Computer simulations and liquid state theoretical studies of disorder in complex fluids

Disorder in complex fluids is an issue of great importance because disorder can change fluid properties significantly and one can design a new material with desired properties. Disorder in complex fluids is also of academic interest since disorder makes computer simulations and theories challenging. This thesis focuses on two types of disorders, architectural disorder in random copolymers and spatial disorder in porous media.; A random copolymer consists of two or more kinds of monomers. The sequence of monomers is random and quenched by chemical bonds. The polymer reference interaction site model (PRISM) integral equation theory is extended to random copolymers and used to calculate static correlations and spinodal lines. The effect of monomer correlation strength on phase separations is investigated using several closure approximations. Inter- and intra-molecular correlation functions are estimated in a self-consistent way by combining PRISM theory with field theoretic methods to consider the conformational change. Randomly coupled multi-block copolymers that consist of random sequences of monomer blocks are also investigated.; In porous media, medium particles are quenched in space. Fluid is not spatially homogeneous and one has to doubly-average properties over both medium and fluid configurations. Polymer configurations in porous media are investigated using Monte Carlo simulations and integral equation theories. The polymer size is a non-monotonic function of a media concentration. An algorithm based on Voronoi tessellation and percolation theory is developed to map pores of plasma membranes onto a lattice. The plasma membrane is modeled as a 2 dimensional porous media with immobile integral proteins as static obstacles. The pore percolation threshold is estimated and the pore connectivity is strongly correlated even for randomly distributed obstacles. The effect of media structure on pore percolation in 2 dimensional polymeric media is investigated. The pore percolation threshold is found to be a non-monotonic function of a polymer chain length. Permeation of porous membrane is investigated using molecular dynamics simulations and Voronoi tessellation. When there is a percolating path for fluid particles, the transport is Fickian. However, for a dense porous membrane with no percolating path, fluid particles can't penetrate the porous membrane.