可控粒径PAA/Fe_3O_4磁性颗粒的制备

A size-controllable preparation of monodisperse PAA/Fe_3O_4 magnetic microspheres

采用水热法通过在反应体系中掺杂丙烯酸一步合成了单分散 PAA/Fe3 O 4磁性微球,其尺寸分布均匀,平均尺寸约为170 nm,且由约13 nm 的小颗粒堆积而成.通过调节反应物的量、反应温度、时间等条件,对该磁性微球的尺寸进行了控制合成,产物尺寸分布在100-500 nm 之间.并对该磁性微球磁性进行了表征,结果表明,随着微球尺寸的增长,其饱和磁化强度逐渐增大,当由小纳米颗粒堆积而成的微球平均尺寸达到497 nm 时,其饱和磁化强度可达104．52 A·m^2/kg.在一定程度上克服了以往小纳米颗粒难以得到高饱和磁化强度的缺点.

Monodispersed PAA/Fe3O4 magnetic microspheres with 100-500 nm average sizes were synthesized according to hydrothermal method to overcome the disadvantages of past particles(<30nm)which was difficult to get the high saturation magnetization.These microparticles are composed of small primary nanocrystals with a size of 13 nm.As the same time,the size of the PAA/Fe3O4 magnetic microspheres can be controlled via altering of the quantity of reagent,the reaction temperature and the reaction time.It shows that with the increase of the microspheres sizes,Mswas increased.Moreover,when the size of PAA/Fe3O4 magnetic microspheres was 490 nm,the Mscan be 104.52A·m2/kg.Finally,the morphologies,magnetic properties had been characterized by transmission electron microscopy(TEM),X-ray diffraction(XRD),Fourier transform infrared spectrometer,vibrating sample magnetometer(VSM).