Comprehensive evaluation on the encapsulation performances of melamine-formaldehyde microcapsules affected by core oils

Core oils’ properties are significant for the microencapsulation process. 12 representative single componential core oils with different chemical structures , logP , solubility, interfacial tension (IFT) and viscosity were specially selected to fabricate melamine-formaldehyde (MF) microcapsules. Afterward, the effect of core oils’ properties on the performance of microcapsules was investigated. It was found that the morphology, the average particle sizes (7.83 µm∼27.06 µm), the encapsulation efficiencies (47.35 ± 3%∼92.86 ± 4%), zeta potentials (−52.37 ± 2.97 mV∼−65.03 ± 0.79 mV) and the rupture forces (0.28 ± 0.20mN∼0.82 ± 0.3mN) of microcapsules were influenced by core oils’ properties. Further comprehensive analysis indicated that logP≥ 1.66 and the solubility≥ 0.055 mL 3 /g were the premises for the successful encapsulation processes. Moreover, by increasing logP, IFT and viscosity, the size of microcapsules increased; as microcapsules size increased, the release rate decreased; the high IFT and the solubility increased the encapsulation efficiency of microcapsules; the mechanical property was influenced by logP. This work provided to use logP as the criterion to predict the encapsulation work, which hasn’t been studied before; and the correlations between microcapsules’ various performances and core oils’ properties were initially established. This work was meaningful since logP was used as a clear criterion to select core oils for encapsulation work and core oils’ properties were used to predict the application performances of microcapsules.