title: Unzipped multiwalled carbon nanotube oxide/multiwalled carbon nanotube hybrids for polymer reinforcement.
abstract: Multiwalled carbon nanotubes (MWNTs) have been widely used as nanofillers for polymer reinforcement. However, it has been restricted by the limited available interface area of MWNTs in the polymer matrices. Oxidation unzipping of MWNTs is an effective way to solve this problem. The unzipped multiwalled carbon nanotube oxides (UMCNOs) exhibit excellent enhancement effect with low weight fractions, but agglomeration of UMCNOs at a relatively higher loading still hampered the mechanical reinforcement of polymer composites. In this paper, we interestingly found that the dispersion of UMCNOs in polymer matrices can be significantly improved with the combination of pristine MWNTs. The hybrids of MWNTs and UMCNOs (U/Ms) can be easily obtained by adding the pristine MWNTs into the UMCNOs aqueous dispersion, followed by sonication. With a π-stacking interaction, the UMCNOs were attached onto the outwalls of MWNTs. The morphologies and structure of the U/Ms were characterized by several measurements. The mechanical testing of the resultant poly(vinyl alcohol) (PVA)-based composites demonstrated that the U/Ms can be used as ideal reinforcing fillers. Compared to PVA, the yield strength and Young's modulus of U/M-PVA composites with a loading of 0.7 wt % of the U/Ms approached ∼145.8 MPa and 6.9 GPa, respectively, which are increases of ∼107.4% and ∼122.5%, respectively. The results of tensile tests demonstrated that the reinforcement effect of U/Ms is superior to the individual UMCNOs and MWNTs, because of the synergistic interaction of UMCNOs and MWNTs.
authors.affiliation: School of Chemistry and Chemical Technology, State Key Laboratory for Metal Matrix Composite Materials, Shanghai Jiao Tong University, 200240 Shanghai, People's Republic of China.
authors.forename: Jinchen
authors.initials: J
authors.lastname: Fan
authors.forename: Zixing
authors.initials: Z
authors.lastname: Shi
authors.forename: Ming
authors.initials: M
authors.lastname: Tian
authors.forename: Jialiang
authors.initials: J
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Yin
mesh_terms: D019245:Compressive Strength; D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010087:Oxides / Q000737:chemistry; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D046911:Macromolecular Substances; D037742:Nanotubes, Carbon; D010087:Oxides; D011108:Polymers