2020-
Permanent URI for this collection
Browse
Browsing 2020- by Subject "3D printing"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Open Access Fundamental and applied studies of polymeric photonic crystals: the role of polymer architecture and 3D printing(Colorado State University. Libraries, 2020) Boyle, Bret Michael, author; Miyake, Garret, advisor; McNally, Andrew, committee member; Menoni, Carmen, committee member; Prawel, David, committee memberBlock copolymers (BCP) provide a bottom-up, economical approach to synthesizing polymeric photonic crystals (PC) through the process of self-assembly. Photonic crystals (PC) are defined as periodic, dielectric nanostructures able to reflect certain wavelengths of light within a photonic band gap. The ability to directly tailor the synthesis, conformation, and self- assembly of a BCP to affect the properties of the resulting PC material creates a modular platform for PC materials design. Even though this platform exists for polymeric PC materials, the direct result of modulating the polymer architecture on the dynamics, self-assembly, and application of PC materials remains relatively unexplored. To help close this gap, this dissertation presents the polymer synthesis, characterization, and self-assembly of macromolecules within two unique classes of polymer architecture, dendritic block copolymers (DBCP) and bottlebrush block copolymers (BBCP). DBCPs were shown to possess many characteristics similar to those of bottlebrush polymers such as a rod-like conformation, a reduced capability for chain entanglement, and lower glassy moduli compared to non-rigid, linear polymers. Further, DBCPs possess high free energy parameters, as well as glass transition temperatures below melt extrusion 3D printing operating conditions, and were shown to self- assemble into PCs during the process of 3D printing. DBCP PCs represented the first example of 3D printing structural color. For BBCPs, the backbone composition's effect on the global BBCP conformation and in modulating self-assembly processes was examined. The backbone composition was shown to dramatically shift the wavelength of reflection of the PC material at similar molecular weights as well as improve the fidelity of the nanostructure morphology as the molecular weight increases from 50,000 g/mol to 2 million g/mol. The structure-property relationships illuminated herein have laid the groundwork for new research efforts into engineering BCPs for novel PC applications.Item Open Access Mechanical and antimicrobial performance analysis of a shark skin bio-mimicked fabric swatch via 3D printing(Colorado State University. Libraries, 2020) Purandare, Saloni Prasanna, author; Li, Yan Vivian, advisor; Yan, Ruoh-Nan, committee member; Prawel, David, committee memberBiomimicry is a long-practiced concept concerned with development of products with nature as the source of inspiration. Bio mimicked textiles is a branch of textiles wherein textile products are developed to replicate desirable elements of nature such as lotus-leaf inspired water repellent fabric, high-strength spider silk inspired by the spider web and shark skin biomimicry. The scaled texture on shark skin, known as riblet effect, exhibits drag reduction and antimicrobial properties. Accurate biomimicry of shark skin is an on-going continual process This study is concerned with 3D printing bio mimicked fabric swatches by replication of riblet effect followed by characterization of the developed fabric swatches. The swatches were printed using Autodesk Ember photopolymer 3D printer, allowing printing of minutely detailed denticles in the base. The materials used were polycarbonate/acrylonitrile butadiene styrene (PC/ABS) and polyurethane (PU) material. PU allowed creation of rigid tough denticles embedded in flexible and soft base, indicating as a better raw material to 3D print bio-mimicked swatches for functional clothing. The PU swatches were studied further in morphological, mechanical, and antimicrobial analysis. The morphological analysis resulted into optical images exhibiting the developed texture resembling characteristic riblet effect of shark skin. Mechanical analysis in terms of tensile stress testing exhibited stronger and tougher fabric samples with thick (1.05mm) base in comparison with those having thin (0.75mm) base. Also, the mechanical analysis indicated good elastomeric properties for the fabric swatches suggesting potential in functional clothing. Lastly, the antimicrobial test conducted exhibited reduced antimicrobial growth for samples with riblet texture against untextured samples, copper foil as well as aluminum foil thus exhibiting potential use of the textured fabric swatches as non-toxic antimicrobial material. Shark skin biomimicry through riblet effect replication has been studied majorly for hydrodynamic properties while shark skin inspired material intended for antimicrobial properties such as by Sharklet® technology is not concerned with riblet effect replication. Thus, to our best knowledge study focusing on mechanical and antimicrobial analysis of shark skin biomimicry through replication of riblet effect is missing. This study will help determine potential of shark skin biomimicry by replication of riblet effect in functional clothing, through mechanical and antimicrobial analysis.