Band Structure, Morphology, Functionality, and Size- Dependent Properties of Metal Nanoparticles

Abstract

Metallic nanoparticles are gradually emerging as important materials because of their novel shape and size-dependent chemical and physical properties that differ drastically from their bulk counterparts. The main challenges in the field of nano-chemistry are the rational control and manipulation of synthesis to derive materials with one of their dimensions in nanometer regime, and upscale production of nanomaterials for device fabrication. This chapter reviews the fundamentals of the quantum properties of metals and quantum mechanical size effects with special focus on clusters of Pd, Pt, Au and Ag. Effects of reduction in size of metal nanoparticles to nanoscale on their various properties (structural, thermal, mechanical, chemical, electronic, magnetic and optical) are reviewed. The chapter concludes with a review of select medical applications of metal nanoparticles.

Metal Nanoparticles: a Promising Treatment for Viral and Arboviral Infections

“…Metal NPs exhibit properties and catalytic activity that is size dependant and influenced by their metal ion [22]. These properties include physical [23], chemical, biological [24], mechanical [25], optical, magnetic [26], etc. The smaller the size of the NP, the higher the melting point, thermal conductivity performance, and viscosity [23].…”

“…These properties include physical [23], chemical, biological [24], mechanical [25], optical, magnetic [26], etc. The smaller the size of the NP, the higher the melting point, thermal conductivity performance, and viscosity [23]. Surface area and surface free energy are increased in smaller size NPs compared with the larger size, which results in changes in interatomic spacing [23].…”

“…The smaller the size of the NP, the higher the melting point, thermal conductivity performance, and viscosity [23]. Surface area and surface free energy are increased in smaller size NPs compared with the larger size, which results in changes in interatomic spacing [23]. The optical band gap energy increases with the decrease in particle size.…”

“…The optical band gap energy increases with the decrease in particle size. Therefore, metal NPs in colloidal solution appear in a variety of colors that are size and shape related due to the surface plasmon resonance [23]. The presence of a higher specific surface area, heterogeneous catalysis [27][28][29], and metal ions, such as transitional [30,31], in smaller sized NPs, is considered advantageous for catalytic support.…”

“…Furthermore, the biological activities (i.e., antibacterial, antiviral, antifungal, and anticancer) of NPs significantly increase with decreasing particle size [1]. Besides, the reduced particle size offers the possibility of intravenous administration of poorly soluble NPs without any blockade of the blood capillaries [23]. The biological activities of NPs also depend on their metal ions, shape, zeta potential, concentration, and method of preparation [1,32].…”