| Reference | [1]. Dalton Trans. 2016 Jan 21;45(3):1225-32. doi: 10.1039/c5dt03671b.<br />
Mechanical mixtures of metal oxides and phosphorus pentoxide as novel precursors for the synthesis of transition-metal phosphides.<br />
Guo L(1), Zhao Y(2), Yao Z(2).<br />
Author information: (1)College of Basic Medical Sciences, Changsha Medical University, Changsha, 410219, P.R. China. (2)College of Chemistry, Chemical Engineering and Environmental Engineering, Liaoning Shihua University, Fushun, 113001, P.R. China. [email protected].<br />
This study presents a new type of precursor, mechanical mixtures of metal oxides (MOs) and phosphorus pentoxide (P2O5) are used to synthesize Ni2P, Co2P and MoP phosphides by the H2 reduction method. In addition, this is first report of common solid-state P2O5 being used as a P source for the synthesis of metal phosphides. The traditional precursors are usually prepared via a complicated preparation procedure involving dissolution, drying and calcination steps. However, these novel MOs/P2O5 precursors can be obtained only by simple mechanical mixing of the starting materials. Furthermore, unlike the direct transformation from amorphous phases to phosphides, various specific intermediates were involved in the transformation from MOs/P2O5 to phosphides. It is worthy to note that the dispersions of Ni2P, Co2P and MoP obtained from MOs/P2O5 precursors were superior to those of the corresponding phosphides prepared from the abovementioned traditional precursors. It is suggested that the morphology of the as-prepared metal phosphides might be inherited from the corresponding MOs. Based on the results of XRD, XPS, SEM and TEM, the formation pathway of phosphides can be defined as MOs/P2O5 precursors → complex intermediates (metals, metal phosphates and metal oxide-phosphates) → metal phosphides.<br />
DOI: 10.1039/c5dt03671b PMID: 26667235<br />
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[2]. J Colloid Interface Sci. 2013 Sep 1;405:296-304. doi: 10.1016/j.jcis.2013.04.046. Epub 2013 May 11.<br />
Effect of various additives on microstructure, mechanical properties, and in vitro bioactivity of sodium oxide-calcium oxide-silica-phosphorus pentoxide glass-ceramics.<br />
Li HC(1), Wang DG, Hu JH, Chen CZ.<br />
Author information: (1)Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials, Ministry of Education, Shandong University, Ji'nan 250061, Shandong, People's Republic of China. [email protected]<br />
The partial substitution of MgO, TiO2, or CaF2 for CaO in the Na2O-CaO-SiO2-P2O5 (45S5) system was conducted by the sol-gel method and a comparative study on structural, mechanical properties, and bioactivity of the glasses was reported. Based on thermogravimetric and differential thermal analysis, the gels were sintered with a suitable heat treatment procedure. The glass-ceramic properties were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and so on, and the bioactivity of the glass-ceramic was evaluated by in vitro assays in simulated body fluid (SBF). Results indicate that with the partial substitution of MgO, TiO2, CaF2 for CaO in glass composition, the mechanical properties of the glass-ceramics have been significantly improved. Furthermore, CaF2 promotes glass crystallization and the crystallization does not inhibit the glass-ceramic bioactivity. All samples possess bioactivity; however, the bioactivity of these glass-ceramics is quite different. Compared with 45S5, the introduction of MgO decreases the ability of apatite induction. The addition of TiO2 does not significantly improve the bioactivity, and the replacement of CaO by CaF2 shows a higher bioactivity.<br />
DOI: 10.1016/j.jcis.2013.04.046 PMID: 23777867 ]<br />
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[3]. J Dent. 2008 Mar;36(3):171-7. doi: 10.1016/j.jdent.2007.11.003.<br />
Synthesis of phosphate monomers and bonding to dentin: esterification methods and use of phosphorus pentoxide.<br />
Ogliari FA(1), da Silva Ede O, Lima Gda S, Madruga FC, Henn S, Bueno M, Ceschi MA, Petzhold CL, Piva E.<br />
Author information: (1)Operative Dentistry Department, School of Dentistry, Federal University of Pelotas, RS, Brazil.<br />
OBJECTIVES: The aim of this study was to synthesize an acidic monomer using an alternative synthetic pathway and to evaluate the influence of the acidic monomer concentration on the microtensile bond strength to dentin. METHODS: The intermediary 5-hydroxypentyl methacrylate (HPMA) was synthesized through methacrylic acid esterification with 1,5-pentanediol, catalyzed by p-toluenesulfonic acid. To displace the reaction balance, the water generated by esterification was removed by three different methods: anhydrous sodium sulfate; molecular sieves or azeotropic distillation. In the next step, a phosphorus pentoxide (4.82 mmol) slurry was formed in cold acetone and 29 mmol of HPMA was slowly added by funnel addition. After the reaction ended, solvent was evaporated and the product was characterized by 1HNMR and FTIR. The phosphate monomer was introduced in a self-etch primer at concentrations of 0, 15, 30, 50, 70 and 100 wt%. Clearfil SE Bond was used as commercial reference. Microtensile bond strength to dentin was evaluated 24h after the bonding procedures, followed by fracture analysis (n=20). Data was submitted to ANOVA and Tukey's post hoc test. RESULTS: The highest yield was obtained (62%) when azeotropic distillation was used, while the reaction with molecular sieves was not feasible. The phosphoric moiety attachment to the monomer was successfully performed with a quantitative yield that reached around 100%. The acidic monomer concentration significantly affected the bond strength and the highest mean (55.1+/-12.8 MPa) was obtained when 50% of acidic monomer was used. CONCLUSION: The synthesis pathways described in the present study appear to be a viable alternative for developing phosphate monomers.<br />
DOI: 10.1016/j.jdent.2007.11.003 PMID: 18243472<br />
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[4]. J Assoc Off Anal Chem. 1976 May;59(3):602-5.<br />
Phosphorus pentoxide as a drying agent for bacterial culture extracts analyzed by gas-liquid chromatography.<br />
Finne G, Matches JR.<br />
The procedure for gas chromatographic analysis of metabolic products of microbial fermentation includes solvent extraction of the aqueous growth media, drying of the extract, and direct chromatographic analysis of the solvent. In this study, 2 drying agents, magnesium sulfate and phosphorus pentoxide, were compared. Both were effective in removing water; however, phosphorus pentoxide removed water more completely and at a faster rate than magnesium sulfate. When a thermal conductivity detector is used, it is important to completely remove water from the solvent to prevent interference with volatile acids and alcohols. When water is present, short-chain alcohols (C2-C5) are eluted together with the water, causing peak overlap and shoulder separations. Phosphorus pentoxide quickly and effectively removed water so that a baseline was established following the solvent front on the chromatogram. The use of phosphorus pentoxide is particularly advantageous for identification or fermentation studies on Clostridium and Propionibacterium when rapid identification is desired or when large numbers of cultures are to be tested.<br />
PMID: 1270388<br />
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[5]. J Chem Phys. 2011 Dec 21;135(23):234513. doi: 10.1063/1.3666017.<br />
A density functional theory study of structural, mechanical and electronic properties of crystalline phosphorus pentoxide.<br />
Ainsworth RI(1), Di Tommaso D, de Leeuw NH.<br />
Author information: (1)Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom. [email protected]<br />
Quantum mechanical calculations of single crystal phosphorus pentoxide (P(2)O(5)) have been conducted using the plane-wave ultrasoft pseudopotential technique based on the density functional theory (DFT), in the generalized gradient approximation, with dispersive correction (DFT-D). The implementation of the dispersive correction is shown to improve significantly the structural agreement with experiment, compared to standard plane-wave DFT. The second order elastic constants for the o'(P(2)O(5))(∞) and o(P(2)O(5)) orthorhombic phases were obtained from a polynomial fit to the calculated energy-strain relation. Both phases are shown to be highly elastically anisotropic due to structural features. Polycrystalline aggregate properties have been evaluated to give complete mechanical descriptions. Further investigation of the electronic band structure and density of states has been completed. Analysis of the complex chemical bonding has been carried out using Löwdin atomic charge and valence charge density data showing mixed ionic and covalent character in both phases.<br />
DOI: 10.1063/1.3666017 PMID: 22191892
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