Colloidal crystals engineered with DNA are fascinating structures that constitute an emerging form of programmable matter. Indeed, the use of DNA as a programmable bond has led to thousands of new crystal types, with exquisite control over crystal symmetry and lattice parameters. However, synthesizing large (> 100 µm) single-crystals has been impossible, making it difficult to fully study their properties. This thesis describes a systematic investigation of the kinetic and thermodynamic parameters known to influence colloidal crystallization processes mediated with DNA. The knowledge gleaned from these studies enabled synthesis of unprecedentedly large single crystals (Chapter 2), allowing their characterization by in situ optical microscopy and single-crystal x-ray diffraction methods. In particular, optical microscopy and single-crystal x-ray diffraction measurements show that these structures are unusually flexible and resilient, a consequence of their DNA bonding elements. Remarkably, the crystals exhibit a shape memory behavior and are able to withstand deformations that are typically considered irrecoverable in conventional molecular and atomic crystals (Chapter 3). An isothermal pathway, achieved by holding particle precursors above their melting transition temperature as opposed to the slow cooling approach described in Chapter 2, was found to favor the enthalpy (face-to-face)-driven assembly of anisotropic nanoparticles, enabling isolation of previously unrealizable high-volume fraction colloidal crystals (not accessible by slow cooling alone, Chapter 4). Finally, the role of colloidal crystal design parameters, such as DNA length and particle size, on crystal defect structures and the degree of crystallinity were investigated using X-ray ptychography, which ultimately provided strong evidence that these DNA-colloidal crystals grow by aggregation of smaller crystals followed by nanoparticle rearrangement (Chapter 5). Since single-crystals are the basis for many optical and electronic device components, the synthetic routes to and deformation properties of the colloidal crystals described in this work lay the foundation for the realization of advanced structural materials in applications that benefit from the integration of moieties with soft and crystalline properties, spanning optics to sensing.

Creator

• Calcaterra, Heather

DOI

• https://doi.org/10.21985/n2-n4aq-p577

Subject

• Nanoscience

Language

• en

Alternate Identifier

• http://dissertations.umi.com/northwestern:16430
• etdadmin_upload_964119

Date created

• 2023-01-01

Resource type

• Dissertation

Rights statement

• In Copyright