Mussel‐Inspired Photografting on Colloidal Spheres: A Generalized Self‐Template Route to Stimuli‐Responsive Hollow Spheres for Controlled Pesticide Release

A thermo‐controlled pesticide release system composed of poly(2‐(dimethylamino)ethyl methacrylate) (PDMAEMA) thin film grafted polydopamine (PDA) (PDMAEMA‐g‐PDA) microcapsules is reported. SiO₂ microparticles are used as a template to prepare PDA‐coated SiO₂ microparticles. The thermally‐responsive PDMAEMA thin films are grafted on PDA surfaces using a metal‐free surface‐initiated photopolymerization approach without adding any photo­initiator or photosensitizer under UV light irradiation. The subsequent acid etching yields PDMAEMA‐g‐PDA hollow microcapsules. PDMAEMA‐g‐PDA microcapsules exhibit well‐controlled release of avermectin (Av). The results show that the loading ability of PDMAEMA‐g‐PDA microcapsules of Av is up to 52.7% (w/w). The release kinetics of Av demonstrate that Av@PDMAEMA‐g‐PDA microcapsules exhibit temperature‐controlled release performance. This work is significant for controlled release systems. This simple design is expected to be used in various applications, such as in controlled drug release and agriculture‐related fields.