Competition Between Self-Assembly and Surface Adsorption

Published

February 25, 2009

Author(s)

Jacek Dudowicz, Jack F. Douglas, Karl Freed

Abstract

We investigate a minimal equilibrium polymerization model of the general competition between self-assembly on a boundary and in solution that arises when an assembling system is near a boundary. Adsorption generally occurs upon cooling, but assembly (equilibrium polymerization) may arise either upon cooling or heating. Both cases are shown to exhibit di erent manifestations of the coupling between adsorption and self-assembly. When both assembly and adsorption proceed upon cooling, a simply change in the ratio of the enthalpy of adsorption to the enthalpy of assembly in solution can switch the system between a predominance of of self-assembly in solution and a dominance of assembly on the substrate. If assembly occurs upon heating and adsorption upon cooling, as in many self-assembling proteins in aqueous solution, then a self-assembly analog of a closed loop phase boundary is found. In particular, the order parameter for assembly on the surface exhibits a peak as a function of temperature. As demonstrated by examples, the coupling between surface adsorption and self-assembly provides a powerful means of switching self-assembly processes on and off. Understanding and controlling this phenomenon will be useful in designing and directing self-assembly processes on surfaces for nanomanufacturing applications and in developing treatments for diseases arising from pathological adsorption-induced assembly.

Citation

Journal of Chemical Physics

Volume

130

Issue

8

Pub Type

Journals

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Keywords

adsorption, self-assembly, adsortion-induced assembly, equilibrium polymerization, amyloid fiber formation

Citation

Dudowicz, J. , Douglas, J. and Freed, K. (2009), Competition Between Self-Assembly and Surface Adsorption, Journal of Chemical Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=854465 (Accessed October 31, 2024)