Cellulose Nanocrystals As A Material For Microencapsulation, 2013 Purdue University
Cellulose Nanocrystals As A Material For Microencapsulation, Lauren C. Kennedy, Congwang Ye, Colton Steiner, Carlos Martinez
The Summer Undergraduate Research Fellowship (SURF) Symposium
Cellulose is an abundant, biodegradable, and inexpensive renewable polymer that is light in weight with high mechanical strength (Habibi, Lucia, Rojas 2010). Full fibers of cellulose have been used in many products such as plastics and textiles for over a century and a half, but recently, modern extraction techniques have made it possible to investigate uses for minuscule cellulose fibers (Habibi, Lucia, Rojas 2010). Through acid hydrolysis, cellulose fibers become rod-like nanostructures with a high aspect ratio that are known as Cellulose Nanocrystals (CNCs) (Habibi, Lucia, Rojas 2010). Since CNCs are biodegradable and derive from a renewable resource, finding ways …
Next Generation Crystal Viewing Tool, 2013 Purdue University
Next Generation Crystal Viewing Tool, Zach Schaffter, Gerhard Klimeck
The Summer Undergraduate Research Fellowship (SURF) Symposium
The science and engineering community is limited when it comes to crystal viewing software tools. Each tool lacks in a different area such as customization of structures or visual output. Crystal Viewer 2.0 was created to have all of these features in one program. This one tool simulates virtually any crystal structure with any possible material. The vtkvis widget offers users advanced visual options not seen in any other crystal viewing software. In addition, the powerful engine behind Crystal Viewer 2.0, nanoelectronic modeling 5 or (NEMO5), performs intensive atomic calculations depending on user input. A graphical user interface, or GUI, …
Efficiently Dispersing Carbon Nanotubes In Polyphenylene Sulfide, 2013 Purdue University
Efficiently Dispersing Carbon Nanotubes In Polyphenylene Sulfide, Kevin M. Sommer, R. Byron Pipes
The Summer Undergraduate Research Fellowship (SURF) Symposium
Thermal plastics are replacing conventional metals in the aerospace, sporting, electronics, and other industries. Thermal plastics are able to withstand relatively high temperatures, have good fatigue properties, and are lighter than metals. Unfortunately, they are not very electrically conductive. However, adding carbon nanotubes to thermal plastics such as polyphenylene sulfide (PPS) can drastically increase the plastic's conductivity at a low weight percent of nanotubes called the percolation threshold. The percolation threshold is the point where adding a little more carbon nanotubes brings together the network of nanotubes and greatly increases the conductivity. We need to learn how to increase the …
Testing Self Healing Properties In Polymers, 2013 Purdue University
Testing Self Healing Properties In Polymers, Hamsini Gopalakrishna, John Blendell
The Summer Undergraduate Research Fellowship (SURF) Symposium
Mussels and barnacles have the ability to stick to underwater surfaces with the help of a cross-linked protein structure. Reduction in the plastic consumption can be achieved by using toughened polymers. Synthesized cross-linking polymers can be used for underwater adhesion by mimicking the protein structure used by mussels and barnacles. One such polymer is poly(3,4-dihydroxystyrene-co-styrene) having enhanced toughness. Traditionally, blister tests measure the adhesion between a substrate to a surface but this was modified to serve as the driving force to drive crack propagation in controlled flaws. The modified blister tests were carried out on polystyrene (PS) samples. Once the …
Interfacial Rheological Mechanics Of A Non-Ionic, Tri-Block Copolymer At Water/Hexadecane Interface, 2013 Purdue University
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, 2013 University of Dayton
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 …
Investigation Of The Morphology Of Polypropylene-Nanoclay Nanocomposites, 2013 SelectedWorks
Investigation Of The Morphology Of Polypropylene-Nanoclay Nanocomposites, Raghavendra R. Hegde Dr
Raghavendra R Hegde Dr
The morphology development in polypropylene − nanoclay composites with different weight percentages of nanoclay additives was studied using a combination of wide-angle X-ray diffraction, small-angle X-ray scattering (SAXS), polarized optical microscopy and transmission electron microscopy. SAXS studies showed an increase in long period with increase in additive weight percentage. Thermal analysis showed that even if the clay platelets are not completely exfoliated they can act as effective nucleating agents. Studies indicated that the ultimate morphology formation is influenced by both the thermodynamics of mixing and crystallization and spherulite formation. During spherulite growth, unenclosed clay platelets were excluded at the spherulite …
Scaling Reversible Adhesion In Synthetic And Biological Systems, 2013 University of Massachusetts Amherst
Scaling Reversible Adhesion In Synthetic And Biological Systems, Michael D. Bartlett
Michael Bartlett
Electrospinning Of Core-Shell Collagen Nanofibers, 2013 The University of Western Ontario
Electrospinning Of Core-Shell Collagen Nanofibers, Ying Li
Electronic Thesis and Dissertation Repository
In tissue engineering, the scaffold plays a critical role in guiding and supporting cells to function and grow optimally. The electrospun nanofibrous scaffold can serve as a near ideal substrate for tissue engineering because it has high surface area and the three-dimensional interconnected porous network can enhance cell attachment and proliferation. Core-shell nanofibrous scaffolds produced with coaxial electrospinning allow bioactive molecule encapsulation to improve cell adhesion, mediate and promote the proper signaling among the cells for their functioning and growth. In the current study, core-shell collagen nanofibers were fabricated via coaxial electrospinning with horizontal and vertical configurations. Core-shell nanofibers with …
Structure And Morphology Of Sulfonated Polysulfone And Perfluorosulfonic Acid Ionomers, 2013 University of Tennessee, Knoxville
Structure And Morphology Of Sulfonated Polysulfone And Perfluorosulfonic Acid Ionomers, Chen Wang
Doctoral Dissertations
The limitations of conventional perfluorosulfonic acid (PFSA) based membrane materials have provoked the search for alternative materials which can function as the electrolyte in PEM fuel cells operated at higher temperatures (> 100 °C) and without humidification. A novel class of sulfonated poly(phenylene) sulfone (sPSO2) ionomers have shown much higher proton conductivity than typical PFSA membranes at elevated temperatures. In this dissertation, both computational and experimental methods were used to investigate proton transfer, morphological and structural properties of sPSO2 and PFSA ionomers. We have undertaken ab initio electronic structure calculations to understand the primary hydration and the transfer of protons …
The Effect Of Processing Parameters On Barrier Properties Of Polymers, 2013 University of Tennessee, Knoxville
The Effect Of Processing Parameters On Barrier Properties Of Polymers, Russell Louis Hallman Jr.
Doctoral Dissertations
The intent of this work was to learn if polyethylene could be made with predictable water transfer rates by control of the microstructure. A series of films were formed from three different polyethylenes with a range crystallinities using melt pressing, a controlled cooling rate, and subsequent heat treatments. The samples were tested on a novel device called the polymer characterization device that measures the water transfer flux as a function of temperature. The samples’ morphology was examined using differential gradient column, differential scanning calorimetry, Fourier transform infrared microscopy, wide-angle X-ray diffractions, small-angle X-ray scattering, and small angle light scattering, and …
Tuning Cell Fate On Self-Assembled Structures, 2013 University of Tennessee, Knoxville
Tuning Cell Fate On Self-Assembled Structures, Xiaohui Wu
Doctoral Dissertations
This dissertation presents novel biodegradable copolymers with dendritic architecture, classic polymers, and inorganic materials with controlled surface topography, stiffness, and surface energy for investigating cell-material interactions and targeting tissue engineering applications. Chapter I reviews the recent progress in bone and nerve regeneration, the key factors of materials influencing cell-material interaction, and self-assembled polymer structures. Chapter II presents a divergent method to synthesize biodegrable com-dendritic tri-block copolymers consisting of poly(ethylene glycol) and poly(L-lactide) or poly(ε-caprolactone) and the MC3T3-E1 cell response to their spherulites. Chapter III presents the fabrication of deformable poly(ε-caprolactone) honeycomb films prepared via a surfactant-free breath figure method in …
Improved Deinkability Of Lep (Liquid Electrophotography) Digital Prints, 2013 Western Michigan University
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, 2013 University of Nebraska-Lincoln
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 …
Strength And Deformation Of “Tunable” Clay-Polymer Composites, 2013 University of Tennessee, Knoxville
Strength And Deformation Of “Tunable” Clay-Polymer Composites, Matthew David Bishop
Masters Theses
There are many different types of clay that exist throughout the world, and many are characterized by undesirable engineering properties. Soil improvement techniques are often implemented on these soils such as solidification, reinforcement, etc. However, these solutions are a “static” approach, as the soil’s properties cannot be modified over time. The development of the specific clay-polymer composites used in this study was motivated by the idea of creating a geomaterial that could be modified over time by adjusting its fabric, namely in the form of controlling interparticle and interlayer spacings. Therefore, the composites that are used in this study are …
Development Of A Novel Handheld Device For Active Compensation Of Physiological Tremor, 2013 The University of Western Ontario
Development Of A Novel Handheld Device For Active Compensation Of Physiological Tremor, Abhijit Saxena
Abhijit Saxena
In microsurgery, the human hand imposes certain limitations in accurately positioning the tip of a device such as scalpel. Any errors in the motion of the hand make microsurgical procedures difficult and involuntary motions such as hand tremors can make some procedures significantly difficult to perform. This is particularly true in the case of vitreoretinal microsurgery. The most familiar source of involuntary motion is physiological tremor. Real-time compensation of tremor is, therefore, necessary to assist surgeons to precisely position and manipulate the tool-tip to accurately perform a microsurgery. In this thesis, a novel handheld device (AID) is described for compensation …
Influence Of Van Der Waals Forces On Increasing The Strength And Toughness In Dynamic Fracture Of Nanofibre Networks: A Peridynamic Approach, 2013 University of Nebraska at Lincoln
Influence Of Van Der Waals Forces On Increasing The Strength And Toughness In Dynamic Fracture Of Nanofibre Networks: A Peridynamic Approach, Florin Bobaru Ph.D.
Florin Bobaru Ph.D.
The peridynamic method is used here to analyse the effect of van der Waals forces on the mechanical behaviour and strength and toughness properties of three-dimensional nanofibre networks under imposed stretch deformation. The peridynamic formulation allows for a natural inclusion of long-range forces (such as van der Waals forces) by considering all interactions as ‘long-range’. We use van der Waals interactions only between different fibres and do not need to model individual atoms. Fracture is introduced at the microstructural (peridynamic bond) level for the microelastic type bonds, while van der Waals bonds can reform at any time. We conduct statistical …
Complementarities Of Probabilistic And Evidence Approaches: An Uncertainty Assessment For Selection Of Composite Material, 2013 Old Dominion University
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, 2013 Technological University Dublin
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 (Website), 2013 Rhode Island School of Design
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.