Study On Controlled Evaporative Self-assembly And The Polymer Brushes Functionalization

Evaporative self-assembly is a simple and easy method of patterning and widely concerned by researchers. Different self-assembly morphologies can be prepared via evaporative self-assembly. However, the regularity of these self-assembly morphologies is not well, meanwhile, controlled evaporative self-assembly(CESA) can effectively solve this problem and form highly structured self-assembly morphologies. These self-assembly morphologies can be used as template to fabricate polymer brushes via self-initiated photografting and photopolymerization(SIPGP). This paper studies the CESA and polymer brushes functionalization of carbon nanotubes(CNTs), p Hresponsive polymer and magnetic nanoparticles. The detailed contents are listed as follows:First, we studied the CESA of GO-modified CNTs to achieve the self-assembly patterns of CNTs. Based on CESA, the patterned polymer brushes were fabricated via SIPGP to achieve the hybridization of carbon materials and polymer materials.Then, we studied the CESA of poly(acrylic acid)(PAA) solution with different p H values and concentrations. The PAA solutions were loaded and trapped between the sphere and flat substrate(i.e. sphere-flat geometry) to form self-assembly patterns via CESA. The surface morphologies were characterized by optical microscopy and atomic force microscopy. The results showed that different self-assembly morphologies were formed with different p H values. In addition, similar self-assembly morphologies were formed with different concentrations. The patterned polymer brushes can be fabricated via SIPGP from the template of regular PAA morphologies.Last, we studied the self-assembly of Fe3O4 nanoparticles via CESA assisted by magnetic field. The self-assembly morphologies were affected by evaporation temperature, magnetic field rotation frequency and concentrations of Fe3O4 nanoparticles solution. Two-dimensional selfassembly of Fe3O4 nanoparticles could be achieved at an optimal temperature and static magnetic field. SIPGP was employed to graft polystyrene brushes from the two-dimensional patterns of Fe3O4 nanoparticles. Magnetic composite free-standing film could be further obtained. The characterization results of optical microscopy and scanning electron microscopy showed that the patterns of Fe3O4 nanoparticles are still retained on magnetic composite free-standing film.