Thermal And Mechanical Numerical Modeling Of Extrusion-Based 3d Printed Reinforced Polymers For Selecting Manufacturing Process Parameters, Sunil Bhandari
Electronic Theses and Dissertations
Extrusion-based 3D printing of thermoplastic polymer composites manufactures parts that have nonhomogenous, orthotropic, and process-dependent macro-scale material properties. As a part of the dissertation, research works were carried out to: • improve the interlayer mechanical properties and reduce the orthotropy, • use experimentally homogenized orthotropic material properties to numerically model the mechanical behavior of the non-homogenous orthotropic 3D printed parts, • create an efficient numerical thermal model to predict the process-dependent thermal history of the 3D printed part, and • aid the manufacturing process by selecting a suitable set of processing parameters based on a simplified sequentially coupled thermomechanical model. The dissertation presents four ...
Silver Microparticle And Submicron Wire - Polylactic Acid Composites For Additive Manufacturing, 2021 University of New Orleans, New Orleans
Silver Microparticle And Submicron Wire - Polylactic Acid Composites For Additive Manufacturing, Jenna W. Robichaux
University of New Orleans Theses and Dissertations
This thesis explores the incorporation of silver microparticle and submicron wire additives into thermoplastic filament feedstock for fused filament fabrication (FFF) to create multifunctional three-dimensional (3D) printable composites. The impact of silver microparticle and submicron wire additives on mechanical behavior along with antibacterial effect of the silver microparticle and submicron wire additives on printed objects were assessed.
Composite FFF filaments were fabricated by solution processing, granulation, and extrusion. Differential Scanning Calorimetry (DSC) was conducted to measure the glass transition and melting point temperatures of the composite filaments for 3D printing. The effect of the additive addition on the thermal properties ...
Automated Mini-Tubular Ceramic Production, 2021 California Polytechnic State University, San Luis Obispo
Automated Mini-Tubular Ceramic Production, Hunter Brooks, Daniel Freeman, Leo Taranta-Slack
Researchers at Lawrence Livermore National Laboratory need a way to increase the rate of manufacturing of mini-tubular ceramics to be used in testing particulate air filters. This document outlines our process from researching and writing an initial scope of work all the way to fabricating and testing a final prototype. This journey takes us through the background research, ideation process and selection of a final design. We also detail the desired engineering specifications and our concept selection process. We dedicate a significant portion of this report to discussion of our final design. We delve into how it was manufactured as ...
Optimization In The Application Of Varnishes Barrier On Cartonboard Packaging, 2021 IPT – Instituto de Pesquisas Tecnológicas do Estado de São Paulo
Optimization In The Application Of Varnishes Barrier On Cartonboard Packaging, Andre Ramalheiro De Andrade, Maria Isabel Rodrigues Phd, Eduardo Luiz Machado Phd
Journal of Applied Packaging Research
In this work adjustments in the rotogravure printing process are proposed to the varnish water vapor transmission rate (WVTR) aiming to obtain results smaller than 20g/m²/24h. One case study was used for the propositions for improvements, where focused on varnish application process in a gravure printer for an eight-printing unit cartonboard packaging, maximum printing speed of 175 m/min and a 285 g/m² weight cartonboard. The possible variables that influenced the WVTR result were selected from the technical expertise of the people involved in the project, the analysis in the printing process with the application of directed ...
Electrospinning Processing Techniques For The Manufacturing Of Composite Dielectric Elastomer Fibers, 2021 University of Wisconsin - Milwaukee
Electrospinning Processing Techniques For The Manufacturing Of Composite Dielectric Elastomer Fibers, Rani Elhajjar
Civil and Environmental Engineering Faculty Articles
Dielectric elastomers (DE) are novel composite architectures capable of large actuation strains and the ability to be formed into a variety of actuator configurations. However, the high voltage requirement of DE actuators limits their applications for a variety of applications. Fiber actuators composed of DE fibers are particularly attractive as they can be formed into artificial muscle architectures. The interest in manufacturing micro or nanoscale DE fibers is increasing due to the possible applications in tissue engineering, filtration, drug delivery, catalysis, protective textiles, and sensors. Drawing, self-assembly, template-direct synthesis, and electrospinning processing have been explored to manufacture these fibers. Electrospinning ...
Development Of The Composition Of A Composite Material Based On Thermoreactive Binder Ed-20, 2021 Tashkent State Transport University, Tashkent, Uzbekistan
Development Of The Composition Of A Composite Material Based On Thermoreactive Binder Ed-20, Umida Ziyamukhamedova, Gavhar Miradullayeva, Erkin Rakhmatov, Jasur Nafasov, Mavtuna Inogamova
CHEMISTRY AND CHEMICAL ENGINEERING
The aim of the study is to determine the effect of the type of structural modifier and filler on the structure formation and technological properties of potting composite polymeric materials (HCPM) and protective coatings for sheet and complex-configuration technological equipment, taking into account their rheological properties. Compositions of composite polymer materials based on a thermosetting binder of epoxy-diane resin ED-20 filled with a mineral filler - kaolin modified with gassipol resin (GS) - were developed using Newton's interpolation formula and the Lagrange method. The optimal amount of gossypol resin determined in the composition of the composite – in the amount of 6-10 ...
Effect Of Talc On The Properties Of A Compound Based On Ethylene-Propylene Copolymer, 2021 LLC JV “UZAUTO-CEPLA”, Tashkent, Uzbekistan
Effect Of Talc On The Properties Of A Compound Based On Ethylene-Propylene Copolymer, Ikromjon Usmanov, Farrukh Kurbanbekov, Bobir Aykhodjaev, Ravshan Adilov
CHEMISTRY AND CHEMICAL ENGINEERING
The aim of the research is to study the possibility of replacing Korean-made talc with inexpensive talc from an Afghan deposit, processed in Uzbekistan and used for the production of polypropylene compounds. In the future, these compounds are used for the manufacture of plastic car parts. A block copolymer produced by Uz Kor Gaz Chemical was chosen as a binder. For this, the influence of the content and type of talc on the properties of a compound based on an ethylene-propylene copolymer was studied.
The properties of the obtained compounds checked using ISO standards. The fractional composition of the studied ...
Poly(2-Hydroxyethyl Methacrylate) Hydrogels For Contact Lens Applications–A Review, 2021 Department of Mechanical Engineering, Faculty of Engineering and Technology, Sampoerna University, Jakarta Selatan 12780, Indonesia
Poly(2-Hydroxyethyl Methacrylate) Hydrogels For Contact Lens Applications–A Review, Kushendarsyah Saptaji, Nurlaely Rohmatul Iza, Sinta Widianingrum, Vania Katherine Mulia, Iwan Setiawan
Makara Journal of Science
The emerging technology in biomedical engineering requires biocompatible materials, which are also referred to as biomaterials. For a material to be considered biocompatible, it should not interact with human tissues in a harmful way, and vice versa. Various properties of biocompatible materials, such as mechanical and optical properties, have to be considered for different biomedical applications. One of the most popular applications of biomaterials is for contact lenses. Hydrogels, specifically poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels, are among the most popular ones in ophthalmologic applications, especially in soft contact lenses. This paper reviews the use of PHEMA hydrogels as one of ...
Seaweed Polysaccharide In Food Contact Materials (Active Packaging, Intelligent Packaging, Edible Films, And Coatings), 2021 Technological University Dublin
Seaweed Polysaccharide In Food Contact Materials (Active Packaging, Intelligent Packaging, Edible Films, And Coatings), Kalpani Y. Perera, Shubham Sharma, Amit K. Jaiswal, Swarna Jaiswal
Food contact materials (FCMs) are materials that come in contact with food products such as food packaging which play a significant role in the food quality and safety. Plastic, which is a major food packaging material, harms the eco-system, wildlife, and the environment. As a result, numerous researches have been in progress on alternative polymers, which has similar properties as plastic but is also environmentally friendly (biodegradable). In recent years, the utilization of seaweed polysaccharides has piqued interest due to its biodegradability, non-toxicity, antioxidant capabilities, and excellent film formation ability. However, it has a number of drawbacks such as low ...
Tools And Strategies For The Patterning Of Bioactive Molecules And Macromolecules, 2021 The Graduate Center, City University of New York
Tools And Strategies For The Patterning Of Bioactive Molecules And Macromolecules, Daniel J. Valles
Dissertations, Theses, and Capstone Projects
Hypersurface Photolithography (HP) is a printing method for fabricating structures and patterns composed of soft materials bound to solid surfaces and with ~1 micrometer resolution in the x, y, and z dimensions. This platform leverages benign, low intensity light to perform photochemical surface reactions with spatial and temporal control of irradiation, and, as a result, is particularly useful for patterning delicate organic and biological material. In particular, surface- initiated controlled radical polymerizations can be leveraged to create arbitrary polymer and block- copolymer brush patterns. Chapter 1 will review the advances in instrumentation architectures from our group that have made these ...
Evaluation Of Stretch Film Behavior During Long-Term Storage Under Different Atmospheric Conditions, 2021 Rochester Institute of Technology
Evaluation Of Stretch Film Behavior During Long-Term Storage Under Different Atmospheric Conditions, Kyle Dunno, Maria Symanski
Journal of Applied Packaging Research
This study examined the post-application behavior of two 20.3 micron machine stretch films, one categorized as high-performance and one as general-performance, for thirty days while stored at either 23°C or 38°C. For each film type, the stretch film was applied to a simulated unit load to produce neutral and positive applied total stretch scenarios. The relaxation curves developed from each test indicate the relaxation rate of the films varied based on the storage condition. Observed was an average of 41% containment loss for both high-performance and general-purpose films when the simulated loads were stored at 38°C ...
Characterization Techniques And Cation Exchange Membrane For Non-Aqueous Redox Flow Battery, 2021 University of Tennessee, Knoxville
Characterization Techniques And Cation Exchange Membrane For Non-Aqueous Redox Flow Battery, Kun Lou
The motivation of this work comes from one of the major problems of emerging non-aqueous flow battery (NAFB) that a separator or membrane which facilitates conductivity and blocks redox species crossover does not exist. Although many aspects of principles can be mirrored from mature fuel cell and aqueous flow battery, it is found that some well-defined membrane properties in aqueous systems such as swelling, transport and interactions are different in non-aqueous solvents to some extent. However, the approach of this work does follow the way perfluorosulfonate ion exchange membrane (PFSA) facilitated development of fuel cell and aqueous flow battery in ...
Degumming Of Hemp Fibers Using Combined Microwave Energy And Deep Eutectic Solvent, 2021 Louisiana State University and Agricultural and Mechanical College
Degumming Of Hemp Fibers Using Combined Microwave Energy And Deep Eutectic Solvent, Bulbul Ahmed
LSU Master's Theses
Hemp is considered as one of the sustainable agricultural fiber materials. Degumming or surface modification of hemp bast is needed to produce single fibers for ensuing textile and industrial applications. The traditional degumming process necessitates a high amount of alkali, which causes detrimental environmental pollution. This study offers a new method to degum hemp fibers with reduced use of harmful alkali and precious water resources. In this work, hemp bast fibers were degummed by using combined microwave energy and deep eutectic solvent (DES). The properties of hemp fibers manufactured by this method were investigated and compared with the traditional alkali ...
Designing Stimuli-Responsive Nanocomposites To Investigate Interface Dynamics, 2021 University of Massachusetts Amherst
Designing Stimuli-Responsive Nanocomposites To Investigate Interface Dynamics, Huyen Vu
Inspired by nature, this research focuses on designing multifunctional renewable nanocomposites with high toughness and stimuli-responsiveness. In recent years, cellulose nanocrystals (CNCs) have been explored due to their abundance, renewable resource, and unique mechanical strength and structural coloration. CNCs naturally self-assemble into the helicoidal (Bouligand) structure that effectively endure high impacts but is brittle without an attendant soft phase. A thermoresponsive polymer, poly(diethylene glycol methyl ether methacrylate) (PMEO2MA), was incorporated into CNCs via evaporation-induced self-assembly to improve toughness of the resulting nanocomposites and to study responses in polymer dynamics under varying temperature and humidity conditions.
To study ...
Thermoelectric Transport In Disordered Organic And Inorganic Semiconductors, 2021 University of Massachusetts Amherst
Thermoelectric Transport In Disordered Organic And Inorganic Semiconductors, Meenakshi Upadhyaya
The need for alternative energy sources has led to extensive research on optimizing the conversion efficiency of thermoelectric (TE) materials. TE efficiency is governed by figure-of-merit (ZT) and it has been an enormously challenging task to increase ZT > 1 despite decades of research due to the interdependence of material properties. Most doped inorganic semiconductors have a high electrical conductivity and moderate Seebeck coefficient, but ZT is still limited by their high lattice thermal conductivity. One approach to address this problem is to decrease thermal conductivity by means of alloying and nanostructuring, another is to consider materials with an inherently low ...
Tribological Studies Of Thick Polytetrafluoroethylene Coatings Enhanced By Polydopamine And Nanoparticles, 2021 University of Arkansas, Fayetteville
Tribological Studies Of Thick Polytetrafluoroethylene Coatings Enhanced By Polydopamine And Nanoparticles, Sujan Kumar Ghosh
Graduate Theses and Dissertations
Polytetrafluoroethylene (PTFE) is a popular low friction solid lubricant with high chemical and thermal stability. Thick PTFE coatings have the potential for many tribological applications, such as replacing Tin-based Babbitt materials in journal bearings. However, the weak bonding strength to the substrate and the high wear rate of PTFE coatings are current limiting factors. The lack of understanding of their tribological properties and wear mechanisms in oil-lubricated conditions and how coating thickness affects the tribological performance further hindered the use of PTFE coatings. In this dissertation, polydopamine (PDA), a bio-inspired adhesive, is used as an underlayer for or as a ...
Phase-Field Modeling Of The Polymer Membrane Formation Process For Micro- And Ultra-Filtration, 2021 University of Arkansas, Fayetteville
Phase-Field Modeling Of The Polymer Membrane Formation Process For Micro- And Ultra-Filtration, Michael Rosario Cervellere
Graduate Theses and Dissertations
Porous polymer membrane filters are widely used in separation and filtration process. Micro- and ultra-filtration membranes are commonly used in biopharmaceutical applications such as filtering viruses and separating proteins from a carrier solution. The formation of these membrane filters via phase inversion is a complex and interconnected process where varying casting conditions can have a wide variety of effects on the final membrane morphol- ogy. Tailoring membrane filters for specific performance characteristics is a tedious and time consuming process. The time and length scales of membrane formation make it extremely difficult to experimentally observe membrane formation. Modeling the membrane formation ...
Engineering Advanced Material Properties For Polymeric Materials Through Miscible And Immiscible Additives, 2021 University of Massachusetts Amherst
Engineering Advanced Material Properties For Polymeric Materials Through Miscible And Immiscible Additives, Chinmay M. Saraf
This dissertation focuses on engineering polymeric formulations using strategically selected additives or novel processes to achieve advanced material properties. The first chapter reviews the state-of-the-art impact modification and discusses micro-mechanics associated with soft particle toughening of polymeric materials. We present an analytical solution to elucidate the effect of concentration of rubbery domains on matrix yielding and energy absorption. Soft particle toughening relies on particle size, interparticle spacing, and concentration of rubbery phase. The second chapter demonstrates developing impact modified stereolithography (SLA) resins for the superior energy absorption of the SLA printed thermosets. SLA resins are engineered using additives that remain ...
Direct Printing/Coating/Plating Of Key Components For Electronic Devices, 2021 University of Massachusetts Amherst
Direct Printing/Coating/Plating Of Key Components For Electronic Devices, Xiyu Hu
Miniaturization has been a technological trend for several decades for electronic devices. From the practical point of view, the successful miniaturization of fully integrated systems mainly depends on their components. This dissertation examines the inkjet printing of copper oxide inks on flexible substrates for applications in microfluidic valving systems. We expand the knowledge of low-cost and high-performance electrowetting valves and fabricate the microfluidic device for fluidic control, which is necessary to enable the next-generation microfluidic devices. In addition, we also study the electromagnetic interference (EMI) shielding material, which is a crucial part of electronic devices. The basic theory of EMI ...
Experimental Investigation Of The Performance Of A Hybrid Self-Healing System In Porous Asphalt Under Fatigue Loadings, 2021 Delft University of Technology
Experimental Investigation Of The Performance Of A Hybrid Self-Healing System In Porous Asphalt Under Fatigue Loadings, Shi Xu, Liu Xueyan, Amir Tabakovic, Erik Schlangen
Self-healing asphalt, which is designed to achieve autonomic damage repair in asphalt pavement, offers a great life-extension prospect and therefore not only reduces pavement maintenance costs but also saves energy and reduces CO2 emissions. The combined asphalt self-healing system, incorporating both encapsulated rejuvenator and induction heating, can heal cracks with melted binder and aged binder rejuvenation, and the synergistic effect of the two technologies shows significant advantages in healing efficiency over the single self-healing method. This study explores the fatigue life extension prospect of the combined healing system in porous asphalt. To this aim, porous asphalt (PA) test specimens with ...