在聚合物納米復(fù)合材料定義和研究中的應(yīng)用

1、在聚合物納米復(fù)合材料定義和研究中的應(yīng)用 1991年，日本電子公司（NEC）的飯島澄男博士在用電子顯微鏡觀察石墨電極直流放電的產(chǎn)物時(shí)，發(fā)現(xiàn)一種新的碳結(jié)構(gòu)碳納米管（Carbon Nanotubes, CNTs），自此開辟了碳科學(xué)發(fā)展的新篇章，也把人們帶入了納米科技的新時(shí)代。 History什么是碳納米管？ 碳納米管是一種具有特殊結(jié)構(gòu)（徑向尺寸為納米量級(jí)，軸向尺寸為微米量級(jí)、兩端基本上都封口）的一維量子材料。它主要由呈六邊形排列的碳原子構(gòu)成數(shù)層到數(shù)十層的同軸圓管。層與層之間保持固定的距離，約為，直徑一般為22Onm。 Single-wall nanotubes (left) and Multi-wa

2、ll nanotubes (right)(from Thomas Swan Company)(Iijima 1991)(Iijima & Bethune 1993)碳納米管的分類SEM (a) and TEM (b) microphotographs of MWCNT. Morphology(a)(b)碳納米管的制備 電弧放電法激光法化學(xué)氣相沉積法（CVD） 流化床反應(yīng)器碳納米管的獨(dú)特性能納米尺寸的微結(jié)構(gòu) 超高的力學(xué)性能 特殊的電學(xué)性質(zhì) 熱穩(wěn)定性復(fù)合材料理想的填充物超高的力學(xué)性能 MaterialsElastic Modulus (MPa)Steel2 105Diamond106Carbon

3、Fibers8 105CNTsn 106 (n 1)碳納米管的應(yīng)用 1.碳納米管/聚合物復(fù)合材料 增強(qiáng)材料 功能材料 2.電子器件 3.熱學(xué)應(yīng)用 4.儲(chǔ)氫材料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.碳納米管/聚合物復(fù)合材料制備方法原位聚合法溶液復(fù)合法熔體復(fù)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（殼聚糖）/MWNTs nanocomposite films containing 0.8 and 2.0 wt % MWNTs.溶液復(fù)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)熔體復(fù)合法碳納米管/聚合物復(fù)合材料 關(guān)鍵問題 碳納米管在聚合物基體中的分散性和界面黏結(jié)強(qiáng)度。 解決途徑 碳納米管的預(yù)處理 調(diào)控碳納米管在聚合物基體中的百分含量碳納米管的預(yù)處理超聲分散碳納米管的化學(xué)修飾 混（單）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研究實(shí)例Introduction 甲殼素是一種豐富的天然生物有機(jī)高聚物。殼聚糖是一種甲殼素脫乙?；蟮漠a(chǎn)物?；瘜W(xué)名為-1，4，2-氨基-2-脫氧-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糖苷鍵連起來的直鏈多糖。 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)研究實(shí)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多壁碳納米管/聚乳酸納米復(fù)合材料的形態(tài)、結(jié)晶行為和性能的研究 專 業(yè)：材料學(xué) 答辯人: 趙媛媛導(dǎo) 師：邱兆斌 教授北京化工大學(xué)碩士學(xué)位論文答辯2009年4月10日 論文的研究目的及意義選取PLLA為基體，以MWNTs作為增強(qiáng)材料，通過溶液超聲法制備綜合性能更為優(yōu)越的PLLA/MWNTs納米復(fù)合材料，對(duì)其進(jìn)行改性研究；MWNTs化學(xué)修飾與否及百分含量將對(duì)其在PLLA基體中的分散性、

16、形態(tài)以及PLLA的結(jié)晶行為、力學(xué)性能和水解行為產(chǎn)生影響；探索聚合物結(jié)構(gòu)與性能之間的關(guān)系，達(dá)到改善性能和拓展應(yīng)用領(lǐng)域的目的。尤其是我國將對(duì)PLLA進(jìn)行規(guī)?；a(chǎn)，對(duì)其的綜合性能進(jìn)行改善以促進(jìn)其應(yīng)用是非常具有現(xiàn)實(shí)意義的。 34 納米復(fù)合材料樣品制備PLLA ：由Biomer公司（德國）提供，Mw =2.06105 f-MWNTs和p-MWNTs：均購于四川成都有機(jī)研究所，直徑3050nm. 長(zhǎng)度10-20m三氯甲烷（氯仿）：北京化工廠，分析純PLLA/p-MWNTs和PLLA/f-MWNTs nanocomposites35常溫超聲1h 常溫?cái)嚢枞芙?MWNTs-CHCl3懸浮液 PLLA溶液 超

17、聲攪拌6h 常溫?fù)]發(fā) 70真空干燥2天 共混液 復(fù)合材料膜 MWNTs+CHCl3PLLA+CHCl3 表 征 掃描電鏡（SEM）和透射電鏡（TEM） 差示掃描量熱儀（DSC） 偏光顯微鏡（POM） 廣角X射線衍射（WAXD） 水解實(shí)驗(yàn)（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. 等溫結(jié)晶以20/min的升溫速率從室溫升高到190，恒溫3

21、min，消除熱歷史后，以40/min的降溫速率降到一定溫度(117.5、120、122.5、125、127.5)，再以20/min的升溫速率升高到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