the unbalanced force is sufficiently strong, the drop slips from the pin...

The temporal evolution of viscoelascticity is manifested as the change in power spectral density (PSD) of translation (X & Z) and rotational (pitch) represents different mechanical modes of air-water interface with pNiPAM monolayer.

Mechanical properties of particle laden interfaces is crucial for various applications. For water droplets containing soft microgel particles, passive microrheology studies have revealed that the dynamically varying surface area of the evaporating drop results in a viscous to viscoelastic transition along the plane of the interface. However, the be...

We investigate the sessile drop evaporation aided self-assembly of microgel particles by varying their softness. Evaporation of sessile drops containing amphiphilic microgel particles at suitable concentrations results in uniform monolayer deposits that span the entire drop area. At lower concentrations, the deposits are in the form of monolayer co...

We have reported experimental studies on the self-assembly and degree of ordering of a binary mixture of soft colloids in monolayer deposits obtained by controlled evaporation. A sessile drop containing soft colloids is evaporated on a solid surface to achieve a loosely-packed two-dimensional deposit with a hexagonal arrangement. The soft microgel...

We show that loosely packed homogeneous monolayers of soft colloidal particles can be fabricated via simple evaporative drying of aqueous dispersion containing colloidal particles. Owing to the inherent amphiphilicity of the soft microgels, they are preferentially adsorbed onto the water-vapor interface of the drying droplet, resulting in a uniform...