Search results for "phosphoric acid"
showing 10 items of 86 documents
CCDC 681287: Experimental Crystal Structure Determination
2009
Related Article: M.D.Santana, L.Lopez-Banet, G.Garcia, L.Garcia, J.Perez, M.Liu|2008|Eur.J.Inorg.Chem.||4012|doi:10.1002/ejic.200800345
How Many Phosphoric Acid Units Are Required to Ensure Uniform Occlusion of Sterically Stabilized Nanoparticles within Calcite?
2019
Polymerization-induced self-assembly (PISA) mediated by reversible addition-fragmentation chain transfer (RAFT) polymerization offers a platform technology for the efficient and versatile synthesis of well-defined sterically stabilized block copolymer nanoparticles. Herein we synthesize a series of such nanoparticles with tunable anionic charge density within the stabilizer chains, which are prepared via statistical copolymerization of anionic 2-(phosphonooxy)ethyl methacrylate (P) with non-ionic glycerol monomethacrylate (G). Systematic variation of the P/G molar ratio enables elucidation of the minimum number of phosphate groups per copolymer chain required to promote nanoparticle occlusi…
To incinerate or not? - Effects of incineration on the concentrations of heavy metals and leaching efficiency of post-precipitated sewage sludge (RAV…
2020
The major element and heavy metal concentrations of post-precipitated sewage sludge (PPS) and its ash residue (PPA) were determined using microwave digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS). To the best of our knowledge, this has not been previously done. In both PPS and PPA the heavy metal concentrations were clearly below the average concentrations than those encountered in sewage sludge in Europe. The leaching efficiency of the metal (Al/ Fe) used as a precipitation agent from post-precipitated sludge and its ash residue with phosphoric acid was also investigated with previously optimized leaching conditions. T…
Modelling of the ternary system H3PO4/H2O/TBP
2002
Abstract A thermodynamic model is presented for the extraction of phosphoric acid from water by tri-n-butylphosphate (TBP), from aqueous solutions containing 0–6 mol/kg phosphoric acid. The activity coefficient of phosphoric acid was calculated from experimental data using Pitzer’s equation, and those of the components in the organic phase were calculated by Sergievskii–Danus’s relationship. The proposed model gives a satisfactory description of the distribution of phosphoric acid and water, in the considered concentration range, by taking into account the formation of the following species: TBP, TBP·H2O, H3PO4·TBP and (TBP)2·H3PO4·H2O.
Current dental adhesives systems. A narrative review.
2012
Adhesive dentistry is based on the development of materials which establish an effective bond with the tooth tissues. In this context, adhesive systems have attracted considerable research interest in recent years. Successful adhesive bonding depends on the chemistry of the adhesive, on appropriate clinical handling of the material as well as on the knowledge of the morphological changes caused on dental tissue by different bonding procedures. This paper outlines the status of contemporary adhesive systems, with particular emphasis on chemical characteristics and mode of interaction of the adhesives with enamel and dentinal tissues. Dental adhesives are used for several clinical application…
How can droplet formation occur in endodontically treated teeth during bonding procedures?
2008
PURPOSE: The aim of this in vivo study was to clarify how blistering formation occurs along intraradicular dentin bonded interfaces. MATERIALS AND METHODS: Patients were selected and post space was prepared in vivo in endodontically treated teeth. Post space was etched, dried with ethanol, and bonded with one of the following adhesive systems: All Bond 2, XP-Bond, Clearfil SE Bond, Xeno III. The four adhesives were considered as representative of each bonding system class. An additional group was prepared with phosphoric acid treatment + application of Pre-Bond unfilled resin of All Bond 2, without the use of the primer agent. Etching was avoided for self-etching materials. Replicas of the …
Microporous alumina membranes electrochemically grown
2003
Abstract The electrochemical fabrication of alumina membranes by anodizing of aluminium in phosphoric acid and oxalic acid solutions, in the temperature interval from −1 to 16 °C, was investigated in order to study the influence of different parameters (initial treatment of aluminium surface, nature and composition of electrolyte, temperature) on the final characteristics of the membranes. Porous layers were grown using a linear potential scan at 0.2 V s −1 up to 160 V in H 3 PO 4 solution and 70 V in oxalic acid solution. The efficiency of porous layer formation was calculated by using Faraday's law and weight measurements. Pore size distribution and porosity of membranes prepared in 0.4 M…
Facilitated SLM extraction of peptides with D2EHPA as a carrier
2004
Abstract The extraction of short peptides through a supported liquid membrane containing di-2-(ethylhexyl)phosphoric acid (D2EHPA) as a carrier was investigated. The extraction was carried out from the aqueous donor phase with pH 3 to amore acidic acceptor phase. The proton gradient between the donor and the acceptor phase was the main driving force of the mass transfer in this system. The influence of various parameters such as diluent of the carrier, pH of the donor and acceptor phase, peptide structure and concentration on the extraction efficiency was presented.
Mesoporous aluminum phosphite
2009
Abstract High surface area pure mesoporous aluminum-phosphorus oxide-based derivatives have been synthesized through an S+I− surfactant-assisted cooperative mechanism by means of a one-pot preparative procedure from aqueous solution and starting from aluminum atrane complexes and phosphoric and/or phosphorous acids. A soft chemical extraction procedure allows opening the pore system of the parent as-prepared materials by exchanging the surfactant without mesostructure collapse. The nature of the pore wall can be modulated from mesoporous aluminum phosphate (ALPO) up to total incorporation of phosphite entities (mesoporous aluminum phosphite), which results in a gradual evolution of the acid…
Fabrication of metal nano-structures using anodic alumina membranes grown in phosphoric acid solution: Tailoring template morphology
2007
Abstract The influence of experimental parameters on the morphology of the porous structure and on the formation kinetics has been investigated for anodic alumina membranes (AAM) grown in aqueous H 3 PO 4 at 160 V. It was found that pore aspect ratio and membrane porosity on the solution-side surface are influenced by tensiostatic charge, bath temperature and the presence of Al 3+ ions in solution. Morphological and kinetic data, recorded in different conditions, give useful information on the growth mechanism of pore channels in phosphoric acid solution. Nickel nano-structures have been fabricated using AAM as template. Electroless deposition, performed by adding the reducing agent to a su…