damping augmentation of nanocomposites using...

Hindawi Publishing CorporationJournal of NanomaterialsVolume 2006, Article ID 32803, Pages 1–7DOI 10.1155/JNM/2006/32803

Damping Augmentation of Nanocomposites UsingCarbon Nanofiber Paper

Jihua Gou,1 Scott O’Braint,1 Haichang Gu,2 and Gangbing Song2

1 Department of Mechanical Engineering, University of South Alabama, Mobile, AL 36688-0002, USA2 Department of Mechanical Engineering, University of Houston, Houston, TX 77204-4006, USA

Received 11 January 2006; Accepted 4 May 2006

Vacuum-assisted resin transfer molding (VARTM) process was used to fabricate the nanocomposites through integrating carbonnanofiber paper into traditional glass fiber reinforced composites. The carbon nanofiber paper had a porous structure with highlyentangled carbon nanofibers and short glass fibers. In this study, the carbon nanofiber paper was employed as an interlayer andsurface layer of composite laminates to enhance the damping properties. Experiments conducted using the nanocomposite beamindicated up to 200–700% increase of the damping ratios at higher frequencies. The scanning electron microscopy (SEM) charac-terization of the carbon nanofiber paper and the nanocomposites was also conducted to investigate the impregnation of carbonnanofiber paper by the resin during the VARTM process and the mechanics of damping augmentation. The study showed a com-plete penetration of the resin through the carbon nanofiber paper. The connectivities between carbon nanofibers and short glassfibers within the carbon nanofiber paper were responsible for the significant energy dissipation in the nanocomposites during thedamping tests.

Copyright © 2006 Jihua Gou et al. This is an open access article distributed under the Creative Commons Attribution License,which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

1. INTRODUCTION

In recent years, nanoparticles have been attracting increas-ing attention in the composite community as they are ca-pable of improving the mechanical and physical proper-ties of traditional fiber reinforced composites [1–4]. Theirnanometer size, leading to high specific surface areas of upto more than 1000 m2/g and extraordinary mechanical, elec-trical, and thermal properties make them unique nano-fillersfor structural and multifunctional composites. Commonlyused nanoparticles in nanocomposites include multiwallednanotubes (MWNTs), single-walled nanotubes (SWNTs),carbon nanofibers (CNFs), montmorillonite (MMT) nan-oclays, and polyhedral oligomeric silsesquioxanes (POSS).Other nanoparticles, such as SiO2, Al2O3, TiO2, and nanosil-ica are also used in the nanocomposites. Compared toother particulate additives, carbon nanotubes and carbonnanofibers offer more advantages. The addition of small sizeand low loading of carbon nanotubes and carbon nanofiberscan enhance the matrix-dominated properties of compos-ites, such as stiffness, fracture toughness, and interlaminarshear strength [5–9]. They have proven to be excellent ad-ditives to impart electrical conductivity in nanocompositesat lower loadings due to their high electrical conductiv-ity and aspect ratio [10–12]. In addition, they have better

performance as flame retardant by reducing the heat releaserate of polymer and conducting heat away from the flamezone [13, 14].

While there are many reported benefits of carbon nan-otubes and carbon nanofibers in composites, the potentialof carbon nanotubes and carbon nanofibers to enhance thedamping properties of composites has been less explored.Traditional damping enhancements of composites are basedon viscoelastic polymer materials [15], carbon fiber prepregs[16], and magnetostrictive particles [17]. The major limi-tations of the viscoelastic polymer materials are the struc-tural integrity issue, the sacrifice of stiffness and strengthof the composite system due to the resin penetration, andpoor thermal stability. Kishi et al. [16] evaluated the damp-ing properties of composite laminates with/without the in-terleaved films. The effects of the lay-up arrangements ofcarbon fiber prepregs on the damping properties of the in-terleaved laminates were examined. The viscoelastic proper-ties of interleaved polymer films were reflected in the damp-ing properties of the corresponding interleaved laminates.Magnetostrictive particles have been used in a polymer ma-trix as active transducer and passive damper, providing stiff-ness and strength while incorporating damping capabilities.Pulliam et al. [17] developed a novel manufacturing tech-nique based on magnetic fields to distribute magnetostrictive

2 Journal of Nanomaterials

particles in polymer resins and applied them in thin-layer onthe surfaces for vibration damping. Recently, carbon nan-otubes have been used in the composite system for struc-tural damping and stiffness augmentation. Suhr et al. [18]conducted direct shear testing of epoxy thin films contain-ing multiwalled carbon nanotubes and reported strong vis-coelastic behavior with up to 1400% increase in loss factor(damping ratio) of the baseline epoxy resin. The great im-provement in damping was achieved without sacrificing themechanical strength and stiffness of the polymer, and withminimal weight penalty. Koratkar et al. [19, 20] fabricatedmultiwalled nanotube thin films by using catalytic chemi-cal vapor deposition of xylene-ferrocene mixture precursor.The nanotube films were employed as interlayers to rein-force the interfaces between composite plies, enhancing lam-inate stiffness and structural damping. The flatwise bend-ing tests of a piezosilica composite beam with an embed-ded nano-film sublayer indicated up to 200% increase in thedamping level and 30% increase in the baseline bending stiff-ness.

Traditionally, researchers fabricated composites by di-rectly mixing carbon nanotubes and carbon nanofibers intopolymers and then using casting and injection techniquesto make nanocomposites. Gou et al. [21, 22] have de-veloped a new technique approach to fabricate nanocom-posites using single-walled carbon nanotube bucky papers.The experimental details of fabrication of single-walledcarbon nanotube bucky paper can be found in reference[23]. The dynamic mechanical analysis (DMA) results in-dicated an enhancement of the thermomechanical proper-ties of single-walled carbon nanotube bucky paper/epoxyresin nanocomposites. The present work describes the inte-gration of carbon nanofiber paper as damping material intolarge structural level laminates-glass fiber reinforced com-posites. The very first time an example of carbon nanofiberpaper-enabled nanocomposites in the dimension of a struc-tural element is presented. The manufacturing via VARTMand the investigation of the damping properties and ten-sile properties of the fabricated nanocomposites are de-scribed.

2. EXPERIMENTAL DETAILS

2.1. Materials

The carbon nanofiber paper used in this study was ob-tained from Applied Sciences, Inc. The carbon nanofiber pa-per had good strength and flexibility to allow for handlinglike traditional glass fiber mat. The carbon nanofiber paperwas composed of short glass fibers and vapor grown car-bon nanofibers (Polygraf III) with diameter of 100–150 nmand length of 30–100 μm. The short glass fiber and carbonnanofibers appeared in an entangled and porous form withinthe paper. The unsaturated polyester resin (product code:712–6117, Eastman Chemical Company) was used as matrixmaterial for glass fiber reinforced composites. The polyesterresin was used with the MEK peroxide hardener at a weightratio of 100 : 1.

2.2. Manufacturing of carbon nanofiberpaper-enabled nanocomposites

The VARTM process has been widely used to produce low-cost, high-quality, and geometrically complicated compos-ite parts. In this study, the VARTM process was used to fab-ricate the carbon nanofiber paper-enabled nanocomposites,which was carried out in three steps. In the first step, glassfiber mats carbon nanofiber paper were placed on the bot-tom half of a mold. After the lay-up operation was com-pleted, a peel ply, resin distribution media, and vacuum bagfilm were placed on the top of fiber mats. The vacuum filmbag was then sealed around the perimeter of the mold and avacuum pump was used to draw a vacuum within the moldcavity. The next step was the mold filling during which resinwas sucked into the mold under atmospheric pressure. In theVARTM process, the distribution media provided a high per-meability region in the mold cavity, which allowed the resinto quickly flow across the surface of the laminate and thenwet the thickness of the laminate. Therefore, the dominantimpregnation mechanism in the VARTM process was thethrough-thickness flow of resin. In the final step, the com-posite part was cured at room temperature for 24 hours andpost-cured in the oven for another 2 hours at 100ÆC.

In this study, the test laminates consisted of six plies offiberglass with a single layer of carbon nanofiber paper em-bedded at the surface or the midplane. In the manufactur-ing of composite laminates with carbon nanofiber as an in-terlayer, one layer of carbon nanofiber paper was placed be-tween the fiber mats. The peel ply and resin distribution me-dia were used on both top and bottom sides to facilitate theresin flow through the thickness.

2.3. Damping test of carbon nanofiber paper-enablednanocomposites

The regular composite beam without carbon nanofiber pa-per and the nanocomposite beam with carbon nanofiber pa-per were used as the specimens for damping test. For eachbeam, a PZT (lead zirconate titanate, a type of piezoce-ramic material) patch (20 mm � 20 mm) was attached onone side as an actuator to excite the beam and a smaller PZTpatch (10 mm� 8 mm) was attached on the other side of thebeam as a sensor to detect the beam’s vibration, as shown inFigure 1. A micro laser sensor (NAIS-LM10-ANR12151) wasalso used to detect the beam’s tip displacement. The microlaser sensor had a resolution of 20 μm (0.0008 inch). The test-ing specimen was clamped on an aluminum stand as shownin Figure 2.

2.4. Tensile test of carbon nanofiber paper-enablednanocomposites

The tensile tests were performed using the VARTM man-ufactured composite laminates with and without carbonnanofiber paper. The tensile tests on the composite beamswere conducted according to ASTM test standards. All thesetests were performed on a Qualitest testing machine.

Jihua Gou et al. 3

PZT actuators

Nanocomposite beam

Regular composite beam

Figure 1: Regular composite beam and nanocomposite beam fordamping test.

2.5. Electron microscopy

The SEM images were taken to study the porous structureof carbon nanofiber paper and the impregnation of carbonnanofiber paper by the resin. The interface between the car-bon nanofiber paper and the resin was examined. The SEMspecimens of the nanocomposites were obtained by the ultramicrotome cutting.

3. RESULTS AND DISCUSSION

3.1. SEM observations of carbon nanofiber paperand nanocomposites

Figure 3(a) shows the carbon nanofiber paper used in this re-search, which can be handled like traditional glass fiber mats.The SEM images of carbon nanofiber paper are shown in Fig-ures 3(b) and 3(c). These images show the multiscale porousstructure of carbon nanofiber paper formed by short glassfibers and carbon nanofibers. The pore size formed by shortglass fibers was in the range of 100–200 μm and the poresformed by carbon nanofibers had an average opening around1 μm. The carbon nanofibers within the paper have an aver-age diameter about 100–150 nm. Figure 3(d) shows the SEMimage of the fracture surface of the nanocomposites embed-ded with carbon nanofiber paper. This sample was fracturedunder tensile force. It can be clearly seen that the resin hadcompletely penetrated the carbon nanofiber paper throughthe thickness direction during the VARTM process.

3.2. Damping properties of carbon nanofiber-enabledcomposite laminates

The damping test was conducted on the composite lami-nates with carbon nanofiber paper as midlayer and surfacelayer. During the damping test, the sweep sinusoidal signalswere used as excitation source for the PZT actuator to get

Laser sensor

Beam

Figure 2: Experimental setup for damping test.

the frequency response of the system. Two different sweepsine signals were used for the test. One sweep sine was from0.1 Hz to 100 Hz to get detailed information about the firstmode frequency. The other sweep sine was from 10 Hz to1000 Hz to excite the first few modes. The sweeping periodof both sweep sines was set as 20 seconds. The sampling fre-quency was set as 40 kHz. For the nanocomposite beam withcarbon nanofiber paper as midlayer, the time responses ofboth sweep sine excitations are shown in Figures 4 and 5,respectively. The peak value in the sweep sine response rep-resents resonance at a certain natural frequency. From thesweep sine responses, it can be clearly seen that the peaks offirst mode, second mode, and third mode are significantly re-duced for the nanocomposite beam, which indicates that thenanocomposite beam has improved damping property.

To further demonstrate the improved damping for thenanocomposite beam, the frequency responses of the regularcomposite beam and the nanocomposite beam are comparedin Figure 6, which clearly shows that the peak magnitude ofthe first three modes has dropped dramatically. This meansthat the damping ratio values of the nanocomposite beam atthese three natural frequencies are much larger than those ofthe regular composite beam.

To estimate the damping ratio for each mode, the half-power bandwidth method was used. Corresponding toeach natural frequency, there is a peak in the magnitude-frequency plot of the system. 3 dB down from the peak, thereare two points corresponding to half-power point. A largerfrequency range between these two points means a largerdamping ratio value. The damping ratio is calculated byusing the following equation:

2ζ = ω2 � ω1

ωn, (1)

where ω1, ω1 are the frequencies corresponding to the half-power point, ωn is the natural frequency corresponding tothe peak value, and ζ is the damping ratio. Table 1 shows thefirst three modal frequencies and associated damping ratioof the two beams. From the damping ratio comparison, it is


(a)

SEM MAG: 1.2 kxDate: 11/10/05

200 μmHV: 25 kVWD: 8.9836 mm

Vega ©Tescan

Digital microscopy imaging

(b)

SEM MAG: 59.99 kxDate: 11/10/05

5 μmHV: 25 kVWD: 8.93 mm

Vega ©Tescan


(c)

SEM MAG: 200 xDate: 11/11/05

1 mmHV: 25 kVWD: 35.2847 mm

Vega ©Tescan


(d)

Figure 3: Carbon nanofiber paper and nanocomposites: (a) carbon nanofiber paper in the dimension of a structural element, (b) the porousstructure formed by short glass fiber within the paper, (c) the porous structure formed by carbon nanofibers within the paper, and (d) thefracture surface of the nanocomposites.

clear that the damping ratio of the nanocomposite beam hasincreased up to 200–700% at the 2nd mode and 3rd modefrequencies. However, there is little change in mode frequen-cies, which means that there is slight change in the stiff-ness of the composites. This demonstrates an advantage ofnanocomposite over regular composite with viscoelastic lay-ers. The regular composites with viscoelastic layers will sac-rifice in reduced stiffness, though damping is improved.

For the nanocomposite beam with carbon nanofiber pa-per as surface layer, the analysis shows good agreementwith the test data for the nanocomposite beam with carbonnanofiber paper as midlayer, as shown in Figure 7. Therefore,it is concluded that the incorporation of carbon nanofiber

paper could result in a significant increase in structuraldamping of conventional fiber reinforced composites.

3.3. Tensile properties of carbon nanofiberpaper-enabled nanocomposites

As stated earlier, the tensile properties of the composite lam-inates with and without carbon nanofiber paper were inves-tigated. Table 2 shows the results from the tensile tests per-formed on the two sets of tensile specimens. It can be seenthat the incorporation of carbon nanofiber paper had slighteffects on the modulus and the strength of the compositelaminates.

Jihua Gou et al. 5

0 5 10 15 20

Time (s)

�1

0

1

Am

plit

ude

(V) First mode

Regular composite

(a)

0 5 10 15 20

Time (s)

�1

0

1

Am

plit

ude

(V) First mode

Nanocomposite

(b)

Figure 4: Sweep sine response (0.1 Hz to 100 Hz) of the composite beam without carbon nanofiber paper and the nanocomposite beamwith carbon nanofiber paper as midlayer.

0 5 10 15 20

Time (s)

�1

0

1

Am

plit

ude

(V)

Second mode Third mode

Regular composite

(a)

• •

• •

0 5 10 15 20

Time (s)

�1

0

1

Am

plit

ude

(V)

Second mode Third mode

Nanocomposite

(b)

Figure 5: Sweep sine response (10 to 1000 Hz) of the composite beam without carbon nanofiber paper and the nanocomposite beam withcarbon nanofiber paper as midlayer.

0 200 400 600 800

Frequency (Hz)

0

5

10

15

20

25

Mag

nit

ude

(dB

)

First mode

Second mode

Regular comopsite Third mode

Nanocomopsite

NanocompositeRegular composite

Figure 6: Frequency response of the first three modes for the com-posite beam without carbon nanofiber paper and the nanocompos-ite beam with carbon nanofiber paper as midlayer.

0 1 2 3 4 5 6 7 8 9�103

Frequency (Hz)

�20

�10

0

10

20

30

40

Mag

nit

ude

(dB

)

Regular comopsite

Nanocomopsite

NanocompositeRegular composite

Figure 7: Frequency response of the first three modes for the com-posite beam without carbon nanofiber paper and the nanocompos-ite beam with carbon nanofiber paper as surface layer.


Table 1: Damping ratio calculated by half-power bandwidth method.

1st mode 1st mode 2nd mode 2nd mode 3rd mode 3rd mode

frequency damping frequency damping frequency damping

( Hz) ratio ( Hz) ratio ( Hz) ratio

Regular composite beam 31.93 0.0278 210.8 0.0251 572.5 0.0349

Nanocomposite beam 34.60 0.0373 198.5 0.1985 558 0.1104

Table 2: Results from the tensile tests performed on the laminates with/without carbon nanofiber paper.

Test specimensAverage Average Average Tensile Tensile

thickness width length modulus strength

(inch) (inch) (inch) (ksi) (ksi)

1 Laminates without carbon nanofiber paper 0.10 0.75 5.75 1,220 25.7

2 Laminates with carbon nanofiber paper as midlayer 0.15 0.96 5.75 1,120 24.5

3 Laminates with carbon nanofiber paper as surface layer 0.10 0.75 6.25 1,300 24.1

4. CONCLUSIONS

This paper presented the damping tests conducted using thenanocomposite beams with an embedded carbon nanofiberpaper as interlayer or surface layer. The composite laminateswithout carbon nanofiber paper were also tested. The testsindicated up to 200–700% increase of the damping ratios athigher frequencies and slight change in tensile strength andYoung’s modulus of composite laminates due to the incor-poration of carbon nanofiber paper. The SEM characteriza-tion of the carbon nanofiber paper and the nanocompos-ites showed the entanglement of carbon nanofibers and shortglass fibers within the carbon nanofiber paper and the com-plete penetration of the resin through the carbon nanofiberpaper. These cross-linkages within the carbon nanofiber pa-per are expected to be responsible for the energy dissipationin the nanocomposites due to the strong bonding and non-bonding interactions between carbon nanofibers and shortglass fibers.

ACKNOWLEDGMENTS

The authors would like to acknowledge the financial sup-port provided by the University of South Alabama ResearchCouncil (USARC Grant no. 3–61619) and National ScienceFoundation (CAREER Grant no. 0093737). The assistance byDr. Kendall Clarke and Mr. Steven Sumerlin is gratefully ac-knowledged.

REFERENCES

[1] O. Breuer and U. Sundararaj, “Big returns from small fibers:a review of polymer/carbon nanotube composites,” PolymerComposites, vol. 25, no. 6, pp. 630–645, 2004.

[2] E. T. Thostenson, Z. Ren, and T.-W. Chou, “Advances in thescience and technology of carbon nanotubes and their com-posites: a review,” Composites Science and Technology, vol. 61,no. 13, pp. 1899–1912, 2001.

[3] K.-T. Lau and D. Hui, “The revolutionary creation of new ad-vanced materials—carbon nanotube composites,” CompositesPart B: Engineering, vol. 33, no. 4, pp. 263–277, 2002.

[4] F. H. Gojny, M. H. G. Wichmann, B. Fiedler, W. Bauhofer, andK. Schulte, “Influence of nano-modification on the mechan-ical and electrical properties of conventional fibre-reinforcedcomposites,” Composites Part A: Applied Science and Manufac-turing, vol. 36, no. 11, pp. 1525–1535, 2005.

[5] F. H. Gojny, M. H. G. Wichmann, U. Kopke, B. Fiedler, and K.Schulte, “Carbon nanotube-reinforced epoxy-composites: en-hanced stiffness and fracture toughness at low nanotube con-tent,” Composites Science and Technology, vol. 64, no. 15, pp.2363–2371, 2004.

[6] D. Qian, E. C. Dickey, R. Andrews, and T. Rantell, “Loadtransfer and deformation mechanisms in carbon nanotube-polystyrene composites,” Applied Physics Letters, vol. 76,no. 20, pp. 2868–2870, 2000.

[7] L. S. Schadler, S. C. Giannaris, and P. M. Ajayan, “Load trans-fer in carbon nanotube epoxy composites,” Applied PhysicsLetters, vol. 73, no. 26, pp. 3842–3844, 1998.

[8] H. Ma, J. Zeng, M. L. Realff, S. Kumar, and D. A. Schi-raldi, “Processing, structure, and properties of fibers frompolyester/carbon nanofiber composites,” Composites Scienceand Technology, vol. 63, no. 11, pp. 1617–1628, 2003.

[9] C. Bower, R. Rosen, L. Jin, J. Han, and O. Zhou, “Deforma-tion of carbon nanotubes in nanotube-polymer composites,”Applied Physics Letters, vol. 74, no. 22, pp. 3317–3319, 1999.

[10] Z. Ounaies, C. Park, K. E. Wise, E. J. Siochi, and J. S. Harri-son, “Electrical properties of single wall carbon nanotube re-inforced polyimide composites,” Composites Science and Tech-nology, vol. 63, no. 11, pp. 1637–1646, 2003.

[11] J. Sandler, M. S. P. Shaffer, T. Prasse, W. Bauhofer, K. Schulte,and A. H. Windle, “Development of a dispersion process forcarbon nanotubes in an epoxy matrix and the resulting electri-cal properties,” Polymer, vol. 40, no. 21, pp. 5967–5971, 1999.

[12] S. J. Park, S. T. Lim, M. S. Cho, H. M. Kim, J. Joo, andH. J. Choi, “Electrical properties of multi-walled carbonnanotube/poly(methyl methacrylate) nanocomposite,” Cur-rent Applied Physics, vol. 5, no. 4, pp. 302–304, 2005.

Jihua Gou et al. 7

[13] T. Kashiwagi, E. Grulke, J. Hilding, et al., “Thermal andflammability properties of polypropylene/carbon nanotubenanocomposites,” Polymer, vol. 45, no. 12, pp. 4227–4239,2004.

[14] S. Peeterbroeck, M. Alexandre, J. B. Nagy, et al., “Polymer-layered silicate-carbon nanotube nanocomposites: uniquenanofiller synergistic effect,” Composites Science and Technol-ogy, vol. 64, no. 15, pp. 2317–2323, 2004.

[15] W. H. Liao and K. W. Wang, “On the analysis of viscoelas-tic materials for active constrained layer damping treatments,”Journal of Sound and Vibration, vol. 207, no. 3, pp. 319–334,1997.

[16] H. Kishi, M. Kuwata, S. Matsuda, T. Asami, and A. Murakami,“Damping properties of thermoplastic-elastomer interleavedcarbon fiber-reinforced epoxy composites,” Composites Scienceand Technology, vol. 64, no. 16, pp. 2517–2523, 2004.

[17] W. Pulliam, D. Lee, G. Carman, and G. McKnight, “Thin-layer magnetostrictive composite films for turbomachineryfan blade damping,” in Smart Structures and Materials 2003:Industrial and Commercial Applications of Smart StructuresTechnologies, vol. 5054 of Proceedings of SPIE - The Interna-tional Society for Optical Engineering, pp. 360–371, San Diego,Calif, USA, March 2003.

[18] J. Suhr, N. A. Koratkar, P. Keblinski, and P. Ajayan, “Vis-coelasticity in carbon nanotube composites,” Nature Materi-als, vol. 4, no. 2, pp. 134–137, 2005.

[19] N. A. Koratkar, B. Wei, and P. M. Ajayan, “Multifunctionalstructural reinforcement featuring carbon nanotube films,”Composites Science and Technology, vol. 63, no. 11, pp. 1525–1531, 2003.

[20] N. A. Koratkar, B. Wei, and P. M. Ajayan, “Carbon nanotubefilms for damping applications,” Advanced Materials, vol. 14,no. 13-14, pp. 997–1000, 2002.

[21] J. Gou, B. Minaie, B. Wang, Z. Liang, and C. Zhang, “Com-putational and experimental study of interfacial bondingof single-walled nanotube reinforced composites,” Computa-tional Materials Science, vol. 31, no. 3-4, pp. 225–236, 2004.

[22] Z. Wang, Z. Liang, B. Wang, C. Zhang, and L. Kramer, “Pro-cessing and property investigation of single-walled carbonnanotube (SWNT) buckypaper/epoxy resin matrix nanocom-posites,” Composites Part A: Applied Science and Manufactur-ing, vol. 35, no. 10, pp. 1225–1232, 2004.

[23] J. Gou, Z. Liang, and B. Wang, “Experimental design andoptimization of dispersion process for single-walled carbonnanotube bucky paper,” International Journal of Nanoscience,vol. 3, no. 3, pp. 293–307, 2004.

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Modeling and Characterization of the Interaction ofElectromagnetic Wave with Nanocomposites andNanostructured Materials

Call for PapersNanostructured materials represent a size limit of theminiaturization trend of current technology. Interest innanophases has expanded as investigators have recognizedthat many of the properties of finely divided matter stronglydepend on the interfacial properties of the constituents byvirtue of the high fraction of the overall material which isin the vicinity of an interface as well as of the confinementof electrons, excitons, and photons in small volumes. One ofthe interesting and important issues in predicting and un-derstanding nanostructures and their functional behaviors iswhether the properties of matter evolve gradually from bulk,as system size is reduced, and what determines this evolutionbehavior.

The electromagnetic characterization of nanomaterialscan be considered a major part of the emerging field ofnanotechnology. The potentially profound implications bothfor the transport properties and optics are only beginningto be explored. In that respect, multicomponent magneticnanophases are of significant technological interest, that isthey can be considered as prospective granular magneticfilms for tunable or nonreciprocal millimeter wave devicesfor monolithic microwave integrated circuit (MMIC) appli-cations. This has also stimulated studies of the magnetoelec-tric effect, that is the polarization of a material in an appliedfield or an induced magnetization in an external electric field.

The practical importance and industrial interest in thesematerials demand optimization of several types of proper-ties in these materials. These properties include: polarization,magnetization, and stability of the materials to mechanical,electrical, and magnetic fields applied during processing andoperation. One of the fundamental goals of this field shouldbe the understanding of the relationships of these propertieson the composition, particle size and boundaries variations,defect structure and separation of the residual pores, but inmost cases they are not wellunderstood.

In classical electrodynamics, the response of a materialto electric and magnetic fields is characterized by two fun-damental quantities: the permittivity ε and the magnetic

permeability μ. In spite of the advances made, there is still nogeneral agreement on interpretation of the experimental dataof ε and μ of nanostructured materials since these quantitiesdepend sensitively on the microstructural properties such asgrain size, particle shape, and grain boundaries type.

Another related issue is the modeling of the polariza-tion and magnetization mechanisms for these nanophases.In the effective medium approaches derived from continuumelectromagnetism, only the volume fraction, or the parti-cle number density, appears, while it is now well acceptedthat for dispersed two-phase nanostructures, appropriate de-scriptors of the interfaces should also appear. Therefore, col-lective magnetic and electromagnetic behaviors in nanosys-tems are challenging in terms of both experimental observa-tion and development of theoretical analyses.

Papers are solicited in, but not limited to, the followingareas:

• Transport behavior in heterogeneous nanoscaled ma-terials and composites

• Effective medium modeling of nanoscale hetero-tructures

• Electromagnetic response of clusters• Near-field microwave and optical spectroscopy on

nanometer length scales• Measurement of material parameters spectra (per-

mittivity and permeability) in nanocomposites andnanostructures

• Ferromagnetic resonance (FMR), spin wave (SW)characterization of magnetic nanoparticles and nanos-tructures


Manuscript Due February 15, 2007

Acceptance Notification June 15, 2007

Final Manuscript Due September 15, 2007


GUEST EDITOR:

Christian Brosseau, Département de Physique, Univer-sité de Bretagne Occidentale, Brest, France; [email protected]


Prof. Michael Z. HuOak Ridge National LaboratoryOak Ridge, Tennessee 37831 - 6181 - USA

Dear Colleague,

Journal of Nanomaterials (JNM) is an international refereed journal. The overall aim of the journalis to bring science and applications together on nanoscale and nanostructured materials with emphasison synthesis, processing, characterization, and applications of materials containing true nanosizedimensions or nanostructures that enable novel/enhanced properties or functions. It is directed atboth academic researchers and practicing engineers. JNM will highlight the continued growth andnew challenges in nanomaterials science, engineering, and nanotechnology, both for applicationdevelopment and for basic research.

JNM is an open access journal; hence the full text of all articles is freely available on the journal’swebsite immediately after publication. The main advantage of open access journals is that theirreadership is not limited to the subscribing institutes, leading to higher rates of downloads andcitations than comparable subscription-based journals. This should help in increasing its impactfactor. In addition, authors retain the copyright of their papers by signing a Creative CommonsAttribution License, which gives the readers the right to download, print, and redistribute any articleas long as it is properly cited.

Another important issue is the improved review and publication speed of the journal. The publisher’selectronic Manuscript Tracking System (MTS) helps reduce the review time significantly, since iteliminates many of the delays that occur during peer-review. We are then aiming for an averagepublication time of a few weeks following acceptance.

As Editor-in-Chief of Journal of Nanomaterials, I would like to invite you to submit your paper forpublication in the journal and maximize the readership and impact of your research articles. Youcan submit your contributions at http://www.hindawi.com/mts/

Please do not hesitate to contact me at [email protected] if you need further information.

Sincerely yours,

Dr. Michael Z. HuJNM Editor-in-Chief

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