title: Anionic complexes of MWCNT with supergiant cyanobacterial polyanions.
abstract: Multi-walled carbon nanotubes (MWCNTs) were well dispersed in an aqueous solution of the cyanobacterial polysaccharide, sacran, with an ultra-high molecular weight >10 million g/mol. MWCNTs powder was put into aqueous solutions of various polysaccharides including sacran and was dispersed under sonication. As a result of the turbidity measurement of the supernatant, it was found that sacran showed the highest MWCNT-dispersion efficiency of all the polysaccharides used here. Cryogenic transmission electron microscopic (Cryo-TEM) studies directly demonstrated the existence of MWCNTs in the supernatant, and high-resolution TEM observation revealed that MWCNTs covered by sacran chains made their efficient dispersion in water. Raman spectroscopy demonstrated the existence of MWCNT in dried sample from supernatant and the interaction between MWCNT and sacran. The ζ-potential measurement of the dispersion indicated the negative surface charges of the sacran/MWCNT complexes. Then the MWCNT complexes were able to fabricate by ionic interaction; electrophoresis of the anionic complex formed the sacran/MWCNT gels on the anode while the droplet of sacran/MWCNT dispersion formed gel beads in the presence of the lanthanoid cations.
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan.
authors.forename: Maiko K
authors.initials: MK
authors.lastname: Okajima
authors.forename: Amit
authors.initials: A
authors.lastname: Kumar
authors.forename: Akihiko
authors.initials: A
authors.lastname: Fujiwara
authors.forename: Tetsu
authors.initials: T
authors.lastname: Mitsumata
authors.forename: Daisaku
authors.initials: D
authors.lastname: Kaneko
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ogawa
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kurata
authors.forename: Seiji
authors.initials: S
authors.lastname: Isoda
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Kaneko
mesh_terms: D000458:Cyanobacteria / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon / Q000737:chemistry; D000071228:Polyelectrolytes; D011108:Polymers / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry; D013499:Surface Properties
chemical_list: D028581:Lanthanoid Series Elements; D037742:Nanotubes, Carbon; D000071228:Polyelectrolytes; D011108:Polymers; D011134:Polysaccharides; C571099:sacran