Anisotropic Janus particles are of great interest for many applications. It is well known that behavior and utility of Janus particles are highly dependent on their chemistry and geometry. Herein, we report the synthesis of monodisperse polymeric Janus microparticles that were anisotropic not only in chemistry and shape but also in surface morphology and porosity, via a modified seeded polymerization technique. Chemical composition, shape, morphology and porosity of the polymeric Janus microparticles were flexibly controlled by utilizing different quantities and species of monomer and porogen. The polymeric Janus microparticles exhibited hierarchically porous structure, including micro- and meso-pores as evidenced by isothermal nitrogen adsorption and desorption. Due to the high specific surface area, anisotropy of the polymeric Janus microparticles was enhanced according to the greater fluorescence contrast on distinct sides of the polymeric Janus microparticles. Moreover, swelling and phase-separation processes of cross-linked seeds were in situ observed on an optical microscope to demonstrate the formation mechanism of the polymeric Janus microparticles.

各向异性的Janus粒子在许多应用中都引起了极大的兴趣。众所周知，Janus颗粒的行为和效用高度依赖于其化学性质和几何形状。在这里，我们报道了通过改进的种子聚合技术，合成了不仅在化学和形状上而且在表面形态和孔隙率上各向异性的单分散聚合物Janus微粒。通过使用不同数量和种类的单体和致孔剂，可以灵活地控制聚合物Janus微粒的化学组成，形状，形态和孔隙率。聚合的Janus微粒表现出分层的多孔结构，包括微孔和中孔，这由等温氮的吸附和解吸证明。由于比表面积大，聚合物Janus微粒的各向异性随着聚合物Janus微粒不同侧面上更大的荧光对比而增强。此外，在光学显微镜上原位观察了交联种子的溶胀和相分离过程，以证明聚合物Janus微粒的形成机理。