Author/Authors :
Xiong، نويسنده , , Huiming and Zheng، نويسنده , , Joseph X. and Van Horn، نويسنده , , Ryan M. and Jeong، نويسنده , , Kwang-Un and Quirk، نويسنده , , Roderic P. and Lotz، نويسنده , , Bernard and Thomas، نويسنده , , Edwin L. and Brittain، نويسنده , , William J. and Cheng، نويسنده , , Stephen Z.D.، نويسنده ,
Abstract :
A poly(l-lactic acid)-block-polystyrene-block-poly(methyl methacrylate) (PLLA-b-PS-b-PMMA) triblock copolymer was synthesized with a crystalline PLLA end block. Single crystals of this triblock copolymer grown in dilute solution could generate uniformly tethered diblock copolymer brushes, PS-b-PMMA, on the PLLA single crystal substrate. The diblock copolymer brushes exhibited responsive, characteristic surface structures after solvent treatment depending upon the quality of the solvent in relation to each block. The chemical compositions of these surface structures were detected via the surface enhanced Raman scattering technique. Using atomic force microscopy, the physical morphologies of these surface structures were identified as micelles in cyclohexane and “onion”-like morphologies in 2-methoxyethanol, especially when the PS-b-PMMA tethered chains were at low tethering density.
