Arya Uthaman

Fire hazards and injuries are major concerns in the construction, automobile, packaging, electronics, and aerospace industries. The selection of an additive that reduces the flammability of the structure or composites is one of the crucial parts of designing the formulation. This chapter briefly explains flame retardant additives with a particular emphasis on clay nanoparticles as an excellent additive to reduce the flammability of plastic materials. The first section of this chapter covers a brief introduction to flame retardant additives. Later the production techniques of flame retardant composites and their various characterization techniques are discussed in detail. The content in this chapter is designed mainly on clay-based fire-retardant nanocomposites for various applications.

The superior mechanical properties of multi-walled carbon nanotubes (MWCNTs) play a significant role in the improvement of the mechanical and thermal stability of an epoxy matrix. However, the agglomeration of carbon nanotubes (CNTs) in the epoxy is a common challenge and should be resolved to achieve the desired enhancement effect. The present paper investigated the thermal, mechanical, and water uptake properties of epoxy nanocomposites with surfactant-modified MWCNTs. The nanocomposites were prepared through the incorporation of different weight concentrations of MWCNTs into the epoxy matrix. Comparative analysis of neat epoxy and epoxy/CNT nanocomposites were conducted through thermal, mechanical, microscopic, and water uptake tests to reveal the improvement mechanism. The homogenous distribution of the CNTs in the epoxy was achieved by wrapping the surfactant onto the CNTs. The addition of surfactant-modified CNTs into the epoxy caused an obvious increase in the mechanical and thermal properties. This improvement mechanism could be attributed to the uniform dispersion of the CNTs in the epoxy matrix reducing the free volume between the polymer chains and restricting the chain segmental mobility, leading to strong interfacial bonding and an efficient load transfer capability between the CNTs and the epoxy matrix. However, the mechanical and thermal properties of the epoxy/CNT nanocomposite decreased owing to the agglomeration effect when the concentration of the CNTs exceeded the optimal percentage of 1.5%. Additionally, the CNTs could impart a reduction in the wettability of the surface of the epoxy/CNT nanocomposite, leading to the increase in the contact angle and a reduction in the water uptake, which was significant to improve the durability of the epoxy. Moreover, the higher weight concentration (2%) of the CNTs showed a greater water uptake owing to agglomeration, which may cause the formation of plenty of microcracks and microvoids in the nanocomposite.

The infections from viral pathogens pose a significant global health challenge. The emergence of viral strains resistant to conventional antiviruses and the adverse side effects due to their prolonged use slow down the application of many antiviral therapies. The silver nanoparticles are considered a potentially useful tool for preventing various pathogens. The silver nanoparticles have already proven its potential as an efficient antiviral agent offered by their unique physical and chemical properties. The silver nanoparticles provide an excellent opportunity for novel antiviral therapies as it can attack a broad range of viruses with a lower possibility for developing resistant antiviral strains compared to conventional antiviral drugs. This chapter discusses the application of silver nanoparticles as an efficient antiviral agent against human immunodeficiency virus, respiratory syncytial virus, hepatitis B virus, monkeypox virus. Furthermore, the effect of silver nanoparticles against coronaviruses and the development of silver nanoparticles on their application as an effective antiviral therapeutic agent against pathogenic viruses have been discussed in this chapter.

The usage of polymer composites in various engineering fields has increased. However, the long-term service performance of such materials under aggressive conditions is still poorly understood, which limits the development of safe and economically effective designs. In this study, the aging of an epoxy resin and its carbon fiber-reinforced polymer (CFRP) composites upon immersion in water, acidic, and alkaline solutions was evaluated at different temperatures. The service life of the CFRP composites under various conditions could be predicted by the Arrhenius theory. The thermal and mechanical analysis results indicated that the CFRP composites were more vulnerable to HCl owing to the higher moisture absorption and diffusion of HCl into their cracks. The scanning electron microscopy results showed that the polymer matrix was damaged and degraded. Therefore, to allow long-term application, CFRP composites must be protected from acidic environments.