Characterization of Miniemulsion Droplet Size and Stability Using Capillary Hydrodynamic Fractionation

Miniemulsion polymerization of styrene using the oil-soluble initiator AMBN

“…However, when KPS is used as the initiator, the droplets are unstable because cetyl alcohol alone is unable to preserve the size of the droplets produced by the Microfluidizer. 23 Figure 6 shows the measured TEM particlesize distributions at various conversions for samples that were withdrawn during the polymerization of a miniemulsion formed without any predissolved polymer and were initiated using AMBN. Figure 7 shows the similar distributions for a miniemulsion formed with 1% predissolved polymer.…”

Population Balance Model for Miniemulsion Polymerization, 1

“…This is given by the quasi-steady state Equation (24), which is the Smith-Ewart recursion relation: [32] k e ½F iÀ1 ðv; tÞ À F i ðv; tÞ þ k de ½ði þ 1ÞF iþ1 ðv; tÞ À iF i ðv; tÞ…”

“…It was found that with the increase in the hexadecanol amount, the rearrangement behavior was retarded and the final average size decreased. [10,24] A theoretical analysis to reconcile the afore-mentioned experimental observations in terms of a suitable theoretical framework was conducted. [13,14] The instability may arise as a result of coalescence which results from an insufficient barrier (electrostatic, viscoelastic, etc.)…”

“…[4,5] Miller observed the effects of change in the pre-emulsification and emulsification steps on the resulting average size of the droplet size distribution using capillary hydrodynamic flow fractionation method. [10,24] In the absence of knowledge regarding the full droplet size distribution, defining the distribution in terms of analytical functions seems to be a convenient recourse. [19] Incorporation of information regarding the shape and any two size variables of the distribution (e.g., mean and standard deviation, or maximum and minimum diameter, etc.)…”

Population Balance Model for Miniemulsion Polymerization, 2

“…The microfluidizer generates uniform shear and is known to give very narrow droplet size distribution as evident from the final particle size distribution, [27][28][29] and therefore, in the present validation, it is considered to be monodisperse. Further, the standard deviation of the initial droplet size distribution has to be lower than the final particle size distribution because the duration of the nucleation period will further broaden it.…”