Al（OH）3胶体的制备及其对铀的吸附机理

为了研究在地浸采铀中胶体对矿层的阻塞及对铀酰离子吸附迁移影响,采用硝酸铝与氨水为原料制备Al（OH）₃,并用在pH = 6条件下制备所得的Al（OH）₃对铀进行吸附实验研究,考察了吸附的pH值、初始浓度及吸附时间等对Al（OH）₃吸附铀的影响。对实验数据使用准一级、复合二级与Elovich 动力学模型进行计算与分析,得出Elovich 动力学方程更适合描述Al（OH）₃对铀吸附,吸附主要是表面吸附;使用 Freundlich与Langmuir等温吸附方程对实验数据进行拟合,结果表明Langmuir模型更适合描述Al（OH）₃对铀酰离子的吸附;对吸附前、后的Al（OH）₃进行SEM与激光粒度分析。     

球型纳米颗粒Ca（OH）2的制备及其强化污泥电渗透干化研究

为了探究纳米Ca（OH）₂强化污泥电渗透干化的可行性,在常温条件下采用液相沉淀法制备Ca（OH）₂,并将制备得到的球型纳米颗粒Ca（OH）₂用于强化城市污泥的电渗透干化。结果表明,在分散剂的用量为8 mL、表面活性剂质量为0.2 g、搅拌时间为30 min、NaOH用量为60 mL、滴加速率为4.6～5 mL/min时,纳米Ca（OH）₂的纯度可达到94.02%。制得的纳米Ca（OH）₂为结晶度完整的球型和椭球型颗粒,并对污泥电渗透干化具有良好的强化作用,当通电电压为40 V、纳米Ca（OH）₂质量分数为20 mg/g DS时,电渗透干化污泥的含水率可降至57.69%。     

一种耐高温硅橡胶的制备及性能研究

通过采用80 000 MPa·s室温硫化甲基硅橡胶(107胶)为基胶，辅以碳酸钙补强、对气相白炭黑、偶联剂和耐热助剂等助剂，制备一种耐高温的硅橡胶。研究了不同种类耐热助剂及添加量、偶联剂、预处理的白炭黑的添加量对硅橡胶耐热性的影响，结果表明：α-Fe₂O₃、Al(OH)₃和ZnO³种耐热助剂，均可以不同程度提高硅橡胶的耐热性，其中Al (OH)₃的耐热性最好。通过不同添加量比较，发现Al(OH)₃添加量为4%、偶联剂为1.5%、白炭黑为15%时，制备的硅橡胶耐热性较好。     

阶段升温工艺对 SiO2改性 Al颜料包覆性能的影响

研究了正硅酸乙酯（TEOS）在片状铝颜料表面水解缩聚形成 SiO₂包覆膜制备 Al颜料的反应过程，重点探讨了两阶段升温变化对包覆性能的影响。 FE-SEM和刮板试验结果表明：第一阶段温度 50 ℃，第二阶段 80 ℃时，能在片状铝颜料表面形成一层均匀、致密且遮盖性高、光泽高的 SiO₂薄膜； EDS和粒径分布测试结果表明：与未包覆的铝颜料相比， SiO₂包覆的 Al颜料表面硅元素含量增加了 1. 48%，氧元素含量由 1. 81%增加到 4. 60%，SiO₂包覆的 Al颜料的 D50增大了约 15%，表明在铝颜料表面形成的 SiO₂包覆膜非常薄；在 pH为 9的弱碱性溶液中， 220 h后析出的 H₂体积仅为未包覆铝颜料的2. 2%，具有良好的耐弱碱性。     

Cu2(NO3)(OH)3催化过硫酸盐降解苯酚

基于过硫酸盐的高级氧化工艺在高浓度含酚废水处理中引起了越来越多的关注。我们研究了Cu₂（NO₃）（OH）₃和过硫酸盐对于废水中苯酚的降解效果和机理。结果表明,Cu₂（NO₃）（OH）₃-过硫酸盐体系在较广泛的pH条件下（pH值为5.0~10.0）对苯酚的降解效率均较高。溶液中的总有机碳（TOC）分析表明,在pH值为8.0,1 g·L^-1过硫酸盐和1 g·L^-1 Cu₂（NO₃）（OH）₃条件下,该体系可在4 h内将初始浓度为100 mg·L^-1的苯酚完全矿化而没有产生二次污染。猝灭剂实验和电子顺磁共振（EPR）分析进一步证实Cu₂（NO₃）（OH）₃-过硫酸盐体系中的主要氧化物种是O₂^·-、SO₄^·-和¹O₂。     

Ca(OH)2对污泥焚烧灰渣中Pb含量的影响

将添加有Ca(OH)₂的污泥在管式炉中焚烧，通过原子吸收分光光度计（AAS）测定灰渣中Pb的含量，分析Ca(OH)₂对灰渣中Pb含量的影响。结果表明：在污泥焚烧过程中，Pb的挥发率随焚烧温度呈先上升后下降再上升趋势，结合X射线衍射（XRD）分析发现，这主要是由于硅铝酸盐对Pb的固留作用和挥发动力学的相互影响。添加Ca(OH)₂后，污泥灰渣中Pb的含量有明显的降低，而且随着Ca(OH)₂添加量的增加，污泥灰渣中Pb的含量持续降低，表明Ca(OH)₂的添加，促进Pb的挥发，减少Pb在灰渣中的含量。将灰渣中Pb的形态分为浸出态和残渣态，通过分析X射线衍射（XRD）和灰渣中两种形态Pb的变化规律，得到Ca(OH)₂促进Pb挥发的机理主要是：添加的钙元素与硅铝酸盐反应，降低了硅铝酸盐与Pb反应的概率，从而使Pb转变为挥发形态的可能性增大，因此提高了挥发率。     

溶剂热浸渍法制备高稳定性Zn(OAc)2/SiO2催化剂及其催化合成苯氨基甲酸甲酯

Zn(OAc)₂对由碳酸二甲酯（DMC）和苯胺合成苯氨基甲酸甲酯（MPC）的反应具有优异的催化性能,但存在易失活、不能重复使用的缺点。为此,以DMC为溶剂,利用溶剂热浸渍法制备Zn(OAc)₂/SiO₂催化剂,并对其催化性能进行了研究。利用XRD、FTIR和TG-DTA等方法对其进行了表征,结果表明,Zn(OAc)₂/SiO₂催化剂表面存在Zn(OAc)₂和ZnO,且其在SiO₂表面分散较好;优化了Zn(OAc)₂/SiO₂催化剂的反应条件,当反应温度为190℃、反应时间为5h、苯胺与DMC的摩尔比为1∶20、催化剂与苯胺质量比为0.2时,苯胺的转化率为97.2%,MPC的选择性为89.4%。和等体积浸渍法制备的催化剂相比,溶剂热浸渍法制备的Zn(OAc)₂/SiO₂催化剂具有较好的稳定性,重复使用7次,苯胺的转化率下降至79.1%,MPC的选择性下降至79.2%。Zn(OAc)₂/SiO₂活性下降的原因是由于ZnO的生成,并对其进行了再生,再生后的催化剂活性与新鲜催化剂接近。     

碳酸钠浓度对废电池铅膏脱硫影响机制与动力学

以铅膏为研究对象，采用碳酸钠为脱硫剂，系统研究了碳酸钠浓度对铅膏脱硫率及铅收得率的影响，并借助化学分析、扫描电镜分析仪（SEM-EDS）、X射线衍射分析仪（XRD）揭示了铅膏脱硫反应机理，计算了动力学参数。结果表明，铅膏脱硫率随碳酸钠浓度的增加而增大，而铅收得率变化规律相反。铅膏主要由硫酸铅及铅的氧化物组成。在碳酸钠浓度小于0.150 mol/L时，脱硫产物中主要以PbCO₃和Pb₃（CO₃）₂（OH）₂形式存在；随着浓度的增加，PbCO₃不断向Pb₃（CO₃）₂（OH）₂转化，并最终转化为NaPb₂（CO₃）₂（OH）₂，导致铅收得率降低。铅膏脱硫过程活化能随浓度的增大而减小，受化学反应控制。浓度低于0.208 mol/L时，活化能降低幅度较大，由7.275 kJ/mol降至5.312 kJ/mol，之后活化能随浓度的增加变化程度较小。     

钙钛矿中空结构CoSn（OH）6纳米粉体的制备与表征

钙钛矿结构材料在发光、催化等多种功能材料领域都占有重要地位,是当前材料科学领域的研究热点。以四氯化锡（SnCl₄）、无水乙醇（C₂H₆O）、二氯化钴（CoCl₂）、柠檬酸钠（Na₃C₆H₅O₇）为原料,通过溶剂辅助法制备了中空结构六羟基锡酸钴[CoSn（OH）₆]纳米粉体。通过X射线衍射仪（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、X射线光电子能谱（XPS）分别对产物六羟基锡酸钴粉体的物相结构及表观形貌进行了表征,线性扫描伏安法（LSV）对电极材料进行电催化性能测试。结果表明：采用溶剂辅助合成,可以成功制得物相纯净、粒度为150 nm的中空纳米立方结构的钙钛矿六羟基锡酸钴粉体,其电流密度为35.1 mA/cm²、塔菲尔斜率为72.5 mV/dec,有望用于电化学析氢反应。     

蛋白土与硫酸铵煅烧反应产物及过程动力学

蛋白土具有良好的应用前景,但是其自然白度较低制约了其开发应用。蛋白土硫酸铵煅烧法可去除其中的显色金属氧化物,提高蛋白土的白度,同时提取其中Al₂O₃。本文采用热重-差示扫描量热（TG-DSC）、同步热分析与红外质谱（TG-FTIR-MS）联用系统,结合X射线衍射对煅烧过程的固相及气相产物进行了表征分析,明析了其化学过程。结果表明,蛋白土中的Al₂O₃和Fe₂O₃在200~350℃时反应生成（NH₄）₃（Al,Fe）（SO₄）₃,同时逸出NH₃和H₂O;350~450℃时,进一步反应转化为NH₄（Al,Fe）（SO₄）₂,同时逸出NH₃、H₂O、SO₂和O₂;450~550℃时,NH₄（Al,Fe）（SO₄）₂分解生成（Al,Fe）₂（SO₄）₃,同时逸出NH₃、H₂O、SO₂和O₂;550~750℃时（Al,Fe）₂（SO₄）₃分解生成Al₂O₃和Fe₂O₃,同时逸出SO₂和O₂。采用Kissinger微分法与Ozawa积分法分别计算出4个阶段表观活化能后取二者平均值,分别为101.74kJ/mol、104.52kJ/mol、201.40kJ/mol、232.51kJ/mol,并获得对应4个热化学反应阶段的频率因子、反应级数和动力学方程。     

SDS/MAP复配表面活性剂改性纳米氢氧化镁作用机理研究

十二烷基硫酸钠（SDS）/磷酸酯（MAP）复配表面活性剂作为改性剂,对纳米氢氧化镁进行改性研究。通过X射线衍射（XRD）、透射电镜（TEM）、红外光谱分析（FT-IR）、BET法比表面积测定和在液体石蜡中的悬浮液体积测定等手段,研究了SDS与MAP以1︰1的质量比复配时其添加量对改性纳米氢氧化镁性能的影响,并初步探讨了改性机理。结果表明：随着SDS/MAP添加量的增加,样品表面的疏水性能呈现先增加后减小的趋势,其用量为样品质量的0.2%时达到最大值;粒径呈现先减小后增大又减小的变化规律,其用量分别在0.2%和0.5%时出现拐点;比表面积的变化规律与粒径一致。说明在水相中随着SDS/MAP添加量的不同,其可能分别以双分子层和单分子层吸附于氢氧化镁颗粒表面。     

Synthesis and H2 uptake of Cu2(OH)3Cl, Cu(OH)2 and CuO nanocrystal aggregate

Monodispersed Cu₂(OH)₃Cl nanoplatelets, Cu(OH)₂ nanowires, CuO nanoparticles and nanoribbons with a spherical morphology were synthesized using hydrothermal and heat-treatment reactions, and their H₂ storage characteristics were examined. The Cu₂(OH)₃Cl nanoplatelets particles formed immediately after mixing the reactant, which subsequently formed larger uniform spherical particles in the submicron range. This procedure highlights a practical strategy for producing spherical Cu(OH)₂ and CuO materials consisting of monodispersed nanocrystals. The spherical aggregates of Cu₂(OH)₃Cl nanoplatelets heat-treated at 473 K could reversibly store up to 2.35 wt.% H₂ at 38 bar and 293 K.     

Preparation and characterization of a PMMA/Ce(OH)3, Pr2O3/graphite nanosheet composite

An easy process for the synthesis of poly(methyl methacrylate)/Ce(OH)₃, Pr₂O₃/graphite nanosheet (PMMA/Ce(OH)₃, Pr₂O₃/NanoG) composite was developed. Graphite nanosheets (NanoG) were prepared by treating the expanded graphite with sonication in aqueous alcohol solution. The PMMA/Ce(OH)₃, Pr₂O₃/NanoG composites were prepared via in situ polymerization of MMA monomer in the presence of graphite nanosheets and Ce(OH)₃, Pr₂O₃ through reverse micelle template, in which the methyl methacrylate was designated as the oily phase. The composites were then dispersed with chloroform and coated on glass slides to form films. Scanning and transmission electron microscopy were used to characterize the structure and dispersion of the graphite nanosheets and the composites. The results showed that the high-aspect-ratio structure of the nanosheets played an important role in forming a conducting network in the PMMA matrix. From thermogravimetric analysis, the introduction of graphite nanosheets and inorganic nanopartices exhibited a beneficial effect on the thermal stability of PMMA.     

Study of interactions at water-soluble polymer/Ca(OH)2 or gibbsite interfaces by XPS

In an attempt to better understand interactions occuring at hydrated cement/organic polymer interfaces, the reaction mechanism and products formed at the interfaces between poly(acrylic acid), p(AA) or poly(acrylamide), p(AM), and Ca(OH)₂ or gibbsite, Al₂O₃·3H₂O, were explored using x-ray photoelectron spectroscopy (XPS). It was estimated that at p(AA)/Ca(OH)₂ interfaces, a Ca-complexed carboxylate interfacial reaction product was formed by an ionic reaction between the COOH in p(AA) and Ca²⁺ ions from Ca(OH)₂. A similar reaction product was formed at p(AM)/Ca(OH)₂ interfaces as a result of an inter-facial transformation of amide in p(AM) into carboxylic acid, caused by the alkali-catalyzed hydrolysis of the amide. The proton-accepting hydroxyl groups existing at the outermost surface sites of Al₂O₂·3H₂O react favorably with proton-donating COOH groups in p(AA). This acidbase interaction at the p(AA)/Al₂O₃·3H₂O joint formed hydrogen bonds. Whereas, when the p(AM) was applied on Al₂O₃·3H₂O surfaces, interfacial electrostatic bonds were formed through charge-transferring reaction mechanisms in which the charge density was transferred from the Al in Al₂O₃·3H₂O to the C=0 oxygen in p(AM).     

Photocatalytic degradation of aqueous organocholorine pesticide on the layered double hydroxide pillared by Paratungstate A ion, Mg12Al6(OH)36(W7O24)·4H2O

Layered double hydroxide pillared by Paratungstate A ion, Mg₁₂Al₆(OH)₃₆(W₇O₂₄)·4H₂O, was prepared via anion exchange reaction of the synthetic precursor, Mg₄Al₂(OH)₁₂TA·xH₂O (TA²⁻=terephthalate), and [W₇O₂₄]⁶⁻ ion. Some physico-chemical properties were measured and the preparation conditions were studied. Trace aqueous organocholorine pesticide, hexachlorocyclohexane (HCH), was totally degraded and mineralized into CO₂ and HCl by irradiating a Mg₁₂Al₆(OH)₃₆(W₇O₂₄)·4H₂O suspension in the near UV area. Disappearance of trace HCH follows Langmuir–Hinshelwood first-order kinetics. The model and mechanism for the photocatalytic degradation of HCH on the Mg₁₂Al₆(OH)₃₆(W₇O₂₄)·4H₂O were proposed, indicating that the interlayer space is the reaction field, and that photogeneration of OH√ radicals are responsible for the degradation pathway.     

工业氢氧化钙中氧化钙、氢氧化钙及碳酸钙测定方法的研究

目前,多数分析方法难以计算工业氢氧化钙中氧化钙、氢氧化钙和碳酸钙的含量。将蔗糖滴定法和热重分析相结合,对工业氢氧化钙中的氧化钙、氢氧化钙和碳酸钙做了分析。采用GB/T 5762—2012《建材用石灰石、生石灰和熟石灰化学分析方法》测定氢氧化钙中有效钙的含量。根据氢氧化钙和碳酸钙分解温度的差异,使用热重分析测定工业氢氧化钙中氢氧化钙和碳酸钙的含量。之后,将有效钙中的氢氧化钙部分扣除并换算,得到氧化钙的含量。实验得到氧化钙、氢氧化钙和碳酸钙这3种物质的含量,其余部分为杂质。该方法具有操作相对简单、测定成分种类较多的优点。     

Hydrothermal transformation of the calcium aluminum oxide hydrates CaAl2O4·10H2O and Ca2Al2O5·8H2O to Ca3Al2(OH)12 investigated by in situ synchrotron X-ray powder diffraction

The hydrothermal transformation of calcium aluminate hydrates were investigated by in situ synchrotron X-ray powder diffraction in the temperature range 25 to 170 °C. This technique allowed the study of the detailed reaction mechanism and identification of intermediate phases. The material CaAl₂O₄·10H₂O converted to Ca₃Al₂(OH)₁₂ and amorphous aluminum hydroxide. Ca₂Al₂O₅·8H₂O transformed via the intermediate phase Ca₄Al₂O₇·13H₂O to Ca₃Al₂(OH)₁₂ and gibbsite, Al(OH)₃. The phase Ca₄Al₂O₇·19H₂O reacted via the same intermediate phase to Ca₃Al₂(OH)₁₂ and mainly amorphous aluminum hydroxide. The powder pattern of the intermediate phase is reported.     

Ni(OH)2修饰对a-Fe2O3薄膜光电化学性能的增强效应

利用一种简便的电沉积方法制备氧化铁薄膜,并在过程中引入Ni(OH)₂进行修饰,对具体电沉积实验参数进行优化,从而建立最佳制备条件。利用场发射扫描电子显微镜、X射线粉末衍射对Fe₂O₃/Ni(OH)₂光电极膜的结构进行表征。利用循环伏安和计时电流测量析氧过电位和光电流密度。结果表明,Ni(OH)₂修饰的α-Fe₂O₃薄膜可提高光生电子与空穴的分离效率,从而显著提高光电催化活性。     

Novel hierarchical yolk-shell α-Ni(OH)2/Mn2O3 microspheres as high specific capacitance electrode materials for supercapacitors

For high performance supercapacitors, novel hierarchical yolk-shell a-Ni(OH)₂/Mn₂O₃ microspheres were controllably synthesized using a facile two-step method based on the solvothermal treatment. The unique a-Ni(OH)₂ based yolk-shell microstructures decorated with numerous interconnected nanosheets and the hetero-composition features can synergistically enhance reactive site exposure and electron conduction within the microspheres, facilitate charge transfer between electrolyte and electrode materials, and release structural stress during OH⁻ chemisorption/desorption. Moreover, the Mn₂O₃ sediments distributed over the a-Ni(OH)₂ microspheres can serve as an effective protective layer for electrochemical reactions. Consequently, when tested in 1 mol·L⁻¹ KOH aqueous electrolyte for supercapacitors, the yolk-shell a-Ni(OH)₂/Mn₂O₃ microspheres exhibited a considerably high specific capacitance of 2228.6 F·g⁻¹ at 1 A·g⁻¹ and an impressive capacitance retention of 77.7% after 3000 cycles at 10 A·g⁻¹. The proposed a-Ni(OH)₂/Mn₂O₃ microspheres with hetero-composition and unique hierarchical yolk-shell microstructures are highly promising to be used as electrode materials in supercapacitors and other energy storage devices.     

The effect of Al(OH)3 coating on the Li[Li0.2Ni0.2Mn0.6]O2 cathode material for lithium secondary battery

Layered Li[Li_0.2Ni_0.2Mn_0.6]O₂ powder was modified by coating its surface with amorphous Al(OH)₃. Energy dispersive spectroscopy (EDS) showed that nano-sized Al(OH)₃ powders were homogeneously dispersed in the parent Li[Li_0.2Ni_0.2Mn_0.6]O₂ powders. Al(OH)₃ coated Li[Li_0.2Ni_0.2Mn_0.6]O₂ exhibited an greater retention capacity at higher rates compared to uncoated Li[Li_0.2Ni_0.2Mn_0.6]O₂. The low area specific impedance (ASI) value of the Al(OH)₃ is the major factor for its higher rate performance. The 1.4 wt.% Al(OH)₃ coated sample had an impedance of 41 Ω cm² while uncoated Li[Li_0.2Ni_0.2Mn_0.6]O₂ had a 57 Ω cm² at 30-80% state of charge. Electrochemical impedance spectroscopy (EIS) also showed that the Al(OH)₃ coated sample had a lower charge transfer resistance (R_ct) than the uncoated sample. Differential scanning calorimetry (DSC) analysis showed that Al(OH)₃ coating improved the thermal stability. Al(OH)₃ coating increased the onset temperature of thermal decomposition and reduced the amount of heat for the exothermic peak.