Synthesis and characterization of carboxymethyl chitosan carrying ricinoleic functions as an emulsifier for azadirachtin

► Molecular weight had main influence on ricinoleic acid's degree of substitution. ► Core-shell nanoparticles with porous structure was observed. ► Concentrations ratios between 5 and 15 induced stable and uniform nanoparticles. ► Loading efficiency varied with the concentrations ratios and particles sizes. ► Carrier restrained azadirachtin degradation much efficiently during outdoor testing.