Surface complexation modeling Karamalidis, Athanasios K; Dzombak, David A
c2010., 2010, 2010-12-22, 2011-02-14
eBook
This book provides a description of the generalized two layer surface complexation model, data treatment procedures, and thermodynamic constants for sorption of metal cations and anions on gibbsite, ...the most common form of aluminum oxide found in nature and one of the most abundant minerals in soils, sediments, and natural waters. The book provides a synopsis of aluminum oxide forms and a clearly defined nomenclature. Compilations of available data for sorption of metal cations and anions on gibbsite are presented, and the results of surface complexation model fitting of these data are given. The consistency of the thermodynamic surface complexation constants extracted from the data is examined through development of linear free energy relationships which are also used to predict thermodynamic constants for ions for which insufficient data are available to extract constants. The book concludes with a comparison of constants extracted from data for sorption on gibbsite with those determined previously for hydrous ferric oxide (HFO), hydrous manganese oxide (HMO), and goethite. The overall objective of this book is the development and presentation of an internally consistent thermodynamic database for sorption of inorganic cations and anions on gibbsite, an abundant and reactive mineral in soils, sediments, and aquatic systems. Its surface has a high affinity for sorption of metal cations and anions, including radionuclides. The gibbsite database will enable simulation and prediction of the influence of sorption on the fate of these chemical species in natural systems and treatment processes in which aluminum oxides are abundant. It thus will help to advance the practical application of surface complexation modeling.
The presence of surface ligands not only plays a key role in keeping the colloidal integrity and non‐defective surface of metal halide perovskite quantum dots (PQDs), but also serves as a knob to ...tune their optoelectronic properties for a variety of exciting applications including solar cells and light‐emitting diodes. However, these indispensable surface ligands may also deteriorate the stability and key properties of PQDs due to their highly dynamic binding and insulating nature. To address these issues, a number of innovative surface chemistry engineering approaches have been developed in the past few years. Based on an in‐depth fundamental understanding of the surface atomistic structure and surface defect formation mechanism in the tiny nanoparticles, a critical overview focusing on the surface chemistry engineering of PQDs including advanced colloidal synthesis, in‐situ surface passivation, and solution‐phase/solid‐state ligand exchange is presented, after which their unprecedented achievements in photovoltaics and other optoelectronics are presented. The practical hurdles and future directions are critically discussed to inspire more rational design of PQD surface chemistry toward practical applications.
The surface chemistry of metal halide perovskite quantum dots (PQDs) plays a key role in determining their structural stability and electronic properties. A critical overview focusing on the surface ligand engineering of PQDs, including advanced synthesis, in situ passivation, and ligand exchange, toward efficient and stable optoelectronic applications is presented.
In this paper, we focus on the recent advances on the physical chemistry of lignin. Emerging trends of incorporating lignin in promising future applications such as controlled release, ...saccharification of lignocelluloses, bioplastics, composites, nanoparticles, adsorbents and dispersants, in electro-chemical applications and carbon fibers, are also reviewed. We briefly describe the complexity of the lignin structure that influences the solution behavior, both as a macromolecule and a colloid, as well as the potential of being a renewable precursor in the development of high-value applications. Special attention is paid on summarizing the present knowledge on lignin colloidal stability and surface chemistry.
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•The present knowledge on lignin colloidal stability and surface chemistry.•Recent advances of incorporating lignin in promising high-value applications.•The development of carbon fibers from lignin as a promising approach.
Unveiling the ligand binding mode on the crystalline surfaces is important for deciphering the long-standing structural enigma in self-assembled monolayers (SAMs). Here, the binding and patterning ...structures of thiolates (SR) on the Au(100) crystalline facet are revealed on the basis of the atomic structure of a highly regular, single crystalline Au92(SR)44 nanocrystal. The six exposed facets of this tetragonal nanocrystal give rise to six pieces of “nanoSAMs”. We found that thiolates bind to the planar (100) facets of the nanocrystal via a simple bridge-like mode and are assembled into an overlayer with c(2 × 2) symmetry. The Au–S binding mode and translational symmetry in the kernel and on the surface of the Au92 nanocrystal can be generalized infinitely to construct the bulk two-dimensional SAMs and various tetragonal nanocrystals.
The co-occurrence of microplastics (MPs) with potentially toxic metals in the environment stresses the need to address their physicochemical interactions and the potential ecological and human health ...implications. Here, we investigated the reaction of aqueous U with agricultural soil and high-density polyethylene (HDPE) through the integration of batch experiments, microscopy, and spectroscopy. The aqueous initial concentration of U (100 μM) decreased between 98.6 and 99.2 % at pH 5 and between 86.2 and 98.9 % at pH 7.5 following the first half hour of reaction with 10 g of soil. In similar experimental conditions but with added HDPE, aqueous U decreased between 98.6 and 99.7 % at pH 5 and between 76.1 and 95.2 % at pH 7.5, suggesting that HDPE modified the accumulation of U in soil as a function of pH. Uranium-bearing precipitates on the cracked surface of HDPE were identified by SEM/EDS after two weeks of agitation in water at both pH 5 and 7.5. Accumulation of U on the near-surface region of reacted HDPE was confirmed by XPS. Our findings suggest that the precipitation of U was facilitated by the weathering of the surface of HDPE. These results provide insights about surface-mediated reactions of aqueous metals with MPs, contributing relevant information about the mobility of metals and MPs at co-contaminated agricultural sites.
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•Accumulation of U on HDPE was confirmed by microscopy and spectroscopy.•HDPE modified the accumulation and mobilization of U in soil as a function of pH.•Uranium precipitation onto the surface of weathered MPs in water.•Exposure to U-bearing plastic solids is a critical understudied pathway.
This reference describes the role of various intermolecular and interparticle forces in determining the properties of simple systems such as gases, liquids and solids, with a special focus on more ...complex colloidal, polymeric and biological systems. The book provides a thorough foundation in theories and concepts of intermolecular forces, allowing researchers and students to recognize which forces are important in any particular system, as well as how to control these forces. This Third Edition is expanded into three sections and contains five new chapters over the previous edition. Key features:Starts from the basics and builds up to more complex systemsCovers all aspects of intermolecular and interparticle forces both at the fundamental and applied levelsMultidisciplinary approach: bringing together and unifying phenomena from different fieldsThis new edition has an expanded Part III and new chapters on non-equilibrium (dynamic) interactions, and tribology (friction forces)
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