Self-aggregate performance of hexyl alginate ester derivative synthesized via SN2 reaction for controlled release of λ-cyhalothrin

To change the strong hydrophilicity of alginate and make it have good amphiphilic property, thereby broadening its application as a new pesticide-controlled release system, the hexyl alginate ester derivative (HAED) was synthesized by the bimolecular nucleophilic substitution (S(N)2) reaction, using 1-bromohexane as the hydrophobic modifier. The structure and self-aggregate performance of the synthesized HAED were contrastively characterized. Moreover, the loading and release performance of lambda-Cyhalothrin (LCH) for the HAED microcapsules prepared by the high-speed shearing method was also studied. The synthesized HAED exhibited enhanced molecular flexibility and good self-aggregate performance, which could form the stable self-aggregated spherical micelles with the average hydrodynamic diameter and zeta potential of 416 nm (PDI = 0.29) and - 39.9 mV, respectively, due to the intra- or intermolecular hydrophobic associations. Furthermore, the obtained HAED microcapsules displayed the high encapsulation efficiency and sustained-release property in comparison with the SA microcapsules for the good affinity of HAED to hydrophobic LCH that retarded the drug diffusion. On the basis of the excellent advantages of HAED, it was expected to become the ideal candidate for hydrophobic drug delivery in controlled-release pesticide formulations.