Pickering emulsions stabilized by self-assembled colloidal particles of copolymers of P(St-alt-MAn)-co-P(VM-alt-MAn).
A new type of copolymer containing two alternating segments, poly-(styrene-alt-maleic anhydride)-co-poly (7-(4-vinylbenzyloxyl)-4-methylcoumarin-alt-maleic anhydride) P(St-alt-MAn)-co-P(VM-alt-MAn)(PSMVM), was prepared. The copolymer self-assembled into nanoparticles with internal microphase structures in water because the hydrophilicity of segment P(VM-alt-MAn) is higher than that of P(St-alt-MAn). The particle size, morphology, ζ potential and surface properties and their dependence on the pH and slat concentrations were studied with a combination of techniques. The nanoparticles of PSMVM showed surface activity and pH sensitivity for producing Pickering oil-in-water emulsions. The emulsion volume increased and the size of oil/water droplet decreased with increasing salt concentration. Furthermore, cross-linked nanoparticles (CLPs) were obtained by photo-dimerization of the pendent coumarin groups in PSMVM under UV irradiation. The emulsions produced by using the CLPs as emulsifiers showed even better stability upon standing. Solid oil-phase droplets were obtained by preparation of CLPs-stabilized Pickering emulsions with an oil phase of styrene containing the initiator AIBN followed by the polymerization of styrene. Thus, the enrichment and aggregation of the CLPs on the emulsion droplets was visible because the solid droplets remained unchanged during the SEM sample preparation.
Liu
Xiaoya
X
Key Laboratory for Molecular Engineering of Polymers, Ministry of Education, Department of Macromolecular Science, Fudan University, Shanghai 200433, China.
Yi
Chenglin
C
Zhu
Ye
Y
Yang
Yiqun
Y
Jiang
Jinqiang
J
Cui
Zhenggang
Z
Jiang
Ming
M
D003102:Colloids / Q000138:chemical synthesis* / Q000737:chemistry; D003374:Coumarins / Q000138:chemical synthesis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry; D009821:Oils / Q000737:chemistry; D010316:Particle Size; D011137:Polystyrenes / Q000138:chemical synthesis* / Q000737:chemistry; D013499:Surface Properties; D014867:Water / Q000737:chemistry
D003102:Colloids; D003374:Coumarins; D009821:Oils; D011137:Polystyrenes; C554829:poly(styrene-alt-maleic anhydride)-co-poly(7-(4-vinylbenzyloxyl)-4-methylcoumarin-alt-malic anhydride); D014867:Water