Surface curvature affects the patterns formed by phase separating surfactant mixtures adsorbed on spherical surfaces of nanoscopic diameter due to additional conformational entropy gained from microphase, vs. bulk, separation [1-3]. Using dissipative particle dynamics simulations, we show that similar physics may be exploited to achieve controlled patterns on cylindrical surfaces by varying their degree of curvature. We find that, due to the relative asymmetry of a cylinder, several new patterns are seen on tubes or rods that are not observed on flat or spherical surfaces. We also show how curvature-induced stress helps merge kinetically-arrested patches into elongated or stripe-like patterns.
1. AM Jackson, JW Myerson, F Stellacci, “Spontaneous assembly of subnanometre-ordered domains in the ligand shell of monolayer-protected nanoparticles”, Nature Materials, 3, 330-336 (2004).
2. C Singh, PK Ghorai, MA Horsch, AM Jackson, RG Larson, F Stellacci and SC Glotzer, “Entropy-Mediated Patterning of Surfactant-Coated Nanoparticles and Surfaces”, Physical Review Letters 99, 226106 (2007).
3. RP Carney, GA DeVries, C Dubois, H Kim, JY Kim, C Singh, PK Ghorai, JB Tracy, RL Stiles, RW Murray, SC Glotzer and F Stellacci, "Size Limitations for the Formation of Ordered Striped Nanoparticles", Journal of American Chemical Society, (Communication), 130(3), 798-799 (2008).