Electrostatic repulsion-controlled formation of polydopamine-gold Janus particles.
Polydopamine (PDA)-Au Janus particles were obtained by simply adding HAuCl(4) to a PDA particle suspension, prepared via self-polymerization of dopamine in basic solution at room temperature. The structures of the PDA-Au particles are readily controlled by electrostatic repulsion between the constituent particles, which can be realized simply via adjusting the environmental pH. PDA-Au Janus particles are formed only in a narrow pH range of 2.5-3.0 due to the properly enhanced electrostatic repulsion between the Au particles growing on as-prepared PDA particles and between the Au and PDA particles. The obtained PDA-Au Janus particles can become interfacially active and self-assemble at oil/water interfaces as a result of spatially well-separated hydrophilic (PDA) and hydrophobic (Au) domains on the surfaces, reminiscent of amphiphilic molecules.
Ian Wark Research Institute, University of South Australia, SA 5095, Australia. haolan.xu@unisa.edu.au
Haolan
H
Xu
Xiaokong
X
Liu
Ge
G
Su
Bin
B
Zhang
Dayang
D
Wang
D002712:Chlorides / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D017612:Gold Compounds / Q000737:chemistry; D007211:Indoles / Q000737:chemistry*; D015394:Molecular Structure; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D055672:Static Electricity; D013499:Surface Properties
D002712:Chlorides; D017612:Gold Compounds; D007211:Indoles; D011108:Polymers; C568283:polydopamine; D006046:Gold; C024568:gold tetrachloride, acid