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Broadband Measurement Of Rate-Dependent Viscoelasticity At Nanoscale Using Scanning Probe Microscope: Poly(Dimethylsiloxane) Example, Zhonghua Xu, Kyongsoo Kim, Qingze Zou, Pranav Shrotriya 2017 Iowa State University

Broadband Measurement Of Rate-Dependent Viscoelasticity At Nanoscale Using Scanning Probe Microscope: Poly(Dimethylsiloxane) Example, Zhonghua Xu, Kyongsoo Kim, Qingze Zou, Pranav Shrotriya

Pranav Shrotriya

A control approach to achieve nanoscale broadband viscoelasticmeasurement using scanning probe microscope(SPM) is reported. Current SPM-based force measurement is too slow to measure rate-dependent phenomena, and large (temporal) measurement errors can be generated when the sample itself changes rapidly. The recently developed model-less inversion-based iterative control technique is used to eliminate the dynamics and hysteresis effects of the SPM hardware on the measurements, enabling rapid excitation and measurement of rate-dependent material properties. The approach is illustrated by the mechanical characterization of poly(dimethylsiloxane) over a broad frequency range of three orders of magnitude (∼1 Hz to 4.5 KHz).


Achieving Bicontinuous Microemulsion Like Morphologies In Organic Photovoltaics, Dylan Kipp, Olga Wodo, Baskar Ganapathysubramanian, Venkat Ganesan 2017 University of Texas at Austin

Achieving Bicontinuous Microemulsion Like Morphologies In Organic Photovoltaics, Dylan Kipp, Olga Wodo, Baskar Ganapathysubramanian, Venkat Ganesan

Baskar Ganapathysubramanian

It is believed that the optimal morphology of an organic solar cell may be characterized by cocontinuous, interpenetrating donor and acceptor domains with nanoscale dimensions and high interfacial areas. One well-known equilibrium morphology that fits these characteristics is the bicontinuous microemulsion achieved by the addition of block copolymer compatibilizers to flexible polymer–polymer blends. However, there does not exist design rules for using block copolymer compatibilizers to produce bicontinuous microemulsion morphologies from the conjugated polymer/fullerene mixtures typically used to form the active layer of organic solar cells. Motivated by these considerations, we use single chain in mean field simulations ...


Fabrication And Applications Of Multifunctional Superhydrophobic Surfaces Based On Surface Chemistry And Morphology, Yang Liu 2017 The Graduate Center, City University of New York

Fabrication And Applications Of Multifunctional Superhydrophobic Surfaces Based On Surface Chemistry And Morphology, Yang Liu

All Graduate Works by Year: Dissertations, Theses, and Capstone Projects

Superhydrophobic surfaces are gaining great interests in both fundamental researches and technological applications, because of their unique non-wetting and self-cleaning properties. By mimicking the hierarchical surface structure of the natural superhydrophobic surface, i.e. lotus leaf, numerous artificial surperhydrophobic surfaces were developed. However, the challenge is how to fabricate superhydrophobic surfaces by a scalable and economical method. To address this challenge, our group has developed methodologies that enable the fabrication of superhydrophobic surfaces in inexpensive and potentially scalable ways, such as lamination and 3-D printing. To expand on applications, we also combined other desired functionalities into the superhydrophobic surfaces.

The ...


Processing And Characterization Of Nanocomposites Prepared By High Torque Melt Mixing, Lionel W. Cross Jr 2017 Clark Atlanta University

Processing And Characterization Of Nanocomposites Prepared By High Torque Melt Mixing, Lionel W. Cross Jr

Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University

The rapid development of polymer nanocomposites has received extensive attention over the last few decades. The ability to alter functionalities of composites, dramatically improving properties and performance at low filler content creates flexibility in designing materials for advanced applications in various industrial fields. This work focuses on nanocomposites relevant to the packaging and aerospace industries.

This work evaluated the ability to homogeneously distribute nanomaterials into a polymer matrix, understand the effects on rheological properties, understand changes to microstructure and effects, and characterize properties of resulting nanocomposite. High torque melt mixing was used to disperse surface modified cellulose nanocrystals in a ...


Performance Of Liquid Benzoxazine-Peg Blend Resin Systems For Potential Industrial Composites Processing, Emily Brown 2017 Western Washington University

Performance Of Liquid Benzoxazine-Peg Blend Resin Systems For Potential Industrial Composites Processing, Emily Brown

Graduate Student Conference

The manufacturing of technology and materials based on benzoxazine resin is limited by melt or solvent-based processing in which benzoxazine monomer is either dissolved in a solvent or melted to transfer onto fiberglass or carbon fiber. Solvent based processing depends on the use of organic solvents which impart health and financial risks. Benzoxazine monomer also suffers from high curing temperatures where the benzoxazine polymerizes to form structures with desirable mechanical and thermal properties. Non-flammable liquid benzoxazine resin with low curing temperatures are attractive for their exclusion of organic solvents and ease of processing. In this study three series of blends ...


Effect Of Molecular Structure Of Side Chain Polymers On "Click" Synthesis Of Thermosensitive Molecular Brushes, Christie Maggie Lau 2017 University of Tennessee, Knoxville

Effect Of Molecular Structure Of Side Chain Polymers On "Click" Synthesis Of Thermosensitive Molecular Brushes, Christie Maggie Lau

University of Tennessee Honors Thesis Projects

No abstract provided.


Effect Of Chain Rigidity On Network Architecture And Deformation Behavior Of Glassy Polymer Networks, Kyler Reser Knowles 2017 University of Southern Mississippi

Effect Of Chain Rigidity On Network Architecture And Deformation Behavior Of Glassy Polymer Networks, Kyler Reser Knowles

Dissertations

Processing carbon fiber composite laminates creates molecular-level strains in the thermoset matrix upon curing and cooling which can lead to failures such as geometry deformations, micro-cracking, and other issues. It is known strain creation is attributed to the significant volume and physical state changes undergone by the polymer matrix throughout the curing process, though storage and relaxation of cure-induced strains remain poorly understood. This dissertation establishes two approaches to address the issue. The first establishes testing methods to simultaneously measure key volumetric properties of a carbon fiber composite laminate and its polymer matrix. The second approach considers the rigidity of ...


Rate Acceleration Of Organocatalytic Ring-Opening Polymerization Rough The Application Of Bis- And Tris- ( Io)Urea H- Bond Donors, Samuel S. Spink 2017 University of Rhode Island

Rate Acceleration Of Organocatalytic Ring-Opening Polymerization Rough The Application Of Bis- And Tris- ( Io)Urea H- Bond Donors, Samuel S. Spink

Senior Honors Projects

Well-defined and functionalized polymers have a wide variety of applications in biomedical studies. Advancements in the fields of drug delivery, microelectronics, and medical imaging, among other applications, are predicated upon the development of methods for the synthesis of precision polymers. Organocatalytic ring-opening polymerization (ROP) of cyclic monomers is an effective route to the production of polymeric materials, namely polyesters and polycarbonates, whose biodegradable properties make them a viable option in biomedical research. Arguably, H-bond mediated catalysts are among the most selective catalysts for ROP, giving rise to highly functionalized polycarbonates, well-controlled polymerizations, and other custom tailored applications. With respect to ...


An Investigation Of The Use Of Cerium And Polyhedral Oligomeric Silsesquioxanes For The Protection Of Polymeric Epoxy Compounds In The Low Earth Orbit Environment, Jessica Miriam Piness 2017 University of Southern Mississippi

An Investigation Of The Use Of Cerium And Polyhedral Oligomeric Silsesquioxanes For The Protection Of Polymeric Epoxy Compounds In The Low Earth Orbit Environment, Jessica Miriam Piness

Dissertations

Low Earth orbit presents many hazards for composites including atomic oxygen, UV radiation, thermal cycling, micrometeoroids, and high energy protons. Atomic oxygen and vacuum ultraviolet radiation are of concern for space-bound polymeric materials as they degrade the polymers used as matrices for carbon fiber composites, which are used in satellites and space vehicles due to their high strength to weight ratios. Epoxy-amine thermosets comprise a common class of matrix due to processability and good thermal attributes. Polyhedral oligomeric silsesquioxanes (POSS) have shown the ability to reduce erosion in polyimides, polyurethanes, and other polymers when exposed to atomic oxygen. The POSS ...


Exploring Thermoresponsive Affinity Agents To Enhance Microdialysis Sampling Efficiency Of Proteins, Thaddeus Vasicek 2017 University of Arkansas, Fayetteville

Exploring Thermoresponsive Affinity Agents To Enhance Microdialysis Sampling Efficiency Of Proteins, Thaddeus Vasicek

Theses and Dissertations

Affinity agents increase microdialysis protein relative recovery, yet they have not seen widespread use within the microdialysis community due to their additional instrumentation requirements and prohibitive cost. This dissertation describes new affinity agents for microdialysis that require no additional instrumentation to use, have nearly 100% particle recovery, are 7 times more cost efficient than alternatives, and have low specificity enabling their use for a wide variety of proteins. Initially gold nanoparticles were chosen as an affinity ligand support due to their high surface area/volume ratio and colloidal stability. Poly (N-isopropylacrylamide) was immobilized to the gold nanoparticles, which served to ...


Improving Water Barrier Properties Of Epoxy Coatings With Addition Of Graphene Oxide, Sang H. Kim 2017 College of William and Mary

Improving Water Barrier Properties Of Epoxy Coatings With Addition Of Graphene Oxide, Sang H. Kim

Undergraduate Honors Theses

Epoxy coating paint is commonly used in metal coatings in aircraft and marine constructions due to its excellent mechanical properties and chemical resistance. However, being in a harsh environment, they are susceptible to degradation by water which significantly reduces the lifetime of the coatings. To better protect the material from corrosion, stress, degradation and absorption of water, nanofillers can be incorporated to improve the barrier properties. This paper explores the effect of incorporating graphene oxide (GO) as a nanofiller and the effect of different functionalization and surface modification of graphene oxide on reducing the water vapor permeability and water absorption ...


Sustainable Polymers: Plastics From Plants, Chris Schaller 2017 College of Saint Benedict/Saint John's University

Sustainable Polymers: Plastics From Plants, Chris Schaller

Forum Lectures

Plastics and related soft materials are ubiquitous in today's world. This presentation takes a look at why polymers have useful properties, where they come from, and why attention has shifted toward new, biorenewable materials.


High-Quality Polyurethane Foams And Sheets From Sustainable Natural Resources, Sanket Bhoyate, Chungyang Zhang, Mihail Ionescu 2017 Pittsburg State University

High-Quality Polyurethane Foams And Sheets From Sustainable Natural Resources, Sanket Bhoyate, Chungyang Zhang, Mihail Ionescu

Paper Presentations

Bio-polymers from sustainable natural resources serve mankind keeping environmental factors under consideration. Resources such as soybean, castor and orange oil are among highly cultivable agro-resources. Polyols formulated from these oils shows clean-environmental pathway for synthesizing polyurethane foams and sheets. Facile single-step synthesis, with negligible waste as well as byproducts produces 100% qualitative yield for polyurethane foams. Present work displays use of synthesized polyols in developing polyurethane foams and casts. Viscometry, FTIR spectroscopy, GPC and other chemical analysis were done to ensure the quality of the raw materials. Cast Sheets and foams were produced by chemical polymerization with di-phenyl methane diisocyanate ...


Combination Therapy Of Prostate Cancer Utilizing Functionalized Iron Oxide Nanoparticles Carrying Tnf-A And Lactonic Sophorolipids, James Beach, Tuhina Banerjee, Jyothi Kallu, Ryan Higginbotham, Richard Gross 2017 Pittsburg State University

Combination Therapy Of Prostate Cancer Utilizing Functionalized Iron Oxide Nanoparticles Carrying Tnf-A And Lactonic Sophorolipids, James Beach, Tuhina Banerjee, Jyothi Kallu, Ryan Higginbotham, Richard Gross

Paper Presentations

Prostate cancer is one of the most prevalent forms of cancer afflicting men in the United States. In recent years, advances in the field of nanotechnology have allowed for new and innovative ways to treat various types of cancer and various other diseases. Our research focuses on the treatment of the LNCaP line prostate cancer utilizing iron oxide nanoparticles (IONPs) loaded with soluble TNF-a and lactonic sophorolipids (LSLs). TNF-a is a cytokine responsible for apoptosis initiation, while LSLs are naturally-glycolipids shown to alleviate inflammation and improve immune response in certain diseases. We hypothesized that this combination may possess a synergistic ...


High Performance Supercapacitor Device Based On Polymer Derived Carbon Nanofiber With Enhanced Capacity At Elevated Temperatures, Charith Ranaweera 2017 Pittsburg State University

High Performance Supercapacitor Device Based On Polymer Derived Carbon Nanofiber With Enhanced Capacity At Elevated Temperatures, Charith Ranaweera

Paper Presentations

Recently, supercapacitors are attracting considerable interest as a promising energy storage device. In this study, we report the high performing supercapacitor based on cobalt oxide embedded carbon nanofibers (CNF@CO) fabricated by electrospinning of cobalt acetate and polyacrylonitrile mixture in to carbon nanofibers (CNF) and subsequent pyrolyzed at 800 oC under nitrogen atmosphere. Morphology and electrochemical properties of the fabricated CNF@CO was studied in detailed. Embedding of cobalt oxide in to CNF showed a remarkable improvement in the charge storage capacitance, specific capacitance of 360 F/g and 1100 F/g were observed for CNF and CNF@CO, respectively ...


High Performance Carbon Nanofiber Supercapacitor Electrode With Tuned Porous Structure, Sanket Bhoyate 2017 Pittsburg State University

High Performance Carbon Nanofiber Supercapacitor Electrode With Tuned Porous Structure, Sanket Bhoyate

Paper Presentations

High performance capacitor devices based on electric double layer capacitor (EDLC) principle has wide advantage of higher range of cyclic stability, rate capability, temperature durability and chemically resistant. Carbon based materials such as graphene, carbon nanotubes, activated carbon and carbon nanofibers are well known supercapacitor materials derived till date. Creating pores within the physical structure has found to improve the EDLC capabilities of the material. Exfoliation of graphene, activation of carbon and activation of nanofibers via various different techniques seem to be too complicated, non-consistent and needs wide range of control parameters. Facile immiscible polymer blend technique followed by thermal ...


Use Of Decahydrodecaborate As Flame Retardants In Coatings, Austin Bailey 2017 Pittsburg State University

Use Of Decahydrodecaborate As Flame Retardants In Coatings, Austin Bailey

Paper Presentations

As the need to protect the environment continues to increase, there is a growing demand for non-halogenated flame retardants. Two different decaborate compounds were combined with triphenylphosphine oxide into polyurethane and characterized. The thermal stability and the potential flame retardancy of the new materials were tested via thermogravimetric analysis and cone calorimetry. The cone test provided heat release rates and smoke release rates. Per the results of these tests the combination of the new decaborate, and triphenylphosphine oxide showed potential for flame retardancy at minimal amounts of flame retardant.


Shape Recovery With Concomitant Mechanical Strengthening Of Amphiphilic Shape Memory Polymers In Warm Water, Ben Zhang, Janae E. DeBartolo, Jie Song 2017 University of Massachusetts Medical School

Shape Recovery With Concomitant Mechanical Strengthening Of Amphiphilic Shape Memory Polymers In Warm Water, Ben Zhang, Janae E. Debartolo, Jie Song

University of Massachusetts Medical School Faculty Publications

Maintaining adequate or enhancing mechanical properties of shape memory polymers (SMPs) after shape recovery in an aqueous environment are greatly desired for biomedical applications of SMPs as self-fitting tissue scaffolds or minimally invasive surgical implants. Here we report stable temporary shape fixing and facile shape recovery of biodegradable triblock amphiphilic SMPs containing a poly(ethylene glycol) (PEG) center block and flanking poly(lactic acid) or poly(lactic-co-glycolic acid) blocks in warm water, accompanied by concomitant enhanced mechanical strengths. Differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WXRD), and small-angle X-ray scattering (SAXS) analyses revealed that the unique stiffening of the amphiphilic ...


The Synthesis And Natural Distribution Of The Major Ketone Constituents In Echinacea Pallida, George A. Kraus, Jaehoon Bae, Lankun Wu, Eve Wurtele 2017 Iowa State University

The Synthesis And Natural Distribution Of The Major Ketone Constituents In Echinacea Pallida, George A. Kraus, Jaehoon Bae, Lankun Wu, Eve Wurtele

Eve Wurtele

The first synthesis of a series of ketones naturally occurring in E. pallida is described. The natural distribution of these ketones among different Echinacea species is also reported.


Synthesis And Natural Distribution Of Anti-Inflammatory Alkamides From Echinacea, George A. Kraus, Jaehoon Bae, Lankun Wu, Evve S. Wurtele 2017 Iowa State University

Synthesis And Natural Distribution Of Anti-Inflammatory Alkamides From Echinacea, George A. Kraus, Jaehoon Bae, Lankun Wu, Evve S. Wurtele

Eve Wurtele

The synthesis of the alkamides 2Z,4E-undeca-2,4-dien-8,10-diynoic acid isobutyl amide (1) and 2Z,4E-undeca-2,4-dien-8,10-diynoic acid isobutyl amide (5) was accomplished by organometallic coupling followed by introduction of the doubly unsaturated amide moiety. The distribution of these two amides in accessions of the nine species of Echinacea was determined.


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