纳米材料课件1.pdf

纳米材料简介An Introduction to Nanomaterials李 彦北京大学化学学院材料化学系李 彦Tel:62756773Email:http:/ moving into nanoworldA.Intellectual driveMiniaturization is of interestLess space,faster,less materials,less energyMore important:Novel properties/phenomena/process-New structure and functions;Engineering beyond natureUnity and generality-At the building blocks of all natural/artificial things,systemsMost efficient length scale for manufacturing-Less energy than for subatomic or macroscopicTranscendent effects:at the confluence of steams-S&T;Living/non-living;interdisciplinary;Relevance areasB.Promise of nanotechnology(example of societal implications)?Knowledge base:better comprehension of nature,life?A new world of products:-$1trillion/y in 10-15years-Materials beyond what chemistry can do:$340B/y in 10 years for materials and processing,(estimation by industry group)-Electronnics in 10-15 years:$300B/Y for semiconductor industry,times more for global integrated circuts(estimation by SIA)-Pharmaceutics in 10-15 years about half of production will depend on nanotechnology,affecting about$180B/Y Chemical plants in 10-15years:nanostructured catalysts in petroleum and chemical processing about$100B/YAerospace:about$70B/Y in 10 yearsTools(measurement,simulation)-$22B/Y in 10y?Improved healthcare:extend life-span,its quality,human physical capabilities(-$31B in tools for healthcare in 10 years)?Sustainability:agriculture,water,energy(-45B/y in 10 years)materials,environment,exiting lighting energy reduction 10%or$100B/Y什么是纳米材料？什么是纳米科学？Noble Prize laureate,Feynman,in his 1960 article“Theres plenty room at the bottom”discussed the advantages that could be provided by controlling the structure of matter atom by atom.For example,he pointed out that if a bit of information requires only 100 atoms,then all the books ever written could be stored in a cube with sides 0.02 in long.纳米纪事?最早的纳米材料：中国古代的铜镜的保护层：纳米氧化锡中国古代的墨及染料?1857年，法拉第制备出金纳米颗粒?1861年，胶体化学的的建立?1962年，久保(Kubo)提出了著名的久保理论?上世纪七十年代末至八十年代初，开始较系统的研究?1985年，Kroto和Smalley等人发现C60?1990年7月，在美国巴尔的摩召开第一届纳米科技会议?1994年，在波士顿召开的MRS秋季会议上正式提出纳米材料工程STM操纵原子和分子Xe on NiCOiron atom on copper(1)纳米物理学；(2)纳米化学；(3)纳米材料学；(4)纳米生物学；(5)纳米电子学；(6)纳米加工学；(7)纳米力学；(8)纳米机电系统自然界的纳米材料?人体和兽类的牙齿?海洋中的生命粒子?蜜蜂的“罗盘”腹部的磁性纳米粒子?螃蟹的横行 磁性粒子“指南针”定位作用的紊乱?海龟在大西洋的巡航 头部磁性粒子的导航纳米材料的分类按结构：零维纳米材料：量子点 纳米粒子一维纳米材料：如纳米线(量子线)、纳米管二维纳米材料：薄层纳米孔材料：如介孔分子筛按组成：金属纳米材料、半导体纳米材料、有机和高分子纳米材料、复合纳米材料复合纳米材料：无机纳米粒子与有机高分子符合材料无机半导体的核壳结构量子阱(超晶格)材料纳米材料的组装体及纳米材料的阵列和超晶格SCHEME:Solvent Evaporation from Nanocrystal Dispersion on a Substrate:Entropy Drives the Ordering of Hard Spheres When the Particle Volume Fraction Exceeds a Critical Value,0.49TEM images of a two-dimensionalhcp silver nanocrystal superlattice(left),and the 2-D Fourier transform power spectrun of the imageJ.Phys.Chem.B1998,102,8379-8378TEM micrograph of monolayer films of 3.7 nm Au clustersSelf-assembly of a LCN(ScienceV273,1690-1693,1996)Assemble and compress nanoparticles by L-B filmsTEM images of compressed films consisting of Ag particles,27A in diameter (A)separated by 6A,(B)by 12A(Science,277,1978-1980,1997)利用DNA片段的碱基配对作用来带动纳米粒子的组装Alivisatos et al.,Nature,1996,382,609C.A.Mirkin et al.,Nature,1996,382,607