Surface Interactions Surpass Carbon鈥揅arbon Bond: Understanding and Control of the Scission Behavior of Core鈥揝hell Polymer Brushes on Surfaces

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• 作者：Zhicheng Zheng ; Markus M眉llner ; Jun Ling ; Axel H. E. M眉ller
• 刊名：ACS Nano
• 出版年：2013
• 出版时间：March 26, 2013
• 年：2013
• 卷：7
• 期：3
• 页码：2284-2291
• 全文大小：719K
• 年卷期：v.7,no.3(March 26, 2013)
• ISSN：1936-086X

文摘

A tapping-mode AFM investigation of core鈥搒hell cylindrical polymer brushes (CPBs) on mica shows that they can be ruptured upon spin-coating. Three different CPBs were synthesized, having a methacrylate backbone, carrying branches of poly[oligo(ethylene glycol)methacrylate] (POEGMA), POEGMA-block-poly[2-(dimethylamino)ethyl methacrylate] (POEGMA-b-PDMAEMA), and POEGMA-block-poly[2-(methacryloyloxy)ethyl trimethylammoniumiodide] (POEGMA-b-PMETAI). The polymer backbone of core鈥搒hell CPB with POEGMA-b-PDMAEMA or POEGMA-b-PMETAI branches is ruptured upon drying on a mica surface, while they are stable in aqueous solution. We propose that the scission behavior is induced by Coulomb interactions between PDMAEMA or PMETAI corona and the solid surface and that this interaction is stronger than one or more carbon鈥揷arbon single bonds. We control this scission behavior by tuning the surface interactions through switching the surface nature, varying pH, or adding multivalent counterions. Our study demonstrates that core鈥搒hell CPB serves as a template to directly compare the weak intermolecular forces with the strong carbon鈥揷arbon covalent bonds.
<h4>Keywords: h4> cylindrical polymer brushes; polyelectrolytes; surface charges; intermolecular attractions; surface interaction energy; carbon鈭抍arbon bond energy; scission behavior