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CNMS Science Program Highlight • Covalently Bonded Three-Dimensional Carbon Nanotube Solids via BoronInduced NanojunctionsD.P. Hashim,1 N.T. Narayanan,1 J.M. Romo-Herrera,2 D.A. Cullen,3 M.G. Hahm,1P. Lezzi,4 J. R. Suttle,1 D. Kelkhoff,5 E. Munoz-Sandoval,6 S. Ganguli,7 A.K. Roy,7D.J. Smith,8 R. Vajtai,1B.G. Sumpter,3 V. Meunier,4 H. Terrones,3,9M. Terrones,10 P.M. Ajayan1 1Rice University, Houston, TX, 2Universidade de Vigo, Spain, 3Oak Ridge National Laboratory, Oak Ridge, TN., 4Rensselaer Polytechnic Institute, Troy, NY, 5University of Illinois, Urbana, IL, 6Instituto de Microelectro´nica de Madrid, Tres Cantos, Spain, 7Air Force Research Laboratory, Dayton, OH, 8Arizona State University, Tempe, AZ, 9Universite´ Catholique de Louvain, La Neuve, Belgium, 10The Pennsylvania State University, University Park, PA. and Shinshu University, Nagano, Japan • Achievement • Detailed theoretical analysis revealed that boron will promote the formation of negative curvature ‘‘elbow-like’’ junctions into carbon nanotubes (c).Those curvature changes will cause the grown nanotubes to form low density interwoven networks (a). • An experimental method for growth of macroscale 3D networked boron substituted multi-walled nanotubes solids was developed, enabling large-scale synthesis. Characterization of synthesized samples verify the formation of a low density interwoven network that yields a 3D “sponge”-like monolith possessing high thermal conductivity and stability, ultra-light weight, super-hydrophobicity, high porosity, and mechanical flexibility (b), and high lipophilicity. • The 3D sponges are highly efficient at adsorbing oil in seawater (d,e) and the oil an be easily recovered by mechanical compression (f) or removed by burning (f) and the sample can be reused (g). Also the position of the sample can be easily controlled with magnetic tracking (g) a b c D. P. Hashim et al., Nature Scientific Reports DOI: 10.1038/srep00363 (2012). This research was supported in part at the Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. Figure: a,b: A model showing the entangled sponge network; c: Relative substitutional energies computed for B, N, and S dopants are shown at different curvatures on a nanotube; d: Sponge dropped into the oil at t=0; inset shows sponge before use;e: sponge sample absorbingthe oil at t = 2; inset shows t = 5 min; f:Burning or squeezing (inset) age the oil; g:Repetitive reuse; a magnet can track or move the oil.