Ultrafast hydrothermal synthesis of high quality magnetic core phenol-formaldehyde shell composite microspheres using the microwave method.
An ultrafast, facile, and efficient microwave hydrothermal approach was designed to fabricate magnetic Fe(3)O(4)/phenol-formaldehyde (PF) core-shell microspheres for the first time. The structure of the Fe(3)O(4)/PF core-shell microspheres could be well controlled by the in situ polycondensation of phenol and formaldehyde with magnetic Fe(3)O(4) clusters as the seeds in an aqueous solution without any surfactants. The effect of synthetic parameters, such as the feeding amounts of phenol, the dosages of formaldehyde, the reaction temperatures, and the microwave heating time, on the morphologies and sizes of the Fe(3)O(4)/PF microspheres were investigated in details. The phenol-formaldehyde shell is found to be evenly coated on Fe(3)O(4) clusters within 10 min of the irradiation. The as-prepared microspheres were highly uniform in morphology, and the method was found to allow the shell thickness to be finely controlled in the range of 10-200 nm. The properties of the composite microspheres were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetic analysis (TGA), Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The as-prepared Fe(3)O(4)/PF microspheres were monodisperse and highly dispersible in water, ethanol, N,N-dimethyformamide, and acetone, a beneficial quality for the further functionalization and applications of the Fe(3)O(4)/PF microspheres.
State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Laboratory of Advanced Materials, Fudan University, Shanghai 200433, People's Republic of China.
Li-Jun
LJ
You
Shuai
S
Xu
Wan-Fu
WF
Ma
Dian
D
Li
Yu-Ting
YT
Zhang
Jia
J
Guo
Jack J
JJ
Hu
Chang-Chun
CC
Wang
D052203:Ferrosoferric Oxide / Q000138:chemical synthesis / Q000737:chemistry; D005557:Formaldehyde / Q000737:chemistry*; D060328:Magnetic Phenomena; D008863:Microspheres; D008872:Microwaves; D010316:Particle Size; D010636:Phenols / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature
D010636:Phenols; D005557:Formaldehyde; D052203:Ferrosoferric Oxide