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为了提高羟基磷灰石(HAP)的除氟容量,利用羟基铝(Al-OH)改性HAP制备羟基铝-羟基磷灰石复合材料(Al-OH-HAP),通过红外光谱(FTIR)、扫描电镜(SEM)、X-射线粉末衍射(XRD)和N2吸附-脱附曲线等方法对样品进行表征分析,结合吸附热力学和动力学模型拟合,探讨Al-OH-HAP对水溶液氟离子的吸附特性.实验结果表明:Al-OH改性后Al3+和OH-进入HAP晶格中,且改性后HAP的衍射峰更尖锐,结晶度增大.Al-OH改性后HAP的比表面积分别从106.75 m2/g增加到220.45 m2/g,且大部分孔为介孔结构.吸附拟合模型表明Al-OH-HAP对氟离子的吸附更加遵循Langmuir模型,说明Al-OH-HAP对F-的吸附更趋近于单层吸附,吸附过程中化学吸附占主导地位.热力学参数吸附吉布斯自由能(ΔGo)小于0、焓变(ΔHo)和熵变(ΔSo)大于0,说明Al-OH-HAP对F-的吸附是一个自发吸热的熵增过程,Al-OH-HAP对F-的吸附更符合拟二级反应动力学过程.Al-OH-HAP可以成为一种有潜力的饮用水除氟剂. 相似文献
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羟基磷灰石(HA)是一种性能优良的骨替代材料,镁离子掺杂HA (Mg-HA) 晶须不仅可以改变HA的生物学性能,还能起到增强作用.但Mg2+掺入后会改变HA的晶格结构并影响它的热稳定性.采用水热合成法制备了镁离子掺杂HA晶须,并通过XRD、FTIR和SEM研究了镁离子掺杂HA的晶体结构、热稳定性及影响因素.结果表明:当镁离子掺杂量≤5;时,随着镁离子掺杂量的增加,HA晶须的结晶度降低,晶胞参数a基本不变、c值有所降低;当镁离子的掺量增加至8;时,有少量Ca7Mg2P6O24杂质峰出现.镁离子掺杂HA在800 ℃下就能发生分解,生成HA/β-TCP双相磷酸钙.镁离子的掺杂量、煅烧温度和生物玻璃添加量都能促进HA的分解. 相似文献
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采用羟基磷灰石(HAP)和活性炭(AC)共混,经过活化烧结制得HAP/AC复合吸附剂.考察了HAP/AC质量比、聚乙烯醇(PVA)浓度、焙烧时间和焙烧温度等因素对吸附剂去除水中氟离子的影响.实验结果表明:HAP/AC质量比为4∶1、PVA浓度3wt;、焙烧温度350 ℃、焙烧时间3.5 h,吸附剂对氟离子的去除效率达到最大值为70.69;.将HAP/AC复合吸附剂用于对模拟含氟废水的吸附研究,通过静态吸附实验和动态柱吸附实验考察了吸附剂对模拟含氟废水的吸附性能,对其吸附机理进行了探讨.结果表明Langmuir等温吸附模型更优于Freundlich模型,且吸附剂对氟离子的吸附主要以表面单分子层吸附为主,吸附过程中具有离子交换能力的活性中心起主导作用.最后将HAP/AC复合吸附剂应用于地氟病区实际含氟废水的处理,以探讨其实际运用的可行性. 相似文献
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采用均相沉淀法,以生物碳酸钙作为钙源,EDTANa2为模板剂、尿素为沉淀剂,成功制备出高纯相、尺寸均匀、孔径可控的多孔羟基磷灰石(HAP)微球.研究了反应条件和添加剂浓度对样品形貌、尺寸和物相的影响.SEM分析结果显示:微球形貌和尺寸随反应温度、搅拌时间、沉淀时间、尿素和EDTANa2浓度的变化而变化.XRD分析结果显示:微球物相组成为单一羟基磷灰石相,[0001]、[10(1)0]、[10 (1)1]晶面族均有显露,添加剂浓度及反应条件对微球的物相没有影响.微球对Cu2+和F-均具有较高离子交换/吸附容量. 相似文献
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通过共沉淀法制备了氟和碳酸根复合掺杂纳米羟基磷灰石(CFHA)。研究了合成温度、掺杂离子浓度和pH值对CFHA形貌、替代类型和替代量的影响。用透射电镜观察合成粉体的形貌,用红外光谱和碳硫仪表征了碳酸根替代的类型和含量,用氟选择电极法测定了样品中的氟含量。结果表明:合成温度、碳酸根掺杂浓度和pH值对CFHA形貌有明显影响。随着合成温度的升高、碳酸根掺杂浓度和pH值的减小,晶粒尺寸和长径比增加;合成粉体中氟和碳酸根含量随掺杂离子浓度的增加而非线性增加,但实际替代量与理论计算值有较大偏差;高pH值有利于碳酸根和氟的替代。 相似文献
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采用共滴定法、溶胶-凝胶法、冷冻干燥法并以氨水为交联剂制备了纳米HAP/COL/KGM多孔复合骨支架,利用IR、XRD、SEM、TEM及EDS对所制备的粉体和骨支架进行分析表征,根据有关标准对骨支架进行了平均孔径、抗压强度、体外降解、干细胞相容性实验、动物皮下植入实验.结果表明,共滴定法所制备的粉体为10~ 100 nmHAP/COL复合纳米粉,最终获得的骨支架为三维多级连通孔网络结构;随着氨水量即交联度增加骨支架平均孔径和抗压强度增大并分别达到350 μm和3 MPa,随着氨水量增加支架降解率减小;骨支架有利于兔BMSCs黏附增殖生长,干细胞相容性良好;体内大量细胞能黏附在骨支架表面并迁移到支架内部中心且生长良好,支架有较好组织相容性和体内降解性. 相似文献
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制备工艺对羟基磷灰石包覆碳纳米管的影响 总被引:1,自引:1,他引:0
利用原位合成法获得羟基磷灰石包覆的碳纳米管复合粉体,对制备过程中可能影响羟基磷灰石包覆层效果的因素进行了探索.结果表明:羟基磷灰石可以在阴离子修饰后的多壁碳纳米管上形核结晶;在实验过程中,pH值影响最终产物的组成,而陈化温度和陈化时间对包覆层中羟基磷灰石晶粒的尺寸和厚度有明显影响. 相似文献
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The performed study involves measurements of a specific surface area via a BET method, of the pore volume, FT-IR, and a derivatographic study of a series of Al2O3-supported nickel-molybdenum catalysts modified with fluoride and chloride ions. It was found that fluoride ions lead to a decrease in the specific surface area of catalysts, whereas chloride ions have a small effect on this parameter. Modification does not change the type of pores of the catalysts, yet it affects their size and increases concentration of OH groups adsorbed on the surface of the catalysts relative to the carrier and the unmodified catalyst. Addition of fluoride ions decreases the thermal stability of the catalyst, whereas chloride ions does not cause any change. 相似文献
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在LiNbO3中掺进ZnO和In2O3以Czochralski技术生长Zn∶In∶LiNbO3晶体.采用光斑畸变法测试Zn∶In∶LiNbO3晶体抗光损伤能力.Zn∶In∶LiNbO3晶体抗光损伤能力比LiNbO3晶体提高二个数量级.测试晶体的红外光谱,Zn∶In∶LiNbO3晶体吸收峰的位置相对LiNbO3晶体发生紫移,且随着Zn2+和In3+浓度增加紫移程度增加.晶体的倍频性能(相位匹配温度和倍频转换效率)研究表明:Zn∶In∶LiNbO3晶体相位匹配温度在室温附近.并研究了Zn∶In∶LiNbO3晶体抗光损伤机理和OH-吸收峰紫移的机理. 相似文献
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Z. Sarbak 《Crystal Research and Technology》1997,32(4):491-497
The structural properties of alumina as well as its fluoride and sodium modifications were characterized by X-ray diffraction, infrared spectroscopy and differential thermal analysis. We have shown, that fluoride ions interact with hydroxyls type Ia of γ-Al2O3 forming Al–F species, which then react at 400 °C forming β-Al2O3. Morever, F/Al2O3 sample heated up to 400 °C contain two acidic hydroxyls type IIa and III, which are also represented on a differential thermal curve as endoeffect with minima at 470 and 500 °C. For Na/Al2O3 sample the same types of hydroxyls interact with Na+ ions leading to substitution of their protons. After heating at 400 °C this sample contains also hydroxyls type IIa and III, which are represented by two endothermal effects with minima at 450 and 520 °C. Differential thermal analysis shown to be a powerful and simple technique to characterize surface hydroxyl types of Na and F samples supported on γ-alumina. 相似文献
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Single crystals of Copper-doped Lithium sodium potassium sulphate were grown at room temperature. The optical absorption spectra were recorded at room and liquid-nitrogen temperatures. The observed absorption bands have been attributed to an ion of Cu2+ in tetragonal symmetry with 2B1 as the ground state. A successful interpretation of all the observed bands have been made by taking into consideration spin-orbit coupling associated with a tetragonal field. The crystal field parameters derived are Dq = 1045 cm−1, Ds = 1352 cm−1 and Dt = 457 cm−1. 相似文献
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Optical absorption and EPR spectra of Li2SO4 · H2O crystals doped with Cr3+ are studied at liquid nitrogen temperature. The bands are found in absorption spectra with maxima about 17000, 23 800 and 37 200 cm−1, assigned to the 4A2 → 4T2, 4A2 → 4T1 and 4A2 → 4T1 (4P) transitions, respectively. The crystal field theory parameters were determined and appeared to be as follows: Dq = 1700 cm−1, B = 667 cm−1, C = 3002 cm−1. The lines resulting from Cr3+ ions are found in EPR spectra. All lines are doublets, which is indicative of presence of two magnetically unequivalent centre positions, and have the hyperfine structure resulting from interaction of the unpaired electron spin with Cr53 isotope nucleus. Centres are oriented in such a way, that z-axes, corresponding to two centre positions, are situated at both sides of a-axis at an angle of about 3°. Spin Hamiltonian parameters were found as follows: gx = 1.985, gy = 1.984, gz = 1.988, D = 0.130 cm−1, E = 0.016 cm−1, |A| = 17.8 · 10−4 cm−1. 相似文献
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以硝酸钙、硝酸镁、磷酸氢二铵为原料,在94℃恒温条件下制备出了掺镁羟基磷灰石晶须.通过XRD、FT-IR、SEM和EDS对其进行表征,结果表明:镁可以掺入羟基磷灰石晶须中,所得晶须长径比高、均一性好. 相似文献
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