Choose Sides: Differential Polymer Adhesion

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• 作者：Lars Sonnenberg ; Julien Parvole ; Ferdinand K&uuml ; hner ; Laurent Billon ; Hermann E. Gaub
• 刊名：Langmuir
• 出版年：2007
• 出版时间：June 5, 2007
• 年：2007
• 卷：23
• 期：12
• 页码：6660 - 6666
• 全文大小：431K
• 年卷期：v.23,no.12(June 5, 2007)
• ISSN：1520-5827

文摘

AFM-based single molecule desorption measurements were performed on surface end-grafted poly(acrylic acid)monolayers as a function of the pH of the aqueous buffer to study the adhesion properties of polymers that bridgetwo surfaces. These properties were found to depend on the adhesion forces of both surfaces in a differential manner,which is explained with a simple model in analogy to the Bell-Evans formalism used in dynamic force spectroscopy.The measured interaction forces between the poly(acrylic acid) chains and silicon nitride AFM tips depend on thegrafting density of the polymer monolayers as well as on the contour length of the polymer chains. This studydemonstrates that the stability of polymer bridges is determined by the adhesion strengths on both surfaces, whichcan be tuned by using pH-dependent polyelectrolyte monolayers.