6. Carbon nanotubes/cobalt oxide (Co3O4) nanoparticles

### 6.1 Synthesis procedure

The f-SWCNT/Co3O4 nanocomposite was prepared by Abdolmaleki et al. [26] using the electrostatic coprecipitation route. They noted that the specific

adsorption and/or by impacting genetic material by causing various types of chro-

Toxicity tests on Allium cepa of ND-Co3O4 nanoparticles (A–D), various concentrations of cobalt oxide (E–G), and cND-Co3O4 (H–K). A = prophase, B = metaphase, C = anaphase, D = telophase, E = chromosomal break, F = cytoplasmic bridge, G = disturbed anaphase, H = laggard, I = sticky anaphase, J = scattered

anaphase, K = prophase nuclei with micronucleus in interphase, L = binucleate cells [24].

of cND-Co3O4 also confirm that cND-Co3O4 was unable to interfere with the normal development of mitosis mainly by its incapacity to prevent cells from entering the prophase and blocking the mitotic cycle during interphase inhibiting DNA/protein synthesis. Moreover, 20 μg/mL of cND-Co3O4 compared to 5, 10, and 20 μg/mL of Co3O4 and 10 μg/mL of cND-Co3O4 presents insignificant and infrequent chromosome aberrations (such as stickiness, breaks, disturbed, and scattered metaphase); therefore, these results strongly support the environment-friendly nature of the cND-Co3O4 nanocomposite, as demonstrated by the toxicity tests

In summary, insignificant changes in MI with moderate concentration (10 μg/mL)

mosomal aberrations.

Cobalt Compounds and Applications

Figure 15.

44

capacitance of f-SWCNT/Co3O4 is high with a value of 343F=g, while that of the Co3O4 nanoparticles is only 77F=g (Figure 17). Zarnegar et al. [27] used a new sonochemical synthesis of polyhydroquinolines having as catalyst Co3O4-CNT nanocomposites for aldehydes, dimedone, ethyl acetoacetate, and ammonium acetate in an ethanol medium. These nanocomposites proved to be a highly effective

catalytic system, and they provide a green strategy to generate a variety of polyhydroquinolines under sonic conditions. The TEM image of Co3O4 nanoparticles (Figure 18A), carbon nanotubes (Figure 18B), Co3O4-CNT nanocomposites at microscope 100 nm range (Figure 18C), and Co3O4-CNT nanocomposites at microscope 40 nm range (Figure 18D) is shown in Figure 18.

The Cobalt Oxide-Based Composite Nanomaterial Synthesis and Its Biomedical and Engineering…

The cobalt oxide-based composite nanoparticles and its engineering and medical

applications were discussed in this book chapter. The pure Co3O4 nanoparticles reveal the presence of toxicity, whereas cobalt compounds are nontoxic. In this book chapter, the synthesis procedure for cobalt and cobalt-based compounds such as GO/Co3O4, ND-Co3O4, zeolite Y/Co3O4, and MWCNT-Co3O4. All the synthesized cobalt-based compound materials present magnetic properties, which can be benefit for the thermal applications, electrical applications, and medical applications. Cobalt oxide-based compounds have improved synergistic properties as

The author (LSS) acknowledges the Foundation for Science and Technology (FCT, Portugal) for the financial support received through the grant SFRH/BPD/ 100003/2014. The author (ACMS) acknowledges the 2017 Visiting Scientist Fellowship awarded to him under the Chinese Academy of Sciences President's International Fellowship Initiative. TEMA/DEM researchers also acknowledge the FCT grant UID/EMS/00481/2019-FCT, the infrastructures support CENTRO-01-0145- FEDER-022083-Centro Portugal Regional Operational Programme (Centro2020), and Project 33912-AAC no. 03/SI/2017, under the Portugal 2020 Partnership

\*, Manoj K. Singh1,2\*, António M.B. Pereira1

1 Department of Mechanical Engineering, Centre for Mechanical Technology and

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

2 Centre for Nano and Material Sciences, JAIN (Deemed-to-be University),

\*Address all correspondence to: sslingala@gmail.com and mksingh@ua.pt

Agreement, through the European Regional Development Fund.

Automation (TEMA-UA), University of Aveiro, Portugal

7. Conclusions

Acknowledgements

Author details

47

Lingala Syam Sundar<sup>1</sup>

and Antonio C.M. Sousa<sup>1</sup>

Bengaluru, Karnataka, India

provided the original work is properly cited.

compared to pure cobalt oxide nanoparticles.

DOI: http://dx.doi.org/10.5772/intechopen.88272

Figure 17. Synthesis procedure of MWCNT-Co3O4 nanoparticles [26].

#### Figure 18.

TEM results of MWCNT-Co3O4 nanoparticles [27], (a) Co3O4, (b) MWCNT, (c) MWCNT-Co3O4 nanoparticles at 100 nm range and (d) MWCNT-Co3O4 nanoparticles at 100 nm range.

The Cobalt Oxide-Based Composite Nanomaterial Synthesis and Its Biomedical and Engineering… DOI: http://dx.doi.org/10.5772/intechopen.88272

catalytic system, and they provide a green strategy to generate a variety of polyhydroquinolines under sonic conditions. The TEM image of Co3O4 nanoparticles (Figure 18A), carbon nanotubes (Figure 18B), Co3O4-CNT nanocomposites at microscope 100 nm range (Figure 18C), and Co3O4-CNT nanocomposites at microscope 40 nm range (Figure 18D) is shown in Figure 18.
