Part of the book: Advances in Nanocomposite Technology
Part of the book: Nanocomposites
Zinc oxide nanoparticles (ZnO-NPs) are among nanoscale materials displaying exponentially growing production due to their applications in the field of cosmetology, medicine, as antibacterial agent and catalyst. The ZnO nanomaterials release into the aquatic ecosystems through domestic and industrial wastewaters has the potential to induce pernicious effects on fish and other organisms. Increasing concerns on the environmental hazard to aquatic biota have been highlighted by the toxic potential of some metal-based nanomaterials. Several characteristics of ZnO-NPs (e.g. size, shape, surface charge and agglomeration state) play a central role in biological effects such as genotoxic, mutagenic or cytotoxic effects. Overall, Zn bioaccumulation, histopathological, and hematological changes with oxidative and cellular stress have been reported in ZnO-NPs exposed animals.
Part of the book: Toxicology
Polymer based nanocomposites containing metal nanoparticles (e.g. Au, Ag) have gained increased attention as a new class of SERS (Surface Enhanced Raman Scattering) substrates for analytical platforms. On the other hand, the application of SERS using such platforms can also provide new insights on the properties of composite materials. In this chapter, we review recent research on the development of SERS substrates based on polymer nanocomposites and their applications in different fields. The fundamentals of SERS are briefly approached and subsequently there is a reference to the strategies of preparation of polymer based nanocomposites. Here the main focus is on SERS studies that have used a diversity of polymer based nanocomposites, highlighting certain properties of the materials that are relevant for the envisaged functionalities. A final section is devoted to the joint use of Raman imaging and SERS in nanocomposites development, a topic that presents a great potential still to be explored as shown by the recent research in this field.
Part of the book: Raman Spectroscopy
Heterogeneous semiconductor photocatalysis has received much interest because of its applications in important global energy and environmental challenges in a cost-effective sustainable way. The photocatalytic efficiency of semiconductor photocatalysts under solar irradiation has been pointed out by difficulties associated with low visible-light absorption range, fast recombination of photogenerated carriers, and low chemical stability in operational conditions. Graphitic materials have attracted great interest due to properties, such as high surface area, mechanical strength, and photochemical stability. Thus, their combination with metal sulfides, has been explored as promising strategies to produce new photocatalysts. These nanocomposites show great potential in photodegradation of contaminants of emerging concern (CEC), which might be detected in water sources, such as traces of Pharmaceutics and pesticides. Here, we briefly review fundamental principles photocatalysis in general, with the focus on the use of carbon-nanomaterials of distinct structural dimensionalities associated with nanocrystalline metal sulfides, envisaging their application as heterogeneous photocatalysts for water remediation. Key aspects concerning the photocatalyst properties, such as light absorption, charge separation and transfer, and stability, are also approached. Graphene and graphene derivatives have demonstrated great potential for increasing photogenerated charge-carrier separation and migration efficiency, as well as in extending the light absorption range and adsorption capacity.
Part of the book: Photocatalysts