模拟土壤介质中仿古铸铁腐蚀产物的形貌及其生长过程

采用金相、显微激光拉曼和X射线衍射等技术研究了仿古铸铁在模拟土壤介质(0.06 mol•L^-1 NaCl+0.03 mol•L^-1 Na₂SO₄+0.01 mol•L^-1 NaHCO₃溶液)中的腐蚀形态、腐蚀产物的形貌及其生长和发展过程.结果表明,在最初的34 h内,铸铁发生铁的选择性腐蚀,在试样表面留下许多白色圈状的Fe(OH)₂沉淀,圈内则是分散状的Fe(OH)₂;浸泡120 h时,观察到试样表面有一层深绿色的腐蚀产物,其组分主要为GR(Cl^-)（化学式为Fe^Ⅱ₃Fe^Ⅲ（OH）₈Cl•2H₂O）和GR(SO^2-₄)（化学式为Fe^Ⅱ₄Fe^Ⅲ₂（OH）₁₂SO₄•2H₂O）,绿锈表面呈黄色;约288 h后,腐蚀产物呈现分层,内层主要由黑色结晶状的FeO和Fe₃O₄组成,外层主要为疏松多孔的砖红色γ-FeOOH,后者是铁器表面的一种有害锈.     

手性磷酸锌钠的低热固相合成及调控

对合成多孔功能材料手性磷酸锌钠的新方法进行了研究,以聚乙二醇-400 （PEG-400）为表面活性剂,Na₃PO₄·12H₂O和无机锌盐为原料,用低热固相反应一步法成功合成得到P6₁22空间群的手性NaZnPO₄·H₂O。实验考察了不同的锌盐、磷酸盐,以及不同pH值对产物的影响。结果表明, pH值起着重要的作用,其调控着产物的结构;锌盐的种类不影响产物的结构;磷酸盐的种类则通过pH值的调控作用对产物产生影响。当pH在11、7～9、5、3左右时,得到的产物分别为(1) P6₁22空间群的手性NaZnPO₄·H₂O与非手性的NaZnPO₄(OH)的混合物;(2)P6₁22空间群的手性的 NaZnPO₄·H₂O;(3)非手性的NaH(ZnPO₄)₂;(4)非手性的Zn₃(PO₄)₂·4H₂O。以PEG-400为表面活性剂,Na₃PO₄·12H₂O及无机锌盐为原料,在P/Zn=1.18（摩尔比）,pH=7～9,反应混合物于50℃陈化6 h的条件下,合成产物为手性NaZnPO₄·H₂O。     

Fenton处理对氯酚过程中间产物对Fe3+的还原作用

为探明Fenton处理对氯酚（4-CP）过程中Fe²⁺再生的途径,考察了反应过程Fe²⁺的浓度变化,同时对4-CP降解中间产物和Fe³⁺之间的氧化还原反应进行了研究.Fenton氧化对氯酚过程中Fe²⁺的浓度基本不变;而在•OH捕获剂丙醇的存在下,反应开始后1 min Fe²⁺的浓度急剧下降到10％.研究结果表明：H₂O₂、•OH、HO₂•与O^-₂•等自由基对Fe²⁺的再生净贡献较小,4-CP降解的中间产物对Fe³⁺的还原是Fe²⁺再生的主要途径.Fenton处理4-CP产生的中间产物有对苯二酚和对苯醌.对苯二酚能够快速还原Fe³⁺,使Fe²⁺得到再生;而对苯醌还原Fe³⁺的作用很微弱.这一研究有助于更好地了解Fenton氧化过程中Fe²⁺的再生.     

盐湖粗光卤石中晶体的分布

研究了察尔汗盐湖粗光卤石中各种无机盐晶体的存在形式及形态.通过筛分法将粗光卤石矿分级,运用化学法分析各粒级颗粒的组成.结果表明：90％以上的KCl•MgCl₂•6H₂O以大于0.177 mm粒径的大颗粒存在,75％以上的NaCl以小于0.125 mm粒径的细粒矿存在于体系中,约90%以上的CaSO₄以粒径小于0.074 mm的微细颗粒存在.运用X射线衍射法分析了不同粒径的光卤石矿表面的化学组成,运用光电子能谱法分析了其表面Na/Ca的摩尔比,用扫描电镜及能谱分析直接分析了各种晶体存在的形态.研究结果表明,大部分NaCl和CaSO₄分别以小颗粒游离于粗光卤石矿中,未被大颗粒晶体所包裹.     

Synthesis of tributyl citrate catalyzed by Ce(SO4)2·4H2O/ NH2SO3H

研究了柠檬酸与正丁醇在Ce(SO₄)₂·4H₂O/ NH₂SO₃H复配催化剂催化作用下制备柠檬酸三丁酯的工艺条件。实验结果表明Ce(SO₄)₂·4H₂O/ NH₂SO₃H催化合成柠檬酸三丁酯的最佳反应条件为：醇酸摩尔比为4.0∶1,催化剂用量为1.5%（以柠檬酸质量计）,m[Ce(SO₄)₂·4H₂O]∶m(NH₂SO₃H)=2∶1,反应温度为150 ℃,反应时间为7 h,酯化率＞98.5%,精制后产品纯度>99.5%。     

H2O2沉淀铝酸钠溶液法制备大孔容纳米γ-Al2O3纤维粒子

采用H₂O₂沉淀铝酸钠溶液和乙醇分散并洗涤沉淀相结合的方式成功地制备出了大孔容纳米γ-Al₂O₃纤维.运用XRD、FT-IR、TG-DSC、TEM、BET和压汞法对比研究了水洗和乙醇分散并洗涤两种沉淀处理方式对产物结构、形貌和织构性质的影响.结果表明,乙醇洗涤产物γ-Al₂O₃纤维的直径约为10 nm,长度约在100 nm以上,孔容和比表面分别为2.23 ml•g^-1和222.0 m²•g^-1,而水洗γ-Al₂O₃的二次粒子无固定形状,孔容和比表面仅为0.37 ml•g^-1和162.3 m²•g^-1.乙醇洗涤时形成的CH₃CH₂O—基不仅使γ-Al₂O₃前驱物拟薄水铝石晶粒定向生长成纤维,还阻止了相邻颗粒表面之间因Al—O—Al键形成而产生的硬团聚.     

纳米ZrO2/SnO2催化剂的制备与表征

以ZrOCl₂·8H₂O和SnCl₄·5H₂O为原料，通过溶胶-凝胶法和正丁醇共沸蒸馏处理方法，合成具有纳米尺寸的ZrO₂/SnO₂复合催化剂。通过差示扫描量热仪、X射线衍射及场发射扫描电镜的测定，结果表明，合成得到的复合催化剂晶粒为10～20 nm，具有四面体相和三斜相两相。     

酸性离子液体中苯甲醇催化氧化合成苯甲醛

在没有任何有机溶剂和卤素的条件下，以30%H₂O₂为氧化剂，Na₂WO₄·2H₂O为催化剂，在酸性离子液体[(CH₂)₄SO₃HMIm]TSO中，研究了苯甲醇选择性氧化合成苯甲醛。在n(苯甲醇)∶n（H₂O₂）∶n(离子液体)∶n(Na₂WO₄·2H₂O)=40∶48∶1∶1、90 ℃和3 h条件下，催化效果最好，此时苯甲醇转化率为90.1%，苯甲醛选择性为92.1%。反应结束后，产物和离子液体分层，通过简单的倾倒即可分离产物。分离后的离子液体经真空干燥脱水后重复使用4次，催化活性基本不变。     

杉木粉/ZrO2网络互穿杂化材料的制备、形态、结构与性能

用20%NaOH溶液处理一定尺寸的杉木粉,以ZrOCl₂•8H₂O为无机前驱体,采用水热法将无机物组装在处理后的杉木粉的网络微孔结构中,制备了ZrO₂/杉木粉杂化材料。将杂化材料在空气中经过热处理得到多孔ZrO₂陶瓷。用FESEM、FTIR、XRD和TGA研究了杉木粉和杂化材料的形态、化学与结晶结构和热稳定性。结果表明：处理后的杉木粉显现出清晰的管胞与纹孔的网络微孔结构,纤维素中的部分氢键被破坏,结晶度下降,反应活性得以提高;在水热条件下,无机前驱体渗透到了杉木粉的微孔结构中,氧氯化锆水解后的羟基与杉木粉中的羟基发生了缩合反应,最终形成了无机/有机垂直互穿网络结构。杂化材料的热稳定性优于杉木粉,热分解温度从282℃提高到298℃。多孔ZrO₂陶瓷材料具有笼状结构,孔径约在10～20 μm之间。     

疏水性可见光响应型纳米CuO/TiO2催化降解高浓度硝基苯

采用十二烷基硫酸钠（SDS）对纳米CuO/TiO₂光催化剂进行疏水改性,并在可见光的照射下,研究了疏水性CuO/TiO₂对硝基苯降解的影响因素。实验表明：SDS-CuO/TiO₂催化剂具备完整的锐钛矿和CuO晶体衍射峰;SDS负载量变化对催化剂的紫外可见吸收性能没有影响;催化剂表面的疏水位主要是长链烷基。各影响因素的最佳水平分别是：SDS负载量2.3 g•（2.5 g TiO₂）^-1,初始浓度400～500 mg•L^-1,催化剂用量0.2 g•L^-1,pH 9,H₂O₂添加量6 ml•L^-1。最佳条件下硝基苯2 h降解率为80％,4 h降解率为93％。     

低热固相合成磷酸铵铜微肥及信噪比控制合成

对合成缓溶磷酸铵铜多元微肥的新方法进行了研究，以聚乙二醇-400 （PEG-400）为模板，CuSO4•5H2O和(NH4)3PO4•3H2O为原料，用低热固相反应一步法成功合成得到磷酸铵铜。用产物XRD图谱数据计算得到的信噪比作为试验的考察指标，试验中应用了均匀设计试验法及数据挖掘技术，在数据挖掘成果的指导下进行了试验。试验结果表明，用最优工艺条件合成得到的产物为51nm的NH4CuPO4 ∙H2O。该合成方法除了得到微溶的磷酸铵铜外，还得可溶的硫酸铵或者硫酸氢铵，这些产物均是肥料，故在实际应用中，用本文的合成法合成磷酸铵铜微肥时，无需分离，其产物混合物就可以作为肥料作用了，不仅合成的工艺甚为简洁，而且生产过程没有废水的产生，无论是从工艺上，还是环保上均比液相法具有优势，是一种颇具工业应用前景的合成法。     

Sol-Gel Synthesis,Thermal Behavior of Nanopowders and Chemical Stability of La<Subscript>1 – <Emphasis Type="Italic">x</Emphasis></Subscript>Ho<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>PO<Subscript>4</Subscript> Ceramic Matrices

Nanosized powders of orthophosphates in the LaPO₄–HoPO₄–H₂O system have been synthesized to determine the mutual solubility of LaPO₄ · nH₂O and HoPO₄ · nH₂O initial components and to obtain ceramic matrices by sintering them. Formation of hexagonal, monoclinic or tetragonal solid solutions was revealed, and their limits and thermal stability were determined. A series of limited hexagonal LaPO₄ · nH₂O-based solid solutions was observed within the 0 ≤ x ≤ 0.6 concentration range up to 600°C. Further they transformed to monoclinic LaPO₄-based form within the 0 ≤ x ≤ 0.3 concentration range. Solubility of LaPO₄ · nH₂O and LaPO₄ in tetragonal HoPO₄(· nH₂O) is lower (≤10 mol %). Specific surface area of La_1–xHo_xPO₄ · nH₂O powders was in the range of 90.5–165.0 m²/g depending on x. Leaching rate of La³⁺ and Ho³⁺ from La_1–xHo_xPO₄ matrices in nitric acid solution (pH 1–2) was determined to be 10^–5–10^–2 g/(cm² day) for both ions.     

用尿素作沉淀剂制备不同CeO2前驱体

引言 稀土元素由于其本身特有的f电子构型而具有独特的光、电、磁等性质.二氧化铈是一种重要的稀土材料,在玻璃、陶瓷、磨料、催化剂等方面都有着广泛的应用,因此,其合成及应用具有巨大的开发前景.     

以粉煤灰为原料制备高纯氧化铝

引言 粉煤灰是电厂排放的废弃物,到2000年我国排放量已达12000万吨[1],给环境造成了巨大的污染,因此开展粉煤灰的综合利用具有长远的战略意义.     

Physicochemical Properties of Nanosized Powders of the LaPO<Subscript>4</Subscript>–DyPO<Subscript>4</Subscript>–H<Subscript>2</Subscript>O System

Nanosized La_1–xDy_xPO₄ · nH₂O powders are synthesized by the sol-gel method using direct and reverse precipitation. The formation of a continuous series of hexagonal solid solutions based on LaPO₄ · nH₂O is confirmed by the XRD and DSC/TG methods. A continuous series of monoclinic solid solutions based on LaPO4 is formed at temperatures higher than 600°C. A reflex corresponding to a tetragonal form of DyPO₄ is formed during the calcination of DyPO₄ powder at 850°C. Two types of solid solutions are observed at temperatures of 1000–1200°C, namely, monoclinic solutions based on LaPO₄ (to x ≈ 0.7) and tetragonal solutions based on DyPO₄ (0.90 ≤ x ≤ 1.0). The results are compared depending on the methods of nanopowder synthesis.     

等离子体法控制硝酸铜晶体形貌

介质阻挡放电(DBD)等离子体是一种典型的低温非平衡气体放电现象。本实验主要研究DBD等离子体对硝酸铜水溶液结晶的影响，发现DBD等离子体能有效引发硝酸铜水溶液的初始成核过程从而大大减少成核时间。在无等离子体作用下，室温下稳定的硝酸铜过饱和溶液析出硝酸铜晶体需2-3天，在等离子体作用下几分钟即可析出硝酸铜晶体。同时，通过控制DBD等离子体的施加时间，硝酸铜晶体的形貌也可以得到控制，呈现出四边形、六棱柱及六角星型等各种形貌。     

CMAS corrosion behavior of a LaPO4 ceramic prepared by spark plasma sintering

At high temperatures in gas turbines, traditional yttria stabilized zirconia materials fail prematurely owing to CMAS (calcium–magnesium–alumina–silicate) corrosion. Thus, new materials need to be developed urgently. In this study, LaPO₄ powder was synthesized by chemical coprecipitation and heat treatment using lanthanum nitrate (La(NO₃)₃∙6H₂O) and ammonium dihydrogen phosphate (NH₄H₂PO₄) as starting materials, and LaPO₄ bulk was prepared by spark plasma sintering. The surface of the LaPO₄ bulk was coated with CMAS (CaO–MgO–Al₂O₃–SiO₂) powder, and the CMAS interaction with the LaPO₄ bulk at different temperatures was investigated. The phase and microstructure of the LaPO₄ powder and bulk, as well as the CMAS corrosion products, were characterized using X-ray diffraction and scanning electron microscope. The superior CMAS resistance of the LaPO₄ bulk was attributed to the low wettability of LaPO₄ by the CMAS melt and the development of dense layers of new corrosion products, which effectively protected the LaPO₄ bulk from CMAS infiltration.     

Highly efficient synthesis of titanium phosphate precursor for electroactive materials

In recent years titanium phosphates (TiPs) have aroused considerable interest as multi-functional materials. Known methods of TiPs synthesis are rather complicated because they are based on wet chemistry in terms of which one-step synthesis of pure TiP fails. It is highly welcomed to develop a new approach to TiP production. In this work the novel minimalistic approach to the synthesis of two titanium phosphates of different composition from a solid TiOSO₄·H₂O precursor has been proposed. Despite the fact that the TiOSO₄ solutions are widely used for the synthesis of titanium phosphates, the solid compound as a titanium source has never been used before. The new mechanochemistry-based synthesis provides easy access to obtaining TiO(OH)(H₂PO₄)·H₂O and Ti(HPO₄)₂·H₂O (α-TiP) for 3 h and 5 h, respectively. The substitution of protons in α-TiP with Li⁺ and Al³⁺ by ion-exchange reactions provide the formation of Li_1.5Al_0.5Ti_1.5(PO₄)₃ which is electroactive material. The proposed synthesis procedure is more technologically attractive compared with traditional methods, and enables direct production of highly dispersed monophasic powder (100–300 nm) of desired composition at 823 K. The material obtained demonstrates high conductivity value of 7.8·10^?4 S cm^?1 at 298 K, low activation energy of 0.27 eV, and can be used as a solid electrolyte for practical application in all-solid-state lithium batteries.     

288 K下Li+,K+//CO2-3,B4O2-7-H2O四元体系的相平衡

Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li⁺,K⁺//CO^2-₃,B₄O^2-₇-H₂O at 288 K were experimentally studied with the isothermal equilibrium method. The phase diagram of the system consisted of two invariant points E and F, five univariant curves, and four crystallization fields that belonged to K₂CO₃·3/2H₂O,Li₂B₄O₇·3H₂O,K₂B₄O₇·4H₂O and Li₂CO₃. The composition of the solution corresponding to E was w（CO^2-₃）=2.27 %,w（B₄O^2-₇）=6.05 %,w（K⁺ ）=4.30%,w(Li⁺)=0.30 % and the equilibrium solids were Li₂B₄O₇· 3H₂O+K ₂B₄O₇·4H₂O+Li₂CO₃;The composition of the solution for F was w(CO^2-₃)=22.45%,w(B₄O^2-₇)=1.88%,w(K⁺ )=29.96%,w(Li⁺ )=0.03% and the equilibrium solids were K₂CO₃·3/2H₂O+K ₂B₄O₇·4H₂O+Li₂CO₃. K₂CO₃ possesses strong salting-out effect on K₂B₄O₇,Li₂CO₃ and Li₂B₄O₇.