Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 6 of 6

Full-Text Articles in Entire DC Network

Assembly Of Particles Onto Rigid Cylinders And Flexible Membranes: Probing Effects Of Surface Curvature And Deformation, Derek Wood Nov 2017

Assembly Of Particles Onto Rigid Cylinders And Flexible Membranes: Probing Effects Of Surface Curvature And Deformation, Derek Wood

Doctoral Dissertations

In this thesis we explore two specific topics within the broad field of particle adhesion. First, we examine the effect of substrate shape and geometry on the self assembly of adsorbed particles, by performing molecular dynamics simulations of interacting particles constrained to the surface of cylinders of varying diameters. We find the diameter of the cylinder imposes a constraint on the shape and crystallographic orientation of the self-assembled lattice, essentially determining the optimal arrangement of particles a priori. We propose a simple one-dimensional model to explain the optimal arrangement of particles as a function of the particle interaction potential …


Protein-Nanoparticle Co-Engineering: Self-Assembly, Intracellular Protein Delivery, And Crispr/Cas9-Based Gene Editing, Rubul Mout Nov 2017

Protein-Nanoparticle Co-Engineering: Self-Assembly, Intracellular Protein Delivery, And Crispr/Cas9-Based Gene Editing, Rubul Mout

Doctoral Dissertations

Direct cytoplasmic delivery of gene editing nucleases such CRISPR/Cas9 systems and therapeutic proteins provides enormous opportunities in curing human genetic diseases, and assist research in basic cell biology. One approach to attain such a goal is through engineering nanotechnological tools to mimic naturally existing intra- and extracellular protein delivery/transport systems. Nature builds transport systems for proteins and other biomolecules through evolution-derived sophisticated molecular engineering. Inspired by such natural assemblies, I employed molecular engineering approaches to fabricate self-assembled nanostructures to use as intracellular protein delivery tools. Briefly, proteins and gold nanoparticles were co-engineered to carry complementary electrostatic recognition elements. When these …


Solution-Based Assembly Of Conjugated Polymers Into Nanofibers For Organic Electronics, Daniel E. Acevedo Cartagena Nov 2017

Solution-Based Assembly Of Conjugated Polymers Into Nanofibers For Organic Electronics, Daniel E. Acevedo Cartagena

Doctoral Dissertations

Solution-based crystallization of conjugated polymers offers a scalable and attractive route to develop hierarchical structures for electronic devices. The introduction of well-defined nucleation sites into metastable solutions provides a way to regulate the crystallization behavior, and therefore the morphology of the material. A crystallization method for generating metastable solutions of poly(3-hexylthiophene) (P3HT) was established. These metastable solutions allow P3HT to selectively crystallize into nanofibers (NFs) on graphene-coated surfaces. It was found that the crystallization kinetics is faster with increasing P3HT molecular weight and concentration. Through in situ atomic force microscopy, it was confirmed that NFs grow vertically in a face-on …


Particles Confined By Fluid Interfaces: Imaging Particle Motion, Interface Deformation And Capillary Forces, Paul Y. Kim Mar 2017

Particles Confined By Fluid Interfaces: Imaging Particle Motion, Interface Deformation And Capillary Forces, Paul Y. Kim

Doctoral Dissertations

Small solid particles, confined in two-dimensions by fluid interfaces, were studied by a variety of experimental methods to understand particle motion, menisci shapes near interface-supported particles, and capillary interactions among such particles. Unwanted evaporation was circumvented by adopting non-volatile ionic liquids to create the fluid interfaces. A related application, employment of ionic liquids to float cryo-microtomed polymer sections, was also developed. The Brownian motions of nanospheres and nanorods in free-standing ionic liquid films were visualized in situ by high resolution scanning electron microscopy, which images features almost 100× smaller than possible in an optical microscope. For suspensions that are dilute …


Reducing The Size Sale Of The Block Copolymer Microdomains And Morphology Study Of Brush Block Copolymers Containing Homopolymer, Gajin Jeong Mar 2017

Reducing The Size Sale Of The Block Copolymer Microdomains And Morphology Study Of Brush Block Copolymers Containing Homopolymer, Gajin Jeong

Doctoral Dissertations

Block copolymers (BCPs), due to their ability to self-assemble into periodic nanoscale morphologies, have been extensively studied over the past few decades. The thermodynamic parameters governing self-assembly of BCPs generally leads to periodic morphologies with characteristic length scales ranging from 10 to 100 nm. Several applications have been demonstrated utilizing BCPs as a template for the fabrication of nanostructured materials. Fabricating structures beyond the 10-100 nm range, remains a challenge and constitutes one of the goals of the proposed research. This dissertation is divided into two parts. The first focuses on the sub 10 nm length scale, when by chemically …


Sequence And Entropy-Based Control Of Complex Coacervates, Li-Wei Chang, Tyler K. Lytle, Mithun Radhakrishna, Joel J. Madinya, Jon Vélez, Charles E. Sing, Sarah L. Perry Jan 2017

Sequence And Entropy-Based Control Of Complex Coacervates, Li-Wei Chang, Tyler K. Lytle, Mithun Radhakrishna, Joel J. Madinya, Jon Vélez, Charles E. Sing, Sarah L. Perry

Chemical Engineering Faculty Publication Series

Biomacromolecules rely on the precise placement of monomers to encode information for structure, function, and physiology. Efforts to emulate this complexity via the synthetic control of chemical sequence in polymers are finding success; however, there is little understanding of how to translate monomer sequence to physical material properties. Here we establish design rules for implementing this sequence-control in materials known as complex coacervates. These materials are formed by the associative phase separation of oppositely charged polyelectrolytes into polyelectrolyte dense (coacervate) and polyelectrolyte dilute (supernatant) phases. We demonstrate that patterns of charges can profoundly affect the charge–charge associations that drive this …