Nano-I-beam

Nano-I-beams are nanostructures characterized by their Ɪ-shaped cross-section, resembling the letter Ɪ in macroscopic scale. They are typically made from hybrid organic/inorganic materials and have unique properties that make them suitable for various applications in structural nano-mechanics.[1][2]

Rotating single-walled zigzag carbon nanotube

Typical cross-section of I-beams

Compared to traditional carbon nanotubes,[3] nano-I-beams exhibit higher structural stiffness, reduced induced stress, and longer service life. They have the potential to outperform carbon nanotubes in various applications, offering enhanced mechanical properties and improved functionality. The Wide Flange Nano-I-beam variation has been found to provide even higher structural stiffness and longer service life compared to the Equal Flange & Web Nano-I-beam.[4]

Origin of the name

Nano-I-beams are named after the I-beams used in construction and structural engineering. The I-beam, also known as the H-beam[5] or universal beam, is a widely used structural element due to its high strength-to-weight ratio and structural stability.[6] The shape of the I-beam, with its central vertical web and horizontal flanges, provides excellent load-bearing capabilities and resistance to bending and torsion.

Inspired by the structural properties of I-beams, the nano-I-beam was developed as a nanoscale counterpart, utilizing the same I-shaped cross-section.[7] The nano-I-beam inherits the geometric characteristics of the macroscopic I-beam, but at a much smaller scale, making it suitable for applications in the realm of nanotechnology[8]

Kinetics and growth of nano-I-beam

The Ritz method,[9] based on the shell theory,[10] is frequently utilised for dynamic analysis of carbon nanotubes (CNTs). The Ritz method, connected to Hamilton's principle, is employed to determine the equilibrium state and minimize the energy functional of a conservative structural system undergoing kinematically admissible growth or deformation. Hamilton's principle considers the interplay of different energy elements, including the kinetic energy (T), strain energy (U), and potential energy (WP). By applying the Ritz method based on Hamilton's principle, the strain energy U of Single & Multi-Walled Nano-I-beams (SWNT) is formulated as:

${\displaystyle U={\int }_{V}({\sigma }_{\rho }{\epsilon }_{\rho }+{\sigma }_{\theta }{\epsilon }_{\theta }+{\sigma }_{z}{\epsilon }_{z}+{\sigma }_{\rho \theta }{\epsilon }_{\rho \theta }+{\sigma }_{\rho z}{\epsilon }_{\rho z}+{\sigma }_{\theta z}{\epsilon }_{\theta z})dV}$

When considering the kinetic energy, observations are often made in a moving frame of reference. To account for this, the time derivative of the observed variables in the fixed frame of reference (ρ, θ, z) is utilized. As a result, the formulation of the kinetic energy, denoted as T, takes into account these considerations.

${\displaystyle T={\frac {1}{2}}\,\gamma {\int }_{V}^{V}[{({\frac {\partial u}{\partial t}})}^{2}+{({\frac {\partial v}{\partial t}})}^{2}+{({\frac {\partial w}{\partial t}})}^{2}]\,dV}$

Application and suitability

Both CNTs and I-beams have distinct properties and advantages, and their suitability depends on the specific application and requirements. CNTs offer exceptional mechanical properties, including high tensile strength and stiffness.[11] They have a high strength-to-weight ratio, making them lightweight yet strong. CNTs also exhibit excellent electrical and thermal conductivity, making them suitable for applications in electronics and energy storage. However, challenges in large-scale production, potential toxicity concerns, and difficulties in achieving uniform dispersion within materials are some drawbacks associated with CNTs.

Among the variations of the Hybrid Organic/Inorganic Nano-I-beam, research highlights the good performance of the Wide Flange Nano-I-Beam.[3] It demonstrates decent structural stiffness, reduced induced stress, and an extended service life when compared to the Equal Flange & Web Nano-I-Beam. This distinction makes the Wide Flange variation particularly desirable for various applications, including nano-heat engines and sensors as an attractive option for cost-effective and high-performance material.

Ultimately, the choice between CNTs and Nano-I-beams depends on the specific requirements of the application, considering factors such as scale, performance needs, and cost-effectiveness. Each material has its own strengths and limitations, and the selection should be based on a careful evaluation of the desired properties and constraints of the project at hand.

References

1. Barretta, Raffaele; Čanađija, Marko; Luciano, Raimondo; Marotti de Sciarra, Francesco (2022-10-01). "On the mechanics of nanobeams on nano-foundations". International Journal of Engineering Science. 180: 103747. doi:10.1016/j.ijengsci.2022.103747. ISSN 0020-7225. S2CID 252290748.
2. Marti, M. E.; Sharma, A. D.; Sakaguchi, D. S.; Mallapragada, S. K. (2013-01-01), Gaharwar, A. K.; Sant, S.; Hancock, M. J.; Hacking, S. A. (eds.), "10 - Nanomaterials for neural tissue engineering", Nanomaterials in Tissue Engineering, Woodhead Publishing Series in Biomaterials, Woodhead Publishing, pp. 275–301, doi:10.1533/9780857097231.2.275, ISBN 978-0-85709-596-1, retrieved 2023-05-27
3. "Carbon nanotubes – what they are, how they are made, what they are used for". www.nanowerk.com. Retrieved 2023-05-27.
4. Elmoselhy, Salah A. M. (2019-12-04). "Hybrid Organic/Inorganic Nano-I-beam for Structural Nano-mechanics". Scientific Reports. 9 (1): 18324. Bibcode:2019NatSR...918324E. doi:10.1038/s41598-019-53588-2. ISSN 2045-2322. PMC 6893021. PMID 31797945.
5. "I-Beam vs H-Beam: What İs the Difference? - Yena Engineering". 2022-05-11. Retrieved 2023-05-27.
6. "Why Are I Beams Used in Structural Steel Construction?". blog.swantonweld.com. Retrieved 2023-05-27.
7. Mohammedali, T K; Mohammed, A H; Khalaf, R D; Sammen, S Sh (2021-02-01). "Finite Element Model for the Optimization of Steel I-Beam with Variable Depth". IOP Conference Series: Materials Science and Engineering. 1076 (1): 012100. Bibcode:2021MS&E.1076a2100M. doi:10.1088/1757-899X/1076/1/012100. ISSN 1757-8981. S2CID 234048784.
8. "Nanotechnology | NIOSH | CDC". www.cdc.gov. 2022-08-05. Retrieved 2023-05-27.
9. Moreno-García, Pablo; dos Santos, José V. Araújo; Lopes, Hernani (2018-07-01). "A Review and Study on Ritz Method Admissible Functions with Emphasis on Buckling and Free Vibration of Isotropic and Anisotropic Beams and Plates". Archives of Computational Methods in Engineering. 25 (3): 785–815. doi:10.1007/s11831-017-9214-7. ISSN 1886-1784. S2CID 255410161.
10. Rouhi, H.; Bazdid-Vahdati, M.; Ansari, R. (2015-12-27). "Rayleigh-Ritz Vibrational Analysis of Multiwalled Carbon Nanotubes Based on the Nonlocal Flügge Shell Theory". Journal of Composites. 2015: 1–11. doi:10.1155/2015/750392. ISSN 2356-7252.
11. Wang, Fei; Zhao, Siming; Jiang, Qinyuan; Li, Run; Zhao, Yanlong; Huang, Ya; Wu, Xueke; Wang, Baoshun; Zhang, Rufan (2022-08-17). "Advanced functional carbon nanotube fibers from preparation to application". Cell Reports Physical Science. 3 (8): 100989. Bibcode:2022CRPS....300989W. doi:10.1016/j.xcrp.2022.100989. ISSN 2666-3864. S2CID 251206127.