Academic literature on the topic 'Graphene Polymer Systems'

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Journal articles on the topic "Graphene Polymer Systems"

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Kausar, Ayesha, Ishaq Ahmad, and Patrizia Bocchetta. "High-Performance Corrosion-Resistant Polymer/Graphene Nanomaterials for Biomedical Relevance." Journal of Composites Science 6, no. 12 (December 1, 2022): 362. http://dx.doi.org/10.3390/jcs6120362.

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Initially, pristine polymers were used to develop corrosion-resistant coatings. Later, the trend shifted to the use of polymeric nanocomposites in anti-corrosion materials. In this regard, graphene has been identified as an important corrosion-resistant nanomaterial. Consequently, polymer/graphene nanocomposites have been applied for erosion protection applications. Among polymers, conducting polymers (polyaniline, polypyrrole, polythiophene, etc.) and nonconducting polymers (epoxy, poly(methyl methacrylate), etc.) have been used as matrices for anticorrosion graphene nanocomposites. The corrosion-resistant polymer/graphene nanocomposites have found several important applications in biomedical fields such as biocompatible materials, biodegradable materials, bioimplants, tissue engineering, and drug delivery. The biomedical performance of the nanomaterials depends on the graphene dispersion and interaction with the polymers and living systems. Future research on the anti-corrosion polymer/graphene nanocomposite is desirable to perceive further advanced applications in the biomedical arenas.
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Njoroge, Jean, Arnab Chakrabarty, and Tahir Çağın. "Shockwave Response of Polymer and Polymer Nanocomposites." Materials Science Forum 856 (May 2016): 64–69. http://dx.doi.org/10.4028/www.scientific.net/msf.856.64.

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We present non-equilibrium molecular dynamic simulations of the shock compression of polyurethane and its graphene-based nanocomposite systems. Using the projectile/wall approach, planar shock waves with piston velocity range from 0.1 to 2.5 km/s is applied for both systems. In this study, direct molecular-level simulations of shock-wave generation and propagation are utilized in order to construct the appropriate shock-Hugoniot relations. Through this study, we determined that inclusion of graphene into the polyurethane system has a significant effect on the shock propagation behavior when incorporated in the polymer matrix
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Kausar, Ayesha, Ishaq Ahmad, M. H. Eisa, and Malik Maaza. "Graphene Nanocomposites in Space Sector—Fundamentals and Advancements." C 9, no. 1 (March 3, 2023): 29. http://dx.doi.org/10.3390/c9010029.

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Graphene is one of the most significant carbon nanomaterials, with a one-atom-thick two-dimensional nanostructure. Like other nanocarbons, graphene has been used as a polymer reinforcement. This review explores the impact of graphene and graphene-based nanocomposites on aerospace applications. The fabrication and indispensable features of graphene-derived nanocomposites have been considered. Numerous polymers and nanocomposites have been employed for aerospace systems such as reinforced thermosetting/thermoplastic polymers and epoxy/graphene nanocomposites. Moreover, graphene-modified carbon-fiber-based composites have been discussed for the space sector. Aerospace nanocomposites with graphene have been investigated for superior processability, structural features, morphology, heat stability, mechanical properties, flame resistance, electrical/thermal conductivity, radiation protection, and adhesion applications. Subsequently, epoxy and graphene-derived nanocomposites have been explored for heat/mechanically stable aerospace engineering structures, radiation-shielding materials, adhesives, coatings, etc.
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Ahmed, Jubair, Tanveer A. Tabish, Shaowei Zhang, and Mohan Edirisinghe. "Porous Graphene Composite Polymer Fibres." Polymers 13, no. 1 (December 27, 2020): 76. http://dx.doi.org/10.3390/polym13010076.

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Since the isolation of graphene, there have been boundless pursuits to exploit the many superior properties that this material possesses; nearing the two-decade mark, progress has been made, but more is yet to be done for it to be truly exploited at a commercial scale. Porous graphene (PG) has recently been explored as a promising membrane material for polymer composite fibres. However, controlling the incorporation of high surface area PG into polymer fibres remain largely unexplored. Additionally, most polymer-graphene composites suffer from low production rates and yields. In this paper, graphene-loaded microfibres, which can be produced at a very high rate and yield have been formed with a carrier polymer, polycaprolactone. For the first time, PG has been incorporated into polymer matrices produced by a high-output manufacturing process and analysed via multiple techniques; scanning electron microscopy (SEM), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Raman spectra showed that single layer graphene structures were achieved, evidence for which was also backed up by the other techniques. Fibres with an average diameter ranging from 3–8 μm were produced with 3–5 wt% PG. Here, we show how PG can be easily processed into polymeric fibres, allowing for widespread use in electrical and ultrafiltration systems
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RAMU, I., Battina N. MALLESWARARAO, J. CHANDRA SEKHAR, M. VENU, and P. SENTHIL KUMAR. "Study on Free Vibration Analysis of a Rotating Fibre-Graphene-Reinforced Hybrid Polymer Composites Pre-Twist Shel." INCAS BULLETIN 15, no. 2 (June 9, 2023): 149–59. http://dx.doi.org/10.13111/2066-8201.2023.15.2.14.

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The present work aims to develop a computational procedure for investigating the vibration behaviour of pre-twisted laminated composite shell containing graphene inclusions in their matrix. According to nanoscopic empirical equations, graphene's mechanical properties are determined by its size dependence. It has been demonstrated that the orthotropic mechanical properties of composite laminates made from carbon fibres and hybrid matrix can be evaluated. Based on pre-twist and geometric configurations, finite element methods have been used to model hybrid materials shells that include carbon fibre, graphene, and graphene-fibre reinforcement. As part of the validation process, the proposed method is compared with other methods when possible. Finally, the vibrational behaviour of the composite shell is extracted by imposing a twisted angle on a cantilever boundary condition. An analysis of vibrations for each configuration is presented in this paper, as well as the effects of graphene inclusions on natural frequencies. As graphene volume fractions in the matrix increase, the natural frequencies of every mode also increase. When the hub radius and rotational speed are increased, the frequency parameter increases with an increase in graphene volume in the hybrid polymer composite pre-twisted shell.
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Chen, Shih-Hsiung, Naveed Ahmad, and Chung-Feng Jeffrey Kuo. "Development of Multifunctional Nano-Graphene-Grafted Polyester to Enhance Thermal Insulation and Performance of Modified Polyesters." Polymers 14, no. 18 (September 13, 2022): 3821. http://dx.doi.org/10.3390/polym14183821.

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Nano-graphene materials have improved many thermal properties based on polymer systems. The additive polymers’ thermal insulation cannot be significantly increased for use as a reinforcement in multifunctional thermally insulating polymer foam. Herein, we present the development of far-infrared emissivity and antistatic properties using multifunctional nano-graphene polyester fibers. Nano-graphene far-infrared thermal insulation polyester was synthesized with 2% nano-graphene and dispersant polypropylene wax-maleic anhydride (PP wax-MA) using the Taguchi method combined with grey relational analysis (GRA) to improve the thermal properties and the performance of the polymer composite. The thermogravimetric analysis (TGA) shows that the pyrolysis temperature of spinning-grade polyester was increased when the nano-graphene powder was added to the polyester. The differential scanning calorimeter (DSC) analysis confirmed the modification of polyester by nano-graphene, showing the effect of the nucleating agent, which ultimately improved the performance of the polyester. The physical properties of the optimized polyester fibers were improved with a yarn count of 76.5 d, tensile strength of 3.3 g/d, and an elongation at break increased from 23.5% to 26.7% compared with unmodified polymer yarn. These far-infrared emission rates increased from 78% to 83%, whereas the far-infrared temperature increased from 4.0 °C to 22 °C, and the surface resistance increased to 108 Ω. The performance of the optimized modified polyester yarn is far better than single-polypropylene-grafted maleic anhydride yarn. The performance of optimized modified polyester yarn, further confirmed using grey correlation analysis (GRA), can improve the yarns’ mechanical properties and far-infrared functions. Our findings provide an alternative route for developing nano-graphene polyester fabrics suitable for the fabric industry.
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Yasinzai, Maimoona, Ghulam Mustafa, Nazia Asghar, Ikram Ullah, Muhammad Zahid, Peter A. Lieberzeit, Dongxue Han, and Usman Latif. "Ion-Imprinted Polymer-Based Receptors for Sensitive and Selective Detection of Mercury Ions in Aqueous Environment." Journal of Sensors 2018 (2018): 1–6. http://dx.doi.org/10.1155/2018/8972549.

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Interdigital electrodes (IDE) coated with ion-imprinted polymers (IIP) as recognition materials have been tested for screening and ion quantification. For screening of receptors, three polymer systems based on styrene (Sty), N-vinylpyrrolidone (NVP), and Sty-co-NVP were examined to identify an efficient recognition system for mercury ions in an aqueous environment. Results showed that all these polymeric systems can detect analyte even in very low concentration, that is, 10 ppm. Ion-imprinted polystyrene system proved to be an ideal receptor for detecting mercury ions in solution with a detection limit of 2 ppm. The sensitivity of ion-imprinted copolymeric system was further enhanced by making its composite with graphene oxide, and estimated detection limit of composite system was around 1 ppm. Ion- imprinted Sty-co-NVP graphene composite-based sensor system exhibits 2 to 5 times higher sensor response towards templated analyte in comparison to other polymer-based sensor systems. Moreover, the composite-based sensor shows very low or negligible response to competing metal ions with similar or different oxidation states such as Zn, Mg, Na, and As metal ions.
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Rissanou, Anastassia, Apostolos Konstantinou, and Kostas Karatasos. "Morphology and Dynamics in Hydrated Graphene Oxide/Branched Poly(ethyleneimine) Nanocomposites: An In Silico Investigation." Nanomaterials 13, no. 12 (June 15, 2023): 1865. http://dx.doi.org/10.3390/nano13121865.

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Graphene oxide (GO)—branched poly(ethyleneimine) (BPEI) hydrated mixtures were studied by means of fully atomistic molecular dynamics simulations to assess the effects of the size of polymers and the composition on the morphology of the complexes, the energetics of the systems and the dynamics of water and ions within composites. The presence of cationic polymers of both generations hindered the formation of stacked GO conformations, leading to a disordered porous structure. The smaller polymer was found to be more efficient at separating the GO flakes due to its more efficient packing. The variation in the relative content of the polymeric and the GO moieties provided indications for the existence of an optimal composition in which interaction between the two components was more favorable, implying more stable structures. The large number of hydrogen-bonding donors afforded by the branched molecules resulted in a preferential association with water and hindered its access to the surface of the GO flakes, particularly in polymer-rich systems. The mapping of water translational dynamics revealed the existence of populations with distinctly different mobilities, depending upon the state of their association. The average rate of water transport was found to depend sensitively on the mobility of the freely to move molecules, which was varied strongly with composition. The rate of ionic transport was found to be very limited below a threshold in terms of polymer content. Both, water diffusivity and ionic transport were enhanced in the systems with the larger branched polymers, particularly with a lower polymer content, due to the higher availability of free volume for the respective moieties. The detail afforded in the present work provides a new insight for the fabrication of BPEI/GO composites with a controlled microstructure, enhanced stability and adjustable water transport and ionic mobility.
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Rissanou, N., P. Bačová, A. J. Power, and V. Harmandaris. "Atomistic Molecular Dynamics Simulations of Polymer/Graphene Nanostructured Systems." Materials Today: Proceedings 5, no. 14 (2018): 27472–81. http://dx.doi.org/10.1016/j.matpr.2018.09.066.

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Zhang, Jian Wei, Cai Jiang, Gang Shi, and Da Zhi Jiang. "Diffusion of Epoxy Molecules on the Chemically Modified Graphene: A Molecular Dynamics Simulation Study." Materials Science Forum 817 (April 2015): 803–8. http://dx.doi.org/10.4028/www.scientific.net/msf.817.803.

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Buckypaper based polymer composites provides a new technical approach toward realizing conductive/structural multifunctional composites. Resin infiltration in the buckypaper is critical for the fabrication of buckypaper/polymer composites. To investigate the micro-infusion process of the polymer inside the paper, molecular dynamics (MD) simulations are conducted to study the diffusion behavior of epoxy molecules on the modified graphene and between graphene layers. The graphene molecular structures are constructed to represent the wall structures of the carbon nanotubes. Diffusion coefficients of the epoxy molecules on the graphene modified with different functionalization densities and interlayer distances are calculated. The results indicate that the functional groups increase the interfacial interactions between the epoxy molecules and graphene, however, largely decrease the diffusion speeds of the epoxy molecule. The simulations on the graphene layer systems indicate that, the viscous resistance of the resin is the main factor for retarding the diffusion of the epoxy molecules for the unmodified graphene layers; while for the modified graphene layers, functional groups are the main factor for retarding the resin diffusion
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Dissertations / Theses on the topic "Graphene Polymer Systems"

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Chatterjee, Sanjukta. "Structural and Physical Effects of Carbon Nanofillers in Thermoplastic and Thermosetting Polymer Systems." Doctoral thesis, Uppsala universitet, Institutionen för fysik och astronomi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-171449.

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Ever since the discovery of carbon nano materials like carbon nanotube (CNT) and graphene, this class of materials has gained significant attention due to their exotic properties. The principle idea of my present research project is to understand the novel improvements induced in polymer matrices with inclusion of the nanofillers. This thesis is thematically divided into three parts. In the first part we introduce principle materials that we use for preparation of composites. Methods of nanofiller preparation and different nanocomposites as previously reported in literature are discussed to formulate the basis of our study. Different dispersion techniques are discussed which facilitate uniform nanofiller distribution. A variety of experimental methods are described which were employed to investigate the structure and properties of the composites. In the second part we discuss in details polyamide-12 (PA12) composites using CNT and graphene as fillers. A marked improvement is recorded in the toughness of the films with incorporation of CNT, dispersed in PA12 using a surfactant. Electrical percolation is also achieved in the otherwise insulating matrix. With PA-12 fibers we explored the effect of fiber processing and CNT incorporation in the mechanical properties. Extensive wide angle x-ray diffraction was carried out to interpret the structural modifications brought about by CNT in the matrix. The final part of the thesis deals with a thermosetting polymer, epoxy composites. CNT, Graphene and also a mixture of the two nanofillers were used as reinforcing agents. Appreciable improvement was recorded in the mechanical properties, electrical and thermal conductivity of the composites. Detailed optical and electron microscopy was carried out to get a vivid idea of the micro-structure and dispersion. The presented work demonstrates the significant ability of carbon nanofillers to reinforce polymer matrices enhancing their mechanical, electrical and thermal properties and opening a wide horizon for a variety of applications.
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Zhang, Yan. "Study of interfacial interaction effects in different systems including polymer nanocomposites and protein adsorption." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1384870177.

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Li, Wei. "Composite polymer/graphite/oxide electrode systems for supercapacitors." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1439309266.

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Максимцев, Ю. Р., and І. С. Кректун. "Залежність електрофізичних властивостей нанокомпозитів на основі ПВХ." Thesis, Сумський державний університет, 2017. http://essuir.sumdu.edu.ua/handle/123456789/64308.

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Проведено дослідження температурної та частотної залежності електрофізичних характеристик полімерних нанокомпонентних систем на основі ПВХ від типу, вмісту і методу отримання інгредієнтів. В якості наповнювача використовували нанодисперсну мідь, отриману методами електричного вибуху провідника (ЕВП) та електрохімічним (ЕХ) методом, а також високо- та нанодисперсний графіт. Об’ємний вміст наповнювача варіювали в межах від 0 до 0,5 об.% для міді, отриманої методомЕВП та 5 об.% для інших систем. Середній розмір частинок міді становив (45±2) нм, високо–, та нанодисперсного графіту (C) – (10±2) мкм і (45±5) нм відповідно.
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Ke, Kun-Cheng, and 柯坤呈. "Development of Rolling and Curved Surface Hot Embossing System Using Ultra-thin Flexible Electronic Heating Elements of Graphene Polymeric Composite in Polymeric Components Fabrication." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/hag4sb.

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博士
國立臺灣大學
機械工程學研究所
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The polymer process faces the problems of slow temperature rise and uneven temperature. Increasing the heating rate and improving the temperature uniformity become an urgent challenge. In this study, a flexible large-area graphene-composite heating film was developed .The heating films were then applied to the processes of curved micro-hot embossing and micro-hot rolling embossing. First, the effects of different colloids on dispersibility, resistance, sheet resistance and flexible testing were investigated to determine the feasibility of flexible flexible heaters. Then, a flexible graphene composite flat panel heater was developed. The results show that as the voltage increases, the heating rate and steady-state temperature increases. The flexible heater was used to the hot embossing on the curved substrate. With the power of 25V, the temperature was raised from 40 ° C to 160 ° C in 130s. Stable temperature can be maintained. The V-shaped microstructures are replicated with replication rate higher than 97%. A roller heater was developed for roller hot embossing. The heater was fabricated by wire bar coating of graphene polymer composite onto the inner wall of the hollow roller. The electrothermal property, the four-quadrant dynamic temperature uniformity, the lateral dynamic temperature uniformity and the steady-state temperature and voltage are tested by adjusting the voltage. The four-quadrant dynamic temperature control temperature is controlled within 2.8 °C, and the lateral dynamic temperature result is controlled within 1.2 °C. The roller heater was used in micro-hot roller embossing to fabricate microlens array and V-type structures. The relationship between pressure, working temperature and feed rate on forming were investagated. Under the fixed feed rate parameter, the height and diameter of the microlens array were all larger than original sizes of the mold. The V-shaped structure is formed at the fixed rolling speed rate parameter. With the embossing temperature fixed at 120 ° C, the replication rate were higher than 97%. Finally, the application of V-type structure to light intensity enhancement was verified. This study proved the feasibility and potential of the graphene polymer composite heater successfully.
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Αναστασίου, Αλέξανδρος. "Σχέσεις δομής και ιξωδοελαστικών, μηχανικών και συγκολλητικών ιδιοτήτων πολυακρυλικών σε στερεά υποστρώματα μέσω ατομιστικών προσομοιώσεων." Thesis, 2013. http://hdl.handle.net/10889/7975.

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The present Doctoral Thesis focuses on the investigation, characterization and influence of polyacrylic materials in different scientific and technological disciplines via a detailed computer simulation using the Molecular Dynamics (MD) technique, in conjunction with the very accurate, all-atom Dreiding force-field. The main research concepts and objectives are discussed and analyzed in three separate parts. In the first part, atomistic configurations of two model pressure-sensitive acrylic adhesives (PSAs), the atactic homopolymer poly(n-BA) [poly(n-butyl acrylate)] and the atactic copolymer poly(n-BA-co-AA) [poly(n-butyl acrylate-co-acrylic acid)] in the bulk phase or confined between two selected substrates, glassy silica (SiO2) and metallic α-ferrite (α-Fe), were built and simulated by MD in the NPT statistical ensemble. First, an equilibration cycle consisting of temperature annealings and coolings was followed, in order to generate well-equilibrated configurations of the PSA systems. Detailed results from the atomistic simulations are presented concerning their volumetric behavior, glass transition temperature, conformational, structural, viscoelastic and dynamic properties. Particular emphasis was given to the analysis and characterization of the hydrogen bonds that form in the poly(n-BA-co-AA) system. By analyzing the MD trajectories, poly(n-BA-co-AA) was found to exhibit a higher density than poly(n-BA) by about 7% at all temperatures, to be characterized by smaller-size chains for a given molecular weight (MW), to exhibit significantly slower terminal and segmental dynamics properties, and to be characterized by a glass transition temperature that was approximately 40% higher than that of poly(n-BA). We also examined the type and degree of adsorption of the two acrylic systems on the selected substrates by analyzing the MD results for the local mass density as a function of distance from the solid plane and the distribution of adsorbed chain segments in train, loop, and tail conformations, and by computing the work of adhesion at the two substrates. The results revealed a stronger adsorption for both acrylics on the SiO2 surface due to highly attractive interactions between polymer molecules and substrate atoms, and as a consequence a higher value for the work of adhesion compared to that on the α-Fe surface. Furthermore, we have developed a generalized non-equilibrium molecular dynamics (NEMD) algorithm to simulate the mechanical response of the two adhesives under a uniaxial stretching deformation. In the second part of the Thesis, results have been obtained from a hierarchical simulation methodology that led to the prediction of the thermodynamic, conformational, structural, dynamic and mechanical properties of two polymer nanocomposites based on syndiotactic poly(methyl methacrylate) or sPMMA. The first was reinforced with uniformly dispersed graphene sheets and the second with fullerene particles. How graphene functionalization affects the elastic constants of the resulting nanocomposite has also been examined. The phase behavior of the nanocomposite (in particular as we varied the relative size between the sPMMA chains and the diameter of fullerene molecules) has also been studied as a function of fullerene volume fraction. The simulation strategy entailed three steps: 1) Generation of an initial structure, which was then subjected to potential energy minimization and detailed molecular dynamics (MD) simulations at T = 500K and P = 1atm to obtain well relaxed melt configurations of the nanocomposite. 2) Gradual cooling of selected configurations down to room temperature to obtain a good number of structures representative of the glassy phase of the polymer nanocomposite. 3) Molecular mechanics (MM) calculations of its mechanical properties following the method originally proposed by Theodorou and Suter. By analyzing the results under constant temperature and pressure, all nanocomposite systems were found to exhibit slower terminal and segmental relaxation dynamics than the pure polymer matrices. The addition of a small fraction of graphene sheets led in all cases to the enhancement of the elastic constants; this was significantly more pronounced in the case of functionalized graphene sheets. We further mention that, for all polymer/fullerene nanocomposites addressed here, no phase separation or variation of polymer chain dimensions was observed as a function of fullerene size and/or fullerene volume fraction. In the third part of the Thesis, and motivated by the use of acrylic polymers for the design of membranes with aligned carbon nanotubes (CNTs) for several separation technologies (such as water desalination and wastewater treatment), we report results from a detailed computer simulation study for the nano-sorption and mobility of four different small molecules (water, tyrosol, vanillic acid, and p-coumaric acid) inside smooth single-wall CNTs (SWCNTs). Most of the results have been obtained with the molecular dynamics (MD) method, but especially for the most narrow of the CNTs considered, the results for water molecule were further confirmed through an additional Grand Canonical (μVT) Monte Carlo (GCMC) simulation using a value for the water chemical potential μ pre-computed with the particle deletion method. Issues addressed in the Thesis include molecular packing and ordering inside the nanotube for the four molecules, average number of sorbed molecules per unit length of the tube, and mean residence time and effective axial diffusivities, all as a function of tube diameter and tube length. In all cases, a strong dependence of the results on carbon nanotube diameter was observed, especially in the way the different molecules are packed and organized inside the CNT. For water for which predictions of properties such as local structure and packing were computed with both methods (MD and GCMC), the two sets of results were found to be fully self-consistent for all types of SWCNTs considered. Water diffusivity inside the CNT (although, strongly dependent on the CNT diameter) was computed with two different methods, both of which gave identical results. For large enough CNT diameters (larger than about 13 Å), this was found to be higher than the corresponding experimental value in the bulk by about 55%. Surprisingly enough, for the rest of the (phenolic) molecules simulated in this Thesis, the simulations revealed no signs of mobility inside nanotubes with a diameter smaller than the (20, 20) tube. This has been attributed to strong phenyl-phenyl attractive interactions, also to favorable interactions of these molecules with the CNT walls, which cause them to form highly ordered, very stable structures inside the nanotube, especially under strong confinement. The interaction, in particular, of the methyl group (present in tyrosol, vanillic acid, and p-coumaric acid) with the CNT walls seems to play a key role in all these compounds causing them to remain practically immobile inside nanotubes characterized by diameters smaller than about 26 Å. It was only for larger-diameter CNTs that tyrosol, vanillic acid, and p-coumaric acid were observed to demonstrate appreciable mobility.
Η παρούσα Διδακτορική Διατριβή εστιάζει στη μελέτη της σχέσης μεταξύ δομής και μακροσκοπικών φυσικών ιδιοτήτων υλικών από πολυακρυλικά μέσω μίας λεπτομερούς προσομοίωσης στον υπολογιστή με τη μέθοδο της Μοριακής Δυναμικής (ΜΔ), σε συνδυασμό με ένα πολύ επακριβές πεδίο δυνάμεων (το Dreiding) σε ατομιστική λεπτομέρεια. Οι κύριες ερευνητικές έννοιες καθώς και οι στόχοι συζητιούνται και αναλύονται σε τρία ξεχωριστά μέρη. Στο πρώτο μέρος, ατομιστικές απεικονίσεις δύο προτύπων πίεσο-ευαίσθητων συγκολλητικών υλικών (acrylic pressure sensitive adhesives ή PSAs), του ατακτικού πολυ-βουτυλικού-ακρυλικού εστέρα (poly(n-BA)) και του συμπολυμερούς του με ακρυλικό οξύ (poly(n-BA-co-AA)), τόσο μακριά όσο και κοντά σε υποστρώματα σίλικας (SiO2) και α-φερρίτη (α-Fe), μελετήθηκαν στη βάση ενός φάσματος ιδιοτήτων (θερμοδυναμικές, δομικές, ιξωδοελαστικές, δυναμικές, και συγκολλητικές), όπως και η μηχανική τους απόκριση υπό συνθήκες μονοαξονικής εκτατικής παραμόρφωσης. Στο δεύτερο μέρος παρουσιάζονται τα αποτελέσματα που εξήχθησαν από μία ιεραρχική μεθοδολογία προσομοίωσης που οδήγησε στην πρόβλεψη της φασικής συμπεριφοράς και των μηχανικών ιδιοτήτων νανοσύνθετων πολυμερικών υλικών (polymer nanocomposites ή PNCs) βασισμένων στο συνδιοτατκτικό πολυ-μεθακρυλικό μεθυλεστέρα (syndiotactic poly(methyl methacrylate) ή sPMMA), ενισχυμένο με ομοιόμορφα διεσπαρμένα φύλλα γραφενίου (graphene sheets) ή σωματίδια φουλερενίου (fullerene particles). Στο τρίτο μέρος, υποκινούμενοι από τη χρήση των ακρυλικών πολυμερών στο σχεδιασμό μεμβρανών με ενσωματωμένους ευθυγραμμισμένους νανοσωλήνες άνθρακα (ΝΑ, carbon nanotubes ή CNTs) σε διάφορες τεχνολογίες διαχωρισμού μορίων (με έμφαση στον καθαρισμό του νερού), παρουσιάζουμε αποτελέσματα από προσομοιώσεις, για τη νανο-ρόφηση και την κινητικότητα τεσσάρων διαφορετικών μικρών μορίων (water, tyrosol, vanilic acid, και p-coumaric acid) στο εσωτερικό λείων μονο-στρωματικών ΝΑ (single-wall CNTs ή SWCNTs). Τα θέματα που εξετάζονται περιλαμβάνουν τη μοριακή διευθέτηση και τη διάταξη στο εσωτερικό Ν.Α. των τεσσάρων μορίων, το μέσο χρόνο παραμονής τους, καθώς και τους αξονικούς συντελεστές διάχυσής του, συναρτήσει της διαμέτρου και του μήκους των ΝΑ.
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Book chapters on the topic "Graphene Polymer Systems"

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Sur, Ujjal K. "Graphene and Graphene-Based Polymer Nanocomposites: the New Wonder Materials of the Nanoworld." In Processing and Characterization of Multicomponent Polymer Systems, 101–14. Toronto : Apple Academic Press, 2019.: Apple Academic Press, 2019. http://dx.doi.org/10.1201/9780429469794-6.

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Nakhaei, Mohammad Reza, Ghasem Naderi, and Mir Hamid Reza Ghoreishy. "Microstructure and Mechanical Properties of Nanocomposite Based on PA6/NBR/Graphene." In Eco-friendly and Smart Polymer Systems, 320–23. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-45085-4_76.

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Farhanmoghaddam, Fatemeh, and Azizeh Javadi. "Study on Rheology, Crystallinity and Electrical Resistance of Poly(Lactic Acid)/Graphene Oxide Nanocomposites." In Eco-friendly and Smart Polymer Systems, 71–74. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-45085-4_18.

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Sadroddini, Mohsen, and Mehdi Razzaghi-Kashani. "Dielectric Properties of Polydimethylsiloxane (PDMS) Composites Containing Hybrid Silica-Decorated Reduced-Graphene Oxide (SiO2@rGO)." In Eco-friendly and Smart Polymer Systems, 442–45. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-45085-4_107.

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Mirzaee, Ramin, and Ahmad Aref Azar. "Effect of Compatibilizers on Polyamide 6 and Styrene-Butadiene Rubber Blend: Graphene Oxide and Glycidyl Methacrylate." In Eco-friendly and Smart Polymer Systems, 469–72. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-45085-4_114.

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Rezvani Moghaddam, Amir, Milad Kamkar, Zahra Ranjbar, Uttandaraman Sundararaj, and Ali Jannesari. "Effect of Low-Functionalized Graphene Oxide on the Rheological and Electrical Properties of Water-Based Epoxy Coatings." In Eco-friendly and Smart Polymer Systems, 166–69. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-45085-4_40.

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Naseem, Z., K. Sagoe-Crentsil, and W. Duan. "Graphene-Induced Nano- and Microscale Modification of Polymer Structures in Cement Composite Systems." In Lecture Notes in Civil Engineering, 527–33. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-3330-3_56.

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AbstractRedispersible polymers such as ethylene–vinyl acetate copolymer (EVA) have attracted attention in construction due to their enhanced flexural strength, adhesion, flexibility and resistance against water penetration. However, EVA particles cluster in a highly alkaline cementitious matrix and exhibit poor interaction with the cement matrix. The underlying mechanism of poor dispersibility of EVA is attributed to hydrophobic groups of polymers, a variation in the adsorption rate and molecular diffusion to the interface where they cluster together. This phenomenon can negatively affect the fresh properties of cement and produce a weak microstructure, adversely affecting the resulting composites’ performance. This study highlights how graphene oxide (GO) nanomaterial alters the nano- and microscale structural characteristics of EVA to minimize the negative effects. Transmission electron microscopy (TEM) revealed that the GO sheets modify EVA’s clustered nanostructure and disperse it through electrostatic and steric interactions. Furthermore, scanning electron microscopy (SEM) confirmed altered microscale structural characteristics (viz. surface features) by GO. The altered and enhanced material scale engineering performance, such as the compressive strength of the resulting cement composite, was notable.
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Oliaei, Mitra, and Mohammad Yousefi. "Synthesis of Pyrolytic Carbon from Polyethylene Terephthalate on Graphite Substrate." In Eco-friendly and Smart Polymer Systems, 533–36. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-45085-4_129.

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Van Hemelrijck, D., L. Schillemans, I. Daerden, F. De Roey, and F. Boulpaep. "The Use of Thermoelastic Emission Techniques (SPATE) for Damage Analysis of Graphite Epoxy Composites." In Durability of Polymer Based Composite Systems for Structural Applications, 325–35. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3856-7_24.

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Barsukov, V. Z., V. G. Khomenko, A. S. Katashinskii, and T. I. Motronyuk. "NEW CONCEPT FOR THE METAL-AIR BATTERIES USING COMPOSITES: CONDUCTING POLYMERS / EXPANDED GRAPHITE AS CATALYSTS." In New Carbon Based Materials for Electrochemical Energy Storage Systems: Batteries, Supercapacitors and Fuel Cells, 89–104. Dordrecht: Springer Netherlands, 2006. http://dx.doi.org/10.1007/1-4020-4812-2_8.

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Conference papers on the topic "Graphene Polymer Systems"

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Gund, Ved, and Amit Lal. "Graphene-On-Polymer Flexible Vaporizable Sensor." In 2021 IEEE 34th International Conference on Micro Electro Mechanical Systems (MEMS). IEEE, 2021. http://dx.doi.org/10.1109/mems51782.2021.9375341.

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Rissanou, Anastassia N., and Vagelis Harmandaris. "A molecular dynamics study of polymer/graphene interfacial systems." In TIMES OF POLYMERS (TOP) AND COMPOSITES 2014: Proceedings of the 7th International Conference on Times of Polymers (TOP) and Composites. AIP Publishing LLC, 2014. http://dx.doi.org/10.1063/1.4876805.

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Roy, Ajit K., V. Varshney, S. Ganguli, S. Sihn, J. Lee, and B. Farmer. "Atomistic Scale Thermal Transport in Amorphous Materials and Its Interfaces." In ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajtec2011-44656.

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The thermal loads (excess heat) in all DoD systems (aircrafts and spacecrafts) have steadily been increasing at an alarming rate. The current practice is use fuel as the heat sink to dump the excess heat. This operational approach currently is not adequate to sufficiently cool the electronics and thermal devices, and thus limiting the system performance and its system readiness. Amorphous materials system (polymers, adhesive, etc.), which is known to be thermally non-conductive material, is prevalent in almost all DoD systems. So, there is a big incentive in tailoring its thermal transport characteristics to meet the system requirements. Advent of the conductive nano material constituents (such as, carbon nanotubes, graphite platelets, graphene, etc.) and its adaptation in polymers provides us such opportunity. The success of adapting the nano constituents in polymers in providing the conductive pathways through the polymer phase solely lies on the extent how the interface thermal transport characteristics are tailoring between the polymer and nano constituent interfaces. In order to understand the thermal transport phenomena is amorphous materials and to design its interface consistent to the nano constituent morphology scale, computational methodology using atomistic molecular dynamics (MD) is developed. Examples for tailoring thermal interface of nano constituents with polymer will be presented.
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Wang, Long, Kenneth J. Loh, Ramin Mousacohen, and Wei-Hung Chiang. "Printed Graphene-Based Strain Sensors for Structural Health Monitoring." In ASME 2017 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/smasis2017-3839.

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Strain sensors are one of the most widely used transducers for structural health monitoring, since strain can provide rich information regarding structural integrity. Recently, it has been shown that thin film sensors that incorporate nanomaterials can be engineered to possess unique properties, such as flexibility, high sensitivity, and distributed sensing capabilities, to name a few. To date, a plethora of different nanomaterials have been explored for fabricating strain sensors, such as by using conductive polymers, metal nanowires, and carbon nanotubes, among others. The aim of this work is to leverage the unique properties of graphene to fabricate next-generation thin film strain sensors. While graphene exhibits impressive mechanical and electrical properties, it remains challenging to harness these properties for sensing, primarily because of difficulties associated with high-quality synthesis and to incorporate them in a scalable fashion. In this study, few-layered graphene nano-sheets (GNS) were first synthesized using a low-cost, liquid-phase exfoliation technique. Second, GNS was dispersed in an aqueous solution with a low-concentration polymer acting as the dispersing agent. Third, the dispersion was printed onto flexible polymer substrates to form complex geometrical patterns, such as strain rosettes. Then, the electrical and electromechanical properties of the printed thin film sensors were characterized. It was found that the strain rosettes could resolve multi-axial strains applied during coupon tests. Overall, the GNS-based strain sensors showed excellent signal-to-noise ratio, stable sensing performance, high strain sensitivity, and remarkable reproducibility.
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Gund, V., A. Ruyack, K. Camera, S. Ardanuc, C. Ober, and A. Lal. "Multi-modal graphene polymer interface characterization platform for vaporizable electronics." In 2015 28th IEEE International Conference on Micro Electro Mechanical Systems (MEMS). IEEE, 2015. http://dx.doi.org/10.1109/memsys.2015.7051098.

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Liu, Yumeng, Jiyoung Chang, and Liwei Lin. "A flexible graphene FET gas sensor using polymer as gate dielectrics." In 2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS). IEEE, 2014. http://dx.doi.org/10.1109/memsys.2014.6765617.

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Behfar, K., R. Naghdabadi, A. Vafai, and H. E. Estekanchi. "Nanoscale Vibrational Analysis of an Embedded Multi-Layered Graphene Sheet." In ASME 7th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2004. http://dx.doi.org/10.1115/esda2004-58629.

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In this paper, nanoscale vibrational analysis of a multilayered graphene sheet embedded in an elastic medium is investigated and the corresponding resonant modes and frequencies are determined. It is known that the elastic moduli of a graphene sheet in two orientations x, y are different, so the graphene sheet is assumed to be a general form of an orthotropic plate. The orthotropic sheets stacking at the top of each other bond with carbon-carbon van der Waals forces, also the whole multi-layered graphene sheet is influenced by polymer-carbon van der Waals forces from the surrounding elastic medium.
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ANILAL, ASHISH, JUSTIN BENDESKY, SEHEE JEONG, STEPHANIE S. LEE, and MICHAEL BOZLAR. "EFFECTS OF GRAPHENE ON TWISTING OF HIGH DENSITY POLYETHYLENE." In Proceedings for the American Society for Composites-Thirty Seventh Technical Conference. Destech Publications, Inc., 2022. http://dx.doi.org/10.12783/asc37/36468.

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High density polyethylene (HDPE) is known to form banded spherulites when crystallized from the melt. In such spherulites, concentric bands of alternating light and dark colors emanating from the spherulite nucleation center are observable between cross polarizers and appear as a function of the anisotropy of the dielectric susceptibility as crystal orientations continuously rotate about the growth direction. Recently, we identified PE to be a promising compound to induce twisting in conjugated carbonaceous systems, such as triisopropylsilylethynyl anthradithiophene (TIPS ADT). When blended together in ratios between 10 – 70 wt.% PE, TIPS ADT and PE crystals twist in concert with one another to form composite films of intertwined helicoidal fibrils. In this work, we investigate crystal twisting in HDPE-graphene oxide composites. In addition to its unique multifunctionality, graphene has also recently demonstrated peculiar twisting capabilities that strongly alter its physical properties. Here, we first produce graphene sheets through the chemical oxidation of natural graphite, and then investigate the influence of graphene on the twisting of HDPE composites under various processing parameters (graphene concentration, polymer cooling rate, etc). HDPE-graphene composites have been prepared using melt extrusion in the form of microfibers and films. We measured the influence of twisting on the mechanical and electrical properties of the composites, as well as the crystallographic structure using optical and electron microscopy, and X-Ray diffraction spectroscopy.
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Wang, Ming-Hao, Kei Nikaido, Yechan Kim, Bo-Wen Ji, Hong-Chang Tian, Xiao-Yang Kang, Chun-Sheng Yang, et al. "Flexible cylindrical neural probe with graphene enhanced conductive polymer for multi-mode BCI applications." In 2017 IEEE 30th International Conference on Micro Electro Mechanical Systems (MEMS). IEEE, 2017. http://dx.doi.org/10.1109/memsys.2017.7863453.

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Rao, M. N., R. Schmidt, and K. U. Schröder. "Forced Vibration Analysis of FG-Graphene Platelet Reinforced Polymer Composite Shells Bonded With Piezoelectric Layers Considering Electroelastic Nonlinearities." In ASME 2018 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/smasis2018-7978.

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In the present article, we focus on the forced vibration and control analysis of functionally graded (FG) graphene-polymer composites bonded with piezoelectric layers considering strong electric fields. Different non-uniform gradient distributions of graphene platelets (GPLs) are assumed through the thickness direction. The Modified Halpin-Tsai micromechanics model is used to obtain the effective material properties of GPL/polymer composites. Electromechanical coupling of piezoelectric layers is described by two rotationally invariant non-linear constitutive relations. A four-node shell element considering transverse shear effect based on the Reissner-Mindlins hypothesis has been developed for forced vibration and control analysis of smart FG-GPL/composites using the principle of virtual work considering nonlinear material law for the piezoelectric layers. The developed element is verified and compared with the numerical results those available in the literature. Different configurations of FG-GPL composite shells have been analysed and discussed to compare in terms of settling time, first resonance frequency and absolute amplitude corresponding to first resonant frequency by carrying out time and frequency response analysis, and the effects of weight fraction of GPLs on vibration response of such shell structures are also discussed. The influence of electromechanical nonlinear constitutive relations is also presented and discussed by performing active control analysis on different FG-GPL composite shell structures. Moreover, the results show that the GPL distribution and weight-fraction of GPLs have a significant effect on the vibration and damping characteristics of the FG-GPL composite shell structures.
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Reports on the topic "Graphene Polymer Systems"

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Brossia. L52119 Comparative Consumption Rates of Impressed Current Cathodic Protection Anodes. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 2004. http://dx.doi.org/10.55274/r0010953.

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There is a variety of impressed current anode materials available for onshore applications, including High Silicon Cast Iron (HSCI), Mixed Metal Oxides (MMO), graphite, platinum (or platinum coated titanium), and conductive polymers. Many end users simply select the anode material that they have experience with. What is lacking is a clear, direct comparison of relative anode consumption rates conducted under identical conditions. The present study examined the behavior of the various anode types under different current loads and soil conditions in an effort to establish baseline consumption rates under controlled conditions. Variables that were examined included soil resistivity, the presence of coke backfill, current load, and soil type (sand or 50/50 clay/sand mix). The consumption rates of the anodes evaluated decreased in the order of: AnodeFlex, HSCI, Graphite, Pt, and MMO. A survey of field experiences yielded a slightly different order in terms of anode life with Graphite and HSCI lasting the longest. However, given the wide range of anode sizes used in the various field sites, it is difficult to directly link the field results to the consumption rates measured in the laboratory. Soil composition and resistivity were not observed to have a significant influence on anode consumption rates. The presence of coke, however, led to a decrease in consumption for all anodes in some cases by as much as a factor of nearly 70. Utilizing anode cost estimates and neglecting installation costs, the life-cycle material costs for MMO and Pt anodes are much lower than the other anode materials. Furthermore, AnodeFlex was noted to be the highest cost system from a materials perspective. This may be slightly misleading since installation and replacement costs are not factored in. Given that the installation of AnodeFlex is often much easier and less expensive than the other anode types, this may prove to be a viable financial decision when the other factors are considered. ����������� The primary implications of the present study are: Despite higher material costs, MMO and Pt anodes may offer significant long-term cost savings as compared to other anode types for many applications Use of coke backfill is critical to ensure lower anode consumption rates for AnodeFlex, Graphite, and to a lesser extent HSCI; coke does not appear necessary for MMO or Pt Soil composition (sand vs. clay/sand mix) and resistivity do not appear to significantly influence anode consumption rates, thus consideration of the soil environment (except groundwater chemistry) is not needed in selection of an appropriate anode Because the influence of groundwater chemistry (as part of the soil environment) was not examined, the effects of sulfate, chloride, and pH will need to be evaluated in detail to better aid in anode material selection Field use survey responses showed a wide range in observed anode lifespan, with graphite and HSCI experiencing the longest life and cable anodes the shortest The field survey also revealed that a significant cause of anode failures was connector and cable problems
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