纳米二氧化钛光催化薄膜的研究进展

纳米二氧化钛薄膜由于具有优良的光催化性而受到人们的重视,简要介绍了近年来纳米二氧化钛光催化薄膜的研究进展,综述了其制备方法及改性方法.     

纳米级材料检测与表征的研究之三--纳米二氧化钛与钛白粉

1纳米二氧化钛(钛白粉)制备 制备纳米二氧化钛(钛白粉)的方法有许多种,主要有硫酸法、氯化法、溶胶-凝胶法等. (1)硫酸法     

聚丙烯/改性纳米二氧化钛复合材料的制备与性能

采用自制超分散剂对金红石型纳米二氧化钛进行表面处理,然后采用熔融共混的方法与聚丙烯(PP)进行共混制备纳米复合材料,研究了超分散剂用量及纳米二氧化钛用量对复合材料性能的影响。结果表明,超分散剂处理纳米二氧化钛的最佳用量为2%(质量分数);纳米二氧化钛填充PP的最佳用量为1.5%(质量分数);超分散剂对纳米二氧化钛具有明显的均匀分散效果;并且显著降低了复合材料的熔融黏度,改善加工性能;超分散剂处理的纳米二氧化钛填充PP具有明显的增强增韧作用。     

二氧化钛纳米材料的制备与形貌控制

以草酸钛钾和双氧水为反应物,高纯水为溶剂,在不使用任何表面活性剂的条件下,采用一种简单的水热法制备了形貌可控的二氧化钛纳米材料.利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)对所得产物的晶体结构和形貌进行了表征.测试结果表明所得产物为金红石相二氧化钛纳米带状花,通过改变混合溶液的搅拌时间和水热反应时间,可以实现对反应体系中气泡模板和产物形貌的调控,进而制得二氧化钛纳米棒状花.这种制备二氧化钛纳米带状花和二氧化钛纳米棒状花的简单方法,将为二氧化钛纳米材料的形貌和性能调控提供依据.     

纳米二氧化钛水性分散体性能研究

通过特殊工艺方法制备出了分散性好,粘度低,贮存稳定的纳米二氧化钛水性浓缩浆.透射电镜(TEM)观察到浓缩浆中纳米二氧化钛基本上是以单个粒子形式存在.XRD结果表明了浓缩浆中的二氧化钛仍然保持原来的晶型,没有引入其它杂质.红外图谱证明了分散剂在纳米二氧化钛表面形成了牢固的化学吸附,以此产生电斥力和空间位阻效应,使纳米二氧化钛在分散体系中处于稳定的悬浮状态.     

纳米二氧化钛薄膜的制备方法及表征技术

介绍了纳米二氧化钛薄膜的制备方法及光电子能谱技术、光谱技术、显微分析技术、X射线分析技术等表征技术的原理以及在纳米二氧化钛薄膜研究中的进展.     

晶粒尺寸可控的纳米二氧化钛的制备

采用微乳法和溶胶-凝胶法相结合的方法制备纳米二氧化钛,通过改变制备参数可以将纳米二氧化钛的晶粒尺寸控制在6~30 nm之间。采用X射线衍射、透射电镜等表征手段,对不同的制备条件与晶粒尺寸的关系进行研究。通过在可见光下对亚甲基蓝水溶液的降解测试其光催化活性。结果表明:补充结论纳米二氧化钛具有良好的光催化性能。     

二氧化钛纳米晶薄膜低温制备方法研究进展

二氧化钛纳米晶薄膜优异的性能使其成为研究焦点,低温制备二氧化钛纳米晶薄膜有着重要的现实意义.因此,探索低成本高效低温制备技术,不仅可以降低成本,而且还可以拓展此类薄膜在耐热性较差的高分子材料领域的应用.总结了近几年低温制备方法的研究进展,客观地评价了各种制备方法的优缺点,并简要评述了对其产业化进程.     

双子表面活性剂为模板纳米二氧化钛的制备及光催化活性

以脱氢松香为原料,通过化学合成的方法制备出一种新颖的双子表面活性剂,采用FT-IR及1 HNMR对其结构进行确证;以酞酸四正丁酯（TNB）为起始原料,通过加入自制的双子表面活性剂,采用水热合成法制备了平均粒径为8.81nm的锐钛矿型纳米二氧化钛颗粒;利用FT-IR、TEM、XRD对纳米二氧化钛进行表征;以紫外光为光源,罗丹明B（RhB）为模型污染物考察了纳米二氧化钛的光催化活性,结果表明其催化活性优于未加表面活性剂制备的纳米二氧化钛,且在紫外光下反应3h,RhB的降解率为99.7%,基本完全降解。     

超声化学法制备纳米二氧化钛

二氧化钛因其优良的光催化性能在环境保护方面得到广泛的关注和应用。本文研究了利用超声化学方法制备纳米二氧化钛的反应条件和影响因素。结果表明在超声波作用下 ,钛酸四异丁酯、TiCl4在温和条件下水解即可得到纳米二氧化钛。以钛酸四异丁酯为前驱体时 ,80℃时得到锐钛矿型纳米二氧化钛 ,而以TiCl4为前驱体时 ,得到纯的金红石型二氧化钛     

矿浆电解过程的浸出机理

介绍了高铅铜型难处理金矿矿浆电解浸出机理的研究结果。金精矿在矿浆电解时,铅的浸出可通过化学溶解、化学氧化、阳极氧化三种途径;铅浸出的主要途径是靠化学溶解,矿粒与阳极接触而被氧化对浸出的贡献不大。     

SMA/PA6界面化学反应的流变学测试

采用流变学的方法研究了剪切作用下苯乙烯-马来()酐共聚物(SMA)/尼龙6(PA6)体系的界面化学反应.固定可反应界面面积,从化学反应动力学的角度分析剪切提高界面化学反应速率的原因.研究发现,随着SMA/PA6界面上施加角频率和应变的增大,界面化学反应速率增大,化学反应动力学由一级扩散控制反应向二级化学反应控制转变,表...     

Computational simulation of chemical dissolution‐front instability in fluid‐saturated porous media under non‐isothermal conditions

This paper primarily deals with the computational aspects of chemical dissolution‐front instability problems in two‐dimensional fluid‐saturated porous media under non‐isothermal conditions. After the dimensionless governing partial differential equations of the non‐isothermal chemical dissolution‐front instability problem are briefly described, the formulation of a computational procedure, which contains a combination of using the finite difference and finite element method, is derived for simulating the morphological evolution of chemical dissolution fronts in the non‐isothermal chemical dissolution system within two‐dimensional fluid‐saturated porous media. To ensure the correctness and accuracy of the numerical solutions, the proposed computational procedure is verified through comparing the numerical solutions with the analytical solutions for a benchmark problem. As an application example, the verified computational procedure is then used to simulate the morphological evolution of chemical dissolution fronts in the supercritical non‐isothermal chemical dissolution system. The related numerical results have demonstrated the following: (1) the proposed computational procedure can produce accurate numerical solutions for the planar chemical dissolution‐front propagation problem in the non‐isothermal chemical dissolution system consisting of a fluid‐saturated porous medium; (2) the Zhao number has a significant effect not only on the dimensionless propagation speed of the chemical dissolution front but also on the distribution patterns of the dimensionless temperature, dimensionless pore‐fluid pressure, and dimensionless chemical‐species concentration in a non‐isothermal chemical dissolution system; (3) once the finger penetrates the whole computational domain, the dimensionless pore‐fluid pressure decreases drastically in the non‐isothermal chemical dissolution system.     

日化品瓶铝箔密封性检测方法及其实验研究

目的 提高日化品瓶铝箔密封性的检测准确率。方法 提出一种日化品瓶铝箔密封性检测方法。通过对铝箔密封后的日化品瓶瓶身施加压力,使瓶身产生一定的形变,基于采集施压过程中日化品瓶产生的反作用力,建立空气泄漏模型对日化品瓶铝箔密封性进行判定。设计日化品瓶铝箔密封性测试实验平台,在不同挤压行程和挤压速度下,对日化品瓶铝箔密封性进行实验。结果 将实验得到的数据代入空气泄漏数学模型后得到的泄漏面积数值与实际数值的最大误差为4.5%。结论 日化品瓶铝箔密封性检测方法操作简单、检测精确,为实际生产过程中对日化品瓶铝箔密封性检测提供了依据。     

化学工业园区循环经济标准体系构建研究

构建化学工业园区循环经济标准体系是发展绿色化工的基础性和统领性工作,对于化工产业的发展和循环经济标准化工作深入开展具有重要意义。基于此,依据循环经济理论和化工园区的特点构建化工园区循环经济标准体系框架结构,并以南京化学工业园区为例,建立循环经济标准体系表。     

钝化方式对镀锡钢板耐蚀性及铬含量的影响

使用化学分析、X射线光电子能谱分析以及电化学测试等试验方法,研究化学钝化以及电化学钝化得到的镀锡板的铬含量、铬元素组成及耐蚀性。结果表明:对于镀锡钢板铬酸盐钝化膜,电解钝化膜的总铬含量高于化学钝化膜的总铬含量。钝化膜中主要含有Cr,O以及Sn元素。不同钝化方式得到的钝化膜中铬元素的的价态、组成均不同,化学钝化膜及电解钝化膜中铬元素的组成分别为Cr2O3,Cr(OH)3以及Cr2O3,Cr(OH)3,Cr。电化学钝化膜的耐蚀性高于化学钝化膜。     

Influence of local chemical segregation on the γ′ directional coarsening behavior in single crystal superalloy CMSX-4

The influence of local chemical segregation on the directional coarsening behavior of γ′ phase has been investigated in a nickel-base single crystal superalloy during load-free thermal exposure. It is found that the γ′ phase was preferentially oriented with the direction perpendicular to the dendrite arm growth axis. The chemical gradients caused by local chemical heterogeneities were carefully measured on the scale of a dendrite. It showed that the directions of the γ′ rafting and the chemical gradients are consistent and the magnitude of the chemical gradients affects the rafting rates to some extent. It is suggested that the internal chemical gradients can orientate the development of the γ′ rafts by leading to anisotropy in their growth kinetics during Ostwald ripening. Furthermore, influence of the local chemical segregation on the mechanical properties is also discussed.     

智慧化工园区安全信息化标准体系设计研究

信息化智慧化可以辅助化工园区的安全管理,提高化工园区的风险防患意识,从而保障化工园区的安全。本文在分析当前智慧化工园区安全领域标准化建设现状及其发展趋势的基础上,从与智慧化工园区安全相关的业务应用、基础设施、支撑平台、数据安全和保障措施等方面,对智慧化工园区安全信息化标准体系进行设计并得出研究结论。本次体系设计研究对探索构建智慧化工园区安全标准体系,具有实践参考价值及意义。     

谈谈危险化工产品包装质量问题

阐述了我国危化品包装现状,提出提高危化品包装质量的若干途径,危化品包装发展的方向的几点建议     

Numerical modelling of fluids mixing,heat transfer and non‐equilibrium redox chemical reactions in fluid‐saturated porous rocks

Non‐equilibrium redox chemical reactions of high orders are ubiquitous in fluid‐saturated porous rocks within the crust of the Earth. The numerical modelling of such high‐order chemical reactions becomes a challenging problem because these chemical reactions are not only produced strong non‐linear source/sink terms for reactive transport equations, but also often coupled with the fluids mixing, heat transfer and reactive mass transport processes. In order to solve this problem effectively and efficiently, it is desirable to reduce the total number of reactive transport equations with strong non‐linear source/sink terms to a minimum in a computational model. For this purpose, the concept of the chemical reaction rate invariant is used to develop a numerical procedure for dealing with fluids mixing, heat transfer and non‐equilibrium redox chemical reactions in fluid‐saturated porous rocks. Using the proposed concept and numerical procedure, only one reactive transport equation, which is used to describe the distribution of the chemical product and has a strong non‐linear source/sink term, needs to be solved for each of the non‐equilibrium redox chemical reactions. The original reactive transport equations of the chemical reactants with strong non‐linear source/sink terms are turned into the conventional mass transport equations of the chemical reaction rate invariants without any non‐linear source/sink terms. A testing example, for some aspects of which the analytical solutions are available, is used to validate the proposed numerical procedure. The related numerical solutions have demonstrated that (1) the proposed numerical procedure is useful and applicable for dealing with the coupled problem between fluids mixing, heat transfer and non‐equilibrium redox chemical reactions of high orders in fluid‐saturated porous rocks; (2) the interaction between the solute diffusion, solute advection and chemical kinetics is an important mechanism to control distribution patterns of chemical products in an ore‐forming process; and (3) if the pore‐fluid pressure gradient is lithostatic, it is difficult for the chemical equilibrium to be attained within permeable cracks and geological faults within the crust of the Earth. Copyright © 2005 John Wiley & Sons, Ltd.