We employ the PhaseChip, a (poly)dimethylsiloxane (PDMS) microfluidic device, for statistical studies of protein crystal nucleation. The PhaseChip is designed to decouple nucleation and growth of protein crystals and so improve their yield and quality. Two layers of fluidic channels containing salt reservoirs and nanoliter-sized wells for protein drops in oil are separated by a thin PDMS membra...

This paper analyzes the effect of mixing on nucleation of protein crystals. The mixing of protein and precipitant was controlled by changing the flow rate in a plug-based microfluidic system. The nucleation rate inversely depended on the flow rate, and flow rate could be used to control nucleation. For example, at higher supersaturations, precipitation happened at low flow rates while large cry...

We present measurements of the growth rates of the principal facet surfaces of ice from water vapor as a function of supersaturation over the temperature range −2 ≥ T ≥ −40 C. Our data are well described by a dislocation-free layer-nucleationmodel, parameterized by the attachment coefficient as a function of supersaturation α(σ) = A exp(−σ0/σ). The measured parameters A(T ) and σ0(T ) for the b...

Mineral dust particles include many different components, but are often treated by models as insoluble resulting in limited activation to cloud droplets. Experimental critical supersaturations of mineral dust particles 0.2 μm in diameter from different sources indicate that their composition is partially soluble. Using a Köhler model, the soluble fraction of each dust sample was calculated from...

Atomic force microscope (AFM) observation and analysis of Izumiyama hydrothermal illite (the weaker altered illite-kaolinite zone (IZ-1) and the higher altered illite zone (IZ-2)) were performed to understand the crystal growth mechanism and the relation between morphology and polytype of the illites. Our AFM results suggest that growth of the Izumiyama illite was controlled by a mechanism of s...

The process of nucleation of vapor bubbles from a superheated liquid and of liquid droplets from a supersaturated vapor is investigated using the modified-core van der Waals model density functional theory [J. F. Lutsko, J. Chem. Phys. 128, 184711 (2008)]. A novel approach is developed whereby nucleation is viewed as a transition from a metastable state to a stable state via the minimum free en...

The paper presents a novel control approach for crystallization processes, which can be used for designing the shape of the crystal size distribution to robustly achieve desired product properties. The method is implemented in a hierarchical structure. On the lower level a supersaturation control approach is used that drives the system in the phase diagram according to a concentration versus te...

A new technique is described to study the condensation of supersaturated vapors on nanoparticles under well-defined conditions of vapor supersaturation, temperature, and carrier gas pressure. The method is applied to the condensation of supersaturated trifluoroethanol (TFE) vapor on Mg nanoparticles. The nanoparticles can be activated to act as condensation nuclei at supersaturations significan...