(176g) Unexpected Correlations Observed in Two-Dimensional Ordered Arrays of Colloidal Particles Deposited on Patterned Polyelectrolyte Multilayer Surfaces
AIChE Annual Meeting
2006
2006 Annual Meeting
Engineering Sciences and Fundamentals
Colloidal Assembly and Fabrication
Tuesday, November 14, 2006 - 10:30am to 10:50am
Our recent study demonstrates that two-dimensional (2-D) periodic patterns of polyelectrolyte multilayers (PEM's) can be used as surface templates for assembling highly ordered 2-D colloidal micro arrays (which could then be used as structural templates for epitaxially growing three-dimensional colloid crystals thereon). In this presentation, we will discuss detailed structural features of the 2-D ordered layers of charged microspheres deposited to the oppositely-charged PEM patterns. Particularly, this talk will discuss two unexpected observations that are revealed by statistical image analysis of the 2-D colloid arrays: (i) the distribution of the distances by which the adsorbed particles deviate from the corresponding PEM pattern centers is neither random nor electrostatically governed; (ii) the distribution of the vectors defining the off-centering positions of the particles are correlated over all length scales up to the sample size (i.e., of the millimeters), and display an anomalous transition from positive(i.e.,parallel) to negative(i.e.,anti-parallel) correlation with increasing distance. Possible explanations for the observed behavior will be presented.