【作者】 李瑞勇；

【导师】 李晓杰；

【作者基本信息】 大连理工大学 ， 工程力学， 2006， 博士

【摘要】 纳米粉体材料是上世纪80年代中期以后发展起来的一种新型固体材料。它是由尺寸在(1～100)nm的固体颗粒组成。纳米材料具有良好的表面效应、体积效应、量子尺寸效应和宏观量子隧道效应,在材料、机械、化工、医药、军事等领域都有广泛的用途。其中,纳米氧化铝还具有高硬度、高强度、耐热、耐腐蚀等特性,广泛应用于精细陶瓷、复合材料、催化剂等领域。鉴于纳米氧化铝的应用如此广泛,所以探求一种方便、快捷的制取方法显得尤为重要。另外,与纳米氧化铝的应用研究和制取方法相比,其粉末的制备显得进展缓慢。例如,在纳米氧化铝尺度和晶型的控制及纳米团聚问题等领域里还存在很多的技术及工程难题。针对上述问题,本文提出了两个主要的研究内容:一是从制取纳米氧化铝的方法上探求出一种低成本、高产出的新的制取方法;二是从制备纳米氧化铝的过程中来对其晶型和纳米尺寸实现人为地控制。 本文首先从纳米氧化铝的应用、纳米氧化铝的不同制取方法及特点和纳米氧化铝制备技术上存在的问题三个方面综述了当前纳米氧化铝技术发展的情况。然后提出了利用廉价的硝酸铝、氢氧化铝为主要原料,采用炸药黑索金(RDX)爆轰为手段来制取纳米氧化铝的一种新技术方法—爆轰合成法。本文利用该方法成功地制备出了不同尺寸、不同形状和不同晶型的纳米氧化铝粉体。并且通过实验、计算以及实验检测的方式对具有不同参数的混合炸药与其相应爆轰得到的纳米氧化铝的晶型及纳米尺寸之间的联系进行了研究。最后,本文还介绍了不同晶型纳米氧化铝的低温煅烧特性。论文的主要研究成果有: (1)针对目前现有的制取纳米氧化铝的各种方法的特点和目前在纳米氧化铝技术中存在的问题,提出了一种新的制取纳米氧化铝的技术方法—爆轰合成法。该方法具有合成反应速度快、合成设备工艺简单和易放大产量等优点。另外,爆轰合成本身具备气相合成的特点,合成出高分散性、高纯度的纳米氧化铝具有本身技术上的优势。 (2)利用该方法成功地制取出了球形的纳米γ型氧化铝、球形的纳米α型氧化铝和片状的纳米α型氧化铝以及球形的混合型纳米氧化铝。 (3)从爆轰合成出不同形状及晶型的纳米氧化铝的研究中,获得了爆轰合成专用系列炸药和其制造方法(如粉末与压装、水胶)。例如,硝酸铝系列合成纳米氧化铝专用系列炸药及其制造方法;氢氧化铝系列合成纳米氧化物专用系列炸药及其制造方法等。另外,针对炸药爆轰时产生的有害气体对环境的污染问题,进行了炸药的氧平衡研究。研究结果表明通过往炸药里面添加合适的氧平衡剂可以使炸药在爆轰合成纳米氧化铝的过程中只产生少量或不产生污染气体,从而可解决污染问题。更多还原

【Abstract】 Nanomaterials made up of solid particles with the size of (1-100) run have developed up to a new type of solid materials since the 1980’s. Thanks to well-known surface effects, volume effects, quantum dimension effects and macroscopical quantum tunnel effects, nanomaterials are extensively used in many fields such as material, mechanism, chemical industry, medicine and military affairs, etc. Thereinto, nanometer alumina is of so many characters like high rigidity, high intensity, heat-resistance and corrosion-resistance, etc, and is used widely in fine ceram, composite material and activator, etc. Because of the extensive applications of nanometer alumina, it is necessary to search a convenient and speedy method to produce it. In addition, compared with its research of application and manufacture methods, the preparations of nanometer alumina powders are developed slowly. For example, there are still a lot of technique and engineering problems in control nanodimension and phases of nanometer alumina, and preventing nanogranule to congregate, etc. Aiming at the problems above, two ideas of research are presented in this paper. One is to search a new method with low cost and high yield to prepare nanometer alumina, and the other one is to realize man-made control nanodimension and phases of nanometer alumina during the preparation.At the beginning, this article summarizes the current developments of nanometer alumina in three aspects of the applications, the methods of preparation with different characters and the problems existing in technique of preparation. Further more, a new method to prepare nanometer alumina by low-cost material of aluminum nitrate or aluminum hydroxide through detonation of RDX is presented, which is also called detonation synthesis. Nanometer alumina powders with different dimensions, shapes and phases are prepared by detonation synthesis. And the relations between the mixed explosives with different parameters and the phases, and the nanodimensions of nanometer alumina resulted from the explosives are studied by the means of experiments, calculations and experimental detections. Finally, the characters of low temperatures calcinations of nanometer alumina with different phases are introduced. The main research results of this paper are as follows:(1) Based on the characters of different preparation methods and the problems in the technology of nanometer alumina, a new method called detonation synthesis is presented. The method has advantages in fast synthesis, simple technology process, low-cost equipment and amplificatory yield. In addition, the method itself has the characteristics of vapor phasecomposition, so that it is of technical advantage to synthesize high-dispersing and high-purity nanometer alumina.(2) The spherical nanometer y alumina, spherical nanometer a alumina, lamellar nanometer a alumina and spherical nanometer mixing phases alumina are successfully synthesized by the detonation method.(3) From the study of nanometer alumina with different shapes and phases synthesized by detonation, the special series of explosives used for detonation synthesis and their manufacturing methods (such as loading powder with pressure, water gel) are obtained, for instance, the special explosive of aluminum nitrate and its manufacturing method, the special explosive of aluminum hydroxide and its manufacturing method, etc. Moreover, aiming at the pollution caused by poisonous gas released during the detonation, the balance of oxygen of explosive is researched. The result indicates that by adding the suitable substance of balance of oxygen into the explosive, little poisonous gas or nothing could be released during the preparation of nanometer alumina. Consequently, the pollution can be solved.(4) Aiming at the shortcoming of technique on control synthesis of nanomaterial, the relations between different parameters (such as density of explosive, temperature of explosion, velocity of explosion and press of explosion etc) of special series of explosives used for detonation synthesis and phases and nanodimensions of nanometer alumina are chiefly studied. The corresponding relations are described by experiments, calculations and experimental detections.(5) The characters of low temperatures calcinations of nanometer alumina with different phases are characterized by XRD and curves between dimensions of crystal grains and calcination temperatures. The results indicate the calcination characters of nanometer alumina with different phases differ from high temperatures calcination.In a word, several studies and the innovations in this paper are presented on the base of the current study of nanometer alumina, and the research results are obtained, which are expected to be possibly helpful as reference in this field in the future.更多还原