Computational Soft Nanotechnology with Mesodyn
Leiden University, NL
In nanotechnology (1 nm – 1000 nm) one recognizes two variants: the top-down construction of minute hard objects on hard surfaces, and the bottom-up pattern-formation of soft colloid and polymer materials in bulk or on surfaces. The latter is what we refer to as ‘soft nanotechnology’. The advantage of soft nanotechnology is that is very cheap, and methods can readily be applied to large systems in industrial engineering. The disadvantage is that spontaneous pattern formation seldom leads to perfect structures: rather, the soft objects vary in shape and composition, depending on the details of the molecular structures and preparation process. Computational soft nanotechnology relates to a collection of simulation techniques, relevant to the behavior of colloid and polymer systems on the nanoscale. The objective is to assist the experimentalist with system choice, such that the pattern formation has the desired features. The computation methods we have introduced in Mesodyn are based on a field-theoretic approach, in which we combine transport equations and free energy functions into a differential algebraic set of equations. In particular, Mesodyn integrates the classical theories of colloid and polymer science: the Poisson-Boltzmann theory for electrostatic interactions, the polymer self-consistent field theory for self-assembly, and non-equilibrium thermodynamic theories for diffusion, convection, hydrodynamic fluctuations and reaction phenomena. In this overview of principles and applications, we briefly discuss the philosophy of the approach, and present three examples of applications: the formation of patterns in bulk polymer surfactant systems (for novel plastic engineering materials and health care applications), the formation of composite polymeric vesicles in bulk systems (for drug delivery), and pattern formation in thin AB and ABC block copolymer layers (for micro-electronics and bio-sensor applications).
NSTI Nanotech 2003 Conference Technical Program Abstract