Membrane micro-engineered

An emerging class of emulsification methods is not based on imposing an overall flow field, but rather by making individual droplets on the mouths of membrane pores or micro-engineered channels. Characteristic is that the flow fields applied are much milder energy consumption is much lower, while the droplet sizes are strongly dependent on the shape and dimensions of the pores or micro-channels. A number of processes belong to this class ... 

A second, new class of processes is that of membrane and micro-channel emulsification. A to-be-dispersed phase is here pushed through pores of a membrane or through micro-engineered micron-scale channels. At the pore or channel mouth, droplets are formed. These droplets can spontaneously detach from the pore or channel mouth (interfacial tension driven snap-off), due to the distortion of the droplet shape when it is still attached to the mouth. At higher fluxes or with channel mouths not giving a strong shape distortion, droplets are sheared off by a cross-flowing continuous phase. 

Van Rijn, C.J.M. (2004) Nano- and Micro-Engineered Membrane Technology, Membrane Sdence and Technologies Series, Vol. 10, Elsevier, Netherlands. 

O. Wolfrath, L. Kiwi-Minsker, A. Renken, Filamenteous catalytic beds for the design of membrane micro-reactor propane dehydrogenation as a case study, in M. Matlosz, W. Ehrfeld, J.P. Baselt (Eds.), Proceedings of the 5th International Conference on Microreaction Engineering (IMRET 5), Springer, Berlin, 2001, p. 191. 

Wagdare, N.A., Marcelis, A.T.M., Ho, O.B., Boom, R.M., and van Rijn, C.J.M. High throughput vegetable oil-in-water emulsification with a high porosity micro-engineered membrane. Journal of Membrane Science 347(1-2) (2010) 1-7. 

Wang M, Wang X, Wu S, Tan Z, Liu L, Guo X (2011) Nano porous silicon membrane with channels for micro direct methanol fuel cells. IEEE international conference on nano/micro engineered and molecular systems (NEMS), Kaohsiung, Taiwan... 

Van Rijn CJM. Nano and micro engineered membrane technology. Amsterdam Elsevier 2004. eBook ISBN-9780080512341 Print Book ISBN-9780444514899. 

Dynamic characteristics of a fuel cell engine are of paramount importance for automotive application. Three primary processes govern the time response of a PEFC. They are (1) electrochemical double-layer discharging, (2) gas transport through channel and GDL, and (3) membrane hydration or dehydration (i.e., between a dry and a hydrated state). The time constant of double-layer discharging is between micro- and milliseconds, sufficiently short to be safely ignored for automotive fuel cells. The time constant for a reactant gas to transport through GDL can be estimated simply by its diffusion time, i.e.,... 

In the last years increasing research activities in the fields of membrane science [1, 2], chemical sensors [3], confined matter [4] and micro-reaction engineering [5] have evoked a new interest on porous glass membranes. Furthermore, such membranes are ideal model systems for the investigation of transport processes in porous structures. This broad spectrum of applications demands variable texture properties. 

Kawano R, Osaki T, Takeuchi S. A parylene nanopore for stable planar lipid bilayer membranes. In IEEE 23rd international conference on micro electro mechanical systems (MEMS) 2010. Wanchai, Hong Kong Institute of Electrical and Electronics Engineers 2010. p. 923-6. ISBN 978-1-4244-5761-8. 

Molecular engineering still suffers substantial development. Besides heat, mass, and momentum transfer phenomena, commonly used in classical chemical engineering, it is also necessary to introduce the electron transfer phenomenon. Description of the events is based on molecular mechanics, molecular orbits, and electrodynamics. Principal tools and equipment are micro-reactors, membrane systems, micro-analytical sensors, and micro-electronic devices. Output is, generally, demonstrated as molecules, chemicals (solutions), and biochemicals. 

Kudo, S., Maki, T Kitao, N. and Mae, K. (2009) Efficient hydrogen production from methanol by combining micro channel with carbon membrane catalyst loaded with Cu/Zn. Journal of Chemical Engineering of Japan, 42 (9), 680-686. 

---