Preparation of Polymeric Nanoparticles and Observation on the Structure of Novel Nanosized Physical Hydrogels by AFM and SEM Methods

A series of novel nano-sized physical hydrogels based on the hydrophobic polymeric nanoparticles have been prepared via a modified microemulsion polymerization, which may contain as much as above 90% water with nanosized particle diameter of about 20 nm. The specific structures of the prepared hydrogels were observed successfully by Atomic Force Microscope (AFM) and Scanning Electron Microscope (SEM). The micrographs showed that the polymeric nanoparticles and their aggregated clusters were connected to form the networks of hydrogels, in which water including free water and bound water were embedded. The formation mechanism of the hydrogel has also been discussed in this paper.