自組裝單分子薄膜

1、前言納米材料的表面或界面（Surface & Interface）決定著材料的宏觀性質(zhì)。有人把物質(zhì)的表面層稱做是物質(zhì)的第四種狀態(tài) 。人們通過控制和改變固體表面化學組成獲得具有特定性能的材料。 圖1 自組裝單層膜結(jié)構(gòu)示意圖自組裝單分子薄膜SAMs 的優(yōu)點制備方法簡單SAMs 的優(yōu)點不受基底形狀的限制：無論曲面還是平面 納米球SAMs 的優(yōu)點與基底結(jié)合牢固，穩(wěn)定性高，自組裝分子一般都是與基底以化學鍵結(jié)合，分子鏈間主要以范德華力相互作用；薄膜結(jié)構(gòu)靈活可控，從分子和結(jié)構(gòu)設(shè)計入手，可同時在分子水平和材料水平上實現(xiàn)對薄膜結(jié)構(gòu)的調(diào)控 自組裝單分子薄膜為研究表面現(xiàn)象提供了一個理想的模型，如邊界潤滑、生物傳遞、

2、表面能的控制等，它還在摩擦學、材料學、電子學、非線性光學等諸多領(lǐng)域有重要的應用基礎(chǔ)研究價值。 SAMs的種類長鏈酸類自組裝單層膜 圖 3 Al2O3及AgO表面上長鏈羧酸單層膜的結(jié)構(gòu)示意圖SAMs的種類烷基硫醇類化合物在金屬表面形成的SAMs 圖 4 金基底上含有奇、偶數(shù)目亞甲基長直鏈硫醇的結(jié)構(gòu)示意圖 SAMs的種類有機硅烷類SAMs 圖 5 基底與單層薄膜界面上聚硅氧烷的結(jié)構(gòu)示意圖。SAMs在分子電子學中應用 分子電子學研究的是分子水平上的電子學，其目標是用單個分子、超分子或分子簇代替硅基半導體晶體管等固體電子學元件組裝邏輯電路，乃至組裝完整的分子計算機。 SAMs在分子電子學中應用SAMs

3、在生物學中應用常用儀器掃描探針顯微鏡（SPM）云母的原子STM圖原子力顯微鏡AFM常用儀器橢圓偏光測厚儀衰減全反射紅外光譜反射紅外光譜常用儀器常用儀器X光電子能譜（XPS）XPS ，全稱為X-ray Photoelectron Spectroscopy，是一種基于光電效應的電子能譜，它是利用X射線光子激發(fā)出物質(zhì)表面原子的內(nèi)層電子，通過對這些電子進行能量分析而獲得的一種能譜。 博士論文工作博士論文工作自組裝有機薄膜的內(nèi)在結(jié)構(gòu)與摩擦學性能 含酰胺鍵自組裝單分子薄膜 ITPOA 預水解48h 環(huán)己烷稀釋，沉積24hSY Song et al Langmuir 2006,22, 6010-6015.制

4、備過程結(jié)構(gòu)示意圖SY Song, et al The Journal of Physical Chemistry C, 2008, 112, 3805-3810. 含酰胺鍵自組裝單分子薄膜 II含酰胺鍵自組裝單分子薄膜 IIIDAC18薄膜的理想結(jié)構(gòu)。疏水性，承載能力降低摩擦系數(shù)氨基表面密度高，雙層氫鍵的形成，提高摩擦穩(wěn)定性原子力形貌圖(a)(b)RMS: 0.15 nmRMS: 0.20 nmDA和DAC18膜表面的原子力形貌圖，掃描范圍500nm500nm，豎直方向高度范圍2nm。衰減全反射紅外光譜DA膜和DAC18膜的衰減全反射紅外光譜。 SY Song et al Langmuir,

5、2008, 24, 105-109. 新加坡國立大學博后工作Single-Molecule Force and Fluorescence Lab R. Liu et al Biophysical Journal 96(9), 3810-3821 (2009)在河南大學的科研仿關(guān)節(jié)軟骨結(jié)構(gòu)水凝膠薄膜聚合物刷水凝膠表面引發(fā)原子轉(zhuǎn)移自由基聚合POMA聚合物膜在氨基自組裝膜表面的形成示意圖。SY Song et al Applied Surface Science 2011,257,10254. POMA聚合物薄膜pH敏感聚合物膠束Nanomedicine Nanomedicine is the ap

6、plication of nanotechnology in medicine, including to cure diseases and repair damaged tissues such as bone, muscle, and nerveKey Goals for NanomedicineTo develop cure for traditionally incurable diseases (e.g. cancer) through the utilization of nanotechnologyTo provide more effective cure with fewe

7、r side effects by means of targeted drug delivery systemsNanotechnology in Health Care Thermal ablation of cancer cells assisted by nanoshells coated with metallic layer and an external energy source National Cancer InstituteThermal ablation of cancer cellsNanoshells have metallic outer layer and si

8、lica coreSelectively attracted to cancer shells either through a phenomena called enhanced permeation retention or due to some molecules coated on the shellsThe nanoshells are heated with an external energy source killing the cancer cellsNanotechnology in Health Care TreatmentTargeted drug deliveryN

9、anoparticles containing drugs are coated with targeting agents (e.g. conjugated antibodies)The nanoparticles circulate through the blood vessels and reach the target cellsDrugs are released directly into the targeted cellsTargeted drug delivery Targeted drug delivery using a multicomponent nanoparti

10、cle containing therapeutic as well as biological surface modifying agents Mauro Ferrari, Univ. of Cal. BerkleyNanotechnology in Health Care The microfluidic channel with nanowire sensor can detect the presence of altered genes associated with cancer J. Heath, Cali. Insti. of TechnologyThe nanoscale

11、cantilever detects the presence and concentration of various molecular expressions of a cancer cell A. Majumdar, Univ. of Cal. at BerkeleyNanotechnology offers tools and techniques for more effective detection, diagnosis and treatment of diseasesDetection and DiagnosisLab on chips help detection and

12、 diagnosis of diseases more efficiently Nanowire and cantilever lab on chips help in early detection of cancer biomarkersPotential Risks of NanotechnologyHealth issuesNanoparticles could be inhaled, swallowed, absorbed through skin, or deliberately injectedCould they trigger inflammation and weaken

13、the immune system? Could they interfere with regulatory mechanisms of enzymes and proteins?Environmental issuesNanoparticles could accumulate in soil, water, plants; traditional filters are too big to catch themNew risk assessment methods are neededNational and international agencies are beginning to study the risk; results will lead to new regulationsToxicity of NanomaterialsSiO2納米顆粒能夠降低支氣管癌原細胞的發(fā)育能力，并且細胞的發(fā)育能力隨劑量和暴露時間增加而降低量子點（QDs）會誘導普遍的?；磻?，致使細胞內(nèi)DNA結(jié)構(gòu)出現(xiàn)紊亂，并在