0000000000658572
AUTHOR
G. Lando
Thermodynamics of interaction between risedronic acid and metal cations: investigations in solution and in the solid state
Risedronic acid (see Figure 1) belongs to the class of biphosphonates (BP), widely used in the medical field to treat bone disorders. Bisphosphonates (BPs, e.g., alendronate, risedronate, and ibandronate) help to maintain bone mass, to inhibit osteoclast-mediated bone resorption, and to reduce the risk of both vertebral and non-vertebral fractures. The clinical efficacy of BPs is mainly based on two key properties: their capacity to strongly bind hydroxyapatite crystals of bone, and their inhibitory effects on osteoclast precursors and mature osteoclasts. Interaction of risedronate with metal cations is poorly investigated. Qualitatively, it is indicated that adsorption of risedronate is in…
Protonation Constants of Halloysite Clay Nanotubes
Halloysite is one of the most interesting nano-structured clay materials. It is similar to kaolin but has a hollow tubular structure that can be attributable to particular crystallization conditions. Typically, halloysite nanotubes (HNTs) are formed by 15 – 20 aluminosilicate layers, has a length of 1 ± 0.5 μm and inner and outer diameters of 1 - 30 and 30 - 50 nm, respectively [1,2]. In each layer the SiOH and the AlOH groups are disposed on the external and the internal surfaces, respectively. The particular structure of HNTs makes this kind of material very useful for different purposes in several fields. Among the various applications, worth of mention are: i) their use as additive for …
Sequestering ability of landfill leachate towards toxic metal ions
The great part of municipal solid wastes is worldwide stored in sanitary landfills. The interaction of organic and inorganic wastes with rainwater produces in the landfill a leachate of extremely variable composition. It depends on several variables such as the type of wastes, the age of landfill, the pH, the redox potential, etc [1-2]. Four are the recognized categories of pollutants in landfill leachate: inorganic macrocomponents, dissolved organic matter (DOM), heavy metals and xenobiotic organic compounds [3]. In particular, heavy metals (arsenic, cadmium, copper, lead, mercury, etc.) are usually present at concentration of few ppb and up to some ppm. A variable but consistent fraction …
Modelling of protonation constants of halloysite clay nanotubes in various aqueous media, at different ionic strengths
In the last decade nanoparticles have assumed more and more importance because of their particular properties mainly due to the nanometer-scale dimensions that confer them a large surface/volume ratio. Among nanomaterials one of the most studied is the halloysite that, as well as the other natural clay minerals is safe for human and environmental friendly. Halloysite is abundant and cheap and is present in large deposits worldwide like those in New Zealand, France, Belgium and China [1,2]. It is similar to kaolin but has a hollow tubular structure that can be attributable to particular crystallization conditions. Typically, halloysite nanotubes (HNTs) are formed by 15 – 20 aluminosilicate l…
Thermodynamic Study For The Protonation Of Halloysite
The Halloysite (Al2Si2O5(OH)4·2H2O) is an abundant and cheap clay and is considered one of the most promising nano structured and naturally occurring clay mineral. Large deposits of this material are present in France, Belgium, China, New Zealand and USA [1,2]. Among the spheroidal, tubular or platy morphologies, the tubular is the most common and abundant one. Typically, halloysite nanotubes (HNTs) are formed by 15 – 20 aluminosilicate layers, having a length of 1 ± 0.5 μm, and inner and outer diameters of 10 – 15 nm and 50 -70 nm, respectively [1]. In each layer, the SiOH and the AlOH groups are disposed on the external and the internal surfaces, respectively. As consequence, in each nano…