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 nmRed 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 nmA hydrogen atom is 0.1 nm Fullerenes (C60 / Buckyballs) are 1 nm Quantum Dots (of CdSe) are 8 -50 nm Dendrimers are 10 nm Nanoparti
3、cles 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 understanding
4、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. R
5、oco (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原子一
6、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 molec
7、ular 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, because
8、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. Willi
9、ams, P. Alivisatos, 1999the 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”- Richard Sma
10、lley, 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,Nano-sizing
11、 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 dimension. S
12、ometimes 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过一个小喷嘴进入真
13、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的氢化物便释放出氢气，
14、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，用它来制成的化学传感器
15、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，从而导致人的智能发
16、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
17、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1000个纳米药包的微型芯片；在固定的DNA链上连接上杀癌的药物胶囊，放到病人血液和组织内，一遇上癌细胞的DNA时，DNA链就与癌细胞的DNA结合，这时药物开关受触发而开放，药物便释放出来，杀灭癌细胞；,生物医药：纳米清洁工,科学家设想制造出负责清扫血管的纳米机器人（清洁工），专门负责清扫血管壁上的胆固醇、凝血等沉积物，以预防脑血栓等心血管病；同时也可以制作出清扫体内癌细胞的机器人。,太
18、空云梯,坚韧的碳纤维，其密度是钢的1/6，强度为钢的10100倍，重量则只有钢的1/4。,将纳米碳管做成太空升降机的缆绳，由于它的强度高、重量轻，即使是从太空下垂到地面，它也完全可以承受自身的重量而不会断开，它是目前唯一可作为太空云梯的理想材料。,日常生活,纳米TiO2：在光照条件下，会产生具有非常强的氧化能力的空穴，从而将附在表面上的有机物、细菌及其它灰尘分解掉，直至生成CO2和H2O。 杀菌、除味：由于纳米ZnO具有大的比表面积，可以很快地吸收并分解臭气，同时还能有效地杀菌。对黄色葡萄球菌和大肠杆菌的杀菌率高达95%以上。,抗菌纳米服装：不用清洗信不信由你,军事,吸波：纳米ZnO对雷达电磁
19、波具有很强的吸收能力，所以可以做隐形飞机的重要涂料。,2005年10月20日报道， 目前美国Nice大学的科学家研制出世界第一辆单分子纳米汽车。该汽车在显微镜下可见的金属道路上行驶。车轮是球型的，由包含60个原子的单质碳构成。整辆汽车对角线的长度仅为34纳米，比单股的DNA稍宽。相比而言，人一根头发的直径大约是80，000纳米。,纳米汽车,纳米管收音机,2007 年，美国加利福尼亚大学伯克利分校的物理学家亚历克斯策特尔(Alex Zettl) 。 在该碳纳米管收音机中，碳纳米管承担了收音机的天线、调谐器、放大器和解调器等诸多部件的功能。如图1所示，纳米收音机的碳纳米管被置于真空管中，并将一端固
20、定在电池的负极上。碳纳米管的另一端（即自由端）和电池正极之间留有纳米量级的间隙。如果电极间的电压足够高，正极能将碳纳米管自由端的电子夺过来。当广播电台的无线电信号经过该碳纳米管收音机时，其产生的电场将不断“推”和“拉”纳米管的自由端，也就是碳纳米管随无线电信号发生共振，利用这种共振现象及回路中相应的电流变化就可以探测到无线电信号。这里，回路中受无线电信号感应得到的高频交变电流信号后经碳纳米管“调谐”、“放大”和“解调”后，便会转化为携带声音信息的低频信号，进而，通过喇叭等播出声音。,万能关节,Name: Universal Joint Designer: Mark Sims, based on
21、 a 1992 design by K. Eric Drexler and Ralph Merkle Date: May 25, 2006 Number of components: 4 (which form a single covalent structure) Number of atoms: 3,846 Width: 3.8 nm Height: 3.8 nm Length: 6.4 nm (not including shafts),世界最小的纳米电动机：以碳纳米管为轴，金片为叶，在电流驱动下转动,ATP分子马达,利用碳纳米管制造出一种奇妙的纳米秤，这种秤竟然可以称出单个原子的重量
22、。之所以选用碳纳米管来作为制作纳米秤的材料，是因为碳纳米管中间是空的，而且质量非常轻，对原子的振动非常敏感，这样可以更准确的“秤”出原子的重量 。不过它并不是利用杠杆原理来称量原子的重量。这种纳米秤实际上是一个悬臂，类似于跳水运动员使用的跳板，长约250纳米，一头固定在一个电极上，另一头则不固定。当一个原子落下掉在这个悬臂上，原子的重量会引起悬臂进行振动。这就像跳水板一样，跳水运动员的体重不同，跳水板的振动频率和幅度也会有相应的变化。然后他们利用振动频率的差异来测算出原子的重量。,纳米秤,nano guitar playable and colored,A nanoguitar, devise
23、d at Cornell years ago, has been “played“ for the first time by shooting laser light at the silicon “strings.“ A newer version of the guitar, shown above, twangs at a frequency of 40 megahertz, some 17 octaves (or a factor of 130,000) higher than a normal guitar. Electron-microscope image of the wor
24、lds smallest guitar. Its length is 10 micrometers (10 millionths of a meter). Thats about the size of a red blood cell and about 1/20th the width of a single human hair. Its strings have a width of about 50 nanometers (the size of approximately 100 atoms). If you were to pluck the tiny strings they
25、would produce a high-pitched sound at the inaudible frequency of approximately 10 megahertz. Made by Cornell researchers with a single silicon crystal using the techniques of high voltage electron beam lithography, this tiny guitar is a fun example of nanotechnology. Many of the same techniques are
26、applied by scientists building machines and devices on the nanometer scale to perform useful technological functions and study submicroscopic processes.,纳米上的艺术,日本学者2006年利用FIB-CVD 技术制备的纳米LRC电子电路。,nanocup,Professor Shinji Matsuis research group at the Himeji Institute of Technology (HIT) and Seiko Ins
27、truments Inc. (SII), have made the worlds smallest wine glass. Using highly advanced manufacturing techniques that can produce three dimensional (3D) objects at the nanometer scale, researchers built the glass from carbon with an external diameter of only 2,750 nanometers (nm), approximately 200,000
28、 times smaller than a normal sized glass.,nanocup,Nano flowers,NASA科研人员制备的Si纳米结构,纳米向日葵（美国康纳尔大学科技人员制备的葸氢醌二乙酸酯纳米结构）,2006， made from zinc oxide by Yujin Chen and colleagues at Harbin Engineering University， For alcohol detection,超疏水 SnO2 nanoflowers,a）硫化镉纳米花 （CVD方法）美国能源部：Sandia国家实验室,Carbon上生长的锑纳米草 (新西兰
29、科学家的AFM照片),Si上生长的硫化钼纳米锥 (新加坡国立大学电镜照片),北京大学纳米中心的学者通过AFM针尖对基质Au-Pa合金上的机械刻蚀，书写了世界上最小的唐诗（10微米10微米）,DNA 美洲地图,“Nanoman“ was created by focussed electron beam deposition on the tip of an STM - an illustration of 3D nanostructure fabrication with a precision of 10nm.,原子小人,这是科学家通过原子力显微镜操纵28 个碳原子在铂表面上拼成的小人，28
30、个原子组成的“人”.,Nano toilet,Micro-bull fabricated by FIB,分子的艺术,蚂蚱酮 它是从一种不能飞的蝗虫Romalea microptera用于防御的分泌物中提取的. 科学家们在田野里辛苦地逮蚂蚱、并惹恼它们，再从它们身上“挤奶”得到这种物质，专注的科学家太累了而不想辛苦的对它系统命名，所以他们使用了这个有创意的名字蚂蚱酮。,纳米莆田分子这涉及到如何合成拟人的分子（anthropomorphic molecules），即分子结构看起来就像是一个人。它们（指分子）有着不同的形式，但基本的形式被称为“纳米孩子”（NanoKid），从这里出发，其他不同形式的
31、分子可以被合成，例如“纳米运动员”（NanoAthlete）和“纳米面包师”（NanoBaker）。,国王,企鹅酮,由于它分子的二维结构式类似一只企鹅，所以被命名为“企鹅酮”（Penguinone），但是这种效果在三维模型中却失去了。它的系统命名应该是 3,4,4,5-tetramethylcyclohexa-2,5-dienone.,纳米材料的常见制备方法,The scanning electron microscopic image of a 3D macroporous material that was fabricated by infiltrating a 3D opaline l
32、attice of silica spheres with a hexane solution containing buckyballs. Note that the porous features underneath were also visible through the pores on the surface of the membrane.,Typical fabrication,模板合成,纳米芯壳结构,The scanning electron microscopic image of a 3D crystalline lattice assembled from AuSiO
33、2 core-shell colloids. The gold cores were 50 nm in diameter and the silica shells were 120 nm in thickness.,氧化铝模板,Fabricated in 0.3 M oxalic acid solution, 40V, 2 oC,Typical SEM images of as-prepared AAO templates,SEM images of Co nanowires fabricated by pulse DC electrodeposition,以粒径为6微米的金红石相氧化钛为原
34、料，制备无定形氧化钛纳米粉体的过程：,水热法,(a): 无定形氧化钛产物, (b): 锐钛矿相氧化钛产物, （c): 金红石相氧化钛产物.,Schematic illustration of vapor-liquid-solid nanowire growth mechanism including three stages (I) alloying, (II) nucleation, and (III) axial growth.,CVD制备纳米线,(a) SEM image of ZnO nanowires synthesized via the VLS mechanism (b) TEM
35、 images of the single-crystalline ZnO nanowires.,SEM (a, c) and cross sectional TEM (b) images of SnO2 nanobelts obtained by evaporation and condensation of SnO at 1000 oC.,ZnO nanowire arrays on sapphire substrate. Huang M., Mao S., Feick H., Yan H., Wu Y., Kind H., Weber E., Russo R., and Yang P.,
36、 Room-temperature ultraviolet nanowire nanolasers, Science 292(2001) pp.1897-1899,Site-selective growth of ZnO nanowire arrays on a-plane sapphire substrates. The pattern of nanowire array is defined by the initial Au thin film pattern fabricated by photolithography.Science 292(2001) pp.1897-1899,ST
37、EM image of two nanowires in bright field mode. The scale bar is 500 nm. (b) Line profile of EDS signal from Si and Ge components along the nanowire growth axis. Wu Y., Fan R. and Yang P., Block-by-Block Growth of Single-Crystalline Si/SiGe Superlattice Nanowires, Nano Lett. 2(2002) pp.83-86.,Electr
38、ical field induced nanowire alignment represents another powerful assembly technique. Lieber et al. have fabricated metal electrode arrays on which bias is applied to generate strong electrical filed to align Si and InP nanowires dispersed in between the electrodes (b). Typical SEM images of crossed
39、 arrays of InP nanowires obtained in a two-step assembly process with orthogonal flow directions for the sequential steps. Flow directions are highlighted by arrows in the images. The scale bar corresponds to 2 m.,The microchannels are formed between a flat Si/glass substrate. A droplet of the wire
40、solution/suspension was placed at the open end of the microchannels; the liquid fills the channels under capillary effect. After the evaporation of the solvent， wires were aligned along the edges of the microchannels。 （a）SEM image of the aligned Mo3Se3 - molecular wire bundles on Si wafer. Inset sho
41、ws the cross-junction formed through multiple layer alignment process.,纳米线的排列,The melting starts from two ends at around 650 oC (the melting point of bulk Ge is 930 oC) and moves towards the center of the wire. At 848 oC, the whole wire melts. During cooling process, the recrystallization happens at
42、 much lower temperature (558 oC) than the initial melting temperature. Utilizing the low melting points of the nanowires encapsulated in nanotubes, Sequential TEM images of linking two Ge nanowires within a carbon nanotubes. Wu Y. and Yang P., Melting and welding semiconductor nanowires in nanotubes
43、, Adv. Mater. 13(2001) pp.520-523.,纳米材料常用表征手段,XRD TEM SEM VSM I-V C-V,XRD,1）origin 软件中通过数据得到相应的衍射谱,2）将衍射谱与标准的谱线进行对比,3）得出衍射峰的来源和晶体生长方向,TEM,SEM,SEMEDS（EDX）,VSM,Nano Sites,Useful Internet Sites National Nanotechnology Initiative www.nano.gov National Nanotechnology Infrastructure Network - http:/nnin.o
44、rg/ Nanoscience Education - http:/ Europes Nanotechnology News Portal - http:/ Nanularity - http:/ Materials Research Science and Engineering Center on Nanostructured Interfaces at the University of Wisconsin Madison - http:/www.mrsec.wisc.edu/Edetc/courses/courses.htm Discussion about research in n
45、anotechnology - http:/www.nano.org/home.php Interdisciplinary nature of nanotechnology - http:/www.nsti.org/ Nanotechnology Zyvex - http:/ National Cancer Institute (NCI) - http:/nano.cancer.gov/ National Science Foundation (NSF) - http:/www.nsf.gov/crssprgm/nano/ Nano/Bio Interface Center - http:/w
46、ww.nanotech.upenn.edu/ Institute of Nanotechnology - http:/www.nano.org.uk/ What is Nano Northwestern University, IL - http:/www.discovernano.northwestern.edu/whatis Nanotechnology and the environment - http:/es.epa.gov/ncer/nano/ Nanotechnology investing and stock - http:/ Nanotechnology for kids - http:/cohesion.rice.edu/naturalsciences/nanokids/index.cfm Nanoscience at MIT - http:/web.mit.edu/chemistry/www/faculty/nanoscience.html Societal Implications - http:/www.wtec.org/loyola/nano/NSET.Societal.Implications/ How Nanotechnology will work? - http:/
