Modeling Ostwald ripening rate of styrene miniemulsions stabilized by a homolog of n-alkane costabilizers

• The modified Kabal'nov equation was developed for predicting Ostwald ripening (OR) rate.
• The disperse phase was considered a regular solution instead of an ideal solution.
• The role of intermolecular interactions in disperse phase was presented.
• The model was verified by OR rate data for miniemulsions with n-alkane costabilizers.

The modified Kabal'nov equation developed by a thermodynamic approach dealing with a regular solution of monomer and costabilizer as the two-component disperse phase adequately describes the Ostwald ripening rate data in a wide range of the volume fraction of costabilizer for styrene miniemulsions stabilized by a homolog of n-alkane costabilizers (CnH2n+2; n = 10, 12, 16, 18, 20, 24, 32) upon aging at 25 °C. The results show that the costabilizer with the shortest chain length (C10H22) is not hydrophobic enough to effectively retard the Ostwald ripening process. The effectiveness of n-alkanes as costabilizer in suppressing the Ostwald ripening process increases with increasing n-alkane molecular weight. Nevertheless, further increasing the n-alkane chain length from C24H50 to C32H66 does not lead to significant improvement in the effectiveness of n-alkane as costabilizer. The major characteristics of the modified Kabal'nov equation are also discussed in this work.