Comparative Study of Elastomer Nanocomposites Respectively Containing SWCNTs and MWCNTs

Abstract

Carbon nanotubes (CNTs) are essential for providing polymers with mechanical reinforcement and multifunctional properties. This study investigated two groups of nitrile butadiene rubber (NBR) nanocomposites containing single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs), respectively. SWCNTs were purified to remove appro-ximately 20 wt.% of impurities, and both CNTs were modified with polyethylene glycol tert-octylphenyl ether (Triton X-100) before emulsion compounding and 2-roll milling with NBR. MWCNTs were found to disperse in the elastomer matrix relatively uniformly, while SWCNTs formed aggregates. Consequently, NBR/MWCNT nanocomposites exhibited superior mechanical properties, e.g. a tensile strength of 10.8 MPa at 4.02 vol.% MWCNTs, compared to 5.6 MPa for NBR/SWCNT nanocomposites. Additionally, NBR/MWCNT nanocomposites exhibited more remarkable electrical conductivity and swelling resistance to toluene. The diameter of elastomer macromolecules (0.2-0.5 nm) is close to that of SWCNTs (1-2 nm), and their single graphene wall with a hollow structure makes SWCNTs almost as flexible as elastomer macromolecules. This similarity suggests that SWCNTs should be treated as a special type of polymer. SWCNTs cannot disperse as uniformly as MWCNTs in the elastomer matrix, likely due to their smaller size and lower sensitivity to mechanical shearing during the emulsion compounding and 2-roll milling process.

Keywords

Single-walled carbon nanotubes / Multi-walled carbon nanotubes / Elastomer nanocomposites / Dispersion

Acknowledgments

We gratefully recognize the financial support provided by the ARC Discovery (DP220103275). The authors acknowledge use of the facilities, scientific and technical assistance of Microscopy Australia at the University of South Australia, a facility that is co-funded by the University of South Australia, the State and Federal Governments. P.A expresses gratitude to the University of South Australia for granting the University Presidents Scholarship (UPS). Finally, we extend our sincere appreciation to ChatGPT for its invaluable aid throughout the research and writing phases.

Author Contributions

Conceptualization, P.C.O.A. and J.M.; Methodology, P.C.O.A., H.N. and M.A.; Software, P.C.O.A., H.N. and M.A.; Validation, P.C.O.A. and S.S.C.; Formal Analysis, P.C.O.A., X.S. and J.A.; Investigation, P.C.O.A. and S.S.C.; Resources, J.M.; Data Curation, P.C.O.A. and H.N.; Writing—Original Draft Preparation, P.C.O.A.; Writing—Review & Editing, P.C.O.A. and J.M.; Visualization, P.C.O.A., H.N., M.A., S.S.C., X.S. and J.A.; Supervision, J.M.; Project Administration, J.M.; Funding Acquisition, J.M.

Ethics Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availibility Statement

The data supporting findings of this study are available upon reasonable request.

Funding

This research was funded by the ARC Discovery (DP220103275). The authors acknowledge use of the facilities, scientific and technical assistance of Microscopy Australia at the University of South Australia, a facility that is co-funded by the University of South Australia, the State and Federal Governments. P.A expresses gratitude to the University of South Australia for granting the University Presidents Scholarship (UPS). Finally, we extend our sincere appreciation to ChatGPT for its invaluable aid throughout the research and writing phases.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

References

[1] Araby S, Meng Q, Zhang L, Zaman I, Majewski P, Ma J. Elastomeric composites based on carbon nanomaterials. Nanotechnology 2015, 26, 112001.

[2] Wang S, Long C, Wang X, Li Q, Qi Z. Synthesis and properties of silicone rubber/organomontmorillonite hybrid nanocomposites. J. Appl. Polym. Sci. 1998, 69, 1557-1561.

[3] Wu YP, Zhang LQ, Wang YQ, Liang Y, Yu DS. Structure of carboxylated acrylonitrile-butadiene rubber (CNBR)-clay nanocomposites by co-coagulating rubber latex and clay aqueous suspension. J. Appl. Polym. Sci. 2001, 82, 2842-2848.

[4] Yu Y, Xu Z, Xu L, Li Y, Liu T, Meng Q, et al. Highly stretchable, sensitive and healable polyurethane-urea/graphene nanocomposite sensor for multifunctional applications. Thin-Walled Struct. 2024, 198, 111660.

[5] Su X, Yang Z, Cheng R, Luvnish A, Han S, Meng Q, et al. A comparative study of polycarbonate nanocomposites respectively containing graphene nanoplatelets, carbon nanotubes and carbon nanofibers. Adv. Nanocompos. 2024, 1, 77-85.

[6] La LBT, Nguyen H, Tran LC, Su X, Meng Q, Kuan H-C, et al. Exfoliation and Dispersion of Graphene Nanoplatelets for Epoxy Nanocomposites. Adv. Nanocompos. 2024, 1, 39-51.

[7] Adu PCO, Aakyiir M, Su X, Alam J, Tran LC, Dai J, et al. Challenges and advancements in Elastomer/CNT nanocomposites with mechanochemical treatment, reinforcement mechanisms and applications. Smart Mater. Manuf. 2024, 2, 100053.

[8] Yang Z, Qiu A, Ma J, Chen M. Conducting α-Fe₂O₃ nanorod/polyaniline/CNT gel framework for high performance anodes towards supercapacitors. Compos. Sci. Technol. 2018, 156, 231-237.

[9] Cui K, Chang J, Feo L, Chow CL, Lau D. Developments and Applications of Carbon Nanotube Reinforced Cement-Based Composites as Functional Building Materials. Front. Mater. 2022, 9, 861646.

[10] Lu S, Shao J, Ma K, Chen D, Wang X, Zhang L, et al. Flexible, mechanically resilient carbon nanotube composite films for high-efficiency electromagnetic interference shielding. Carbon 2018, 136, 387-394.

[11] Zhang R, Deng H, Valenca R, Jin J, Fu Q, Bilotti E, et al. Carbon nanotube polymer coatings for textile yarns with good strain sensing capability. Sens. Actuators A Phys. 2012, 179, 83-91.

[12] Vázquez-Martínez Y, Ramírez-Herrera CA, Mondragón M, Elías-Zúñiga A, Elizalde LE. Effect of Single-Walled Carbon Nanotubes on the Cross-Linking Process in Natural Rubber Vulcanization. Polymers 2022, 15, 126.

[13] Aakyiir M, Tanner B, Yap PL, Rastin H, Tung TT, Losic D, et al. 3D printing interface-modified PDMS/MXene nanocomposites for stretchable conductors. J. Mater. Sci. Technol. 2022, 117, 174.

[14] Ma J, Yu ZZ, Kuan HC, Dasari A, Mai YW. A new strategy to exfoliate silicone rubber/clay nanocomposites. Macromol. Rapid Commun. 2005, 26, 830-833.

[15] Xin F, Li L. Effect of Triton X-100 on MWCNT/PP composites. J. Thermoplast. Compos. Mater. 2013, 26, 227-242.

[16] Vaisman W, Wagner H. The role of surfactants in dispersion of carbon nanotubes. Adv. Colloid Interface Sci. 2006, 128, 37-46.

[17] Rastogi R, Kaushal R, Tripathi S, Sharma AL, Kaur I, Bharadwaj LM. Comparative study of carbon nanotube dispersion using surfactants. J. Colloid Interface Sci. 2008, 328, 421-428.

[18] Srivastava SK, Mishra YK. Nanocarbon Reinforced Rubber Nanocomposites: Detailed Insights about Mechanical, Dynamical Mechanical Properties, Payne, and Mullin Effects. Nanomaterials 2018, 8, 945.

[19] Bokobza L. Mechanical, electrical and spectroscopic investigations of carbon nanotube-reinforced elastomers. Vib. Spectrosc. 2009, 51, 52-59.

[20] Zaman I, Phan TT, Kuan H-C, Meng Q, La LTB, Luong L, et al. Epoxy/graphene platelets nanocomposites with two levels of interface strength. Polymer 2011, 52, 1603.

[21] Aakyiir M, Oh J-A, Araby S, Zheng Q, Naeem M, Ma J, et al. Combining hydrophilic MXene nanosheets and hydrophobic carbon nanotubes for mechanically resilient and electrically conductive elastomer nanocomposites. Compos. Sci. Technol. 2021, 214, 108997.

[22] Aakyiir M, Yu H, Araby S, Ruoyu W, Michelmore A, Meng Q, et al. Electrically and thermally conductive elastomer by using MXene nanosheets with interface modification. Chem. Eng. J. 2020, 397, 125439.

[23] Hou P, Liu C, Tong Y, Xu S, Liu M, Cheng H. Purification of single-walled carbon nanotubes synthesized by the hydrogen arc-discharge method. J. Mater. Res. 2001, 16, 2526-2529.

[24] Dillon AC, Gennett T, Jones KM, Alleman JL, Parilla PA, Heben MJ. A simple and complete purification of single-walled carbon nanotube materials. Adv. Mater. 1999, 11, 1354-1358.

[25] Hu H, Zhao B, Itkis ME, Haddon RC. Nitric Acid Purification of Single-Walled Carbon Nanotubes. J. Phys. Chem. B 2003, 107, 13838-13842.

[26] Yaya A, Ewels C, Wagner P, Suarez-Martinez I, Tekley AG, Jensen LR. Purification of single-walled carbon nanotubes. Eur. Phys. J. Appl. Phys. 2011, 54, 10401.

[27] Zimmerman JL, Bradley RK, Huffman CB, Hauge RH, Margrave JL. Gas-Phase Purification of Single-Wall Carbon Nanotubes. Chem. Mater. 2000, 12, 1361-1366.

[28] Tomova A, Gentile G, Grozdanov A, Errico M, Paunović P, Avella M, et al. Functionalization and Characterization of MWCNT Produced by Different Methods. Acta Phys. Pol. A 2016, 129, 405.

[29] Adhikari S, Jaishi KP, Pradhan Joshi L, Shrestha SP. Dispersion of single-walled carbon nanotubes in water in presence of Direct Current field. Indian J. Phys. 2022, 97, 61-66.

[30] Filchakova M, Saik V. Single-walled carbon nanotubes: Structure, properties, applications, and health & safety. Tuball 2021. Available online: https://tuball.com/articles/single-walled-carbon-nanotubes. (accessed on 10 February 2024).

[31] Tarlton T, Sullivan E, Brown J, Derosa PA. The role of agglomeration in the conductivity of carbon nanotube composites near percolation. J. Appl. Phys. 2017, 121, 085103.

[32] Ata S, Nguyen Thi TB, Kolaric I. Effect of matrix polymer viscosity on nanofiller exfoliation during compounding. Polymer Bulletin 2022, 79, 9685-9696.

[33] Han S, Chand A, Araby S, Cai R, Chen S, Kang H, et al. Thermally and electrically conductive multifunctional sensor based on epoxy/graphene composite. Nanotechnology 2019, 31, 075702.

[34] Araby S, Zaman I, Meng Q, Kawashima N, Michelmore A, Kuan HC, et al. high-performance elastomers. Melt compounding with graphene to develop functional. Nanotechnology 2013, 24, 165601.

[35] Araby S, Wang CH, Wu H, Meng Q, Kuan HC, Kim NK, et al. Development of flame-retarding elastomeric composites with high mechanical performance. Compos. Part A Appl. Sci. Manuf. 2018, 109, 257-266.