2.4. Preparation of OSi@CS crosslinked nanospheres
OSi@CS crosslinked nanospheres were synthesized according to
the literature [25]. First of all, chitosan solution (0.5 wt.%) was prepared
by dissolving chitosan in 0.6 wt.% acetic acid. Then, 100 mL
chitosan solution was added into a flask equipped with a condenser,
a magnetic stirrer and a nitrogen inlet, and purged with nitrogen for
30 min with stirring. Subsequently, about 2 mL TMSPM monomer
was added at 80 ◦C. After stirring for 5 min, 1 mL 20 mM TBHP aqueous
solution was added in one time and the reaction under nitrogen
was incubated at 80 ◦C for 4 h. Finally, stable white emulsions
were obtained. The OSi@CS crosslinked nanospheres were carefully
purified with 0.6 wt.% acetic acid aqueous solution by repeated centrifugation
until conductivity of the supernatant was equal to that
of acetic acid solution (0.6 wt.%). The OSi@CS nanospheres were
suspended in 0.6% acetic acid solution for further use.