Hybrid Core-Shell Microspheres from Coassembly of Anthracene-Containing POSS (POSS-AN) and Anthracene-Ended Hyperbranched Poly(ether amine) (hPEA-AN) and Their Responsive Polymeric Hollow Microspheres

We demonstrated a novel core shell microsphere (CSM) fabricated from coassembly of anthracene-ended hyperbranched poly(ether amine) (hPEA-AN) and anthracene containing polyhedral oligomer silsesquioxane (PUSS-AN). The obtained CSMs are cross-linked through photodimerization of anthracene and possess the well-defined core shell structure according to the images of SEM, TEM, and AFM. The shell of the obtained CSM is comprised of hPEA-AN, while PUSS-AN prefers the ordered crystallized aggregation in the core. The size of the obtained CSMs is uniform and tunable. With the increasing content of hPEA-AN in the coassembly, the diameter of CSMs decreased from 930 to 616 nm, while the thickness of shell increased from 95 to 170 nm. Moreover, polymeric hollow microsphere (PHM) was prepared by removing the PUSS AN core of CSM in hydrofluoric acid (HF). The obtained PHM is amphiphilic and fluorescent, and its size is responsive to environmental stimulus such as temperature and pH. PHM can be used in the encapsulation and controlled release of guest molecules. Moreover, the controlled release of guest molecules from PHM can be monitored by itself fluorescence change.