Tips and Tricks for the Surface Engineering of Well-Ordered Morphologically Driven Silver-Based Nanomaterials

Nanoscale Hydrophobicity and Electrochemical Mapping Provides Insights into Facet Dependent Silver Nanoparticle Dissolution

Metal or metallic nanoparticle dissolution influences particle stability, reactivity, potential fate, and transport. This work investigated the dissolution behavior of silver nanoparticles (Ag NPs) in three different shapes (nanocube, nanorod, and octahedron). The hydrophobicity and electrochemical activity at the local surfaces of Ag NPs were both examined using atomic force microscopy (AFM) coupled with scanning electrochemical microscopy (AFM-SECM). The surface electrochemical activity of Ag NPs more significantly affected the dissolution than the local surface hydrophobicity did. Octahedron Ag NPs with dominant surface exposed facets of {111} dissolved faster than the other two kinds of Ag NPs. Density functional theory (DFT) calculation revealed that the {100} facet elicited greater affinities toward H₂O than the {111} facet. Thus, poly(vinylpyrrolidone) or PVP coating on the {100} facet is critical for stabilizing and prevent the {100} facet from dissolution. Finally, COMSOL simulations demonstrated consistent shape dependent dissolution as we observed experimentally.

The Role of Inorganic Fillers in Electrostatic Discharge Composites

The occurrence of uncontrolled electrostatic discharge (ESD) is among the major causes of damage in unprotected electronic components during industrial processes. To counteract this undesired phenomenon, ESD composites showing static-dissipative and antistatic responses are developed. In particular, static-dissipative materials are able to slow down the flow of electric charges, whereas antistatic materials directly suppress the initial charges induced by undesired charging by properly dispersing conductive fillers within an insulant matrix and thus forming a conductive filler network. In this context, the purpose of this review is to provide a useful resume of the main fundamentals of the technology necessary for facing electrostatic charging. The formation mechanisms of electrostatic charges at the material surface were described, providing a classification of ESD composites and useful characterization methods. Furthermore, we reported a deep analysis of the role of conductive fillers in the formation of filler networks to allow electric charge movements, along with an overview of the different classes of inorganic conductive fillers exploitable in ESD composites, evidencing pros/cons and criticalities of each category of inorganic fillers.

Tips and Tricks for the Surface Engineering of Well-Ordered Morphologically Driven Silver-Based Nanomaterials

Particularly-shaped silver nanostructures are successfully applied in many scientific fields, such as nanotechnology, catalysis, (nano)engineering, optoelectronics, and sensing. In recent years, the production of shape-controlled silver-based nanostructures and the knowledge around this topic has grown significantly. Hence, on the basis of the most recent results reported in the literature, a critical analysis around the driving forces behind the synthesis of such nanostructures are proposed herein, pointing out the important role of surface-regulating agents in driving crystalline growth by favoring (or opposing) development along specific directions. Additionally, growth mechanisms of the different morphologies considered here are discussed in depth, and critical points highlighted.