Academic literature on the topic 'Layered nanofillers'
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Journal articles on the topic "Layered nanofillers"
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Galimberti, Maurizio, Valeria Cipolletti, Sara Musto, Serena Cioppa, Giulia Peli, Marco Mauro, Guerra Gaetano, Silvia Agnelli, Riccò Theonis, and Vineet Kumar. "RECENT ADVANCEMENTS IN RUBBER NANOCOMPOSITES." Rubber Chemistry and Technology 87, no. 3 (September 1, 2014): 417–42. http://dx.doi.org/10.5254/rct.14.86919.
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ABSTRACT Nanocomposites were prepared via melt blending, based on organically modified clays (OC), carbon nanotubes (CNT), and graphitic nanofillers made by a few layers of graphene (nanoG). In particular, nanocomposites based on a hybrid filler system, with a nanostructured filler such as carbon black (CB), are examined. It is shown that low crystalline order in the interlayer space of a layered nanofiller (such as OC and nanoG) leads to easier delamination. Nanofillers give rise to filler networking at low concentration, particularly in the presence of CB. Hybrid filler systems lead to nanocomposites' having initial moduli that are much higher than those calculated through the sum of the initial modulus of composites containing either only CB or only the nanofiller. Nanofillers enhance the matrix modulus by a multiplication factor that depends only on the nanofiller type and content, regardless of whether the matrix is a neat or a CB-filled polymer. Furthermore, the filler–polymer interfacial area is shown to be a parameter able to correlate the mechanical behavior of both nano-CNT and nanostructured (CB) fillers. By plotting values of the composite initial modulus versus the filler–polymer interfacial area, points due to CB, CNT, and the hybrid CB-CNT system lie on the same curve.
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Mochane, Mokgaotsa Jonas, Sifiso Innocent Magagula, Jeremia Shale Sefadi, Emmanuel Rotimi Sadiku, and Teboho Clement Mokhena. "Morphology, Thermal Stability, and Flammability Properties of Polymer-Layered Double Hydroxide (LDH) Nanocomposites: A Review." Crystals 10, no. 7 (July 14, 2020): 612. http://dx.doi.org/10.3390/cryst10070612.
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The utilization of layered nanofillers in polymer matrix, as reinforcement, has attracted great interest in the 21st century. This can be attributed to the high aspect ratios of the nanofillers and the attendant substantial improvement in different properties (i.e., increased flammability resistance, improved modulus and impact strength, as well as improved barrier properties) of the resultant nanocomposite when compared to the neat polymer matrix. Amongst the well-known layered nanofillers, layered inorganic materials, in the form of LDHs, have been given the most attention. LDH nanofillers have been employed in different polymers due to their flexibility in chemical composition as well as an adjustable charge density, which permits numerous interactions with the host polymer matrices. One of the most important features of LDHs is their ability to act as flame-retardant materials because of their endothermic decomposition. This review paper gives detailed information on the: preparation methods, morphology, flammability, and barrier properties as well as thermal stability of LDH/polymer nanocomposites.
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Zilg, Carsten, Frank Dietsche, Botho Hoffmann, Christoph Dietrich, and Rolf M�hlhaupt. "Nanofillers based upon organophilic layered silicates." Macromolecular Symposia 169, no. 1 (May 2001): 65–77. http://dx.doi.org/10.1002/1521-3900(200105)169:1<65::aid-masy65>3.0.co;2-f.
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Maiti, Madhuchhanda, Mithun Bhattacharya, and Anil K. Bhowmick. "Elastomer Nanocomposites." Rubber Chemistry and Technology 81, no. 3 (July 1, 2008): 384–469. http://dx.doi.org/10.5254/1.3548215.
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Abstract Recently, elastomer - nanocomposites reinforced with low volume fraction of nanofillers have attracted great interest due to their fascinating properties. The incorporation of nanofillers such as layered silicate clays, carbon nanotubes, nanofibers, calcium carbonate, metal oxides or silica nanoparticles into elastomers improves significantly their mechanical, thermal, dynamic mechanical, barrier properties, flame retardancy, etc. The properties of nanocomposites depend greatly on the chemistry of polymer matrices, nature of nanofillers, and the method in which they are prepared. The uniform dispersion of nanofillers in elastomer matrices is a general prerequisite for achieving desired mechanical and physical characteristics. In this review article, current developments in the field of elastomer nanocomposites reinforced with layered silicates, silica, carbon nanotubes, nanofibers and various other nanoparticles have been addressed. Attention has been paid to the structure and properties of such high-performance nanocomposites, along with the theories and models existing in this field.
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Pradhan, Sharmila, Ralf Lach, Wolfgang Grellmann, and Rameshwar Adhikari. "Nanofiller Reinforced Polyolefin Elastomer: Effect on Morphology and Mechanical Properties of Composites." Nepal Journal of Science and Technology 13, no. 2 (March 8, 2013): 103–8. http://dx.doi.org/10.3126/njst.v13i2.7721.
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The effect of different types of fillers on morphology and mechanical properties of polymer nanocomposites has been investigated using ethylene-1–octene copolymer (EOC), a polyolefin based elastomer, as matrix and various nanofillers {such as multi-walled carbon nanotubes (MWCNT), layered silicate (LS) and boehmite (OS2)}. The morphological structures were studied by scanning electron microscopy (SEM) while the mechanical properties were characterized by tensile testing and microindentation hardness measurements. It has been shown that the nature of the nanofiller may have significant influence on the mechanical properties of the samples. Among the nanocomposites studied so far, the MWCNT filled samples showed the highest reinforcing effect followed by layered silicate. The least reinforcing effect was obtained for the samples filled with boehmite nanoparticles. Nepal Journal of Science and Technology Vol. 13, No. 2 (2012) 103-108 DOI: http://dx.doi.org/10.3126/njst.v13i2.7721
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Enotiadis, Apostolos, Lamprini G. Boutsika, Konstantinos Spyrou, Cataldo Simari, and Isabella Nicotera. "A facile approach to fabricating organosilica layered material with sulfonic groups as an efficient filler for polymer electrolyte nanocomposites." New Journal of Chemistry 41, no. 17 (2017): 9489–96. http://dx.doi.org/10.1039/c7nj01416c.
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Wen, Shipeng, Rui Zhang, Zongchao Xu, Long Zheng, and Li Liu. "Effect of the Topology of Carbon-Based Nanofillers on the Filler Networks and Gas Barrier Properties of Rubber Composites." Materials 13, no. 23 (November 28, 2020): 5416. http://dx.doi.org/10.3390/ma13235416.
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The topology of nanofillers is one of the key factors affecting the gas barrier properties of rubber composites. In this research, three types of carbon-based nanofillers, including spherical carbon black (CB), fibrous carbon nanotubes (CNTs), and layered graphene (GE) were chosen to investigate the effect of the topological structures of nanofillers on the gas barrier properties of styrene-butadiene rubber (SBR) composites. Results showed that the structure and strength of the filler networks in SBR composites were closely associated with the topology of nanofillers. When filled with 35 phr CB, 8 phr CNTs, and 4 phr GE, the SBR composites had the same strength of the filler network, while the improvement in gas barrier properties were 39.2%, 12.7%, and 41.2%, respectively, compared with pure SBR composites. Among the three nanofillers, GE exhibited the most excellent enhancement with the smallest filler content, demonstrating the superiority of two-dimensional GE in improving the barrier properties of rubber composites.
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Danowska, Magdalena, Łukasz Piszczyk, Michał Strankowski, Maria Gazda, and Józef T. Haponiuk. "Rigid polyurethane foams modified with selected layered silicate nanofillers." Journal of Applied Polymer Science 130, no. 4 (May 20, 2013): 2272–81. http://dx.doi.org/10.1002/app.39432.
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Prateek, Shahil Siddiqui, Ritamay Bhunia, Narendra Singh, Ashish Garg, and Raju Kumar Gupta. "Interface modulation in multi-layered BaTiO3 nanofibers/PVDF using the PVP linker layer as an adhesive for high energy density capacitor applications." Materials Advances 1, no. 4 (2020): 680–88. http://dx.doi.org/10.1039/d0ma00240b.
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In this work, we have studied the role of a linker across the interface in a multi-layered polymer nanocomposite-based capacitor using barium titanate (BT) nanofibers (NFs) as nanofillers and polyvinylidene fluoride (PVDF) as the polymer matrix.
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Zhou, Ke Qing, Zhou Gui, and Yuan Hu. "MoS2: Advanced Nanofillers for Polymer Nanocomposites." Advanced Materials Research 1105 (May 2015): 21–25. http://dx.doi.org/10.4028/www.scientific.net/amr.1105.21.
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Since discovery of graphene, great attention had been paid to other two dimensional (2D) layered materials. As a graphene-like layered nanomaterial, molybdenum disulfide (MoS2) had gained enormous attention from the materials fields which had been widely used in many areas such as solid lubricants, lithium ion batteries, photocatalysts, sensors or as conductive fillers in polymer composites. In this work, MoS2 nanosheets were incorporated into polymer matrix as nanofillers by three typical preparation methods, including solvent blending, in situ polymerization and melt blending method. The MoS2 nanosheets were dispersed well in the polymer matrices which improved the thermal stability, mechanical properties and reduced fire hazards of the composites obviously. The improvements in the thermal properties, fire resistance properties and mechanical properties of polymer/MoS2 nanocomposites were mainly attributed to good dispersion of MoS2, physical barrier effects of MoS2 and catalytic char function of MoS2 nanosheets.
Dissertations / Theses on the topic "Layered nanofillers"
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Mauro, Marco. "New Technologies in Tires: From Layered Nanofillers to Metathesis Reactions." Doctoral thesis, Universita degli studi di Salerno, 2014. http://hdl.handle.net/10556/1457.
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2012 - 2013Tires are annually manufactured in more than one billion of artefacts and the ever increasing demand is on the basis of the efforts in finding new solutions for more performant, sustainable and durable products. This PhD thesis presents highly new contributions to the nanotechnology applied to rubber nanocomposites, particularly focussing on clays and graphitic fillers with tunable periodicities and degree of order of their structures. The interaction of layered nanofillers with the rubber matrix was investigated, correlating nanocomposites structure and morphology, studied by means of X-ray diffraction and transmission electron microscopy, with measured tensile and dynamic-mechanical properties. Unique reversible thermal transitions of nanocomposites containing organoclays and graphite oxide intercalation compounds were also investigated through differential scanning calorimetry. Metathesis applied to the rubber chemistry is presented as a strongly innovative technology to produce novel rubber materials, hardly obtainable with conventional synthetic methods and to promote the degradation of rubbers, when the latter process is desired... [edited by author]
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Kelnar, I. "Polymer-polymer Microfibrillar Composites: Effect of Nanofillers on Structure and Properties." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35451.
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Microfibrillar composites (MFCs) are advantageous polymer-polymer composites with in situ formed reinforcing fibrils. The range of applications of MFCs is limited by their low thermal resistance and me-chanical parameters of polymeric microfibres, which are formed by melt or cold drawing of the polymer blend. This study addresses improving MFCs based on HDPE matrix with 20% polyamide 6 microfibrils using organophilized montmorillonite. The complex effect of the nanofiller on the structure and parameters of the MFCs is investigated.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35451
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Costa, Francis Reny. "Mg-Al Layered Double Hydroxide: A Potential Nanofiller and Flame-Retardant for Polyethylene." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2007. http://nbn-resolving.de/urn:nbn:de:swb:14-1195481811992-27563.
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The presented research report deals with the investigation of magnesium aluminum based layered double hydroxide (LDH) as a potential nanofiller and flame-retardant for polymers with special reference to polyethylene. LDH is a mixed hydroxide of di- and trivalent metal ions that crystallizes in the form of mineral brucite. The basic reason for selecting LDH or more specifically magnesium-aluminum based LDH (Mg-Al LDH) is their typical metal hydroxide-like chemistry and conventional clay-like layered crystalline structure. The former is helpful in the direct participation in flame inhibition through endothermic decomposition and stable char formation. On the other hand, the later makes LDH suitable for polymer nanocomposite preparation, which can address the poor dispersibility problem associated with conventional metal hydroxide type fillers in polyolefin matrix. Besides, unlike layered silicate type clays (often reported for their capability to improve flame retardancy of polymers), LDH being reactive during combustion has higher efficiency to reduce the heat released during combustion of the composites. LDH clay with fixed Al:Mg ratio was synthesized using urea hydrolysis method and characterized. The organic modification of Mg-Al LDH using anionic surfactants has been studied in details. The main purpose of such modification is to enlarge the interlayer distance and to render it more organophilic. The surfactants were selected based on their functionality, chain length, etc and the modification was carried out by regeneration method. In the modified LDHs, the surfactants anions are arranged as a monolayer in the interlayer region and expand the interlayer distance according to their tail size. PE/LDH nanocomposites were prepared by melt-compounding method using a co-rotating tightly intermeshed twin-screw extruder and the morphological, mechanical and flammability properties of the nanocomposites were investigated in details. The X-ray diffraction analysis and electron microscopic analysis show a complex LDH particle morphology with hierarchy of particle size and shape starting from exfoliated particles fragments to particle aggregates over few hundred nm size. The exfoliated LDH platelets are distributed both in the vicinity of large particles and also in the bulk matrix. The melt rheological characterization of the nanocomposites also reflects the similar complex particle morphology. The dynamic oscillatory shear experiments showed that with increasing LDH concentration, the rheological behavior of the nanocomposite melts deviates strongly from that of the unfilled polyethylene. Thermogravimetric analysis (TGA) shows that LDH significantly improves the thermal stability of the polymer matrix in comparison to the unfilled polymer. The flammability studies of the PE/LDH nanocomposites have been reported in terms of various standard methods, like limited oxygen index (LOI), cone-calorimetry and UL-94 vertical and horizontal burn tests. The cone-calorimetric investigation shows that the nanocomposites have significantly lower burning rate and heat released during combustion. With increasing concentration of LDH though the LOI value of the nanocomposite increases marginally, the burning behavior, like dripping, rate of burning, etc are significantly improved. The flammability performance of LDH in combination with other commonly used flame-retardant (magnesium hydroxide) was also investigated. It has been observed that in polyethylene, a 50 wt% combination filler (4:1 weight ratio of magnesium hydroxide and LDH) can provide similar flammability ratings (like V0 rating in UL94 test, no dripping, etc) as that observed with 60 wt% magnesium hydroxide alone.
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KUMAR, VINEET. "Few layer graphene reinforced rubber compounds for tires." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2014. http://hdl.handle.net/10281/83643.
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In last decade, “Nanofillers” have been explored extensively in rubber compounds to improve dynamic-mechanical properties. Three classes of nanofillers: Clay minerals, Carbon nanoTubes and Graphitic nanofillers have been often used. Most recently, an attention towards “graphene” as nanofiller was reported due to its exceptional mechanical, thermal and electrical properties. In present Ph.D. thesis, different types of commercially available “few layer graphene” were explored in both apolar and polar diene rubbers. These nanofillers were dispersed with melt mixing technique which is most suitable technology for industrial applications, such as for tires. Structural-morphological characteristics of the nanofillers were made with SEM, TEM, XRD and static adsorption isotherms. Features such as shape anisotropy, number of graphene layers in a stack, BET surface area, surface activity and porosity of nanofillers were obtained. Optical microscopy was employed to obtain filler dispersion index and estimation of filler’s aggregates, agglomerates. Dynamic mechanical properties of the rubber compounds were made with rheometric curves for scorch and curing time, rheological properties through RPA (strain sweep and frequency sweep) for viscoelastic properties and filler networking, stress-strain for tensile strength and multi-hysteresis cycles for energy dissipation, dynamic mechanical thermal analysis for high and low temperature properties, hardness of compound for processing features and tear strength tests for compound durability. The electrical properties of rubber compounds were investigated via dielectric AC conductivity and permittivity tests. Epoxidation of diene rubbers (low rate, <10%) was obtained to investigate the effects of presence of epoxy functional groups along polymer chains on filler networking, polymer-filler interactions, filler dispersion and dynamic mechanical properties of rubber compounds. Quantitative analysis of epoxidation, rate of epoxidation and its influence on rubber matrix (such as change in glass transition temperature) was investigated through 1NMR and DSC tests. Under multi-hysteresis stress-strain cycles, it was found that a stable filler networking can reduce hysteresis losses.
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Costa, Francis Reny [Verfasser]. "Mg-Al layered double hydroxide : a potential nanofiller and flame-retardant for polyethylene / Francis Reny Costa." 2007. http://d-nb.info/987097768/34.
Full textBook chapters on the topic "Layered nanofillers"
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Bergaya, Faïza, Maguy Jaber, and Jean-François Lambert. "Clays and Clay Minerals as Layered Nanofillers for (Bio)Polymers." In Environmental Silicate Nano-Biocomposites, 41–75. London: Springer London, 2012. http://dx.doi.org/10.1007/978-1-4471-4108-2_3.
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Rives, V., F. M. Labajos, and M. Herrero. "Layered Double Hydroxides as Nanofillers of Composites and Nanocomposite Materials Based on Polyethylene." In Polyethylene-Based Blends, Composites and Nanocomposites, 163–99. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2015. http://dx.doi.org/10.1002/9781118831328.ch6.
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Sebri, Nor Jannah Mohd, Ahmad Faiz Abdul Latip, Rohana Adnan, and M. Hazwan Hussin. "Layered double hydroxides (LDHs) as green nanofillers in composites." In Green Sustainable Process for Chemical and Environmental Engineering and Science, 23–42. Elsevier, 2022. http://dx.doi.org/10.1016/b978-0-323-99643-3.00004-8.
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A., Petroula. "Composites of Engineering Plastics with Layered Silicate Nanofillers: Preparation and Study of Microstructure and Thermomechanical Properties." In Nanocomposites and Polymers with Analytical Methods. InTech, 2011. http://dx.doi.org/10.5772/21843.
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Tharu, Shyam, and Mitesh Panchal. "Single layer graphene as nanofiller to enhance mechanical properties of matrix material." In Technologies for Sustainable Development, 299–305. CRC Press, 2020. http://dx.doi.org/10.1201/9780429321573-53.
Full textConference papers on the topic "Layered nanofillers"
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Taha-Tijerina, Jaime, T. N. Narayanan, Soorya Avali, and P. M. Ajayan. "2D Structures-Based Energy Management Nanofluids." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-87890.
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Designing of compact electronic and electrical instruments needs the development of high efficient thermal and electrical management fluids. Recent advances in layered materials enable large scale synthesis of diverse two-dimensional (2D) structures. Some of these 2D materials are good choices as nanofillers in heat/electrical energy transfer fluids; mainly due to their high surface area available for energy conduction. Among various 2D nanostructures, hexagonal boron nitride (h-BN) or graphene (G) exhibit versatile properties such as outstanding thermal conductivity (TC), excellent mechanical stability, and remarkable chemical inertness. These 2D nanostructures have been used to create composite fluids for diverse thermal management applications, such as microelectronics, high voltage power transmission systems, automobiles, solar cells, biopharmaceuticals, medical therapy/diagnosis, and nuclear cooling, among others. The ever increasing thermal loads in applications now require advanced operational fluids, like high TC dielectric insulating fluids for electrical transformers. These fluids require superb filler dispersion, high thermal conduction, as well as electrical insulation. Such thermal oils that conform to this thermal/electrical requirement, and yet remain in highly suspended stable state, have not yet been synthesized. We discuss the synthesis and characterization of stable high TC and electrically conducting and non-conducting Newtonian nanofluids using liquid exfoliated layers of h-BN and G in dielectric mineral oil.
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Tiano, Thomas, Margaret Roylance, Benjamin Harrison, and Richard Czerw. "Intralaminar Reinforcement for Biomimetic Toughening of Bismaleimide Composites Using Nanostructured Materials." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-81689.
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Many conventional composite materials are composed of multiple layers of continuous fiber reinforced resin produced by lamination of b-staged prepreg and subsequent cure. These materials exhibit very high strength and stiffness in the plane, dominated by the properties of the fibers. The Achilles heel of such composites is the interlaminar strength, which is dependent on the strength of the unreinforced resin, often leading to failure by delamination under load. Current methods for increasing the interlaminar shear strength of composites consist of inserting translaminar reinforcement fibers through the entire thickness of a laminated composite, such as z-pin technology developed by Foster-Miller [1]. While effective, this technique adds several processing steps, including ultrasonic insertion of the z-pins into the laminate, subsequently causing a significant cost increase to laminated composites. Described in this paper is a process utilizing single-walled carbon nanotubes (SWNTs) and vapor grown carbon nanofibers as reinforcing elements promoting interlaminar shear strength and toughness in carbon fiber/bismaleimide (BMI) resin composites. The resulting composites mimic the natural reinforcing mechanism utilized in insect cuticles. Three different methods of increasing the affinity of these carbon nanofillers for the BMI matrix were explored. The mechanical properties of these composites were assessed using end notch flexure testing. The results indicated that including nanofiller at the laminae interface could increase the interlaminar shear strength of carbon fiber/BMI composites by up to 58%. SEM micrographs revealed that the nanofiller successfully bridged the laminae of the composite, thus biomimicking the insect cuticle. Composite fabrication techniques developed on this program would have a wide variety of applications in space and aerospace structures including leading and trailing edges of aircraft wings.
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I. Mourad, Abdel-Hamid, Mouza S. Al Mansoori, Lamia A. Al Marzooqi, Farah A. Genena, and Nizamudeen Cherupurakal. "Optimization of Curing Conditions and Nanofiller Incorporation for Production of High Performance Laminated Kevlar/Epoxy Nanocomposites." In ASME 2018 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/pvp2018-85067.
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Kevlar composite materials are getting scientific interest in repairing of oil and gas pipelines in both offshore and onshore due to their unique properties. Curing is one of the major factor in deciding the final mechanical performance of laminated Kevlar/epoxy nanocomposites. The parameters such as curing time, temperature and applied pressure during the hot pressing will affect chemistry of crosslinking of the epoxy matrix and interaction of epoxy with the Kevlar fiber. The present study is carried out to evaluate the optimal curing conditions of the Kevlar/epoxy nanocomposites. Three different nanofillers (namely Multi walled Carbon nanotubes (MWCNT), Silicon Carbide (SiC) and Aluminum Oxide (Al2O3)) are incorporated in different weight percentage. Differential Scanning Calorimetry (DSC) and Thermo-Gravimetric Analysis (TGA) tests are carried out to determine the thermal stability and optimal curing conditions. Mechanical performance is investigated by conducting flexure, and drop weight tests. The results show that, the optimal curing temperature for maximizing the mechanical properties is at 170°C. Peeling off the Kevlar layers are observed for nanocomposite samples cured under 100°C. Mechanical strength of the composites is enhanced by optimizing the curing conditions and nanofiller contents.
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Stelescu, Maria Daniela, Mihai Georgescu, Maria Sonmez, Mihaela Nituica, and Adriana Stefan. "Elastomeric nanomaterials based on natural rubber for the food industry." In The 8th International Conference on Advanced Materials and Systems. INCDTP - Leather and Footwear Research Institute (ICPI), Bucharest, Romania, 2020. http://dx.doi.org/10.24264/icams-2020.iv.23.
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This paper presents the obtaining and characterization of new elastomeric nanocomposites based on natural rubber reinforced with plasticized starch, precipitated silica and layered clay, for obtaining consumer goods for the food industry. Obtaining nanocomposites was carried out by the technique of mixing and melt interleaving. The mixtures were vulcanized in the press, at high temperatures, using peroxides as vulcanizing agents, and triallyl cyanurate as vulcanizing coagent. In order to obtain products with improved characteristics, the influence of the amount of modified organic montmorillonite layered clay (OMMT) Nanomer I31PS and the adhesion promoter between mineral filler and polymer - bis-[3-(triethoxysilyl)-propyl]-tetrasulfane (TEPS) on the characteristics of the mixtures, was analysed. The rheological characteristics of the samples show an increase of the minimum torque at the increase in the amount of OMMT type nanofiller and a decrease in the optimal vulcanization time by adding the adhesion promoter between the rubber and the filler. An improvement of the mechanical characteristics of the samples was observed at the introduction of both OMMT and TEPS. These changes may be due to both the nanofiller reinforcement effect and the changes in the morphology of the mixture. The samples showed a good behaviour after immersion in different environments specific to the food industry (water, ethyl alcohol, 10% glucose solution, 0.9% sodium chloride solution and sunflower oil). SEM analyses indicate that the starch particles, together with the other ingredients of the mixture, are quasi uniform distributed in the elastomer matrix. Several superficial microcracks are observed, on the surface of the analysed material, without structural discontinuities or other defects.
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Perry, Kirsten, Miles Burnett, Mehmet Demirtas, Yingtao Liu, and Mrinal Saha. "Improved Mechanical Property in Fiber Reinforced Plastic Composites Using Spray Coated CNTs." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-51165.
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Carbon nanotubes have been employed as prominent nanofillers in composite matrix systems to improve the mechanical properties as well as thermal and electrical properties. A spray coating method is being developed as an effective way to deposit carbon nanotubes onto carbon fiber fabrics with good control of network formation. Compared to conventional approaches, such as chemical vapor deposition and solvent based dispersion approach, the proposed method is simple and versatile with the potential for industrial scale-up. In this paper carbon nanotubes are dispersed in solvent with optimized fabrication experimental processing procedures and sprayed on carbon fiber fabrics. Once all the solvent has been evaporated, the coated carbon fiber fabrics are examined using scanning electron microscopy system. We fabricate carbon fiber reinforced composites using an optimized wet layer approach. Both the prepared carbon nanotube coated carbon fiber fabrics and pristine carbon fiber fabrics were used with the conventional epoxy for the composite fabrication. The enhanced mechanical properties of the composites are experimentally characterized, especially focusing on the Mode-I toughness and strength. The experimental results showed that the spray coated CNTs can significantly improve the mechanical properties of composite, especially under the Mode-I fracture load conditions.
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Hossain, Mohammad K., Md Mahmudur R. Chowdhury, and Nydeia W. Bolden. "Optimized Mechanical Performance of Carbon Fiber-Epoxy Composite Using Amino-Functionalized Graphene Nanoplatelets." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-51643.
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A systematic study has been conducted on processing and characterizing of carbon fiber reinforced epoxy polymer (CFRP) composites to enhance their properties through the optimization of graphene nanoplatelet (GNP). GNP having a two dimensional structure is composed of several layers of graphite nanocrystals stacked together. GNP is expected to provide better reinforcing effect in polymer matrix composites as a nanofiller along with greatly improved mechanical and thermal properties due to its planar structure and ultrahigh aspect ratio. GNP is also considered to be the novel nanofiller due to its exceptional functionalities, high mechanical strength, chemical stability, abundance in nature, and cost effectiveness. Moreover, it possesses an extremely high-specific surface area which carries a high level of transferring stress across the interface and provides higher reinforcement than carbon nanotubes (CNT) in polymer composites. Hence, this extensive research has been focused on the reinforcing effect of amino-functionalized GNP on mechanical properties of carbon fiber reinforced epoxy composites. Amine functionalized GNP was integrated in EPON 828 at different loadings, including 0.1, 0.2, 0.3, 0.4, and 0.5 wt%, as a reinforcing agent. GNP was infused into Epon 828 resin using a high intensity ultrasonic processor followed by a three roll milling for better dispersion. Epikure 3223 curing agent was then added to the modified resin and mixed using a high-speed mechanical stirrer. The mixture was then placed in a vacuum oven at 40 °C for 10 min to ensure the complete removal of entrapped bubbles and thus reduce the chance of void formation. Finally, both conventional and nanophased carbon fiber reinforced epoxy polymer (CFRP) composites were fabricated by employing a combination of hand lay-up and compression hot press techniques. Carbon woven fabrics were properly stacked into eleven layers while maintaining their parallel orientation. Modified epoxy resin was smeared uniformly on each fabric layer using a brush and a wooden roller. The fabric stack was then wrapped with a bleeder cloth and a nonporous Teflon cloth and placed on the plates of the hot press where pressure and temperature were controlled precisely to ascertain maximum wetting of fibers with matrix and compaction of the layup as well as curing. Temperature was kept at 60 °C for 1 hour to attain enough flow of resin at lower viscosity as compared to room temperature and at the same time not to let it flow out of the layup. Temperature was then increased to 100 °C and maintained for 1 hour to obtain completely cured carbon-epoxy composites. After completion of the curing cycles, the laminate was allowed to cool down slowly to avoid any unwanted shrinkage. The conventional CFRP composite were fabricated in a similar fashion. Mechanical properties were determined through flexure and tensile tests according to ASTM standards. In all cases, 0.4 wt% GNP infused epoxy nanocomposite exhibited the best properties. The 0.4 wt% GNP modified carbon fiber/epoxy composites exhibited 19% improvement in the flexure strength and 15% improvement in the flexure modulus. Tensile test results of CFRP composites showed a maximum improvement in the tensile strength and tensile modulus by about 18% and 19%, respectively, for the 0.4 wt% GNP-infused samples over the control sample. Both flexural and tensile properties were observed to reach the highest at the 0.4 wt% loading due to the better interfacial interaction and effective load transfer between the NH2-GNP and the epoxy resin. Furthermore, morphological analysis ensured better dispersion and improved interfacial adhesion between the matrix and the fiber for GNP reinforced composites.
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Ozbulut, Osman E., Zhangfan Jiang, and Guohua Xing. "Evaluation of Various Factors on Electrical Properties of GNP-Reinforced Mortar Composites." In ASME 2018 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/smasis2018-8062.
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Graphene nanoplatelets (GNPs) have the same chemical structures as carbon nanotubes but their internal structure consists of multiple layers of graphene with thicknesses of only a few nanometers. Due to their increased thickness, GNPs are less prone to agglomeration and entanglement when they are used as nanofillers in composite materials. Although it has been shown that self-sensing cementitious composites can be fabricated using GNPs, further studies are needed to reveal effect of various factors on the performance of such composites. Here, a fabrication method that mainly employs polycarboxylate-based superplasticizers together with high-speed shear mixing to disperse GNPs in cement composites is used to prepare GNP-reinforced mortar composites. The molecular structure of polycarboxylate-based superplasticizer can considerably affect the performance of GNP-cement composites. Therefore, two commercially available polycarboxylate-based superplasticizers that possess varying backbone and side-chain lengths are systematically incorporated to prepare GNP-reinforced multifunctional composites. In addition, the effects of mixing durations on the electrical properties of the developed composites are assessed. Another essential challenge in the development of multifunctional cement composites is to improve the interfacial interaction between GNPs and the hydration products of cement such as calcium-silicate-hydrates (CSH). Here, incorporation of supplementary materials such as silica fume into the matrix is studied to improve the bond between a cementitious matrix and nano reinforcement. The bulk resistivity of the mortar specimens is measured using the four-probe measurement method. The piezoresistive behavior and sensing ability of the GNP-reinforced mortar composites are investigated through compressive tests at quasi-static.
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Hossain, Mohammad K., Md Mahmudur R. Chowdhury, Mahesh Hosur, Shaik Jeelani, and Nydeia W. Bolden. "Enhanced Properties of Epoxy Composite Reinforced With Amino-Functionalized Graphene Nanoplatelets." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-51483.
Full textAbstract:
A systematic study has been conducted on processing and characterization of epoxy polymer composite to enhance its mechanical, viscoelastic, and thermal properties through optimization of graphene nanoplatelets (GNP). GNP having a two dimensional structure is composed of several layers of graphite nanocrystals stacked together. GNP is expected to provide better reinforcing effect in polymer matrix composites as a nanofiller along with greatly improved mechanical and thermal properties due to its planar structure and ultrahigh aspect ratio. GNP is also considered to be the novel nanofiller due to its exceptional functionalities, high mechanical strength, chemical stability, abundance in nature, and cost effectiveness. Moreover, it possesses an extremely high-specific surface area which carries a high level of transferring stress across the interface and provides higher reinforcement than carbon nanotubes (CNT) in polymer composites. Hence, this research has been focused on the reinforcing effect of the amine-functionalized GNP on mechanical, viscoelastic, and thermal properties of the epoxy resin-EPON 828 composite. Amine functionalized GNP was infused in EPON 828 at different loadings including 0, 0.1, 0.2, 0.3, 0.4, and 0.5 wt% as a reinforcing agent. GNP was infused into epoxy resin Epon 828 Part-A using a high intensity ultrasonic liquid processor followed by a three roll milling processor for better dispersion. The GNP/epoxy mixture was then mixed with the curing agent Epikure 3223 according to the stoichiometric ratio (Part A: Part B = 12:1). The mixture was then placed in a vacuum oven at 40 °C for 10 m to ensure the complete removal of entrapped bubbles and thus reduce the chance of void formation. The as-prepared resin mixture was then poured in rubber molds to prepare samples for mechanical, viscoelastic, and thermal characterization according to ASTM standards. Molds containing liquid epoxy nanocomposites were then kept in the vacuum oven at room temperature for seven days to confirm full curing of the samples according to the manufacturer’s suggestion. Similarly, neat epoxy samples were fabricated to obtain its baseline properties through mechanical, viscoelastic, and thermal characterization and compare these properties with those of nanophased ones. The reinforcing effect of the amine-functionalized GNP on the epoxy was characterized through mechanical, viscoelastic, and thermal analyses. Fracture morphology of mechanically tested samples was evaluated through scanning electronic microscopy (SEM) study. The mechanical properties were determined through flexure test according to the ASTM standard. Dynamic mechanical analysis (DMA) and thermo-mechanical analysis (TMA) were performed to analyze viscoelastic and thermal performances of the composite. In all cases, the 0.4 wt% GNP infused epoxy nanocomposite exhibited the best properties. The 0.4 wt% GNP-loaded epoxy sample showed 20% and 40% improvement in flexure strength and modulus, respectively. Moreover, 16% improvement in the storage modulus and 37% decrease in the coefficient of thermal expansion were observed due to the integration of GNP reinforcement into the epoxy system. Scanning electronic micrographs exhibited smooth fracture surface for the neat sample, whereas the roughness of surface increased due to the GNP incorporation. This is an indication of change in the crack propagation during loading and a higher energy requirement to fracture the GNP-loaded sample.
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Gou, J., H. C. Gu, and G. Song. "Carbon Nanopaper Sheets for Damping Applications: Processing and Characterization." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-41914.
Full textAbstract:
Carbon nanotubes and carbon nanofibers have been used as nanofillers for high performance damping composite materials in recent years. The large specific area (1000 m2/g) and aspect ratio (>1000) of carbon nanotubes and nanofibers promote significant interfacial friction between carbon nanotubes/nanofibers and the polymer matrix. The high stiffness and strength of carbon nanotubes and nanofibers enlarge the differences in the strains of individual constituents of the composites, which causes much higher energy dissipation in the polymer matrix. However, adding small amount of carbon nanotubes and nanofibers will significant increase the viscosity of polymer resin, which makes the dispersion and resin flow through the porous fiber mats extremely difficult. In addition, the fiber mats will filter carbon nanotubes and nanofibers during liquid molding process such as Resin Transfer Molding (RTM) and Vacuum-Assisted Resin Transfer Molding (VARTM). A unique concept of manufacturing nanocomposites with carbon nanotube/nanofiber based nanopaper sheets for structural damping applications has recently been explored. This approach involves making carbon nanopaper sheet by the filtration of well-dispersed carbon nanotubes and carbon nanofibers under controlled processing conditions. Subsequently, carbon nanopaper sheets are integrated into composite laminates using Vacuum Assisted Resin Transfer Molding (VARTM) process. In this study, several nanocomposite plates were fabricated with carbon nanopaper sheet as surface layer. For the comparative study, the regular composite plates without carbon nanopaper sheet were also fabricated. To identify the damping characteristics of each specimen, the Frequency Response Function (FRF) was estimated by a pair of piezoceramic patches: one as an actuator to excite the specimen and the other as a sensor to detect the induced vibrations. From the FRF, the damping ratio of the specimen at each modal frequency of interests was calculated. The experimental results clearly show a significant improvement of damping properties of nanocomposites plates. This research demonstrates structural damping enhancement via carbon nanopaper sheets and provided basic understanding of the damping characteristics for the optimal design and fabrication of high performance damping composites, which have the potential to be used as structural components for many applications.