Controlled Syntheses Of Monodisperse Patchy Silica And Polydopamine Nanoparticles Directed By F127

Patchy nanoparticles with asymmetric anisotropic structure and properties have gained a wide attention due to their potential applications in the fields of photonic crystals,pharmacy and photoelectronics.Several methods have been introduced to fabricate patchy nanoparticles.However,there are still some problems needed to be addressed using existing methods,including the complexity of processing and the separation of patchy particles from template or substrate.Although the size of patchy particles varies from hundreds of nanometers to several micrometers,the accurate control of patches on particles with a size of tens of nanomerters has not achieved.In this study,a facile method is designed to fabricate colloidal patchy nanoparticles with fine-tuning patchy morphology and good colloidal dispersion at the nanoscale including inorganic nanomaterials and organic polymers.The preparation and removal of templates in this method are no need.Silica nanospheres,polydopamine nanospheres and corresponding patchy nanoparticles have been synthesized in this article.Monodisperse silica nanospheres with a size from 20 nm to 400 nm have been fabricated by using st?ber and amino acid method.Comparing two methods,it is clear that basic amino acid has played an important role in reducing the reaction rate and synthesizing silica nanospheres with a size of tens of nanometers and narrow distributions.Monodisperse polydopamine nanospheres with different sizes have been successfully synthesized by using amino acids as catalyst in the mixed solution of ethanol and water.Effects of addition amount of ethanol and amino acids on the morphology of polydopamine nanospheres have been found through the results of SEM images.Patchy silica and polydopamine nanoparticles have been synthesized by using arginine and F127 as catalyst and structure-directed agents respectively,to direct area-selective deposition of precursor on the surface of seeds.Effects of additive amount and feeding mode of precursor,types of block copolymers and organic solvents on the morphology of patchy structures have been discussed.And micelle adsorption model used to explain the fabrication process of patchy nanoparticles is first to be proposed.Polydopamine can be used as a good carbon source with high N-doped contents,improving the electrocatalytical performance.Although carbon nanospheres are common,monodisperse carbon spheres with a size of nanometers are uncommon.The aim is to fabricate carbon nanospheres with narrow distributions.