| In this thesis, we have studied molecular motility, self-assembly, and delivery at the nanoscale by computational means and in collaboration with several experimental groups. By using quantum chemistry methods and classical molecular dynamics simulations, we have examined: 1) multiple mechanisms by which motion of molecular machines can be controlled at the nanoscale, 2) self-assembly of copolymers into functional nanoconstructs for use in drug delivery, and 3) self-assembly of nanoparticles for separations of liquid mixtures.;In 1), we explored the mechanisms to achieve, control, and optimize: rotary and linear motion of synthetic nanoconstructs in different media, intramolecular conformation switching of isolated molecules, pumping of solutions by synthetic molecular "swimmers" and by electroosmosis in nanotubes. We have demonstrated motion in carbon-based molecular structures, ligated nanoparticles, and photoactive isolated molecules and discussed its use in nanoscale devices and machines.;In 2), we have modeled the self-assembly of highly PEG-ylated linear and branched (dendron-based) polymers and studied physical properties of the self-assembled micellar aggregates. In collaboration with two experimental groups, we have studied the stabilization of drugs and therapeutic peptides in these micelles. We have identified how different chemical factors contribute to the stabilization of the micelles with solvated therapeutics.;In 3), we have studied in collaboration with experimentalists the self-assembly of ligated metallic nanoparticles into planar and bulk superstructures, with the goal to understand the underlying microscopic mechanisms of the superstructure stabilization. We found that the self-assembly (type of packing) of ligated platinum nanocubes is driven by surface charges induced on their surfaces by the ligand-nanoparticle coupling. With the experimentalists we have also examined the use of nanoparticle membranes for separations of liquid mixtures, and found that the passage of molecules through the membranes occurs through nanometer-sized pores with controllable chemistries. |
