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

Engineering Science and Materials Commons

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

Articles 1 - 6 of 6

Full-Text Articles in Engineering Science and Materials

Controlled Folding In Precisely Functionalized Polyethylenes: Designing Nanoscale Lamellar Structures For Ion Transport, Edward Boynton Trigg Jan 2018

Controlled Folding In Precisely Functionalized Polyethylenes: Designing Nanoscale Lamellar Structures For Ion Transport, Edward Boynton Trigg

Publicly Accessible Penn Dissertations

There is great societal need for improved energy storage technology, in applications ranging from electric vehicles to grid storage to emergency power systems. New polymeric membranes with enhanced ion conductivities are needed in batteries and fuel cells to improve these technologies. Despite decades of research, these membrane materials are still not adequate for commercial use. The primary metric that requires improvement is ion or proton conductivity of the membrane under desirable operating conditions.

Modifying linear polyethylene by the addition of precisely periodic functional groups leads to a rich array of intriguing morphologies and properties. Depending on the functional group chemistry ...


Surface Chemistry Mediated Assembly Of Polymer-Grafted Nanorods In Solution And Polymer Matrices, Robert Charles Ferrier Jan 2015

Surface Chemistry Mediated Assembly Of Polymer-Grafted Nanorods In Solution And Polymer Matrices, Robert Charles Ferrier

Publicly Accessible Penn Dissertations

In the dissertation, I investigate ways to assemble nanorods, typically made of gold, in solution and polymer matrices by controlling surface chemistry. Gold nanorods were anisotropically functionalized with polymer on the side and alkane dithiol on the end causing the gold nanorods to spontaneously assemble in solution. The assembly could be tuned by controlling the incubation time which affected the solution absorbance due to plasmon coupling. Linked gold nanorods were cast in polymer thin films and their optical properties were imparted to the film. This anisotropic functionalization method was utilized to placed DNA or peptides on the ends of the ...


Engineering Extracellular Matrix Signals Into Fibrous Hyaluronic Acid Hydrogels, Ryan Joseph Wade Jan 2015

Engineering Extracellular Matrix Signals Into Fibrous Hyaluronic Acid Hydrogels, Ryan Joseph Wade

Publicly Accessible Penn Dissertations

Hydrogels have gained widespread use in biomedical applications for their ability to mimic certain features of the natural extracellular matrix (ECM) including tissue-like mechanics, water-swollen environments, and biodegradability. Despite these advantages, hydrogels typically do not present the fibrous architecture of natural ECM, even though this structure can guide cell behavior and tissue function. With this in mind, the overall goal of this dissertation is the translation of hydrogels from hyaluronic acid (HA) macromers into more complex, fibrous networks with spatiotemporal control. First, HA macromers that contain protease-cleavable and fluorescent peptides were synthesized and shown to form both isotropic hydrogels and ...


Structure-Property Relationships Of Imidazolium-Containing Polymer Systems: Homopolymers, Block Copolymers, And Block Copolymer/Ionic Liquid Mixtures, Sharon Sharick Jan 2015

Structure-Property Relationships Of Imidazolium-Containing Polymer Systems: Homopolymers, Block Copolymers, And Block Copolymer/Ionic Liquid Mixtures, Sharon Sharick

Publicly Accessible Penn Dissertations

Advanced solid-state polymer electrolytes for electrochemical and energy storage applications are needed to replace conventional liquid electrolytes that are unstable, flammable, and volatile. In particular, a fundamental understanding of morphology-ionic conductivity relationships is necessary to improve the ionic conductivity of ion-containing polymer systems. To this end, we investigate the structure-property relationships of homopolymer and block copolymer systems containing imidazolium-based ionic liquids (ILs). We first explore the effects of anion type and pendant alkyl chain length on the morphologies and properties of polymerized ionic liquid (PIL) homopolymers with bound cations. In both acrylate-based and vinylimidazolium PIL homopolymers, nanoscale segregation of polar ...


Hierarchical Assemblies Of Soft Matters From Polymers And Liquid Crystals On Structured Surfaces, Apiradee Honglawan Jan 2013

Hierarchical Assemblies Of Soft Matters From Polymers And Liquid Crystals On Structured Surfaces, Apiradee Honglawan

Publicly Accessible Penn Dissertations

Hierarchical, multifunctional materials hold important keys to numerous advanced technologies, including electronics, optics, and medicine. This thesis encompasses generation of hierarchical structures with novel morphologies and functions through self-assembly directed by lithographically fabricated templates. Here, two soft materials, amphiphilic random copolymers of photopolymerized acryloyl chloride (ranPAC) and smectic-A liquid crystal (SmA-LC) molecule, 4'(5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-heptadecaflu-orododecyloxy)-biphenyl-4-carboxylic acid ethyl ester, are synthesized as model systems to investigate the governing principles at the topographic surface/interface.

The ranPAC can self-organize into nanomicelles with high regularity and stability ...


Multifunctional Nanomaterials Of Dna Block Copolymers: Synthesis, Self- Assembly, Thermodynamic Studies And Biomedical Applications, Xi-Jun Chen Jan 2013

Multifunctional Nanomaterials Of Dna Block Copolymers: Synthesis, Self- Assembly, Thermodynamic Studies And Biomedical Applications, Xi-Jun Chen

Publicly Accessible Penn Dissertations

Oligonucleotide-conjugated bio-hybrid nanomaterials with a dense DNA layer on the surface have been shown to possess extraordinary selectivity and sensitivity for DNA detection as well as promising results as delivery agents, as demonstrated with the exceptional example of polyvalent oligonucleotide-conjugated gold nanoparticles. However, progress in this field has been slowed, since achieving high DNA density functionalization on the nanoparticle surface for materials other than gold is a major challenge. In this body of work, we have developed a general system to conjugate a dense layer of DNA on the surface of nanoparticles by the self-assembly of DNA block copolymer. These ...