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An interpenetrating polymer network (IPN) structured antibacterial layer was prepared on dental base materials containing quaternary ammonium salt monomers (HMDQAs), polyurethane dimethacrylate oligomers (BIHs) and functionalized SiO2 nanoparticles using a one-step photo-crosslinking method. Scanning electron microscopy (SEM), atomic force microscopy (AFM), ultraviolet near-infrared visible spectrophotometry (UV-3600) and water contact angles were used to study the surface properties of the coatings. SiO2 nanoparticles changed the hydrophilicity of the cationic antimicrobial surface and increased its contact angle. Furthermore, the IPN coatings exhibited highly effective antibacterial activity on the modified dental base material, poly(methyl methacrylate) (PMMA), against Streptococcus mutans, which was evaluated by plate colony counting, optical density (OD), SEM and a live/dead assay. The MTT assay confirmed their biocompatibility. The IPN silicon complexed coating displayed good transparency, excellent antibacterial activity, and no cytotoxicity, which indicated enormous potential for the treatment of denture bases. [ABSTRACT FROM AUTHOR]

In this study, we design and synthesize a novel photosensitive polyurethane material as a functional dielectric layer, which can adjust the crystallization of para-hexaphenyl (p-6P). The novel polymer is synthesized with a new monomer 2,2-bis(hydroxymethyl)butyl 4-cyanobenzoate (HM-4-CB), which contains benzene to provide crystal nucleus sites. The grain size and density of the p-6P crystal can be controlled by the content of HM-4-CB in the polymer structure. Therefore, this method can be used to regulate the grain size of semiconductor crystals and then to change the carrier mobility of the device. The results illustrate that with a suitable grain size of the p-6P semiconductor, excellent performance in terms of charge carrier mobility can be obtained. [ABSTRACT FROM AUTHOR]