The pH of zero net surface charge (pHpzc) of the a-TiO2 (1 1 0) surface was characterized using second-harmonic generation (SHG) spectroscopy. The SHG response was monitored during a series of pH titrations conducted at three NaNO3 concentrations. The measured pHpzc is compared with a pHpzc value calculated using the revised MUltiSIte Complexation (MUSIC) model of surface oxygen protonation. MU...

The constant capacitance model, a chemical surface complexation model, was applied to B adsorption on 17 soils selected for variation in soil properties. A general regression model was developed for predicting soil B surface complexation constants from easily measured soil chemical characteristics. These chemical properties were cationexchange capacity (CEC), surface area, organic carbon conten...

Zeta potential is a physicochemical parameter of particular importance in describing ion adsorption and double layer interactions between charged particles. However, for metal-oxide nanoparticles, the conversion of electrophoretic mobility measurements into zeta potentials is difficult. This is due to their very high surface electrical conductivity, which is inversely proportional to the size o...

We have prepared a novel kind of building block (CD-PI-CD) of polyether imide (PI) with beta-cyclodextrin (beta-CD) at the both ends that self-assembles into vesicles in water. The vesicles are "reactive" in supramolecular chemistry because the host groups of beta-CD equally distribute on the inside and outside surfaces of the vesicles. Isothermal titration calorimetry (ITC) and static light sc...

Complexation reactions of environmentally important inorganic anions such as nitrate, chloride, sulfate, arsenate, and phosphate on the surface of hydrotalcite-like compounds (HT) were investigated to understand the role of HT in the immobilization of hazardous anions in an alkaline environment. The effects of surface complexation reactions on the solid state properties of HT were also evaluate...

Adsorption of aqueous anions, such as sulfate, arsenite, and oxalate, to oxide surfaces is important in the retardation of toxic species in the environment, but predicting the surface speciation as a function of environmental parameters is a major challenge. Recent laboratory spectroscopic studies defining surface speciation must be integrated with surface complexation models. However, the latt...

Lysozyme-silica interactions and the resulting complexation were investigated through adsorption isotherms, dynamic and electrophoretic light scattering, circular dichroism (CD), and isothermal titration calorimetry (ITC). A thermodynamic analysis of ITC data revealed the existence of two binding modes during protein-nanoparticle complexation. Both binding modes are driven by the cooperation of...

Monomolecular films of 9-cis, 11-c/5, 13-cis and all-trans retinal were formed at an air-water interface. Area/molecule and surface potential were measured before, during and after illumina­ tion. The initial quantum yield of the photoisomerization o f 9-cis retinal was 0.25. Irradiation of a retinal monolayer resulted in 30 to 60 m Volt changes in surface potential. Complexation of retinals wi...

Interactions between aqueous amino acids and mineral surfaces influence the bioavailability of amino acids in the environment, the viability of Ti implants in humans, and the role of mineral surfaces in the origin of life on Earth. We studied the adsorption of L-glutamate on the surface of rutile (R-TiO2, pHPPZC=5.4) in NaCl solutions using potentiometric titrations and batch adsorption experim...

Surface complexation models (SCMs) provide a mechanistic and thermodynamicallybased description of sorption reactions on mineral surfaces and can thus be used in geochemical modelling to predict contaminant sorption under a variety of geochemical conditions. In the last years, substantial effort has been put into obtaining multiple lines of evidence for the types of complexes formed on mineral ...