多孔偏磷酸钙(CMP)陶瓷是使用原位自发泡方法制造的。研究了具有不同孔隙率和强度的多孔CMP陶瓷,并研究了制备工艺和所得材料的性能。在低成型压力(≤2.0MPa)或低加热速率(≤0.5°C min -1)的条件下,仅使用Ca(H 2 PO 4)2 ·H 2 O(MCPM)或Ca( H 2 PO 4)2(MCPA)作为原料可以被制成多孔生物陶瓷,而不会变形和没有成孔剂。在这项研究中,MCPA样品在80.0 MPa的压力下成型,加热速率控制在0.5°C min -1。所述合成生物材料显示出38.0%的孔隙率和48.0MPa的强度。
Liquid-phase oxidation with hydrogen peroxide of benzyl alcohol and xylenes on Ca10(PO4)6(OH)2 – CaWO4
作者:María Isabel Domínguez、Bogdan Cojocaru、Madalina Tudorache、José Antonio Odriozola、Miguel Angel Centeno、Vasile I. Parvulescu
DOI:10.1016/j.crci.2015.10.013
日期:2016.10
Résumé A W-containing apatite (W/HAp) catalyst was prepared following a hydrothermal synthesis route and served as a model catalyst. Crystallographic analysis indicated that the resulting material contained hydroxyapatite, Ca10−3xWx(PO4)6(OH)2, W-hydroxyapatite, calcium tungstate, CaWO4, and tricalcium phosphate, Ca3(PO4)2. The catalyst was investigated in liquid phase oxidation of benzyl alcohol and xylenes using hydrogen peroxide as an oxidant. For comparison, commercial calcium phosphate, hydroxyapatite and CaWO4 were tested in the same reaction. Calcium phosphate and hydroxyapatite appeared as inactive and decomposed hydrogen peroxide non-selectively. A moderate activity but low hydrogen peroxide efficiency was observed for the CaWO4 phase. In contrast, the W/HAp catalyst showed a reasonable activity and a better hydrogen peroxide efficiency in the oxidation of benzyl alcohol and xylenes. This new W/HAp catalyst showed, after six cycles, losses of the activity below 15% compared to the fresh catalyst with no effect on the selectivity. It is noteworthy that ICP-OES analyses showed no tungsten leaching that is the main advantage of this catalyst.
Synthesis of Monetite from Calcium Hydroxyapatite and Monocalcium Phosphate Monohydrate under Mechanical Activation Conditions
作者:T. V. Safronova、I. S. Sadilov、K. V. Chaikun、T. B. Shatalova、Ya. Yu. Filippov
DOI:10.1134/s0036023619090171
日期:2019.9
monohydrate Ca(H2PO4)2 ⋅ H2O and calciumhydroxyapatite Ca10(PO4)6(OH)2 in an acetone medium upon mechanical activation in a planetary mill. According to X-ray powder diffraction data, after heat treatment in the range 900–1100°С, the phase composition of the samples was represented by calcium β-pyrophosphate β-Ca2P2O7. The synthesized powder can be used for producing resorbable calcium phosphate ceramic materials
摘要斜磷钙石СаНРО的粉末4与100-300纳米的粒径从磷酸二氢钙一水合物的Ca(H合成2 PO 4)2 ⋅ħ 2 O和钙羟基磷灰石的Ca 10(PO 4)6(OH)2在丙酮在行星式磨机中机械激活后的介质。根据X-射线粉末衍射数据,在900-1100°С的范围内热处理后,将样品的相组成通过钙β-β焦磷酸钙表示2 P 2 ö 7。合成的粉末可用于生产可吸收的磷酸钙陶瓷材料。
Hydroxyapatite?Polyphosphazane Composites Prepared at Low Temperatures
作者:Y. E. Greish、P. W. Brown、J. D. Bender、H. R. Allcock、S. Lakshmi、C. T. Laurencin
DOI:10.1111/j.1551-2916.2007.01780.x
日期:2007.9
Owing to their similarities to bone apatite, calcium phosphate bioceramics, such as hydroxyapatite (HAp), are used as biomaterials for hard tissue replacements. Composites of bioceramics and biomedical polymers can mimic bone structure and properties. The characteristics of composites comprising HAp and a biomedical polymer and prepared at low temperatures are described. The kinetics of HAp formation in the presence of a polyphosphazene polymer that carries carboxylic acid moieties (acid‐PCPP) were established at temperatures from 25° to 50°C. Evolution in the compositions of the solids present, solution chemistry, and microstructure development were established as functions of reaction time and temperature. The polymer participated in HAp formation affecting its rates of nucleation and growth through the formation of calcium cross links. The presence of polymer also enhanced ductility.
Proton Distributions and Hydrogen Bonding in Crystalline and Glassy Hydrous Silicates and Related Inorganic Materials: Insights from High-Resolution Solid-State Nuclear Magnetic Resonance Spectroscopy
作者:Xianyu Xue、Masami Kanzaki
DOI:10.1111/j.1551-2916.2009.03468.x
日期:2009.12
Solid-state 1 H nuclearmagneticresonance (NMR) spectroscopy has developed into a versatile, high-resolution method for elucidating the detailed structures of both crystalline and amorphous materials. Here, we summarize our recent endeavors in applying this method to crystalline and glassy silicates and related inorganic materials. We first present updated correlations between 1 H chemical shift and
固态 1 H 核磁共振 (NMR) 光谱已发展成为一种多功能、高分辨率的方法,用于阐明晶体和非晶材料的详细结构。在这里,我们总结了我们最近将这种方法应用于结晶和玻璃状硅酸盐以及相关无机材料的努力。我们首先提出了 1 H 化学位移与 O…O 和 H…O OH…O 氢键的距离之间的更新相关性,源自包含原始高质量快速魔角的综合 1 H 化学位移数据库旋转 (MAS) 和二维组合旋转和多脉冲光谱 (CRAMPS)-MAS 核磁共振数据和文献 大量无机化合物的 MAS 核磁共振数据,包括磷酸盐、硅酸盐、(羟基)氢氧化物、硼酸盐、硫酸盐和碳酸盐. 这些相关性可用于估计未知结构的无机氧化物材料的氢键距离。然后,我们介绍了应用高分辨率二维 1 H CRAMPS-MAS NMR 来揭示结晶高压水合硅酸盐中质子分布的有序/无序的案例研究。最后,我们总结了通过综合 1 H MAS NMR、 29 Si- 1 H
Remarkable photoluminescence of europium(<scp>ii</scp>)-doped phosphate cyan@red-emitting phosphors with highly dispersed luminescence centers