# Electromagnetic Radiation Shielding Using Carbon Nanotube and Nanoparticle Composites
## 5 Potential Applications and Associated Challenges of Shielding Materials
### Associated Challenges in Shielding  
Though the promising effectiveness of CNT-based materials for gamma-rays and EMI shielding was demonstrated in different research, improvements are needed to overcome various associated challenges, mainly long-term performance, scalability, low-cost synthesis, and optimization, as summarized below [50; 51; 52; 53; 54; 55; 56].  
Long-term performance and scalability: While existing research demonstrates the potential of CNT-based materials for shielding applications, a comprehensive understanding of their long-term performance and scalability is crucial for commercialization. There is a particular need for studies on the durability, environmental stability, and cost scalability of CNT films and additives. Investigations into the durability of NRL/MWCNT nanocomposites under various environmental conditions, such as temperature and humidity, are warranted. Life cycle assessments to understand the environmental footprint of these materials are also important.  
Synthesis and multifunctional applications: Further research is necessary to explore cost-effective synthesis methods for the industrial-scale production of CNT-based shielding materials. Optimizing synthesis methods can enhance material properties while reducing production costs. The cost of CNT sheets is much greater than the cost of powder CNT. Additionally, research into integrating CNTs with other materials for multifunctional composite coatings or layers for radiation protection holds promise.  
Advanced characterization and modeling: Investment in advanced characterization techniques and predictive modeling tools can accelerate the development and optimization of CNT composites. In-depth spectroscopic analysis can elucidate the interfacial interactions between CNTs and the polymer matrix, while computational modeling can predict the electromagnetic-shielding performance of composite structures.  
Expanding EMI-shielding research: Beyond the influence of environmental factors on the performance of CNT composites, future research should explore alternative nanoparticle types with the potential for superior EMI-shielding performance. Metal-organic frameworks and other carbon-based nanomaterials are promising candidates. Continued research efforts could involve advanced characterization techniques, such as in situ spectroscopy and electron microscopy, to elucidate the underlying mechanisms governing EMI shielding. Systematic optimization studies to identify the most effective fabrication processes and life cycle assessments to evaluate the environmental impact throughout the lifecycle are also recommended.  
Microstructural mechanisms and durability: Future research can benefit from employing advanced characterization techniques like electron microscopy and spectroscopy to understand the microstructural mechanisms underlying the observed thermal and electromagnetic properties of CNT hybrid composites. Specific research areas could involve studying the effects of the functionalization and surface treatment of MWCNTs on compos ite film properties, exploring synergistic effects achieved by incorporating combinations of nanomaterials and nanoparticles, the effect of the shape (spherical, rod, platelet, dendrite) of the nanoparticles on shielding effectiveness, and investigating the durability of composite films in harsh operating environments. The effect of the size and shape of nanoparticles on shielding performance should be comprehensively studied.