Author
Thomas W. Healy
Other affiliations: Swinburne University of Technology
Bio: Thomas W. Healy is an academic researcher from University of Melbourne. The author has contributed to research in topics: Adsorption & Aqueous solution. The author has an hindex of 52, co-authored 140 publications receiving 10356 citations. Previous affiliations of Thomas W. Healy include Swinburne University of Technology.
Papers published on a yearly basis
Papers
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TL;DR: In this article, a site-binding model of the oxide/aqueous electrolyte interface is introduced, in which the adsorbed counter ions form interfacial ion pairs with discrete charged surface groups.
Abstract: A site-binding model of the oxide/aqueous electrolyte interface is introduced, in which it is proposed that the adsorbed counter ions form interfacial ion pairs with discrete charged surface groups. This model is used to calculate theoretical surface charge densities of the potential-determining (H+/OH–) ions and the potential at the Outer Helmholtz Plane, which are shown to be consistent with experimental data for oxides. An explanation is provided for the difference between silica and most other oxides in terms of the dissociation constants of the surface hydroxyl groups.
1,231 citations
TL;DR: In this paper, a detailed quantitative model for the adsorption of hydrolyzable metal ions at the oxide-water interface is presented in terms of the competition between the free energy changes faavorble to adaption, and the unfavorable change in solvation energy.
631 citations
TL;DR: In this paper, the adsorption data indicate that the primary hydration sphere of free or hydrolyzed metal ions is not altered in the adaption process, and that the qualitative correlation between adsoption and hydrolysis is shown to break down when examined in detail.
521 citations
TL;DR: In this article, the classical electrochemistry of the electrical double layer appropriate to materials that operate as electrodes is shown to be a limiting description for non-electrode materials such as clays, inorganic oxides, insoluble salts, latex colloids and biosurfaces.
424 citations
TL;DR: In this paper, an analytic expression of the surface charge density/surface potential relationship and double-layer potential distribution for a spherical colloidal particle in 1-1 and 2-1 electrolyte solutions and a mixed 1 1 and 2 1 electrolyte solution was derived.
370 citations
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TL;DR: In this paper, the use of optical measurements to monitor electrochemical changes on the surface of nanosized metal particles is discussed within the Drude model, and the absorption spectrum of a metal sol in water is shown to be strongly affected by cathodic or anodic polarization, chemisorption, metal adatom deposition, and alloying.
Abstract: The use of optical measurements to monitor electrochemical changes on the surface of nanosized metal particles is discussed within the Drude model. The absorption spectrum of a metal sol in water is shown to be strongly affected by cathodic or anodic polarization, chemisorption, metal adatom deposition, and alloying. Anion adsorption leads to strong damping of the free electron absorption. Cathodic polarization leads to anion desorption. Underpotential deposition (upd) of electropositive metal layers results in dramatic blue-shifts of the surface plasmon band of the substrate. The deposition of just 0.1 monolayer can be readily detected by eye. In some cases alloying occurs spontaneously during upd. Alloy formation can be ascertained from the optical absorption spectrum in the case of gold deposition onto silver sols. The underpotential deposition of silver adatoms onto palladium leads to the formation of a homogeneous silver shell, but the mean free path is less than predicted, due to lattice strain in t...
3,454 citations
TL;DR: The atomic force microscope (AFM) is not only used to image the topography of solid surfaces at high resolution but also to measure force-versus-distance curves as discussed by the authors, which provide valuable information on local material properties such as elasticity, hardness, Hamaker constant, adhesion and surface charge densities.
3,281 citations
TL;DR: In this paper, a review of the surface chemistry of carbon blacks and other activated carbons is given, focusing on surface oxides with emphasis on the chemical methods used in the assessment and identification of surface functional groups.
2,705 citations
TL;DR: In this paper, a review of the proton conductivity in materials and the elements of proton conduction mechanisms are discussed with a special emphasis on proton chemistry, including structural reorganization and diffusional motion of extended moieties.
Abstract: In this review the phenomenon of proton conductivity in materials and the elements of proton conduction mechanismsproton transfer, structural reorganization and diffusional motion of extended moietiesare discussed with special emphasis on proton chemistry. This is characterized by a strong proton localization within the valence electron density of electronegative species (e.g., oxygen, nitrogen) and self-localization effects due to solvent interactions which allows for significant proton diffusivities only when assisted by the dynamics of the proton environment in Grotthuss and vehicle type mechanisms. In systems with high proton density, proton/proton interactions lead to proton ordering below first-order phase transition rather than to coherent proton transfers along extended hydrogen-bond chains as is frequently suggested in textbooks of physical chemistry. There is no indication for significant proton tunneling in fast proton conduction phenomena for which almost barrierless proton transfer is suggest...
2,039 citations
TL;DR: In this article, the authors survey progress over the past 25 years in the development of microscale devices for pumping fluids and attempt to provide both a reference for micropump researchers and a resource for those outside the field who wish to identify the best micropumps for a particular application.
Abstract: We survey progress over the past 25 years in the development of microscale devices for pumping fluids. We attempt to provide both a reference for micropump researchers and a resource for those outside the field who wish to identify the best micropump for a particular application. Reciprocating displacement micropumps have been the subject of extensive research in both academia and the private sector and have been produced with a wide range of actuators, valve configurations and materials. Aperiodic displacement micropumps based on mechanisms such as localized phase change have been shown to be suitable for specialized applications. Electroosmotic micropumps exhibit favorable scaling and are promising for a variety of applications requiring high flow rates and pressures. Dynamic micropumps based on electrohydrodynamic and magnetohydrodynamic effects have also been developed. Much progress has been made, but with micropumps suitable for important applications still not available, this remains a fertile area for future research.
1,913 citations