Diffusion degradation

When chloro-octadecane was found to give the same result as a so-called cosurfactant, an argument arose in terms of the real role of this highly hydrophobic compound because it is not surface active and has no cooperation with surfactant. Taking account of these systems, the definition of miniemulsion polymerization will be revised to the polymerization in which a water-insoluble compound in the dispersed phase retards or inhibits diffusion degradation of the emulsion. ... 

The conversion-time curves appear to be very similar to the shape typical of emulsion polymerization, i.e., an S-shaped curve is attributed to the autoacceleration caused by the gel effect (Smith-Ewart 3 kinetics, n>>l). The rate of polymerization-conversion dependence is described by a curve with two rate maxima. The decrease in the rate after passing through the first maximum is ascribed to the decrease of the monomer concentration in particles. Particle nucleation ends between 40 and 60% conversion, beyond the second rate maximum. This is explained by the presence of coemulsifier which stabilizes the monomer droplets against diffusive degradation. 

Emulsions are understood as dispersed systems with liquid droplets (dispersed phase) in another, non-miscible liquid (continuous phase). Either molecular diffusion degradation (Ostwald ripening) or coalescence may lead to destabilization and breaking of emulsions. In order to create a stable emulsion of very small droplets, which is, for historical reasons, called a miniemulsion (as proposed by Chou et al. [2]), the droplets must be stabilized against molecular diffusion degradation (Ostwald ripening, a unimolecular process or r, mechanism) and... 

There are three primary mechanisms by which active agents can be released from a delivery system diffusion, degradation, and swelling followed by diffusion. Any or all of these mechanisms may occur in a given release system. Probable... 

Si X.S., Wang W, Hu Ch-H., Zhou D-H. Pecht M.G. 2012. Remaining Useful Life Estimation Based on a Nonlinear Diffusion Degradation Process. IEEE Transactions on Reliability 61(1) 50-67. 

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