A population balance model is considered for the description of mass transfer in liquidliquid dispersions in a mechanically agitated vessel operated continuously. The dispersions considered are of low dispersed phase fraction in which coalescence processes may be assumed to be negligible. The model incorporates the dynamic nature of breakage processes among the droplet population together with ...

We present an experimental study of a new regime of monodisperse micro–droplet generation that we named the balloon regime. A dispersion of oil in water in a T–junction microfluidic system was studied. Several microfluidic devices having different cross– sections of the continuous and the dispersed phases micro–channels were tested. This new regime appears only for low dispersed phase velocity....

Microfluidic droplet formation at a T-junction in the jetting regime was studied theoretically and an analytical force balance model was proposed to predict the diameter of droplets. The forces governing droplet production in the jetting regime include the shear, interfacial tension, linear momentum and inertial forces. Experiments were carried with non-Newtonian xanthan gum solutions as the di...

background: the dispersed phase volume fraction plays key role in oil-in-water emulsion stability by different mechanisms like partial flocculation, depletion flocculation and bridging flocculation. since the mentioned mechanism is affected by emulsifier concentration presented in system, the major aim of this study was to investigate the effect of dispersed phase volume fraction on physical st...

Effective control of phase growth under harsh conditions (such as high temperature, highly conductive liquids or high growth rate), where surfactants are unstable or ineffective, is still a long-standing challenge. Here we show a general approach for rapid control of diffusional growth through nanoparticle self-assembly on the fast-growing phase during cooling. After phase nucleation, the nanop...

Droplet-based microfluidics has received extensive research interests due to its superior control over the fluid flow. Conventional passive microfluidic flow-focusing devices confront difficulties in controlling droplet sizes in dripping regime especially when the dispersed phase has a large viscosity. External electric fields have been reported as an effective tool to manipulate droplet breaku...

The University Repository is a digital collection of the research output of the University, available on Open Access. Copyright and Moral Rights for the items on this site are retained by the individual author and/or other copyright owners. Users may access full items free of charge; copies of full text items generally can be reproduced, displayed or performed and given to third parties in any ...

The issue discussed in the current publication is a process of emulsions penetration in the granular media driven by the capillary force. The research work focuses on the study of rate and height of multiphase liquids penetration in a porous bed. Changes of the medium porosity and saturation level occurring as a result of pores obstruction by the droplets of an inner phase, were considered. The...

In particulate materials, such as emulsions and granular media, a "jammed" system results if particles are packed together so that all particles are touching their neighbours, provided the density is sufficiently high. This paper studies through experiment, theory and simulation, the forces that particles exert upon one another in such a jammed state. Confocal microscopy of a compressed polydis...

We demonstrate the control of droplet sizes by an ac voltage applied across microelectrodes patterned around a flow-focusing junction. The electrodes do not come in contact with the fluids to avoid electrochemical effects. We found several regimes of droplet production in electric fields, controlled by the connection of the chip, the conductivity of the dispersed phase and the frequency of the ...