Poly(styrene)comb-b-Poly(ethylene oxide)comb Copolymers: Synthesis and AFM Investigation of Intra- and Supramolecular Organization as Thin Deposits

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• 作者：David Lanson ; Michel Schappacher ; Redouane Borsali ; Alain Deffieux
• 刊名：Macromolecules
• 出版年：2007
• 出版时间：December 25, 2007
• 年：2007
• 卷：40
• 期：26
• 页码：9503 - 9509
• 全文大小：479K
• 年卷期：v.40,no.26(December 25, 2007)
• ISSN：1520-5835

文摘

PScomb-block-PEOcomb copolymers having a poly(chloroethyl vinyl ether)-b-poly(hydroxy ethylvinyl ether) backbone with polystyrene chains on one side and poly(ethylene oxide) chains on the other, i.e.(PCEVE-g-PS)-b-(POHEVE-g-PEO), were synthesized. The strategy is based on grafting of polystyryllithiumonto the reactive chloro functions of the poly(chloroethyl vinyl ether) first block and on grafting polyethyleneoxide from the hydroxyl functions of the second block. This procedure allows the preparation of densely graftedamphiphilic diblocklike, Janus-type, comblike copolymers with high molar masses and narrow polydispersity.Thecharacteristics and dimensions of isolated (PCEVE-g-PS)-b-(POHEVE-g-PEO) macromolecules were studied bylight scattering in THF, a good solvent of both PS and PEO branches, as well as using AFM imaging of highlydiluted deposits. Unimolecular rodlike nano-objects with distinct PS and PEO domains were observed, in agreementwith their diblocklike structure. In relation with their amphiphilic nature, the combs can self-assemble in differentmorphologies. When graphite deposits are made from more concentrated methylene dichloride solutions, thePScomb-b-PEOcomb copolymers self-assemble directly on the substrate, forming flowerlike molecular aggregatesinterconnected by their PEO moieties. When deposits are made from a selective solvent (methanol) of the PEOcomb block, hyperbranched micelles formed in the solution retain their structure on the solid substrate, yieldingwell-defined spherical objects.