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1、纳米材料与纳米科技,13th May, 2009,纳 米,1. 什么是纳米科学？ 2. 纳米材料及其特性 3. 纳米技术的应用,What is Nanometer?,A nanometer is about the width of six bonded carbon atoms, and approximately 40,000 are needed to equal the width of an average human hair. DNA (width) is 2 nm Proteins range from 5 to 50 nm Viruses range from 75 to 1
2、00 nm A virus is 100 nm Red blood cells are 7,000 nm in diameter, and 2000 nm in height White blood cells are 10,000 nm in diameter Bacteria range from 1,000 to 10,000 nm A hydrogen atom is 0.1 nm Fullerenes (C60 / Buckyballs) are 1 nm Quantum Dots (of CdSe) are 8 -50 nm Dendrimers are 10 nm Nanopar
3、ticles range from 1 to 100 nm,Importance,“One nanometer is a magical point on the dimensional scale. Nanostructures are at the confluence of the smallest of the human-made devices and the largest molecules of living things. Nanoscale science and engineering here refer to the fundamental understandin
4、g and resulting technological advances arising from the exploitation of new physical, chemical and biological properties of systems that are intermediate in size, between isolated atoms and molecules and bulk materials, where the transitional properties between the two limits can be controlled.” M.C
5、. Roco (National Science Foundation), 2001.,Theres Plenty of Room at the Bottom by Richard P. Feynman December 29th 1959,年，诺贝尔奖获得者、理论物理学家理查得费因曼教授在加州理工大学发表了题为在底部还有很大空间的演讲。在费因曼看来，人类社会目前的生产方式，总是“从上而下(top-down Manufacturing)”的，他提出：为什么我们不可以从单个分子、甚至原子开始出发进行组装 (bottom-up manufacturing) ，达到我们的要求？物理学的规律不排除一个
6、原子一个原子制造物品的可能。”,（纳米科学的开山之作）,Nanoscience Study of fundamental principles of molecules and structures with at least one dimension roughly between 1 and 100 nm. Nanotechnology- sometimes shortened to nanotech, refers to a field of applied science whose theme is the control of matter on an atomic and mo
7、lecular scale. Generally nanotechnology deals with structures 100 nanometers or smaller, and involves developing materials or devices within that size. Nanostructures Smallest solid things it is possible to make.,7,“Nanotechnology is likely to be particularly important in the developing world, becau
8、se it involves little labour, land or maintenance; it is highly productive and inexpensive; and it requires only modest amounts of materials and energy” UN Millennium Project. “Nanoscience and technology will change the nature of almost every human-made object in the 21st century” - M.C. Roco, R.S.
9、Williams, P. Alivisatos, 1999 the National Science and Technology Council “Just waitthe 21st century is going to be incredible. We are about to be able to build things that work on the smallest possible length scales, atom by atom. These nanothings will revolutionize industries and our lives” - Rich
10、ard Smalley, 1999 (1996 noble prize in chemistry) “The convergence of nanotechnology with information technology, biology and social sciences will reinvigorate discoveries and innovation in many areas of the economy.“ - George W. Bush, President of the United States,Macroscale vs. Nanoscale Gold,Nan
11、o-sizing Causes Changes In Melting point:,Macroscale vs. Nanoscale Gold,Nanoscale Materials in Chemistry, K. J. Klabunde, ed., Wiley, 2001, Chapter 8.,一、C60,近年来，科学家们发现，除金刚石、石墨外，还有一些新的以单质形式存在的碳。其中发现较早并已在研究中取得重要进展的是C60分子。 C60分子是一种由60个碳原子构成的分子，它形似足球，因此又名足球烯。,Nanoscience is a subject defined by its dime
12、nsion. Sometimes its fun to play with that a little. If a buckyball was as big as a football, a football would be as big as the earth! These flourinated fullerenes come from the work of Roger Taylor and Adam Darwich,制作过程,足球烯是美国休斯顿赖斯大学的克罗脱和史沫莱等人于1985年提出的。他们用大功率激光束轰击石墨使其气化，用1MPa压强的氦气产生超声波，使被激光束气化的碳原子通
13、过一个小喷嘴进入真空膨胀，并迅速冷却形成新的碳原子，从而得到了C60。,Fullerene Science,1985: C60-discovered (Nature 318, 162) 1990: C60-macroscopic scale synthesis (Nature 347, 354) 1991: Carbon nanotubes-discovered (Nature 354, 56) 1996: Noble prize for C60,C60的应用,气体的贮存 在控制温度和压力的条件下，可以简单地用C60和氢气制成C60的氢化物，它在常温下非常稳定，而在80 215 时，C60的氢
14、化物便释放出氢气，留下纯的C60，它可以被100%地回收，并被用来重新制备C60的氢化物。与金属或其合金的贮氢材料相比，用C60贮存氢气具有价格较低的优点，而且C60比金属及其合金要轻。,C60的应用,因此，相同质量的材料，C60所贮存的氢气比金属或其合金要多。 C60不但可以贮存氢气，还可以用来贮存氧气。与高压钢瓶贮氧相比，高压钢瓶的压力为3.9106 Pa，属于高压贮氧法，而C60贮氧的压力只有2.3105 Pa，属于低压贮氧法。利用C60在低压下大量贮存氧气对于医疗部门、军事部门乃至商业部门都会有很多用途。,有感觉功能的传感器 由于用C60薄膜做基质材料可以制成手指状组合型的电容器，用它
15、来制成的化学传感器具有比传统的传感器尺寸小、简单、可再生和价格低等优点，可能成为传感器中颇具吸引力的一种候选产品。,此外,提高金属硬度 应用于新型催化剂 对光的限制性可应用于对人的眼睛的保护 对癌细胞杀伤 抑制人体免疫缺损蛋白酶的活性 充当水溶性抗氧剂 等等,纳米材料,纳米材料: 在纳米量级(1100nm)内调控物质结构制成的具有特异性能的新材料 四大特点: 尺寸小、比表面积大、表面能高、表面原子比例大 四大效应: 小尺寸效应、量子尺寸效应、宏观量子隧道效应、表面效应 纳米材料特性取决于制备方法,纳米材料应用,环境：处理汽车尾气,含铅汽油中的铅很容易通过血液长期蓄积于人的肝、肾、脾、肺和大脑中
16、，从而导致人的智能发育障碍和血色素制造障碍等后果。,汽车尾气的处理：加入纳米级的复合稀土氧化物后，对尾气的净化特别明显，尾气中的CO、NOx几乎完全转化。,水处理,特种半导体纳米材料使海水淡化； 纳米TiO2可以用来降解有机磷，降解毛纺染整废水，降解石油 ,能源：储氢,碳纳米管是直径非常细的中空管状纳米材料，它能够大量地吸附氢气，成为许多个“纳米钢瓶” 。 研究表明，约2/3的氢气能够在常温常压下从碳纳米管中释放出来。 据预测，到2010年，就可以生产出氢气汽车，只需携带1.5升左右的储氢纳米碳管，即可行驶500km。,纳米碳管,防弹衣,因纳米碳管既轻又强度极高，是钢的10100倍，用它来作防弹衣就像用羽绒做成的防寒服一样，既可折来叠去，又能抵御强大的子弹的冲击力。,纳米泵人造红细胞,它比体内血液中的红细胞要多携带200多倍的氧气。,血液形态图,靶向给药,美国麻省理工学院的研究人员研究一种只有20nm的药物炸弹和包含了10
