Preparation of polyurea capsules using electrocapillary emulsification.
Polyurea capsules have been prepared using the electrocapillary emulsification method in order to control the particle size within the submicron range. The polyurea capsules have been synthesized via the interfacial polycondensation between tetraethylenepentamine (TEP) dissolved in an aqueous phase and toluenediisocyanate (TDI) dissolved in a mixture of cyclohexane and chloroform. The oil phase contains a lipophilic nonionic surfactant (sorbitan sesquioleate, SO-15) as an emulsion stabilizer. Scanning electron microscope (SEM) observations reveal that the capsule size is decreased as (i) the amount of the aqueous phase injected into the oil phase is decreased and (ii) the dropping rate of the aqueous phase is decreased. Indeed, the mole ratio of the two monomers makes a significant impact on the capsule size. Under the best experimental condition examined in this study, we obtained polyurea capsules with a diameter of approximately 200nm, which should be useful in developing bioreactors or carriers.
Sakai
Hideki
H
Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, Japan.
Tanaka
Keisuke
K
Fukushima
Hiroshi
H
Tsuchiya
Koji
K
Sakai
Kenichi
K
Kondo
Tamotsu
T
Abe
Masahiko
M