Study Of Inorganic Coordination Effect On Block Copolymer Phase Structure

To further explore the bind between microphase morphology and novel properties of block copolymer,we focused on inorganic components influence on block copolymer phase behavior.In this thesis,we have systematically investigated the ion influence on Polystyrene-block-poly（4-vinylpyridine）（PS-b-P4VP）and Polystyrene-block-poly（2-vinylpyridine）（PS-b-P2VP）phase structures,and the influences of the solvent preferential affinity on thin film microphase morphology were also discussed.By the method of saturated solvent vapor annealing,the effect of the preferential affinity of the solvents on the phase behavior of PS-b-P4 VP thin films has been studied.When the solvent is preferential affinity for the corona PS block,micelles underwent fusion and fission process and the micelle size decreased along with the narrowing of micelle size distribution.When the solvent is neutral for both two blocks,the microstructure which is consistent with the spontaneous equilibrium microstructure of the diblock copolymer was observed.When the solvent is preferential affinity for the core P4 VP block,the core and corona of micelles were inversed.The pyridine group on PS-b-P4 VP and PS-b-P2 VP molecular chains show a rich basic Lewis character: the nitrogen atom incorporated within aromatic ring tends to share a free-electron pair and form dipole-dipole interaction with many cations and anionic groups.The coordination between ion and pyridine group has great influences on phase behavior of block copolymer micelles.The high priced cations affect the Gibbs energy of micelles which induce significantly increases of micellar size and micellar morphology transition.The anions surround cations electrostatically,making different contribution to micelle size according to their basic Lewis character.Moreover,the coordination type between the cations and pyridine groups as well as the ion distribution in micelles show a major impact on phase behavior of micelles.Owing to the hydrophilic block P4 VP or P2 VP,block copolymer tend to form a dense brush “archored” to the substrate during film deposition.A new interface with non-zero interfacial tension ΔF was formed between archored layer and upper layer.Coordinated with ions,the film may rupture and dewet due to complementary driving forces from autophobic behavior and residual stresses,forming topographical features that depend on the initial film thickness.The rare earth ion(Ln³⁺)/block copolymer hybrids perform unique luminescence properties of rare earth elements.The stable rigid network and isolation effect of block copolymer micelles reduced the non-radiative vibronic deactivation of Ln³⁺ and shielded the quenching on excited Ln³⁺,which result in higher energy transfer efficiencies and emission intensity.