Transport Processes

The effectiveness of any membrane process is determined by the flux of species through the membrane. High fluxes arise because of high permeability of the internal aqueous membrane solution in respect to sorbed solutes. The presence and properties of transport-mediating functional ionic groups can either facilitate or hinder transport processes depending on many specific interactions between mobile species, the charged polyelectrolyte network and solvent. In general, membrane transport phenomena can be described by a general equation derived from the linear thermodynamics of irreversible processes:

i where Ji denotes the flux of an individual permeant, the volume of solvent, heat or electricity transferred across a membrane, and Xik denotes the driving force represented by a difference in chemical potential (Au), temperature (AT), pressure (Ap) or chemical affinity (A). Lik is the phenomenological coefficient linearly relating the flux and driving force. In practice, a general flux equation can be reduced to a description of a specific process by neglecting coupling transport phenomena. Depending on the solution and assumptions, various mathematical relations have been derived and applied to discuss transport rates of ionic substances and water through ion exchange membranes.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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