Engineering Commons^™

Patterning And Mechanical Analysis Of Fiber-Based Materials, Samuel A. Pendergraph

Doctoral Dissertations

The ability to define and control the topography of a surface has been studied extensively due to its importance in a wide variety of applications. The control of a non-planar topography would be very valuable since a number of structures that are pervasive in artificial applications (e.g. fibers, lenses) are curved interfaces. This potential of enabling applications that incorporate non-planar geometries was the motivation for this thesis. The first study of this thesis comprises the study of patterning the circumference of micrometer sized fibers. Specifically, a unique technique was described to pattern the fiber with a periodic array of colloids. …

Self-Assembly Of Block Copolymers By Solvent Vapor Annealing, Mechanism And Lithographic Applications, Xiaodan Gu

Doctoral Dissertations

Block copolymers (BCP) are a unique class of polymers, which can self-assemble into ordered microdomains with sizes from 3 nm to about 50 nm making BCPs an appealing meso-scale material. In thin films, arrays of BCP microdomains with longrange lateral order can serve as ideal templates or scaffolds for patterning nano-scale functional materials and synthesizing nanostructured materials with size scales that exceed the reach of photolithography. Among many annealing methods, solvent vapor annealing (SVA) is a low-cost, highly efficient way to annihilate defects in BCP thin films and facilitates the formation of highly ordered microdomains within minutes. Directing the self-assembly …

Phase Behavior Of Block Copolymers In Compressed Co2 And As Single Domain-Layer, Nanolithographic Etch Resists For Sub-10 Nm Pattern Transfer, Curran Matthew Chandler

Open Access Dissertations

Diblock copolymers have many interesting properties, which first and foremost include their ability to self-assemble into various ordered, regularly spaced domains with nanometer-scale feature sizes. The work in this dissertation can be logically divided into two parts - the first and the majority of this work describes the phase behavior of certain block copolymer systems, and the second discusses real applications possible with block copolymer templates. Many compressible fluids have solvent-like properties dependent on fluid pressure and can be used as processing aids similar to liquid solvents. Here, compressed CO₂ was shown to swell several thin homopolymer films, including …

Patterned Well-Ordered Mesoporous Silica Films For Device Fabrication, Todd A. Crosby

Masters Theses 1911 - February 2014

Developing effective methods of generating thin metal oxide films are important for sensing and separations applications. An obstacle to device fabrication is controlling the size and spatial orientation of domain level pores while retaining the ability to generate arbitrary device level patterns. Well-ordered hexagonally packed cylindrical pores were created by taking advantage of block copolymer self-assembly followed by selective condensation of silica precursors using supercritical carbon dioxide as the solvent. It was possible to control the pore size by choosing PEO-PPO-PEO (Pluronic® series) triblock copolymers of differing molecular weights.

These processes were then incorporated with conventional lithographic techniques to generate …