The influence of manganese(IV) oxide addition on the dispersion characteristics and structural integrity of MWCNTs in metal oxides

Abstract

Recent advancement in material science and engineering has fostered the utilization of metal oxides (MOs) in diverse engineering applications. Despite the widespread application of MOs, they have certain limitations such as brittleness and low thermal conductivity. Therefore, the integration of multiwalled carbon nanotubes (MWCNTs) into their structure will augment the properties of MOs since they posses excellent mechanical, thermal and electrical properties. In order to achieve the effective transfer of the unique properties of MWCNTs into MOs, it is paramount to homogenously disperse the nanotubes within the MO matrix. Past works have emphasized that MWCNTs tend to agglomerate during their incorporation into metal matrices. In this study, the homogeneous dispersion of 1 wt% MWCNTs in metal oxides was accomplished by the introduction of manganese oxide (MnO2) of various (5, 10, 15) weight percentages in titanium oxide (TiO2). This was carried out by the adoption of regulated milling parameters: speed 100 rpm, time 6 h, and ball to powder ratio 10:1 using a high-energy ball mill. The dispersion characteristics and structural integrity of the MWCNTs in MOs were evaluated by the adoption of scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and X-ray diffraction (XRD) techniques. The results indicated that MWCNTs were homogeneously dispersed in the MOs; however, better dispersion with minimal structural strain to the MWCNTs was achieved at a higher weight percent of MnO2 in the composite powder mixture.