Chemical Engineering Commons^™

Electrospinning Applications Air Filtration And Superhydrophobic Materials, Negar Ghochaghi, Adetoun Taiwo

Graduate Research Posters

Electrospinning is a widely applicable technique that generates non-woven fibers in the micro and nano range. In this project two of its applications are highlighted namely filtration media and enhancement of wettability. The first project demonstrates that electrospinning can be used to produce new fiber filtration media with controlled microstructure. The bimodal and unimodal orthogonal and random filters were made and characterized against their filtration efficiency and pressure drop. Figure of Merit (FOM) was also calculated and discussed. It is shown that the FOM increases when the electrospun fibers are arranged into alternating layers of aligned course and fine fibers. …

Layer-By-Layer Assemblies For Membrane-Based Enzymatic Catalysis, Andrew R. Tomaino

Theses and Dissertations--Chemical and Materials Engineering

While considerable progress has been made towards understanding the effect that membrane-based layer-by-layer (LbL) immobilizations have on the activity and stability of enzymatic catalysis, detailed work is required in order to fundamentally quantify and optimize the functionalization and operating conditions that define these properties. This work aims to probe deeper into the nature of transport mechanisms by use of pressure-induced, flow-driven enzymatic catalysis of LbL-functionalized hydrophilized poly(vinyldiene) (PVDF)-poly(acrylic acid) (PAA)-poly(allylamine hydrochloride) (PAH)-glucose oxidase (GOx) membranes. These membranes were coupled in a sealed series following cellulose acetate (CA) membranes for the elimination of product accumulation within the feed-side solution during operation. …

Generation Of Multicomponent Polymer Blend Microparticles Using Droplet Evaporation Technique And Modeling Evaporation Of Binary Droplet Containing Non-Volatile Solute, Venkat N. Rajagopalan

Theses and Dissertations--Chemical and Materials Engineering

Recently, considerable attention has been focused on the generation of nano- and micrometer scale multicomponent polymer particles with specifically tailored mechanical, electrical and optical properties. As only a few polymer-polymer pairs are miscible, the set of multicomponent polymer systems achievable by conventional methods, such as melt blending, is severely limited in property ranges. Therefore, researchers have been evaluating synthesis methods that can arbitrarily blend immiscible solvent pairs, thus expanding the range of properties that are practical. The generation of blended microparticles by evaporating a co-solvent from aerosol droplets containing two dissolved immiscible polymers in solution seems likely to exhibit a …

Plasma Processes And Polymers Special Issue On: Plasma And Cancer, Mounir Laroussi, Michael Keidar

Electrical & Computer Engineering Faculty Publications

During the last two decades, research efforts on the application of low temperature plasmas in biology and medicine have positioned nonequilibrium lowtemperature plasmas as a technology that has the potential of revolutionizing healthcare.[1,2] Low temperature plasmas can be applied in direct contact with living tissues to inactivate bacteria,[3] to disinfect wounds and accelerate wound healing,[4] and to induce damage in some cancer cells.[5–11]

Sulfonated Perfluorocyclobutyl (Pfcb) Aryl Ether Polymers: Synthesis, Reactivity, And Characterization For Polymer Electrolyte Applications, Jiyoung Park

All Dissertations

Perfluorocyclobutyl (PFCB) aryl ether copolymers are excellent candidates for proton exchange membrane (PEM) component in PEM fuel cells. Sulfonated PFCB copolymer membranes exhibit not only high chemical/thermal/mechanical stability but also high proton conductivity. In this regard, PFCB aryl ether copolymers were synthesized via thermal step-growth [2 + 2] cyclopolymerization from aryl bis-(trifluorovinyl ether) (TFVE) monomers and oligomers. Experimental and computational studies confirmed that copolymerization of relatively electron-rich and electron-poor TFVE monomers gave selective-segmented copolymers in an one-pot polymerization. After sulfonation, the PFCB copolymers comprising hydrophilic and hydrophobic segments gave membranes with high proton conductivity. Cross-linked membranes of the sulfonated PFCB …

Optimization Of Polymer Separation By Gradient Polymer Elution Chromatography, Gideon R. Liem, Linda Nien-Hwa Wang

The Summer Undergraduate Research Fellowship (SURF) Symposium

High Performance Liquid Chromatography (HPLC) has been a versatile separation method for polymers for many years. Analysis of different polymers by HPLC is typically done by utilizing the differential solubility of the polymers by mixing a good solvent and an anti-solvent in various compositions. This method is called Gradient Polymer Elution Chromatography (GPEC). While GPEC has been used extensively, it commonly uses a linear gradient to separate components. Linear solvent gradients consume a lot of solvent and take a relatively long time (> 30 minutes) to complete. The goal of this study is to develop a step gradient from a …

Synthesis And Characterization Of Bismuth Telluride Nanoparticles For Use In Flexible Polymer-Nanoparticle Hybrid Thermoelectric Devices, Alexander R. Muller, Bryan Boudouris, Edward P. Tomlinson

The Summer Undergraduate Research Fellowship (SURF) Symposium

Polymer-based thermoelectric materials, which can have readily-tuned properties through simple control of their chemistry, offer the promise of providing flexible, lightweight, and low-cost modules for the environmentally-friendly conversion of waste heat to electricity without the need for moving parts. As such, they have started to be explored in applications ranging from improved building efficiency to increased mileage in automobiles. However, widespread implementation of these materials is limited due to their low performance relative to their mechanically-rigid, heavy inorganic material-based counterparts. Therefore, a critical need exists to design polymer-nanoparticle composite materials to increase the energy conversion of thin film thermoelectric devices. …

Tobacco Mosaic Virus Implemented As An Interfacial Layer In Organic Photovoltaic Cells, Monica D. Del Real, Bryan Boudouris

The Summer Undergraduate Research Fellowship (SURF) Symposium

Organic photovoltaics (OPVs) are flexible, light weight, and economical to produce due to low processing temperatures, solution processing, and print fabrication. This makes them optimal for a wide range of applications. However, the efficiencies of OPVs are currently not high enough for them to be viable in the market or to be able to compete with inorganic photovoltaics. Therefore the integration of new materials and methods into OPVs in order to increase their efficiency is a vital field. One way to increase the efficiency of OPVs is to increase the surface area in-between layers to allow for enhanced electron transport. …

Extending The Shelf Life Of Solid Rocket Motors Through Mechanical Activation Of, Emilio J. Cantu, Hope Klukovich, Timothy Haddad

STAR Program Research Presentations

A great deal of interest has been given to extending the life of our fleet of solid rocket motors. Once poured, these motors are essentially stored, unused, and are therefore subject to various environmental conditions. Cycling between high and low temperatures causes thermal expansion and contraction of motor materials. This will eventually lead to cracks forming and propagating in the rocket motor, rendering it unreliable and thus must be re-poured at great expense. A common binder material used in these motors is hydroxy-terminated polybutadiene (HTPB), which when cured with a diisocyanate, creates the solid matrix to house the energetic materials …

A Localized Controlled Delivery System Utilizing A Block Copolymer To Improve The Current Paradigm Of Chemotherapy, Jason Olbrich

All Dissertations

The goal of the field of Bioengineering has always been to bring about a better standard of care for patients. As a field encompassing a broad array of researchers and talents, such improvements often are brought about through the integration of different fields. This work advances the integration of controlled delivery and chemotherapy. The use of cytotoxic chemotherapy has become and will continue to be a powerful tool for the treatment of solid malignancies. Conventional dose scheduling of cytotoxic agents and newer biological response modifiers are investigated under a clinical paradigm initially designed to identify a drug dose that elicits …

Improving The Efficiency Of P3ht:Icba Organic Solar Cells By Modifying The Photoactive Solution Preparation Step, Matthew Blaine Samson

Electrical & Computer Engineering Theses & Dissertations

Organic solar cells (OSCs) are a promising alternative to conventional silicon solar cells. These organic devices offer the promise of facile low cost large scale solution based processing on lightweight, flexible, plastic substrates. At the present state of the technology, however, OSCs exhibit relatively low power conversion efficiencies. To improve these efficiencies, new materials are constantly being developed.

One such material is the fullerene indene-C₆₀ bisadduct (ICBA). When implemented in a poly(3-hexylthiophene-2, 5-diyl) (P3HT) : ICBA bulk heterojunction solar cell, these devices exhibit open circuit voltages exceeding 0.8 V, a value much higher than the devices made implementing phenyl-C …

Materials Education And Research In Art And Design: A New Role For Libraries (Survey Stats), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Education And Research In Art And Design: A New Role For Libraries (Program Sheet), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Education And Research In Art And Design: A New Role For Libraries (Program Booklet), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Education And Research In Art And Design: A New Role For Libraries (Website), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Collection Creation And Administration: A New Role For Libraries (White Paper), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

The Problem/Opportunity: To define, identify, and guide design-based materials collections in academic settings and foster community among those with existing collections and/or those considering creating and supporting one.

Contents and topics:

1. What is a materials collection?
2. Why have a materials collection?
3. Acquisition strategies
4. Organizational approaches
5. Programming possibilities
6. Symposium summary
7. Resources

Aqueous Suspensions Of Polymer Coated Magnetite Nanoparticles: Colloidal Stability, Specific Absorption Rate, And Transverse Relaxivity, Steven Saville

All Dissertations

The design, functionalization, characterization, and applications of magnetic nanoparticles have garnered significant interest over the past several decades. While this area has garnered increasing attention, several questions remain unanswered about the stability of these systems and it's influence on their biomedical applications. To help answer these questions about the stability of these, a novel tri(nitroDOPA) terminated polymer based ligand has been developed for the stabilization of magnetite nanoparticles. The synthesis involves a process in which ethylene oxide is polymerized using a trivinyl initiator, modified with carboxylic acid using a free radical addition of mercaptoundecanoic acid, and then functionalized with nitroDOPA …

Applied Analysis Of Ionic Polymer Metal-Composite Actuators, Siul Ruiz, Benjamin Mead, Woosoon Yim

College of Engineering: Graduate Celebration Programs

• IPMC is a type of smart material called an electroactive polymer
• Consists of an ionic polymer such as Nafion or Flemion and a conducive metal such as platinum or gold
• COMSOL multi-physics simulations accurately model the experimental displacement results
• Optimization performed using the multi-physics model to find the maximum deflection, force, and twisting
• Using the closed loop control system accurate IPMC tip location can be achieved
• This control system has been extended to function using a computer mouse as an input

Measuring Acoustic Attenuation Of Polymer Materials Using Drop Ball Test, Yi Zhang

Doctoral Dissertations and Master's Theses

Polymers are often used for vibration damping and energy absorption. The effect of a material in reducing the strength of sound waves traveling through it is called acoustic attenuation. In the past, attenuation has mostly been evaluated in the MHz frequency range, using a pulse generator and transmitting transducer as the wave source. However, most real acoustic activities occur at frequencies up to a few hundred kHz. Here, a simple drop ball mechanism is used to generate acoustic source waves in the kHz range, and the attenuation capacities of several solid materials are measured. The recorded waveforms substantially differ between …

Applications Of Antioxidant And Anti-Inflammatory Polymers To Inhibit Injury And Disease, David B. Cochran

Theses and Dissertations--Chemical and Materials Engineering

There is an undeniable link between oxidative stress, inflammation, and disease. Currently, approaches using antioxidant therapies have been largely unsuccessful due to poor delivery and bioavailability. Responding to these limitations, we have developed classes of polymer and delivery systems that can overcome the challenges of antioxidant and anti-inflammatory therapy. In our initial studies, nanoparticles of poly(trolox), a polymeric form of trolox, were surface-modified with antibodies. This modification allows for specific targeting to endothelial cells, affording controllable and localized protection against oxidative stress. We have shown these targeted nanoparticles bind, internalize, and provide protection against oxidative stress generation and cytotoxicity from …

Characterization Of And Controlling Morphology Of Ultra-Thin Nanocomposites, Guy C. Laine

Theses and Dissertations--Chemical and Materials Engineering

Ultrathin film nanocomposites are becoming increasingly important for specialized performance of commercial coatings. Critical challenges for ultrathin film nanocomposites include their synthesis and characterization as well as their performance properties, including surface roughness, optical properties (haze, refractive index as examples), and mechanical properties. The objective of this work is to control the surface roughness of ultrathin film nanocomposites by changing the average particle size and the particle volume fraction (loading) of monomodal particle size distributions. This work evaluated one-layer and two-layer films for their surface properties. Monodispersed colloidal silica nanoparticles were incorporated into an acrylate-based monomer system as the model …

Flexural Rigidity Characterization Of Retrofitted Frp Plates, Steven J. Makonis Jr., Stella B. Bondi, Zia Razzaq

Civil & Environmental Engineering Faculty Publications

Presented herein is a procedure and numerical results for flexural rigidity characterization of Fiber Reinforced Polymer (FRP) plates retrofitted with various types of fabrics. The FRP plates were retrofitted with Kevlar® 49 (Aramid), Carbon Fiber (Harness-Satin H5), and Unidirectional Carbon Fiber (T700 Aerospace Grade) fabrics, respectively. The FRP plate flexural rigidity values were calculated with a central finitedifference iterative scheme while utilizing the experimental load-deflection relations based on bending tests. The tests were performed on each plate by applying a concentrated load at the center. A fourth-order partial differential equation of plate equilibrium was adopted to estimate the plate flexural …

Brazel, Christopher S.: Fundamental Principles Of Polymeric Materials (Book Review), Jeffrey H. Glans

Chemistry & Physics Faculty Publications

Book review by Jeffrey H. Glans:

Brazel, Christopher S. and Stephen L. Rosen. Fundamental principles of polymeric materials. 3rd ed. Wiley, 2012.

ISBN 9780470505427

Did Mineral Surface Chemistry And Toxicity Contribute To Evolution Of Microbial Extracellular Polymeric Substances?, Jie Xu, Jay M. Campbell, Nianli Zhang, William J. Hickey, Nita Sahai

College of Polymer Science and Polymer Engineering

Modern ecological niches are teeming with an astonishing diversity of microbial life in biofilms closely associated with mineral surfaces, which highlights the remarkable success of microorganisms in conquering the challenges and capitalizing on the benefits presented by the mineral-water interface. Biofilm formation capability likely evolved on early Earth because biofilms provide crucial cell survival functions. The potential toxicity of mineral surfaces toward cells and the complexities of the mineral-water-cell interface in determining the toxicity mechanisms, however, have not been fully appreciated. Here, we report a previously unrecognized role for extracellular polymeric substances (EPS), which form biofilms in shielding cells against …

Clay Minerals For Nanocomposites And Biotechnology: Surface Modification, Dynamics And Responses To Stimuli, Hendrik Heinz

College of Polymer Science and Polymer Engineering

Clay minerals find a wide range of application in composites, paints, drilling liquids, cosmetics, and medicine. This article reviews chemical and physical properties of natural and organically modified clay minerals to understand the nanometre-scale structure, surface characteristics, and application in functional materials. The relation between fundamental properties and materials design is emphasized and illustrated by examples. The discussion comprises the following: an overview; surface structure and cation density; solubility and solubility reversal by surface modification; the degree of covalent and ionic bonding represented by atomic charges; the distribution of metal substitution sites; measurements and simulations of interfacial properties at the …

Temperature Dependent Droplet Impact Dynamics On Flat And Textured Surfaces, Azar Alizadeh, Vaibhav Bahadur, Sheng Zhong, Wen Shang, Ri Li, James Ruud, Masako Yamada, Liehui Ge, Ali Dhinojwala, Manohar Sohal

College of Polymer Science and Polymer Engineering

Droplet impact dynamics determines the performance of surfaces used in many applications such as anti-icing, condensation, boiling, and heat transfer. We study impact dynamics of water droplets on surfaces with chemistry/texture ranging from hydrophilic to superhydrophobic and across a temperature range spanning below freezing to near boiling conditions. Droplet retraction shows very strong temperature dependence especially on hydrophilic surfaces; it is seen that lower substrate temperatures lead to lesser retraction. Physics-based analyses show that the increased viscosity associated with lower temperatures combined with an increased work of adhesion can explain the decreased retraction. The present findings serve as a starting …

Can Morphology Tailoring Improve The Open Circuit Voltage Of Organic Solar Cells?, Biswajit Ray, M. S. Lundstrom, Muhammad A. Alam

Birck and NCN Publications

While the effect of interfacial morphology on the short circuit current (I_SC) of organic photovoltaic devices (OPVs) is well known, its impact on open circuit voltage (V_OC) and fill-factor (FF) are less clear. Since the output power of a solar cell Pout = I_SCV_OCFF, such understanding is critical for designing high-performance, morphology-engineered OPVs. In this letter, we provide an explicit analytical proof that any effort to radically improve V_OC by tailoring bulk heterojunction morphology is futile, because any increase in ISC due to larger interface area is counterbalanced by corresponding increase …

Development Of Eco-Friendly Flame Retardant Fabric Using Phosphorus Based Intumescence Chemistry, Vikas P. Joshi

Master's Theses and Doctoral Dissertations

The research aims at developing Eco-friendly flame retardant textile fabric using phosphorous based intumescence chemistry. Phosphorous in the structure of Spirocyclic pentaerythriol diphosphoryl chloride (SPDPC) acts as the main group to impart flame retardancy. Intermediate compounds were synthesized in the laboratory and finally converted into sol. The silane sol was applied to the textile material using pad-dry-cure method. The intermediate compounds and the coated material were tested using Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimeter (DSC), and Thermogravemetric analysis (TGA) testing instruments. Vertical flammability testing was performed as per ASTM D-6413 standards to test the fabric for its flame …

Light-Emitting Nanocomposites And Novel Amorphous Polymers For Optical Applications, Kyle Gipson

All Dissertations

Polymeric optical materials generally are comprised of amorphous polymers that are transparent in at visible wavelengths but exhibit strong absorption bands in the near-infrared making them less useful for many optical applications. Attenuation, which is the absorption per unit length, largely results from the high vibrational energy associated with carbon-hydrogen bonds contained in the polymer backbone. Attenuation can be mitigated by optical amplification utilizing light emitting additives. Investigated in this dissertation are synthesis techniques for the fabrication of light-emitting polymer nanocomposites and their resultant thermal and rheological characteristics for potential use as polymer optical fibers or films.
Inorganic nanocrystals doped …

Determining A Method For Rendering Low Cost Cdse(Zns) Core(Shell) Quantum Dots Aqueous Soluble Via Amphiphilic Polymer Wrapping, Patrick Mcbride

Materials Engineering

Herein is described the procedure of two amphiphilic polymer wrapping techniques that may be employed for obtaining aqueous soluble quantum dots (QDs) for use in biological fluorescent imaging applications. The advent of QDs has led to new nanoscale fluorescent materials that exhibit unparalleled quantum yields (QYs), high resistance to photobleaching, tunable emissions, and
absorption over a large optical range. However, the QD synthesis employed here at Cal Poly to obtain bright, photostable CdSe(ZnS) core(shell) QDs involves the use of organic solvents and surfactants, leading to hydrophobic QDs. Since all of biology relies on aqueous solubility, this hydrophobicity creates a major …