A study of interfacial molecular interactions and surface behavior by electrochemistry, spectroscopy, and surface characterization techniques
Creators: name: Ordikhani Seyedlar, Ramin
Publisher: name: University of Iowa
Year: 2025
Subjects: 3D-printed metal superhydrophobic surfaces
Biomass gasification
In-situ spectroelectrochemical studies on electrode electrolyte interface (EEI)
Recycling rare earth metals from electronic waste
Redox flow batteries
Superhydrophobic metal surfaces
public abstract
Engineering

description: Interfacial chemistry and surface chemistry study chemical interactions and phenomena occurring at the interfaces or surfaces of materials. A material's surface is the region that separates its bulk from its surroundings. An interfacial region is the boundary or region between two different kinds of materials or phases. Typically, these regions are between a few nanometers or a few micrometers in size. Surface properties of solids, liquids, and gases are studied in this field, as well as chemical adsorption and desorption. Intermolecular forces such as London dispersion forces, dipole-dipole interactions, hydrogen bonds, and ion-dipole interactions play an important role in surface chemistry and interfacial chemistry. Through a variety of approaches, this dissertation examines the surface characteristics of materials and explores the interactions taking place in the interfacial thin layer. The intricate nature of these interfaces was investigated using spectroscopic, microscopic, and electrochemical techniques in this dissertation.
description: The first part of the dissertation examines the surface characteristics of materials and their wetting behavior. The dissertation uses surface characterization and spectroscopy techniques to study the surface morphology, topography, and surface chemistry of synthesized metal parts, focusing on the factors affecting superhydrophobicity and surface adhesion. With contact angle measurements, the results reveal that chemical treatment and surface texturing contribute to superhydrophobicity. Various chemical modification techniques have been used to create superhydrophobic properties on metal surfaces. Among these, extended exposure to ambient air is one of the most popular options, however it can take days if not months. This process is shortened to a few hours by our work, along with the use of chemical reagents in optimum concentrations for metal coating.
description: In the second part of the dissertation, a pyrometallurgical approach is developed to gasify electronic waste and recycle coinage metals and rare earth metals using biomass fuel. Using a gasifier, the study is conducted to determine whether metals can be extracted from nodules on the surface of biochar under different experimental conditions. Different surface characterization techniques such as SEM and EDS along with XRF to determine the metal nodule compositions on biochar surfaces. The largest surface nodules are created when an oxidizing atmosphere with N2+O2 is followed by a reducing atmosphere with N2+H2. Instead of relying on chemicals to separate and extract these metal pieces from electronic waste, physical methods can be used.
description: Finally, a spectroelectrochemical cell is designed to conduct in-situ spectroelectrochemical measurements on the electrode-electrolyte interface. The main objective of this part of dissertation is to investigate how electrodes interact with nitrobenzene, which is a suitable anolyte for redox flow batteries because of its electrochemical reversibility and negative redox potential. The dissertation investigates nitrobenzene behavior on the surface using in-situ reflective infrared measurements and electrochemical measurements, with a particular focus on the orientational changes of nitrobenzene during the redox reaction on the surface.
description: Overall, this dissertation offers a comprehensive overview of surface and interfacial chemistry, focusing on how spectroscopy, microscopy, and electrochemistry may improve our understanding of these interfaces.