Materials Science and Engineering Commons^™

Interfacial Rheological Mechanics Of A Non-Ionic, Tri-Block Copolymer At Water/Hexadecane Interface, Jerome J. Nash, Kendra Erk

The Summer Undergraduate Research Fellowship (SURF) Symposium

Growing interest on the stability of foams and emulsions has lead to concentrated research of interfacial rheology. The response of an interfacial layer to mechanical deformation in size and shape is dependent on its composition. [Miller 2010] This research analysis focused on the adsorption and rheological mechanics of the non-ionic, tri-block copolymer, Pluronic 17R4 at the water/hexadecane interface. The adsorption and viscoelastic properties of the interface were measured via methods of pendant drop tensiometry and dynamic oscillation with drop shape analysis software. Interfacial tension measurements were taken to study the surface pressures of Pluronic 17R4 solutions with concentrations ranging from …

The Biological Impact Of Concurrent Exposure To Metallic Nanoparticles And A Static Magnetic Field, Kristen K. Comfort, Elizabeth I. Maurer, Saber M. Hussain

Chemical and Materials Engineering Faculty Publications

The rapid advancement of technology has led to an exponential increase of both nanomaterial and magnetic field utilization in applications spanning a variety of sectors. While extensive work has focused on the impact of these two variables on biological systems independently, the existence of any synergistic effects following concurrent exposure has yet to be investigated. This study sought to ascertain the induced alterations to the stress and proliferation responses of the human adult low calcium, high temperature keratinocyte (HaCaT) cell line by the application of a static magnetic field (approximately 0.5 or 30 mT) in conjunction with either gold or …

Low Volume Dispensing With High Speed Dispensers, Sunny Agarwal

Graduate Dissertations and Theses

With the high pace of innovation in the semiconductor manufacturing industry, there has been an increasing demand for more energy efficient and environmental friendly products. This research relates to a complex process of fluid dispensing at low volumes on a printed circuit board. Currently, a more refined non-contact dispensing terminology named “Streaming” is widely used to stream out material at low volumes for various applications. The key solution is to frame a dispensing method that lends itself most closely to the requirements of a specific production process.

This study represents a detailed approach of dispensing low volumes of materials in …

Improved Deinkability Of Lep (Liquid Electrophotography) Digital Prints, Zheng Wei

Masters Theses

Digital printing plays a very important role in the life of modern society. With the development of digital printing technologies, and the increasing market share of digital printing, the amount of digital prints in waste paper is rapidly increasing. Under “green” manufacturing and environmental sustainability, deinking of digital print inks is an urgent problem that needs to be solved. Indigo is a typical series of HP (Hewlett-Packard) digital presses that use a liquid ink named ElectroInk (Liquid Electrophotography or LEP). The particle size of HP ElectroInk is very small, 1-2 microns, which is smaller than dry toners. But, during flotation, …

Pan Nanofibers And Nanofiber Reinforced Composites, Cheng Ren

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Nanomaterials play an important role in the development of nanotechnology. They possess unique mechanical, physical, and chemical properties coupled with small size and ultrahigh surface area that can provide critical advantages for applications. Continuous nanofibers attract special interest due to their dual nano-macro nature and ability to bridge scales. Nanofibers are being considered for a broad range of applications spanning advanced filters, separation membranes, ultrasensitive sensors, micro/nano actuators, nanoprobes, tissue engineering scaffolds, protective and smart closing, and multifunctional composites. Most of these applications require certain mechanical properties and robustness. However, the literature on the mechanical behavior of nanofibers and their …

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 …

Complementarities Of Probabilistic And Evidence Approaches: An Uncertainty Assessment For Selection Of Composite Material, Stella B. Bondi, Resit Unal, Patrick T. Hester, Trina M. Chytka

Engineering Technology Faculty Publications

A complimentary probabilistic and evidence theory approach is utilized to enhance uncertainty assessments in the area of critical safety characteristics for conceptual design. This research provides additional exploration into the failure modes necessary to utilize Fiber Reinforced Polymer (FRP) and various composites to their fullest potential and to minimize uncertainty by comparing probability and evidence theories. This combined approach has been applied to a selection of composite material that could provide uncertainty assessment design for a space transportation system. Uncertainty estimates presented are bounded by belief and plausibility functions. The results may provide additional information to the decision makers in …

The Equi-Biaxial Fatigue Characteristics Of Epdm Under True (Cauchy) Stress Control Conditions, Mark Johnson

Conference Papers

Strain amplitude control is most often employed when carrying out fatigue testing of rubber components. Often the design engineer requires fatigue test data that is based on load amplitude control. This is analogous to engineering or nominal stress amplitude control. This usually makes it easy to maintain the load within the specified test limits during extended testing. Values of true stress and strain can be obtained from this approach, but the magnitudes of the maximum true stresses in these tests increase with accumulated cycles, whereas the equivalent maximum engineering stress values remain constant. This is easily demonstrated in the uniaxial …

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

Lunalight - Bringing Light To The Expanding World, Gabriela M. Igel, Daniel J. Patrick, Kimberley M. Smith

Materials Engineering

The LunaLight, a solar rechargeable light and cell phone charger, addresses the lack of access to electricity faced by 1.4 billion of the world’s population (International Finance Corporation). The LunaTech team has developed a product that is bright, simple, compact, versatile and competitive with existing products. Through a partnership with the non-profit organization One Million Lights, LunaTech has improved a previous team’s design to address user feedback, concerns of durability, and manufacturability.

The LunaLight design includes a 5 component plastic housing held together by 4 screws, a surface mounted PCB, a lithium-ion (Li-Ion) battery, one high-brightness LED, a solar panel, …

The Fabrication & Characterization Of An Electrokinetic Microfluidic Pump From Su-8, A Negative Epoxy-Based Photoresist, Nash Anderson

Master's Theses

Microfluidics refers to manipulation, precise control, and behavior of fluids at the micro and nanoliter scales. It has entered the realm of science as a way to precisely measure or mix small amounts of fluid to perform highly controlled reactions. Glass and polydimethylsiloxane (PDMS) are common materials used to create microfluidic devices; however, glass is difficult to process and PDMS is relatively hydrophobic. In this study, SU-8, an epoxy based (negative) photoresist was used to create various electrokinetic microfluidic chips. SU-8 is commonly used in microelectromechanical design. Spin coating of various SU-8 formulations allows for 1 μm to 100 μm …

Evaluation Of Corrosion Properties Of Proprietary Metal Alloy Stents For In-Vivo Use, Michael David Bremner

Materials Engineering

To assess corrosion rates of metal alloy bio-absorbable stents an experimental set-up was designed to mimic the coronary artery environment. The artery was modeled using 4mm diameter Tecoflex tubing and the metal alloy stents were inserted into the tubing using a catheter. As is the case in cardiac surgery, the catheter with the stent and a microballoon were maneuvered to the desired position. The microballoon was then slowly inflated to expand the stent and compress it against the tubing walls. The catheter and microballoon were then withdrawn. A circulating pump system was set up to cycle fetal bovine serum (FBS) …

Preparation Of A Polylactic Acid With Hydroxyapatite Reinforcement Composite, Odessa N. Quezon

Materials Engineering

Biodegradable polymers are a prime material choice for temporary biomedical devices due to its ability to degrade into non-toxic products for their use in vivo. However, polylactic acid (PLA) by itself lacks the sufficient strength and stiffness to permit their use as its properties begin to decrease as the polymer degrades. To improve the polymer’s mechanical properties, hydroxyapatite (HA) will be added to the PLA solution to act as reinforcement. The chemical property, glass transition temperature of a polymer, also plays a key role in the mechanical properties of the polymer. PLA’s glass temperature is 130⁰F. A polymer that …

Strength Testing And Material Characterization Of Cactus Spines, Mary Cooper, Jeff Goldstein, Thomas Tarlton

Materials Engineering

Twelve different species of cactus spines from 6 different genera were collected from living specimens and maintained in a dry storage environment. Spines from each species underwent 3-point bend testing, XRD testing, and SEM imaging. XRD analysis was used to verify the presence of cellulose whisker like nanocrystals and to calculate the percent crystallinity of each spine. SEM images were captured of fracture surfaces at viewing angles of 90° and 45° relative to the fracture surface, with magnifications ranging between 150x and 4,000x. A total of six spines from each species were tested in three point bending using a high-resolution …

Design And Construction Of A Simulated Evaporative Heat Exchanger For Testing The Mitigation Effects Of Pipe Coatings On Mineral Scale Deposition, Taylor J. Anderson

Materials Engineering

The thermal efficiency of evaporative heat exchangers is diminishing due to mineral scale buildup on heat exchanger surfaces. A simulated evaporative heat exchanger was designed and constructed for testing the mitigation effects of polymer coatings on mineral scale deposition rates. The heat exchanger was designed to cool hot mud at 200°F using a cooling water supply with a calcium concentration of 1000 ppm. The system was constructed using 1.5-inch diameter polypropylene piping, a DIG Corporation drip irrigation system, a TotalPond 530 GPH pond pump, an Omega CSI32K miniature benchtop controller, Omega FWH321-020 high temperature heater tape, and fifteen copper pipe …

Analyzing The Acoustical Properties Of Alternative Materials In Guitar Soundboards To Reduce Deforestation, Chris Dunn

Materials Engineering

To mitigate the effects of deforestation, man-made alternative materials were analyzed and tested for potential use in the soundboards of acoustic guitars. The materials evaluated included 0.06 in. foamed polycarbonate, 0.12 in. single-ply honeycomb fiberglass, and 0.04 in. epoxy fiberglass. The properties of Sitka spruce, the most common tonewood, were used as a benchmark. The Young’s modulus to density ratio found in Sitka spruce is relatively high, making its properties ideal for soundboard applications. Both Young’s modulus and density were necessary to calculate the acoustic constant of each material that was tested. The samples were subject to the impact of …

Comparison Of Polyurethane And Polysiloxane Coating Systems In Marine Environments, Jake Jarman, Jessica Salvatin

Materials Engineering

This project investigates the performance benefits of polysiloxane and polyurethane coating systems for corrosion protection in marine environments. PPG Industries Amercoat 450H and International Paint Interthane 990HS were the polyurethane topcoats tested. PPG Industries Ameron PSX 700 (New Blend) and International Paint Interfine 878 were the polysiloxane topcoats tested. Each coating was sprayed onto carbon steel panels that were prepared through hand blasting with glass beads. Scribed and unscribed panels were tested in a salt fog chamber for 1,200 hours according to ASTM Standard B0117-11 and in a UV/Humidifier for 1,650 hours according to ASTM Standard D4587-11. Panels were tested …

An Investigation Of Arabinan And Cellulose Based Nano-Composite Fabrication Methods, Marianne Smithfield, Carl Petterson, Robert Miller

Materials Engineering

Microcrystalline cellulose was converted into nanocrystalline cellulose via an acid hydrolysis procedure. Scanning electron microscopy (SEM) was employed to measure the particle size and thus the effectiveness of acid hydrolysis. The nanocrystalline cellulose was poured through a 0.2μm filter to isolate the particles of ideal size. The nanocrystalline cellulose samples were stored in dimethylformamide (DMF) to prevent mold growth and agglomeration upon drying. Numerous composite samples were created by dissolving the arabinan in a solvent, suspending cellulose in the arabinan solution, and then drying the sample. Casting was performed in a silicon mold to allow sample removal without damage. Initial …

Low Velocity Impact Tower Feasibility, Setup, And Impact Testing Of Carbon Fiber Reinforced Epoxy Thermoset And Peek Thermoplastic Matrix Composites, Brent Plehn

Materials Engineering

A low velocity impact tower was donated to Cal Poly's Materials Engineering Department along with four fiber reinforced polymer matrix composites. The tower was set up in building 192 in the Mechanical Testing Laboratory. Improvements were made to the tower including adding velocity detection capabilities, making loose hardware inclusive, adding an extra tower arm for better consistency, adding a double jawed clamp for faster testing, and rerouting the tower's compressed air system to improve performance. A standard operating procedure was drafted, tested, and redrafted for impact testing composite panels. The four composite panels consisted of two quasi-isotropic 16 ply AS-1 …

Surfactant Formulations For Water-Based Processing Of A Polythiophene Derivative, Cameron Dean Danesh

Master's Theses

Conjugated polymers are semiconducting materials that are currently being researched for numerous applications from chemical and biological sensors to electronic devices, including photovoltaics and transistors. Much of the novel research on conjugated polymers is performed in academic settings, where scientists are working to prepare conjugated polymers for commercially viable applications. By offering numerous advantages, inherent in macromolecular materials, conjugated polymers may hold the key to cheap and environmentally friendly manufacturing of future electronic devices. Mechanical flexibility, and solvent-based coating processes are two commonly cited advantages. Transitions in the backbone conformation of polythiophenes (PT) in organic solvents have been widely observed …

Shelf Life Study Of Electrospun Plga Copolymers, Sean Youra, Nick Hudson

Biomedical Engineering

Poly(lactic-co-glycolic acid) (PLGA) is one of the most commonly used copolymers for electrospinning in tissue engineering applications. However, most research has not focused on the copolymer itself in regards to how long it can be used effectively and if varying the concentrations of polylactic acid (PLA) and polyglycolic acid (PGA) affect the resulting properties. Electrospinning is the method we use to create the three-dimensional constructs, or “scaffolds”, for the blood vessel mimic (BVM) in the tissue engineering lab. The aim of our project was to investigate if the morphology and mechanical properties of the scaffolds changed over time when they …

Design And Fundamental Understanding Of Minimum Quantity Lubrication (Mql) Assisted Grinding Using Advanced Nanolubricants, Parash Kalita

Graduate Theses and Dissertations

Abrasive grinding is widely used across manufacturing industry for finishing parts and components requiring smooth superficial textures and precise dimensional tolerances and accuracy. Unlike any other machining operations, the complex thermo-mechanical processes during grinding produce excessive friction-induced energy consumption, heat, and intense contact seizures. Lubrication and cooling from grinding fluids is crucial in minimizing the deleterious effects of friction and heat to maximize the output part quality and process efficiency. The conventional flood grinding approach of an uneconomical application of large quantities of chemically active fluids has been found ineffective to provide sufficient lubrication and produces waste streams and pollutants …

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

Bacterial Growth On Metal And Non-Metal Surfaces In A Static Bioreactor, Rolan Yuk Loong Liong

Master's Theses

Research was conducted to observe bacterial growth on the surface of metals in a static bioreactor. Metal and non-metal samples were subjected to bacterial exposure (1 day and 9 days). The metal samples were surface treated prior to bacterial exposure. The microstructures of the surface treated samples were analyzed by optical microscopy. After exposure, the microstructures of the samples were analyzed by scanning electron microscopy (SEM). The analysis suggested that microbial attachment on the surface was related to the underlying microstructure of steel. The preferential attachment of microbes could potentially be influenced by cathodic and anodic regions created by the …

Study Of An Alternative Process For Oxidizing Vapor Grown Carbon Nanofibers Using Electron Beam Accelerators, Maria Cecília Evora, Donald A. Klosterman, Khalid Lafdi, Lingchuan Li, L.G.A. Silva

Chemical and Materials Engineering Faculty Publications

The use of a high-energy electron beam was explored in this study as an alternative technique for oxidizing vapor grown carbon nanofiber surfaces. The radiation exposures were carried out at three different electron beam facilities with beam energies of 1.5, 3.0 and 4.5 MeV and radiation doses ranging from 1000 to 3500 kGy. XPS analysis showed that oxygen was readily incorporated on the surface: the ratio O1s/C1s increased approximately by a factor of 4 when the carbon nanofibers were irradiated at 3500 kGy. The oxidized nanofibers exhibited better dispersion in a water/methanol solution (50% v/v) than as-received nanofibers. Raman spectroscopy …

High-Stress Shear-Induced Crystallization In Isotactic Polypropylene And Propylene/Ethylene Random Copolymers, Zhe Ma, Lucia Fernandez-Ballester, Dario Cavallo, Tim Gough, Gerrit W. M. Peters

Department of Mechanical and Materials Engineering: Faculty Publications

Crystallization of an isotactic polypropylene (iPP) homopolymer and two propylene/ethylene random copolymers (RACO), induced by high-stress shear, was studied using in situ synchrotron wide-angle X-ray diffraction (WAXD) at 137 °C. The “depth sectioning” method (Fernandez-Ballester, Journal of Rheology 53:5 (2009), pp. 1229−1254) was applied in order to isolate the contributions of different layers in the stress gradient direction and to relate specific structural evolution to the corresponding local stress. This approach gives quantitative results in terms of the specific length of fibrillar nuclei as a function of the applied stress. As expected, crystallization becomes faster with increasing stress—from the inner …