Key aspects of nanofiber morphology in vapor-grown carbon nanofiber (VGCNF)/vinyl ester nanocomposites were characterized using transmission electron microscopy (TEM) images. Three-parameter Weibull probability density functions were generated to describe the statistical variation in nanofiber outer diameters, wall thicknesses, relative wall thicknesses, visible aspect ratios, and visible waviness ratios. Based upon a linear regression of experimental data, the relative nanofiber wall thicknesses were reasonably constant over a range of nanofiber radii. Such information could be used to establish more realistic nanofiber moduli and strengths obtained from nanofiber tensile tests, as well as to develop physically motivated computational models for predicting nanocomposite behavior. While the nanofiber aspect ratios and fiber waviness measurements were restricted to the visible portions of nanofibers lying in the plane of the TEM images, such data can be used to predict bounds on the effective nanocomposite elastic properties. This study represents one of the first attempts to experimentally characterize the distribution of VGCNF features in real thermoset nanocomposites.
GorgaRECohenRE. Toughness enhancements in poly(methyl methacrylate) by addition of oriented multiwall carbon nanotubes. J Polym Sci Part B Polym Phys2004; 42(14): 2690–2702.
2.
LuoJJDanielIM. Characterization and modeling of mechanical behavior of polymer/clay nanocomposites. Compos Sci Technol2003; 63(11): 1607–1616.
3.
ZhouYPervinFJeelaniS. Effect vapor grown carbon nanofiber on thermal and mechanical properties of epoxy. J Mater Sci2007; 42: 7544–7553.
4.
TibbettsGGLakeMLStrongKLRiceBP. A review of the fabrication and properties of vapor grown carbon nanofiber/polymer composites. Compos Sci Technol2007; 67: 1709–1718.
5.
Al-SalehMHSundararajU. A review of vapor grown carbon nanofiber/polymer conductive composites. Carbon2009; 47: 2–22.
6.
SunLGibsonRFGordaninejadFSuhrJ. Energy absorption capability of nanocomposites: a review. Compos Sci Technol2009; 69: 2392–2409.
KangIHeungYYKimJHLeeJWGollapudiRSubramaniamS. Introduction to carbon nanotubes and nanofiber smart materials. Composites Part B2006; 37: 382–394.
9.
LiJVaismanLMaromGKimJ. Br treated graphite nanoplatelets for improved electrical conductivity of polymer composites. Carbon2007; 45: 744–750.
10.
YanJFanZWeiTZhangM. Effect of chemical modification of graphite nanoplatelets on electrochemical performance of MnO2 electrodes. J Mater Sci2010; 21: 619–624.
11.
ZhengCFanZWeiTLuoG. Temperature dependence of the conductivity behavior of graphite nanoplatelets-filled epoxy resin composites. J Appl Polym Sci2009; 113: 1515–1519.
12.
ChatterjeeAIslamMS. Fabrication and characterization of TiO2-epoxy nanocomposite. Mater Sci Eng A2008; 487: 574–585.
13.
MatrinMHanagudSThadhaniNN. Mechanical behavior of nickel + aluminum powder-reinforced epoxy composites. Mater Sci Eng A2007; 443: 209–218.
14.
Yu J, Lacy TE, Toghiani H and Pittman CU. Classical micromechanics modeling of nanoreinforced composites with carbon nanofibers and interphase. J Compos Mater 2011; Pre-published online, DOI: 10.1177/ 0021998311401092.
15.
Nouranian S, Toghiani H, Lacy TE and Pittman Jr CU. Dynamic mechanical analysis and optimization of vapor-grown carbon nanofiber/vinyl ester nanocomposites using design of experiments. J Compos Mater 2010; Pre-published online, DOI: 10.1177/0021998310385027.
EndoMKimYAHayasiTFukaiYOshidaKTerronesM. Structural characterization of cup-stacked-type nanofibers with an entirely hollow structure. Appl Phys Lett2002; 80: 1267–1269.
18.
LawrenceJGBerhanLMNadarajahA. Elastic properties and morphology of individual carbon nanofibers. ACSNANO2008; 2(6): 1230–1236.
19.
KiselevNASloanJZakharovDNKukovitskiiEFHutchisonJLHammerJ. Carbon nanotubes from polyethylene precursors: structure and structural changes caused by thermal and chemical treatment revealed by HREM. Carbon1998; 36: 1149–1157.
LimT. Simplified model for the influence of inclusion aspect ratio on the stiffness of aligned reinforced composites. J Reinf Plast Compos2003; 22: 301–325.
22.
ManoharanMPSharmaAVHaqueMABakisCEWangKW. The interfacial strength of carbon nanofiber epoxy composite using single fiber pullout experiments. Nanotechnology2009; 20: 1–5.
23.
FisherFBradshawRBrinsonL. Fiber waviness in nanotube-reinforced polymer composites - I: modulus predictions using effective nanotube properties. Compos Sci Technol2003; 63: 1689–1703.
24.
FisherFBradshawRBrinsonL. Fiber waviness in nanotube-reinforced polymer composites - II. modelling via numerical approximation of the dilute strain concentration tensor. Compos Sci Technol2003; 63(11): 1705–1722.
25.
Fisher FT. Nanomechanics and the viscoelastic behavior of carbon nanotube-reinforced polymers. PhD thesis, Thesis of Mechanical Engineering, Northwestern University, 2002.
26.
HsiaoHDanielIM. Effect of fiber waviness on stiffness and strength reduction of unidirectional composites under compressive loading. Compos Sci Technol1996; 56: 581–593.
27.
Lee J. Characterization of the effect of material/fabrication parameters on the mechanical response of vapor-grown carbon nanofiber/vinyl ester nanocomposites. MS thesis, Thesis of Aerospace Engineering, Mississippi State University, 2010.
HallinanAJ. A review of the weibull distribution. J Qual Technol1993; 25(2): 85–93.
36.
MoriTTanakaK. Average stress in matrix and average elastic energy of materials with misfitting inclusions. Acta Metallurgica et Materialia1973; 21: 571–574.
37.
BenvenisteY. A new approach to the application of Mori-Tanaka’s theory in composite materials. Mech Mater1987; 6: 147–157.
38.
Nemat-NasserSHoriM. Micromechanics: overall properties of heterogeneous materials. North-Holland: Amsterdam, 1993.
39.
Yu J. Micromechanically based multiscale material modeling of polymer nanocomposites. PhD thesis, Thesis of Aerospace Engineering, Mississippi State University, 2011.
