第二章 化学与材料.ppt

C/C复合材料 高性能炭/炭航空制动材料的制备技术 2004国家技术进步一等 黄伯云院士 * 陶瓷基 用纤维、须晶、颗粒与陶瓷制成复合材料，可提高其强韧性。增强的陶瓷基复合材料抗弯强度和断裂韧度都大大提高，尤其以碳化硅纤维增强的最为显著。 常思家国兴亡责 岂惜艰难百战身 张立同院士（1938-） 耐高温长寿命抗氧化陶瓷基复合材料应用技术 2004国家技术进步一等 * 金属基 与树脂基复合材料相比，金属基复合材料具有强度高，弹性模量高，耐磨性好，冲击韧性好，耐热性、导热性、导电性好，不易燃、不吸潮，尺寸稳定，不老化等优点。但存在密度较大，成本较高，部分材料工艺复杂的缺点。* 复合材料发展趋势 功能化：导电、吸收屏蔽型、压电型、自控发热、导磁、密封功能等。 领域：国防航空、生物医药、信息产业、新能源开发、纳米技术 * 材料科学的前景是美好的！ 1、光电转换材料，分解水的催化材料和储氢材料等能源材料将实现高效化； 2、集多种功能于一身的复合材料可使我们的生活质量得到进一步改善； 3、高温超导材料将进入实用阶段； 4、智能材料和机敏材料将得到广泛应用； 5、纳米材料将在治疗癌症、存储信息等领域大显神通……社会需要材料,材料离不开化学! * * Atom一词源于希腊语，原意是“不可再分的部分” ； Thomson发现 阴极射线就是带负电的电子流 * 原子中有一个极小的核，称原子核，它几乎集中了原子的全部质量，带有若干正电荷。 * 德布罗依提出假设， 微观粒子具有波粒二象性 * * * 能级的高低可以由光谱实验测定。电子的填充遵循泡利不相容原理，能量最低原理，洪特规则。 * Nanotechnology is the creation and utilization of materials, devices, and systems through the control of matter on the nanometer-length scale, that is, at the level of atoms, molecules, and supramolecular structures. The essence of nanotechnology is the ability to work at these levels to generate larger structures with fundamentally new molecular organization. These “nanostructures,” made with building blocks understood from first principles, are the smallest human-made objects, and they exhibit novel physical, chemical, and biological properties and phenomena. The aim of nanotechnology is to learn to exploit these properties and efficiently manufacture and employ the structures. Nanotechnology is the science and technology of materials at the nanometer scale---the world of atoms and molecules. Scientists and engineers explore this world of nanoscale objects with high speed computers and powerful atomic resolution microscopes. In this realm, the rules of quantum physics provide matter with remarkable properties. Understanding and harnessing these properties will lead to breakthroughs in the 21st Century as revolutionary as electricity, antibiotics, plastic and computers were in the 19th and 20th. Compared to the behavior of isolated molecules of about 1 nm or of bulk materials, be