Ethical and Safety Considerations in Nanomaterial Use

Introduction To Nanomaterials

Nanomaterials, defined as materials with at least one dimension on the nanometer scale, offer a fascinating realm of possibilities due to their unique size-dependent properties. This scale, typically ranging from 1 to 100 nanometers, sets nanomaterials apart from bulk materials and unlocks a plethora of novel characteristics and behaviors(Ashokan et al., 2017; Erkoc & Ulucan-Karnak, 2021; Zhen & Xie, 2012). One of the most striking aspects of nanomaterials is their size-dependent properties. Unlike bulk materials, which behave according to classical physics principles, nanomaterials exhibit quantum effects and other size-dependent phenomena. These properties emerge due to the confinement of electrons and phonons within nanoscale dimensions, leading to altered electronic, optical, magnetic, and mechanical behaviors. For example, quantum confinement effects can lead to changes in bandgap energy and electronic structure, resulting in unique optical and electronic properties(Liu et al., 2021; Shah et al., 2009; Younas et al., 2023). The increased surface area-to-volume ratio of nanomaterials is another crucial factor contributing to their distinctive properties. As materials are scaled down to the nanoscale, their surface area increases dramatically relative to their volume. This high surface area allows for enhanced interactions with the surrounding environment, leading to improved catalytic activity, increased reactivity, and greater sensitivity in sensing applications. Additionally, nanomaterials exhibit altered electronic, optical, and magnetic properties compared to their bulk counterparts. For instance, nanoparticles can display tunable optical properties such as fluorescence or surface plasmon resonance, making them highly valuable for applications in sensing, imaging, and catalysis. Similarly, nanomaterials can exhibit unique magnetic properties, such as superparamagnetism or ferromagnetism, which are not observed in bulk materials of the same composition.

The ability to understand and control these size-dependent properties is paramount for tailoring nanomaterials for specific applications. Researchers utilize various synthesis and fabrication techniques to engineer nanomaterials with desired properties, such as size, shape, composition, and surface chemistry(Bonnin et al., 2014; Cai et al., 2021; zeyrek, Celal Tugrul Arpaci, Ozlem Temiz Arisoy, Mustafa Onurdag, 2020). By fine-tuning these parameters, it is possible to design nanomaterials with tailored functionalities for applications ranging from electronics and medicine to energy and environmental remediation. Nanomaterials can be synthesized using bottom-up or top-down approaches, depending on the desired structure and properties. Bottom-up synthesis methods involve building nanomaterials from atomic or molecular precursors, such as chemical vapor deposition, sol-gel synthesis, and self-assembly techniques. These methods offer precise control over the size, shape, composition, and crystallinity of nanomaterials. In contrast, top-down fabrication techniques involve downsizing bulk materials into nanoscale structures, such as lithography, etching, and grinding(Nidhi et al., 2023; Nidhi & Kaur, 2022; Pathania et al., 2023; Rana et al., 2023; R. C. Thakur et al., 2023). Each synthesis method has its advantages and limitations, depending on the target application and material properties. Characterizing the size, shape, composition, structure, and properties of nanomaterials is essential for understanding their behavior and optimizing their performance. Various characterization techniques are used to analyze nanomaterials at the nanoscale, including electron microscopy (e.g., transmission electron microscopy, scanning electron microscopy), spectroscopy (e.g., UV-Vis spectroscopy, X-ray photoelectron spectroscopy), atomic force microscopy, dynamic light scattering, and surface area analysis. These techniques provide valuable insights into the morphology, crystallinity, chemical composition, and surface properties of nanomaterials. Figure 1 shows the various biochemical and mechanobiological methods utilized to study nanotoxicity.