writer：Guangyu Liu, Xinlin Yang*, Yongmei Wang
keywords：Multi-layer polymer microsphere; Ellipsoidal nanoparticles; Inorganic/polymer core-shell material
source：期刊
specific source：Langmuir, 24 (10), 5485-5491 (2008). DOI: 10.1021/la8002004
Issue time：2008年
Ellipsoidal trilayer hematite/silica/poly(divinylbenzene) hybrid particles were prepared by distillation precipitation polymerization of divinyl benzene (DVB) in the presence of hematite/3-(methacryloxy)propyl trimethoxysilane (MPS)-modified silica (SiO2) core-shell particles as the seeds. The polymerization of DVB was performed in neat acetonitrile
with 2,2′-azobisisobtyronitrile (AIBN) as initiator to coat the hematite/MPS-modified SiO2 seeds through the capture of DVB oligomer radicals with the aid of a vinyl group on the surface of the hematite/MPS-modified silica core-shell particles in the absence of any stabilizer or surfactant. The other hematite/silica/polymer trilayer hybrid particles with
different polarity and various functionality, such as hematite/silica/poly(ethylene glycol dimethacrylate) and hematite/silica/poly(divinyl benzene-co-methacrylic acid) could also be prepared by this procedure. Hematite/silica/poly(N,N′-methylenebisacrylamide) composite particles could be prepared with unmodified hematite/silica particles as seeds.
Hollow poly(divinyl benzene) (PDVB) and poly(N,N′-methylenebisacrylamide) (PMBAAm) ellipsoids with movable hematite cores were subsequently developed after the selective etching of the silica midlayer in diluted hydrofluoric acid from hematite/silica/PDVB and hematite/silica/PMBAAm trilayer hybrids. HollowPDVBellipsoids were obtained by removal of the silica midlayer and hematite core of the trilayer hybrids with concentrated HF solution. The resultant trilayer hybrid particles and hollow polymer ellipsoids were characterized by transmission electron microscopy and vibrating sample magnetometer.