title: Equilibrium and non-equilibrium thermodynamics of templating reactions for the formation of nanowires.
abstract: The thermodynamics of the templating of materials on one-dimensional templates, such as DNA, is modeled by considering two terms: the surface tension of the material (γ) and a line energy (σ = 2πr(T)γ(T)) that represents the adhesion of the material to the template (radius r(T)). We show that as long as the reaction stoichiometry does not exceed a certain limit (√[3ν/2π] < r(T) [absolute value]γ(T)[absolute value]/γ ; ν = volume of material per unit length of template) then a sample of smooth, uniform wires is the equilibrium state. If the amount of material exceeds this limit, then the material will comprise a single macroscopic particle at equilibrium. The behavior of the system is similar to a morphological wetting transition and the model can rationalize the available experimental data on the reaction conditions required to form smooth DNA-templated nanowires. Using the framework of linear non-equilibrium thermodynamics, we also show that the model can describe qualitatively the observed evolution of these nanostructures from beads-on-a-string morphologies to smooth nanowires and construct a stochastic differential equation for the process. Numerical simulations and scaling arguments suggest that the same scaling behavior as the Edwards-Wilkinson equation is observed.
authors.affiliation: Chemical Nanoscience Laboratory, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
authors.forename: Scott M D
authors.initials: SM
authors.lastname: Watson
authors.forename: Andrew
authors.initials: A
authors.lastname: Houlton
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Horrocks
mesh_terms: D003198:Computer Simulation; D004247:DNA / Q000737:chemistry*; D008956:Models, Chemical; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D013500:Surface Tension; D013816:Thermodynamics
chemical_list: D004247:DNA