@article{Nanostructures:1424,
      recid = {1424},
      author = {Gibson, Kyle},
      title = {Design and Synthesis of Colloidal Metallic Nanostructures  for Programmable Self-Assembly},
      publisher = {The University of Chicago},
      school = {Ph.D.},
      address = {2018-12},
      pages = {126},
      abstract = {Reliability and predictability in methods that produce  pure, consistent, and monodisperse products is a hallmark  in all aspects of chemistry. Within the subfields of  nanomaterials and nanotechnology, due to the relatively  short amount of time these areas of chemistry have had  research dedicated to their study, there is room for  improvement in the methods and techniques that are often  used to synthesize these materials. I have been working on  two aspects in this area of chemistry: to improve upon the  synthetic techniques and mechanistic understandings of  nanoparticle growth and to greatly expand the capabilities  of discrete programmable self-assembly with highly uniform  and robust universal building blocks. First, a purification  technique known as depletion flocculation is demonstrated  to purify gold bipyramids from the crude synthetic mixture  containing roughly 70% shape impurities. The flocculation  was shown possible owing to the use of  benzyldimethylammonium chloride (BDAC) surfactant. The  purified bipyramids were then used for further nanocrystal  growth to create a new class of nanoparticles based on the  original bipyramid seed. The bipyramids were also oxidized  in the presence of surfactant at high temperatures to form  highly monodisperse low aspect-ratio nanorods. The final  structures of both the growth and oxidation procedures were  shown to be highly dependent on the surfactant present in  solution.

	Second, universal building blocks for the  purpose of discrete programmable self-assembly were  synthesized by a two-step procedure. A partial polymer  encapsulation is performed in a binary solvent system in  combination with a dual ligand functionalization. The  surface energy of the nanoparticle is tuned by coating with  a specific ratio of hydrophobic ligand to hydrophilic  ligand that dictates the eventual surface coverage of the  diblock copolymer. The coverage of the nanoparticle surface  by the polymer renders that area inert to further  functionalization. The second step involves the  functionalization of the exposed surface by thiolated  single-stranded DNA. The polymer confers site-specific and  directional binding of the DNA, and the DNA allows for  specific binding only to the complementary strand. This  enables self-assembly between two nanoparticles  functionalized with complementary DNA strands in a highly  specific and preconceived fashion into discrete assemblies  with exceptional control. I demonstrate 24 self-assemblies  with the universal building blocks, many of which are not  possible through any other self-assembly method. Finally, I  show that the self-assembled structures can be  functionalized with a stimuli-responsive DNA sequence.  Specifically, in response to the pH of the solution, the  triplex-capable DNA strand changes the interparticle  distance, invoking an optical plasmonic response.},
      url = {http://knowledge.uchicago.edu/record/1424},
      doi = {https://doi.org/10.6082/uchicago.1424},
}