Nanoscale phase separation in mixed poly(tert-butyl acrylate)/polystyrene brushes on silica nanoparticles under equilibrium melt conditions.

摘要: This communication reports on the study of microphase separation well-defined mixed poly(tert-butyl acrylate) (PtBA)/polystyrene (PS) brushes silica nanoparticles under equilibrium melt conditions. Mixed PtBA/PS were synthesized from an asymmetric, difunctional initiator-terminated self-assembled monolayer by combining atom transfer radical polymerization and nitroxide-mediated polymerization. Two symmetric brush samples with different molecular weights used in this thermally annealed vacuum at 150 degrees C. For number average (Mn) 24 200 g/mol for PtBA 23 000 PS, two glass transitions observed differential scanning calorimetry analysis. Transmission electron microscopy showed that grafted polymers underwent a lateral separation, forming random worm-like pattern feature size approximately 10 nm particle surfaces. In contrast, Mn 10,400 11,900 PS did not separate. Although are curved substrates, work provides results consistent theoretical prediction homopolymer undergo rather than vertical phase