自组装单分子薄膜宋仕永.ppt

自组装单分子薄膜 Self-Assembled Monolayers,宋仕永 2012.11.15,化工材料系列讲座,前言,纳米材料的表面或界面（Surface & Interface）决定着材料的宏观性质。有人把物质的表面层称做是物质的第四种状态 。 人们通过控制和改变固体表面化学组成获得具有特定性能的材料。,图1 自组装单层膜结构示意图,自组装单分子薄膜,SAMs 的优点,制备方法简单,SAMs 的优点,不受基底形状的限制：无论曲面还是平面,纳米球,SAMs 的优点,与基底结合牢固，稳定性高，自组装分子一般都是与基底以化学键结合，分子链间主要以范德华力相互作用； 薄膜结构灵活可控，从分子和结构设计入手，可同时在分子水平和材料水平上实现对薄膜结构的调控,自组装单分子薄膜为研究表面现象提供了一个理想的模型，如边界润滑、生物传递、表面能的控制等，它还在摩擦学、材料学、电子学、非线性光学等诸多领域有重要的应用基础研究价值。,SAMs的种类,长链酸类自组装单层膜,图 3 Al2O3及AgO表面上长链羧酸单层膜的结构示意图,SAMs的种类,烷基硫醇类化合物在金属表面形成的SAMs,图 4 金基底上含有奇、偶数目亚甲基长直链硫醇的结构示意图,SAMs的种类,有机硅烷类SAMs,图 5 基底与单层薄膜界面上聚硅氧烷的结构示意图。,SAMs在分子电子学中应用,分子电子学研究的是分子水平上的电子学，其目标是用单个分子、超分子或分子簇代替硅基半导体晶体管等固体电子学元件组装逻辑电路，乃至组装完整的分子计算机。,SAMs在分子电子学中应用,SAMs在生物学中应用,常用仪器,扫描探针显微镜（SPM）,云母的原子STM图,原子力显微镜AFM,常用仪器,椭圆偏光测厚仪,衰减全反射红外光谱 反射红外光谱,常用仪器,常用仪器,X光电子能谱（XPS）,XPS ，全称为X-ray Photoelectron Spectroscopy，是一种基于光电效应的电子能谱，它是利用X射线光子激发出物质表面原子的内层电子，通过对这些电子进行能量分析而获得的一种能谱。,博士论文工作,博士论文工作,自组装有机薄膜的内在结构与摩擦学性能,含酰胺键自组装单分子薄膜 I,TPOA, 预水解48h, 环己烷稀释，沉积24h,SY Song et al Langmuir 2006,22, 6010-6015.,制备过程,结构示意图,SY Song, et al The Journal of Physical Chemistry C, 2008, 112, 3805-3810.,含酰胺键自组装单分子薄膜 II,含酰胺键自组装单分子薄膜 III,DAC18薄膜的理想结构。,疏水性，承载能力 降低摩擦系数,氨基表面密度高， 双层氢键的形成， 提高摩擦稳定性,原子力形貌图,(a),(b),RMS: 0.15 nm,RMS: 0.20 nm,DA和DAC18膜表面的原子力形貌图，扫描范围500nm500nm，竖直方向高度范围2nm。,衰减全反射红外光谱,DA膜和DAC18膜的衰减全反射红外光谱。,SY Song et al Langmuir, 2008, 24, 105-109.,新加坡国立大学博后工作,Single-Molecule Force and Fluorescence Lab,R. Liu et al Biophysical Journal 96(9), 3810-3821 (2009),在河南大学的科研,仿关节软骨结构水凝胶薄膜,聚合物刷,水凝胶,表面引发原子转移自由基聚合,POMA聚合物膜在氨基自组装膜表面的形成示意图。,SY Song et al Applied Surface Science 2011,257,10254.,POMA聚合物薄膜,pH敏感聚合物胶束,Nanomedicine,Nanomedicine is the application of nanotechnology in medicine, including to cure diseases and repair damaged tissues such as bone, muscle, and nerve Key Goals for Nanomedicine To develop cure for traditionally incurable diseases (e.g. cancer) through the utilization of nanotechnology To provide more effective cure with fewer side effects by means of targeted drug delivery systems,Nanotechnology in Health Care,Thermal ablation of cancer cells assisted by nanoshells coated with metallic layer and an external energy source National Cancer Institute,Thermal ablation of cancer cells Nanoshells have metallic outer layer and silica core Selectively attracted to cancer shells either through a phenomena called enhanced permeation retention or due to some molecules coated on the shells The nanoshells are heated with an external energy source killing the cancer cells,Nanotechnology in Health Care,Treatment Targeted drug delivery Nanoparticles containing drugs are coated with targeting agents (e.g. conjugated antibodies) The nanoparticles circulate through the blood vessels and reach the target cells Drugs are released directly into the targeted cells,Targeted drug delivery Targeted drug delivery using a multicomponent nanoparticle containing therapeutic as well as biological surface modifying agents Mauro Ferrari, Univ. of Cal. Berkley,Nanotechnology in Health Care,The microfluidic channel with nanowire sensor can detect the presence of altered genes associated with cancer J. Heath, Cali. Insti. of Technology,The nanoscale cantilever detects the presence and concentration of various molecular expressions of a cancer cell A. Majumdar, Univ. of Cal. at Berkeley,Nanotechnology offers tools and techniques for more effective detection, diagnosis and treatment of diseases Detection and Diagnosis Lab on chips help detection and diagnosis of diseases more efficiently Nanowire and cantilever lab on chips help in early detection of cancer biomarkers,Potential Risks of Nanotechnology,Health issues Nanoparticles could be inhaled, swallowed, absorbed through skin, or deliberately injected Could they trigger inflammation and weaken the immune system? Could they interfere with regulatory mechanisms of enzymes and proteins? Environmental issues Nanoparticles could accumulate in soil, water, plants; traditional filters are too big to catch them New risk assessment methods are needed National and international agencies are beginning to study the risk; results will lead to new regulations,Toxicity of Nanomaterials,SiO2纳米颗粒能够降低支气管癌原细胞的发育能力，并且细胞的发育能力随剂量和暴露时间增加而降低 量子点（QDs）会诱导普遍的酰基化反应，致使细胞内DNA结构出