# Electromagnetic Radiation Shielding Using Carbon Nanotube and Nanoparticle Composites
## 8 Conclusions  
With radiation risks spanning a wide variety of industries, there is an increasing need to develop new personal protective equipment (PPE) and materials to ensure worker safety in evolving environments. While metals like lead and tungsten are highly effective in attenuating high-energy radiation due to their high densities, these metals alone are not always practical due to toxicity and weight concerns. CNT hybrid materials offer a promising alternative, as their unique properties can be enhanced by combining with specific atoms to improve radiation attenuation without the use of toxic materials. As described in this perspective, combining CNT films with drawn high-density polyethylene (HDPE)/filler composites can create robust, lightweight materials suitable for radiation-shielding equipment. Functional fillers with radiation-absorbing properties, such as boron, gadolinium, or cadmium compounds, can be added to the HDPE matrix to optimize shielding capabilities. Ceramic materials like boron carbide (B\({}_{4}\)C) and alumina (Al\({}_{2}\)O\({}_{3}\)) can further enhance the radiation-shielding effectiveness due to their high atomic numbers and densities. To achieve the best performance, the shape and size of particles and the composition and thickness of each layer in the hybrid material must be optimized. At higher frequencies, combining CNTs with other materials allows for customized shielding solutions. Computational simulations and experimental testing can help refine these designs for specific radiation types. CNTs provide effective electromagnetic shielding in the GHz frequency range due to their low electrical impedance and small diameter, which reduces the skin effect. CNT powder and other nanomaterials can be added to polymer binders to create tailored shielding materials. A thin and flexible CNT film with integrated metal particles can enhance the overall flexibility of personal protective garments, offering reliable protection against ionizing and non-ionizing radiation, while ensuring comfort and durability to the wearer. Regular inspection and maintenance of the hybrid materials are essential to ensure the integrity and effectiveness of the personal protective garments and laminated \begin{table}
\begin{tabular}{c c c} \hline \hline
**Focus Area** & **Description** & **References** \\ \hline \multirow{6}{*}{Particle crystal structure, fragmentation, secondary radiation, nanocrystalline materials} & \multirow{2}{*}{Because of their large surface area-to-volume ratio, nanoparticles have an increased ability to absorb photons. Different-atomic-number materials are used to reduce the energy of secondary radiation. Nanocrystalline materials provide enhanced radiation resistance as compared to polycrystalline materials. And crystal structures of ultra-small nanoparticles are often markedly different from those of their bulk counterparts. \\ \hline \multirow{2}{*}{Molecules formed, multi-principal element materials, multilayer materials} & Crosslinking may change the durability in the radiation shielding of materials. Composites can have increased radiation resistance due to crosslinking mechanisms. \\ \hline \multirow{6}{*}{Grain size} & The selective enhancement of radiation attenuation by the nanomaterials at lower energies was attributed, in the paper, to the increased number of particles per gram and grain size effects. \\ \cline{2-2}  & Cosmic radiation exposure and prevention of cancer in air crews. Aprons for medical workers. \\ \hline \hline \end{tabular}
\end{table} 
Table 4: _Cont._composite materials, especially for materials frequently exposed to high doses of gamma rays or cosmic radiation. Modeling of nanoparticle composites is needed to optimize their design. Specifically, further testing should consider the shielding effectiveness of a solid metal sheet versus the shielding effectiveness of a fluffy CNT-metal nanocomposite fabric.