在聚合物纳米复合材料定义和研究中的应用

1、在聚合物纳米复合材料定义和研究中的应用 1991年，日本电子公司（NEC）的饭岛澄男博士在用电子显微镜观察石墨电极直流放电的产物时，发现一种新的碳结构碳纳米管（Carbon Nanotubes, CNTs），自此开辟了碳科学发展的新篇章，也把人们带入了纳米科技的新时代。 History什么是碳纳米管？ 碳纳米管是一种具有特殊结构（径向尺寸为纳米量级，轴向尺寸为微米量级、两端基本上都封口）的一维量子材料。它主要由呈六边形排列的碳原子构成数层到数十层的同轴圆管。层与层之间保持固定的距离，约为，直径一般为22Onm。 Single-wall nanotubes (left) and Multi-wa

2、ll nanotubes (right)(from Thomas Swan Company)(Iijima 1991)(Iijima & Bethune 1993)碳纳米管的分类SEM (a) and TEM (b) microphotographs of MWCNT. Morphology(a)(b)碳纳米管的制备 电弧放电法激光法化学气相沉积法（CVD） 流化床反应器碳纳米管的独特性能纳米尺寸的微结构 超高的力学性能 特殊的电学性质 热稳定性复合材料理想的填充物超高的力学性能 MaterialsElastic Modulus (MPa)Steel2 105Diamond106Carbon

3、Fibers8 105CNTsn 106 (n 1)碳纳米管的应用 1.碳纳米管/聚合物复合材料 增强材料 功能材料 2.电子器件 3.热学应用 4.储氢材料Number of journal articles and the issued and pending patents onCNTs and CNT-based polymer composites as a function of yearPerspective article: Polymer Nanocomposites Containing Carbon Nanotubes.M. Moniruzzaman, K. I. Win

4、ey. Macromolecules 2006, 39(16), 5194-5205.Exponential Increase Ajayan P. M., et al. Science 1994, 265 (5176), 1212-1214.碳纳米管/聚合物复合材料制备方法原位聚合法溶液复合法熔体复合法Polyetherimide / CNT (1 wt%) composite prepared by in-situ polymerization.Liu T.X., Tong Y.J., Zhang W.D. Compos. Sci. Technol. 2007, 67(3-4), 406-4

5、12.原位聚合法Optical microscopy images of chitosan（壳聚糖）/MWNTs nanocomposite films containing 0.8 and 2.0 wt % MWNTs.溶液复合法Melt compounding using twin-screw mixerSEM showing homogeneous dispersion ofMWNTs (1 wt%) throughout PA6 matrixZhang W. D., Shen L., Phang I. Y., Liu T. X.Macromolecules 2004, 37, 256-

6、259. Highlighted by Materials Today as a Research News: Materials Today, 2004, 7(4), p.9.Title: “Blending Provides Benefits” Nylon 6 (PA6)熔体复合法碳纳米管/聚合物复合材料 关键问题 碳纳米管在聚合物基体中的分散性和界面黏结强度。 解决途径 碳纳米管的预处理 调控碳纳米管在聚合物基体中的百分含量碳纳米管的预处理超声分散碳纳米管的化学修饰 混（单）酸回流 接枝Functionalization of MWNTsTypical TEM image illustr

7、ating the graphitic layer structure of a MWNT with curvature and defects on one side of the CNTs at higher magnification.Main Purposes: (1) To improve solubility (2) To enhance compatibility with matricesFunctionalization of MWNTsPreparation and Mechanical Properties of Chitosan/Carbon Nanotubes Com

8、positesShao-Feng Wang, Lu Shen, Wei-De Zhang, and Yue-Jin TongBiomacromolecules 2006, 7, 1280-1284研究实例Introduction 甲壳素是一种丰富的天然生物有机高聚物。壳聚糖是一种甲壳素脱乙酰基后的产物。化学名为-1，4，2-氨基-2-脱氧-D-葡萄糖，是由大部分的D-氨基葡萄糖和少量的N-乙酰-D-氨基葡萄糖，以-1，4糖苷键连起来的直链多糖。 Preparation of Materials Chitosan of high molecular weight (Mv average mole

9、cular weight =182 500 gmol-1) MWNTs (CVD): Co-Mo/MgO catalysts VH2SO4:VHNO3=1:2Experimental Section2.2 Preparation of the Nanocomposites Films MWNTs+100 mL of distilled water60 minultrasonic bathshaken for 1 hmixture1 mL of acetic acid 1 g of chitosanmixturesonication 20 minchitosan/MWNTs solutionsp

10、oured into a plastic dish 50dried uniform thin films(0.08 mm)SEM images showing an overall morphology of a failuresurface for chitosan/0.8%MWNTs nanocomposite: (A) low magnification;(B) high magnification; (C)chitosan/2.0%MWNTs nanocomposite.TEM image of a thin section of the chitosan/0.8%MWNTsnanoc

11、omposite.Optical microscopy images of chitosan/MWNTs nanocomposite films containing 0.8 and 2.0 wt % MWNTs. Typical stress-strain curves of neat chitosan and itsMWNTs nanocomposite at a crosshead speed of 5 mm/min. (B)Tensile modulus (E) and yield strength of chitosan/MWNTsnanocomposites as a functi

12、on of MWNTs concentration.Mechanical Properties of Neat Chitosan and Its MWNTs NanocompositesConclusions This paper first reports the high-performance biopolymer chitosan/MWNTs nanocomposites pr-epared by a simple solution-evaporation method.The homogeneous dispersion of MWNTs in the matrix dramatic

13、ally improved the mechanical properties of the chitosan. When compared to those of neat chitosan, with incorporation of only 0.8 wt % MWNTs, the tensile modulus and strength of the nanocomposites are greatly improved by about 93% and 99%, respectively.Melt compounding using twin-screw mixerSEM showi

14、ng homogeneous dispersion ofMWNTs (1 wt%) throughout PA6 matrixZhang W. D., Shen L., Phang I. Y., Liu T. X.Macromolecules 2004, 37, 256-259. one typical example, Nylon 6 (PA6)研究实例AB1 wt% MWNTsDispersion Morphology by TEMTensile PropertyInteraction of functionalized CNTs with polymer chainsInteractio

15、n of polymeric matrix with functionalized MWNTs (with defects)Polymer ChainsFunctional GroupsDefects on MWNTs多壁碳纳米管/聚乳酸纳米复合材料的形态、结晶行为和性能的研究 专 业：材料学 答辩人: 赵媛媛导 师：邱兆斌 教授北京化工大学硕士学位论文答辩2009年4月10日 论文的研究目的及意义选取PLLA为基体，以MWNTs作为增强材料，通过溶液超声法制备综合性能更为优越的PLLA/MWNTs纳米复合材料，对其进行改性研究；MWNTs化学修饰与否及百分含量将对其在PLLA基体中的分散性、

16、形态以及PLLA的结晶行为、力学性能和水解行为产生影响；探索聚合物结构与性能之间的关系，达到改善性能和拓展应用领域的目的。尤其是我国将对PLLA进行规模化生产，对其的综合性能进行改善以促进其应用是非常具有现实意义的。 34 纳米复合材料样品制备PLLA ：由Biomer公司（德国）提供，Mw =2.06105 f-MWNTs和p-MWNTs：均购于四川成都有机研究所，直径3050nm. 长度10-20m三氯甲烷（氯仿）：北京化工厂，分析纯PLLA/p-MWNTs和PLLA/f-MWNTs nanocomposites35常温超声1h 常温搅拌溶解 MWNTs-CHCl3悬浮液 PLLA溶液 超

17、声搅拌6h 常温挥发 70真空干燥2天 共混液 复合材料膜 MWNTs+CHCl3PLLA+CHCl3 表 征 扫描电镜（SEM）和透射电镜（TEM） 差示扫描量热仪（DSC） 偏光显微镜（POM） 广角X射线衍射（WAXD） 水解实验（HYDROLYTIC TESTING）36 Figure 1. SEM images showing an overall morphology of surfaces for the nanocomposites: (a) PLLA/p-MWNTs and (b) PLLA/f-MWNTs. Figure 2. TEM images showing nano

18、tubes dispersion from the ultrathin section of PLLA nanocomposites: (a) PLLA/p-MWNTs and (b) PLLA/f-MWNTs. Effect of functionalization of MWNTsNonisothermal melt crystallization behavior and subsequent melting behavior Figure 3. Nonisothermal melt crystallization and subsequent melting traces of nea

19、t PLLA and its nanocomposites: (a) first cooling and (b) second heating. Table.1. DSC results for the PLLA and its nanocomposites.SampleTca (oC)Hca (J/g)Tg (oC)Tchb (oC)Hchb (J/g)Tm (oC)Hm (J/g)Wc c(%)Neat PLLAPLLA/p-MWNTsPLLA/f-MWNTs96.0101.4102.7-4.22-30.5-35.261.762.562.6132.319.0167.9169.2169.32

20、4.132.936.65.5035.439.4a Melt crystallization at a cooling rate of 5 oC/min (first cooling).b Cold crystallization at a heating rate of 20 oC/min (second heating).c Degree of crystallinity, Wc (%) =100 (Hm-Hch)/Hm0Table.1 DSC results for the PLLA and its nanocomposites. 等温结晶以20/min的升温速率从室温升高到190，恒温3

21、min，消除热历史后，以40/min的降温速率降到一定温度(117.5、120、122.5、125、127.5)，再以20/min的升温速率升高到200。Figure 4. Effect of p-MWNTs and f-MWNTs on the crystallization of PLLA at 125C: (a) development of relative crystallinity with crystallization time and (b) the Avrami plots.Table 2. Crystallization kinetic parameters for ne

22、at PLLA and its nanocompositesSamplesTc (C )nkNeat PLLA410-2120.02.28.9210-3510-3125.02.49.5710-4910-4PLLA/p-MWNTs 710-2120.02.71.8510-2110-2125.02.63.7510-3310-3PLLA/f-MWNTs710-1120.02.83.9810-2310-2125.02.77.82

23、10-3610-32. Isothermal melt crystallization Figure 5. Temperature dependences of (a) t and (b) 1/t for neat PLLA and its nanocomposites. 3. POM Figure 6. Spherulitic morphologies of (a) neat PLLA, (b) PLLA/p-MWNTs, and (c) PLLA/f-MWNTs crystallized at 140 C by POM.Figure 7. WAXD patterns

24、of neat PLLA and its nanocomposites.Table 3. WAXD data for neat PLLA and its nanocomposites.Samplesd010(nm)d200(nm)d203(nm)a(nm)b(nm)c(nm)V (nm3)Neat PLLA0.5960.5300.4661.0610.5962.9191.845PLLA/p-MWNTs 0.6130.5430.4761.0870.6132.9641.974PLLA/f-MWNTs0.6280.5530.4821.1060.6282.9612.0544. XRDFigure 8.

25、Variation of weight loss with hydrolytic degradation time for neat PLLA and its nanocomposites.Table.4. The data summarized from mass loss rate of neat PLLA and its nanocomposites . Mass loss (%) 246810121620 Neat PLLA9.2422.3729.8544.8348.1557.6365.5270.34PLLA/p-MWNTs18.9928.0841.8450.6855.2865.607

26、5.3782.6PLLA/f-MWNTs17.1629.7147.1054.9160.3869.1380.0085.60 Hydrolytic degradation test Effect of the f-MWNTs loading on the dispersion and morphology Figure 9. SEM images of fracture surfaces for (a) PLLA/f-MWNTs 0.5 and (b) PLLA/f-MWNTs 2.0 nanocomposites. Nonisothermal melt crystallization and subsequent melting behavior Figure 10. Nonisothermal melt crystallization and subsequent melting traces of neat PLLA and its nanocomposites; (a) first cooling and (b) second heating. Figure 11. Effect of f