{"id":3752,"date":"2019-06-11T10:52:47","date_gmt":"2019-06-11T05:22:47","guid":{"rendered":"http:\/\/iap.iisc.ac.in\/~abha\/?p=3752"},"modified":"2020-07-07T00:49:53","modified_gmt":"2020-07-06T19:19:53","slug":"mechanical-behaviour-of-meso-and-micro-porous-open-cell-foams","status":"publish","type":"post","link":"https:\/\/iap.iisc.ac.in\/~abha\/mechanical-behaviour-of-meso-and-micro-porous-open-cell-foams\/","title":{"rendered":"Mechanical behavior of meso- and micro-porous open cell foams"},"content":{"rendered":"\n

Three-dimensional assembly comprised from 1D and 2D materials provide ultra-small porous structures beneficial for thermo-mechanical and electro-mechanical coupled applications. Porosity dependent characteristics are monitored through transport studies. The facility includes thermo-mechanical measurements and mechanical deformation testing units. Micro and mesoporous foams are highly desirable for the lightweight impact absorbing systems in the microelectronic packaging industry. Carbon nanostructures based open cell foams like graphene and carbon nanotubes being multifunctional in nature can be exploited widely for their elastic behaviour. Graphene with large surface area and spring like recovery of carbon nanotubes open a great potential to be exploited in the research area of studying their mechanical behaviour.<\/p>\n\n\n\n

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Strain Rate Effects in the Mechanical Response of Polymer-Anchored Carbon Nanotube Foams<\/strong><\/p>\n\n\n\n

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Figure: Flat punch nanoindentation results. a)\nSchematic diagram showing the experimental set up. b) Load\u2013displacement curves\nobtained at different loading rates. c) Stress\u2013strain curves extrapolated by\nthe indentation measurement at varying strain rates upon various loading\/\nunloading cycles showing the presence of a Baushinger-like effect. d)\nDependence of the hysteresis loop amplitude on strain. <\/p>\n\n\n\n

Reference: Adv.\nMater. 2009, 21, 334\u2013338<\/p>\n\n\n\n

https:\/\/doi.org\/10.1002\/adma.200801997<\/a><\/p>\n\n\n\n

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Tailoring the microstructure\nand mechanical properties of arrays of aligned multiwall carbon nanotubes by\nutilizing different hydrogen concentrations during synthesis<\/strong><\/p>\n\n\n\n

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Figure: SEM image of a typical sample\nshowing the mostly-aligned nature of VACNTs as synthesized. Average energy\nabsorbed per unit volume calculated for the first compressive cycle for each\nhydrogen concentration. The inset shows the variation of the peak stress values\nobtained at maximum (0.8) strain as a function of the hydrogen concentration\nused during growth. Energy absorbed in the first compressive cycle plotted as a\nfunction of density for all concentrations of hydrogen.<\/p>\n\n\n\n

Reference: C a r b on 4 9 (2 0 1 1 ) 3 6 3\n1 \u20133 6 3 8<\/p>\n\n\n\n

https:\/\/doi.org\/10.1016\/j.carbon.2011.04.066<\/a><\/p>\n\n\n\n

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Synthesis and\ncharacterization of carbon nanotube-polymer multilayer structures<\/strong><\/p>\n\n\n\n

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Figure: In situ visualization of the compressive\ndeformation of a multilayer sample. (a) Digital snapshots of the deformed configuration\nof the four-layer structure corresponding to the different strain levels\nindicated in panel (b). The white lines show the position of polymer, which\nseparates each CNT layer. (b) Stress-strain curve showing the different strain\nlevels corresponding to the snapshots in panel (a). (c) Schematic diagram\nillustrating the localized deformation of the four-layer structure under compression.<\/p>\n\n\n\n

Reference: ACS Nano, 2011, 5, 7713<\/p>\n\n\n\n

https:\/\/doi.org\/10.1021\/nn202262j<\/a><\/p>\n\n\n\n

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Effect of density variation and non-covalent functionalization on the compressive behavior of carbon nanotube arrays<\/strong> <\/p>\n\n\n\n

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Figure: Microstructure of a CNT sample treated with\nacetone and SDS surfactant; carbon nanotubes form dense bundles. (d)\nMicrostructure of a CNT sample wetted with silica nanoparticles; after the drying\nprocess, nanoparticles adhere to the surface of individual carbon nanotubes. Comparison\nof the maximum value of compressive peak stress in samples wetted with\nsurfactant (data points denoted by circles) and in freestanding, as-grown CNTs\n(control) (data points denoted by squares), at varying strain rates. Variation\nof measured peak stress as a function of strain rate. Data points shown by\ncircles represent samples with nanoparticles, and squares represent the results\nobtained from the as-grown (control) samples. <\/p>\n\n\n\n

Reference: Nanotechnology 22 (2011) 425705<\/p>\n\n\n\n

https:\/\/doi.org\/10.1088\/0957-4484\/22\/42\/425705<\/a><\/p>\n\n\n\n

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Nonlinear viscoelasticity of freestanding and\npolymer-anchored vertically aligned carbon nanotube foams<\/strong><\/p>\n\n\n\n

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Figure: Relaxation exponent m vs\nstrain for (c) freestanding (mF<\/sub>) and (d) double-anchored (mA) CNT\nforests.<\/p>\n\n\n\n

Reference:\nJ. Appl. Phys. 111, 074314 (2012)<\/p>\n\n\n\n

http:\/\/dx.doi.org\/10.1063\/1.3699184<\/a><\/p>\n\n\n\n

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Thermo-mechanical\nstability of a cellular assembly of carbon nanotubes in air<\/strong><\/p>\n\n\n\n

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Figure: Results of the DMA tests\nshowing the variations of (a) storage modulus, E, and (b) damping ratio, tand\nwith time. SEM images of the CNT mat subjected to DMA at 673, and 773 K.<\/p>\n\n\n\n

Reference:\nC a r b on 5 0 ( 2 0 1 2 ) 4 3 7 3 \u20134 3 7 8<\/p>\n\n\n\n

https:\/\/doi.org\/10.1016\/j.carbon.2012.05.013<\/a><\/p>\n\n\n\n

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Mechanical and electrical contact\nresistance characteristics of a cellular assembly of carbon nanotubes<\/strong><\/p>\n\n\n\n

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Figure: Scanning electron micrograph showing the\ncellular structure of CNTs. Structural porosity is indicated with circles.\nLoad, P, and current, I, are plotted against depth of penetration, h, obtained\nfrom the dense and the porous regions of the CNT structures, respectively.\nDifference in initial and final currents before and after loading (at zero\npenetration depth) plotted against the peak load employed for the indentation\nstudy.<\/p>\n\n\n\n

Reference: Nanotechnology 24\n(2013) 015707<\/p>\n\n\n\n

https:\/\/doi.org\/10.1088\/0957-4484\/24\/1\/015707<\/a><\/p>\n\n\n\n

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Influence of Magnetic field on the compressive\nbehavior of  carbon nanotubes<\/strong><\/p>\n\n\n\n

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Figure: High resolution images that show\nthe nanoparticles adhered to the surfaces of CNT. Peak stress is plotted with\nthe magnetic field intensities. Energy absorption is plotted with the magnetic\nfield intensities. Elastic modulus in three regions of strains is plotted with\nthe magnetic field intensities.<\/p>\n\n\n\n

Reference: Appl.\nPhys. Lett. 102, 241919 (2013)<\/p>\n\n\n\n

https:\/\/doi.org\/10.1063\/1.4811707<\/a><\/p>\n\n\n\n

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Tuning of the electro-mechanical behavior of the\ncellular carbon nanotube structures with nanoparticle dispersions<\/strong><\/p>\n\n\n\n

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Figure: Scanning electron micrographs of the cellular CNT mat (a) before (inset shows a high resolution entangled CNT microstructure) and (b) after dispersion of nanoparticles. (a) Representative plots of load, P,\nand current, I, vs. depth of penetration, h, for Ag nanoparticle dispersed CNT\nstructure from at maximum indentation depths of 0.5. (b) Measured values of the\nmaximum loads, Pmax<\/sub>, as a function of the applied maximum depths of\npenetration, hmax<\/sub>, for all mats with different nanoparticles\ndispersions.<\/p>\n\n\n\n

Reference: Appl. Phys. Lett. 104, 101911 (2014)<\/p>\n\n\n\n

https:\/\/doi.org\/10.1063\/1.4868037<\/a><\/p>\n\n\n\n

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Effect of fluid medium on mechanical behavior of\ncarbon nanotube foam of fluid medium on mechanical behavior of carbon nanotube\nfoam<\/strong><\/p>\n\n\n\n

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Figure: Representative SEM micrograph of\nthe as-grown, dry CNT foam sample. Contour plot showing the variation of normalized\nstress at a strain of 50% as a function of the strain rate and the glycerol\nconcentration in the water-glycerol solution. The stress was normalized\ndividing it by the density of the as-grown, dry CNT foam. Best-fit curve\nanalysis of the experimental data. The tables on the right show the values of\nvarious constants calculated from the curve fit analysis at different strain\nrates.<\/p>\n\n\n\n

Reference: Appl. Phys. Lett. 104, 221910 (2014)<\/p>\n\n\n\n

https:\/\/doi.org\/10.1063\/1.4881843<\/a><\/p>\n\n\n\n

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Magnetic field induced\ntailoring of mechanical behavior of fluid filled micro porous carbon nanotube\nfoam<\/strong><\/p>\n\n\n\n

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Figure: Optical image of the CNT Foam. A high-resolution TEM image of\npartially iron filled inside the core of CNT. Peak stresses are plotted with the\napplied magnetic field for CNT mats that are impregnated with  90% glycerol, and silicon oil.<\/p>\n\n\n\n

Reference: Appl. Phys. Lett. 104, 261906 (2014).<\/p>\n\n\n\n

https:\/\/doi.org\/10.1063\/1.4886389<\/a><\/p>\n\n\n\n

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Tailoring viscoelastic\nresponse of carbon nanotubes cellular structure using electric field<\/strong><\/p>\n\n\n\n

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Figure: Representative SEM micrographs showing\nthe configuration of CNT bundles and individual CNT strands in the cellular CNT\nsamples used in this study. Variation of the electric field induced strain in\nthe unstressed freestanding CNT sample and the additional stress that needs to\nbe applied onto the sample to maintain zero macroscopic strain as a function of\nthe electric field. R is the curve fitting parameter. The stress relaxation as\nregistered in a representative CNT sample compressed to various pre-compressive\nstrains with no electric field. Variation of the normalized stress as a\nfunction of the time after application of the \u201cinstantaneous\u201d pre-compressive\nstrain. The pulse voltage increased by 0.02 V in the sequence of 0.07, 0.09,\n1.1, etc. The dotted line represents stress relaxation if electric field was\nnot applied.<\/p>\n\n\n\n

Reference: Nanoscale, 2014, 6, 13668\u201313677<\/p>\n\n\n\n

https:\/\/doi.org\/10.1039\/C4NR04766D<\/a><\/p>\n\n\n\n

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Highly compressible behavior of polymer mediated three-dimensional network of graphene foam<\/strong> <\/p>\n\n\n\n

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Figure: SEM images showing the microstructure:\n(a) three-dimensional GF networks; (b) GF\/PDMS composite. Comparisons of\nmechanical properties of GF, CNT, CNT\/PDMS, and GF\/PDMS foams: energy\nabsorption and elastic modulus.<\/p>\n\n\n\n

Reference: RSC Adv., 2014, 4, 50074\u201350080<\/p>\n\n\n\n

https:\/\/doi.org\/10.1039\/C4RA08321K<\/a><\/p>\n\n\n\n

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Tailored mechanical behavior of magnetic particles loaded carbon nanotube foam in presence of magnetic field<\/strong><\/p>\n\n\n\n

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Figure: SEM images of (a) pristine CNT foam\nand (b) CNT decorated with iron oxide nanoparticles. Peak stress capability\nwith increasing magnetic field intensity. Peak stress variation with the\nvarying concentration of iron oxide nanoparticles loaded in the CNT foam in the\npresence of a magnetic field intensity of 0.12 T.<\/p>\n\n\n\n

Reference: J. Phys. D: Appl. Phys. 48\n(2015) 265301<\/p>\n\n\n\n

https:\/\/doi.org\/10.1088\/0022-3727\/48\/26\/265301<\/a><\/p>\n\n\n\n

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Temperature dependent compressive\nbehavior of graphene mediated three-dimensional cellular assembly<\/strong><\/p>\n\n\n\n

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Figure: Optical image of porous GF\/PDMS\n(black) and PDMS foam (white). Storage modulus and tan delta as a function of\nfrequency in glassy state GF\/PDMS and PDMS foams. <\/p>\n\n\n\n

Reference: Carbon 96 (2016) 439-447<\/p>\n\n\n\n

https:\/\/doi.org\/10.1016\/j.carbon.2015.09.089<\/a><\/p>\n\n\n\n

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Thermo-mechanical behavior of\ngraphene oxide hydrogel<\/strong><\/p>\n\n\n\n

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Figure: (a) Optical image of GO-PEI\nhydrogel. Microstructure of (b) GO-PEI and (c) Fe2<\/sub>O3<\/sub>\/GO-PEI\nhydrogels, inset depicts the schematic diagram of the sample. Storage modulus\nand (b) tan delta of GO-PEI and Fe2<\/sub>O3<\/sub>\/GO-PEI hydrogels in\nwater as a function of temperature.<\/p>\n\n\n\n

Reference: Mater. Res. Express 4 (2017) 025006<\/p>\n\n\n\n

https:\/\/doi.org\/10.1088\/2053-1591\/aa5bf8<\/a><\/p>\n\n\n\n

<\/div>\n","protected":false},"excerpt":{"rendered":"

Three-dimensional assembly comprised from 1D and 2D materials provide ultra-small porous structures beneficial for thermo-mechanical and electro-mechanical coupled applications. Porosity dependent characteristics are monitored through transport studies. The facility includes thermo-mechanical measurements and mechanical deformation testing units. Micro and mesoporous foams are highly desirable for the lightweight impact absorbing systems in the microelectronic packaging industry. […]<\/p>\n","protected":false},"author":1,"featured_media":3923,"parent":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[39],"tags":[],"class_list":["post-3752","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research"],"acf":[],"_links":{"self":[{"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/posts\/3752","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/comments?post=3752"}],"version-history":[{"count":11,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/posts\/3752\/revisions"}],"predecessor-version":[{"id":4185,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/posts\/3752\/revisions\/4185"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/media\/3923"}],"wp:attachment":[{"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/media?parent=3752"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/categories?post=3752"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/tags?post=3752"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}