Using Noncovalent Bonding To Improve The Interface Between Graphene Nanoplatelets And An Epoxy Matrix
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Using Noncovalent Bonding To Improve The Interface Between Graphene Nanoplatelets And An Epoxy Matrix
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Author : Christopher Cugini
language : en
Publisher:
Release Date : 2022
Using Noncovalent Bonding To Improve The Interface Between Graphene Nanoplatelets And An Epoxy Matrix written by Christopher Cugini and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2022 with Electronic dissertations categories.
Epoxy polymers offer superior chemical and thermal resistance, mechanical properties, and are easily processable compared to similar performing materials. Graphene nanoplatelets (GnP) added as a nanofiller to a polymer create polymer nanocomposites with multifunctional properties. GnP, few-layer stacks of atomically thin graphene sheets with diameters in the micron range, have excellent mechanical, thermal, and electrical properties. Composite performance depends on the ability of the polymer to interact strongly with the GnP. Due to the platelet morphology and the chemically inert GnP basal plane surface, interactions with the epoxy resin are limited to a few edge sites and weak van der Waals intermolecular interactions with the basal plane. This dissertation investigates improving the noncovalent interfacial interactions between GnP and an epoxy resin through the use of a bi-functional interfacial molecule that can interact simultaneously with the GnP and epoxy polymer.An interfacial molecule was synthesized to form strong noncovalent interactions with the GnP surface and covalent bonding with the epoxy resin utilizing a condensation reaction between 1-pyrenealdehyde and poly(oxypropylene) diamine. GnP-epoxy nanocomposites were produced using an epoxy/amine polymer matrix. Several model interfacial molecules were used to investigate the effects on the composite properties. A poly(oxypropylene) diamine was adsorbed onto the GnP surface and reacted with the epoxy in the curing process. The resulting composite exhibited reduced flexural modulus and glass transition temperature versus the unmodified GnP composites.1-pyrenealdheyde was investigated as a molecule that could noncovalently attach to the GnP surface through Ï0-Ï0 interactions. Due to the intercalative properties of 1-pyrenealdehyde, the GnP was exfoliated and exhibited higher GnP concentration at the same loading volume. As a result, flexural modulus increased by 40%. However, due to a negligible change in interfacial interactions, the flexural strength, glass transition temperature, and loss modulus remained similar to the baseline GnP composites.A third molecule, Îł-isopropyliminopyrene-Ï9-amino-poly[oxy(2-methylethylene)] (Py-POP), was synthesized in this research to both noncovalently attach to the GnP basal plane and react into the epoxy matrix. The pyrene end strongly interacts with the GnP surface, and the opposite end of the molecule participates in the epoxy curing mechanism. The length of the polypropylene segment increases the ability of this molecule to connect to the crosslinked epoxy network at a distance away from the GnP basal plane surface. The flexural modulus, flexural strength, and glass transition temperature was improved above the unmodified GnP composites. This signifies improved interfacial interactions between the GnP surface and epoxy matrix. Additionally, significantly increased electrical conductivity represents improved GnP dispersion quality and epoxy adhesion.Stronger interfacial interactions between the GnP surface basal plane and epoxy polymer have shown to improve the composite multifunctionality. The combination of strong noncovalent interactions with the GnP basal plane along with covalent bonding with the epoxy resin using Py-POP resulted in stronger interfacial interactions compared with the poly(oxypropylene) diamine and 1-pyrenealdehyde. Noncovalent bonding an interfacial molecule onto the GnP basal plane improved the nanocomposite multifunctionality while reserving the excellent GnP properties.
Graphene Nanoplatelet Based Polymer Composites And Their Multiple Applications
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Author : Zeyang Yu
language : en
Publisher:
Release Date : 2019
Graphene Nanoplatelet Based Polymer Composites And Their Multiple Applications written by Zeyang Yu and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019 with Electronic dissertations categories.
Graphene nanoplatelets (GnP) consist of a few layers of graphene with thicknesses in the nanometer range. GnP is considered a multifunctional nanomaterial since it possesses excellent mechanical, electrical and thermal properties and as a result of its 2D structure, it offers the possibility of improving the barrier properties of a polymer matrix by reducing the permeability of small molecules through the polymer matrix. The aromatic planar basal surface of GnP consisting of carbon in the sp2 state is inert and the carbon atoms at the GnP edges are the few sites at which functional groups can be added to GnP. When GnP is treated with strong acids, graphene oxide (GO) is formed. The carbon atoms are changed from sp2 to sp3 bonding and the basal plane surface has a large population of oxygen groups which change the surface from hydrophobic to hydrophilic. The GO has the potential to act as a coupling agent to improve the interfacial interaction between GnP and the polymer matrix. Besides adding GnP to a polymer to form a multifunctional polymer composite, the GnP can be fabricated into thin 'paper' electrodes by vacuum filtration of a GnP suspension. This GnP thin film has in-plane electrical conductivity similar to metals and when coated with an insulating polymer layer can function as an electrode in an electrostatic actuator. This dissertation investigates the interaction of GnP with polymer matrices, modifying the surface chemistry to improve the interfacial interaction between filler and matrix, and exploring new applications for multifunctional GnP-polymer composites.The dispersion of GnP into a thermoplastic polyurethane (TPU) through melt blending has been investigated. The dispersion and alignment of GnP plays a key role in attaining the multifunctional properties of the composite. 25wt% GnP was incorporated into TPU through an extrusion process, wherein the dispersion and alignment of GnP was controlled by the film extrusion speed. The effect of three film extrusion speeds of 2, 3 and 5 ft/min on the dispersion and alignment of GnP were investigated. The optimum extrusion conditions gave 350% improvement in through-plane thermal conductivity; 75% reduction in oxygen permeability; and the tensile modulus and strength increased by 950% and 470% respectively.Graphene oxide (GO) was selected as a possible modifier to improve the interaction between GnP and an epoxy matrix. The rich oxygen based functional groups on the GO surface could function as reaction sites for chemical bonding directly or sites for adding other chemical groups such as diamines or epoxy. GO and GnP were sonicated together in a water phase forming a GO-GnP complex, followed by treatment with two different diamines ( (p-phenylenediamine (PPDA) and Jeffamine D2000) with different chain lengths. The functionalized GO-GnP complex was added to the GnP-epoxy composite at a 0.86wt% loading. An increase in tensile modulus of ~60% was measured as a result.The GnP was also investigated as a thin 'paper' electrode fabricated through vacuum filtration of a GnP suspension. GnP electrodes were fabricated from the compressed GnP paper and then coated on both sides with a thin epoxy layer. An electrostatic actuator was constructed from two parallel-aligned composite GnP paper electrodes fixed at the anode of the high power supply and with the cathode connected to the ground. The two composite electrodes would separate at the free end when a voltage was applied. The actuating performance was shown to be improved based on either increasing the surface area of electrode or enhancing the relative permittivity of the insulating layer between two electrodes.
Carbon Allotropes
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Author : Jeenat Aslam
language : en
Publisher: CRC Press
Release Date : 2023-12-12
Carbon Allotropes written by Jeenat Aslam and has been published by CRC Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023-12-12 with Science categories.
The study of corrosion-resistant coatings using nanostructured materials is developing and growing at a very rapid rate. Carbon Allotropes: Advanced Anticorrosive Coatings Materials summarizes current research and technology on the significance of carbon allotropes in anticorrosive coatings. The book describes the synthesis, characterization, inhibitory mechanism, and industrial applications of carbon allotropes as a corrosion-resistant coating. The usage of carbon allotropes as nanostructure materials based on corrosion-resistant coatings used in contemporary industrial platforms is discussed in this book. Additionally, this book assesses the potential of carbon allotropes as the foundation for corrosion-resistant nanostructure materials and coatings. For scientists and engineers looking for cutting-edge ideas for nanostructures based on carbon allotropes as corrosion-resistant coating materials, this book is an invaluable resource. Salient Features This book covers nanostructured carbon allotropes as materials for corrosion-resistant coatings. The use of carbon allotropes as anticorrosive has revolutionized modern industrial practices. This offers academics and entrepreneurs an influential foundational, interdisciplinary, and primary literature reading. The most cutting-edge coatings based on carbon allotropes are also highlighted, along with current manufacturing and operating challenges. This maintains ongoing research on corrosion-resistant coatings using nanostructured materials while incorporating fresh advancements across the entire area.
Development Of A Highly Resilient Graphene Nanoplatelet Resin Adhesive
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Author : Babak Ahmadi Moghadam
language : en
Publisher:
Release Date : 2015
Development Of A Highly Resilient Graphene Nanoplatelet Resin Adhesive written by Babak Ahmadi Moghadam and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with categories.
Multiscale Modeling Of Carbon Fibers Graphene Nanoplatelets Epoxy Hybrid Composites For Aerospace Applications
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Author :
language : en
Publisher:
Release Date : 2020
Multiscale Modeling Of Carbon Fibers Graphene Nanoplatelets Epoxy Hybrid Composites For Aerospace Applications written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020 with categories.
Abstract : Significant research effort has been dedicated for decades to improve the mechanical properties of aerospace polymer-based composite materials. Lightweight epoxy-based composite materials have increasingly replaced the comparatively heavy and expensive metal alloys used in aeronautical and aerospace structural components. In particular, carbon fibers (CF)/graphene nanoplatelets (GNP)/epoxy hybrid composites can be used for this purpose owing to their high specific stiffness and strength. Therefore, this work has been completed to design, predict, and optimize the effective mechanical properties of CF/GNP/epoxy composite materials at different length scales using a multiscale modeling approach. The work-flow of modeling involves a first step of using molecular dynamics (MD) with a reactive force field (ReaxFF) to predict the structure and mechanical behavior of the GNP/epoxy materials at the molecular level. A micromechanics approach is then used to model and predict the mechanical properties of the CF/GNP/epoxy hybrid composite at the bulk level. One of the major findings of this study refers to an alignment behavior of phenyl rings in epoxy with the planar GNP surface at the interphase region. This alignment plays an important role to drive the molecular density of epoxy at the interphase and promote the GNP-epoxy interfacial adhesion. The results also validate the use of ReaxFF in MD modeling of such nanocomposites as the predicted properties compare well with experiment. The impact on the mechanical properties of aerospace epoxy materials reinforced with pristine GNP, highly concentrated Graphene Oxide (GO), and Functionalized Graphene Oxide (FGO) has also been investigated in this study. A systematic computational approach to simulate the reinforcing nanoplatelets and probe their influence on the mechanical response of the epoxy matrix at both nanoscale and bulk levels. The nanoscale outcomes indicate a significant degradation in the in-plane elastic and shear moduli of the nanocomposite when introducing large amounts of oxygen and functional groups to the robust sp2 structure of the GNP. However, the wrinkled and rough topology of GO and FGO promotes the nanoplatelet-matrix interlocking mechanism which produces a significant improvement in the out-of-plane shear modulus. In addition, surface functionalization of GNP promotes the nanoplatelet-epoxy interfacial interaction/adhesion significantly which is important for the material toughness. Using micromechanics analysis, the influence of the nanoplatelets content and aspect ratio on the mechanical response of the proposed nanocomposites has also been predicted and validated with experimental data available from the literature. Generally, there is an improvement in the predicted mechanical response of the bulk nanocomposite materials with increasing nanoplatelets content and aspect ratio. The predicted mechanical properties of the nanoplatelet/epoxy nanocomposites are then used to generate hybrid composite models reinforced with unidirectional CF. The micromechanics predictions are used to analyze the reinforcing effect of the proposed nanoplatelets on the unidirectional CF/nanoplatelet/epoxy hybrid composites. Three laminated hybrid composite panels are also modeled and analyzed to address the reinforcing effect of the proposed nanoplatelets on the laminated hybrid composite panels. The predicted mechanical properties of the laminated hybrid composite panels are important in assessing the mechanical performance of in-service structural components.
Fracture Mechanics Testing Methods For Polymers Adhesives And Composites
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Author : D.R. Moore
language : en
Publisher: Elsevier
Release Date : 2001-03-09
Fracture Mechanics Testing Methods For Polymers Adhesives And Composites written by D.R. Moore and has been published by Elsevier this book supported file pdf, txt, epub, kindle and other format this book has been release on 2001-03-09 with Technology & Engineering categories.
This book is an overview of ESIS Technical Committee 4's activities since the mid-1980s. A wide range of tests is described and the numerous authors is a reflection of the wide and enthusiastic support we have had. With the establishment of the Technical Committee 4, two major areas were identified as appropriate for the activity. Firstly there was an urgent need for standard, fracture mechanics based, test methods to be designed for polymers and composites. A good deal of academic work had been done, but the usefulness to industry was limited by the lack of agreed standards. Secondly there was a perceived need to explore the use of such data in the design of plastic parts. Some modest efforts were made in early meetings to explore this, but little progress was made. In contrast things moved along briskly in the standards work and this has dominated the activity for the last fourteen years. The design issue remains a future goal.
Polymer Functionalized Graphene
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Author : Arun Kumar Nandi
language : en
Publisher: Royal Society of Chemistry
Release Date : 2021-06-18
Polymer Functionalized Graphene written by Arun Kumar Nandi and has been published by Royal Society of Chemistry this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021-06-18 with Science categories.
There is an immense variety of research on polymer functionalized graphene (PFG). Functionalization of graphene is necessary for improvement of the compatibility with polymers. Applications of these graphene polymer hybrids include in chemical and biological sensing, photovoltaic devices, supercapacitors and batteries, dielectric materials and drug/gene delivery vehicles. This book will shed light on the synthesis, properties and applications of these new materials, covering two methods (covalent and noncovalent) for producing polymer functionalized graphene. Chapters cover physical, optical, mechanical and electronic properties, applications of polymer functionalized graphene in energy harvesting and storage, and uses in biomedicine and bioengineering. Written by an expert in the field, Polymer Functionalized Graphene will be of interest to graduate students and researchers in polymer chemistry and nanoscience.
Composite Materials Applications In Engineering Biomedicine And Food Science
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Author : Shafiquzzaman Siddiquee
language : en
Publisher: Springer Nature
Release Date : 2020-09-07
Composite Materials Applications In Engineering Biomedicine And Food Science written by Shafiquzzaman Siddiquee and has been published by Springer Nature this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020-09-07 with Medical categories.
Composite materials are formed when the combination of separate materials acquire new properties distinct from its components. They have a range of applications in fields such as mechanical and electrical engineering, food science and biomedicine and represent a fast-growing area of research. Composite Materials: Applications in Engineering, Biomedicine and Food Science provides an overview of current technologies and applications related to composite materials in these fields. Organized by discipline, the text encompasses a wide variety of composite materials, including polymer, ceramic, biomaterial, hydroxyapatite, nanofiber and green composites. Early chapters detail the enhanced mechanical, magnetic, dielectric properties of electrical and thermal conductive composite materials, which are essential in daily science. Subsequent chapters focus on filler or reinforcement materials, including carbon materials, hybrid materials and nanomaterials. Particular emphasis is placed on nanocomposite materials, as these have increasingly diverse field applications. Various manufacturing methods, such as the synthesis method and top-down/bottom-up manufacturing, are also discussed. Coverage of the recent progress, challenges and opportunities surrounding composite materials make this text a one-stop reference for engineers, scientists and researchers working in this exciting field.
21st Century Surface Science
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Author : Phuong Pham
language : en
Publisher: BoD – Books on Demand
Release Date : 2020-11-26
21st Century Surface Science written by Phuong Pham and has been published by BoD – Books on Demand this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020-11-26 with Technology & Engineering categories.
Surface sciences elucidate the physical and chemical aspects of the surfaces and interfaces of materials. Of great interest in this field are nanomaterials, which have recently experienced breakthroughs in synthesis and application. As such, this book presents some recent representative achievements in the field of surface science, including synthesis techniques, surface modifications, nanoparticle-based smart coatings, wettability of different surfaces, physics/chemistry characterizations, and growth kinetics of thin films. In addition, the book illustrates some of the important applications related to silicon, CVD graphene, graphene oxide, transition metal dichalcogenides, carbon nanotubes, carbon nanoparticles, transparent conducting oxide, and metal oxides.
Toughening Mechanisms In Composite Materials
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Author : Qing-Hua Qin
language : en
Publisher: Elsevier
Release Date : 2015-05-26
Toughening Mechanisms In Composite Materials written by Qing-Hua Qin and has been published by Elsevier this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015-05-26 with Technology & Engineering categories.
Toughening Mechanisms in Composite Materials aims to provide a comprehensive and technically detailed coverage of composites and their toughening mechanisms. Unique in its direct and comprehensive approach, the book presents fundamental knowledge on composites’ toughening mechanisms as well as a comprehensive treatment of numerical methods. This volume summarizes the current state-of-the-art and presents the most recent research outcomes in the field. It details the development of each of the techniques, beginning with basic principles, and new concepts are illustrated with examples wherever possible. Covers particle-reinforced composites, fibre-reinforced composites and other toughening mechanisms Analyses toughening mechanisms in a broad range of composite materials Developments in nanotube toughened composites and toughened graphene ceramic composites are examined