聚合物纳米复合材料.ppt

1、聚合物纳米复合材料,卢红斌 博士、副教授 复旦大学高分子科学系 跃进楼210室 电话：55664589（办） Email:,2004年10月13日,Flexible chain,Stiff chain,Semi-Stiff chain,C T E,Low,High,Molecular Structure Adjustment,Topological Structure Adjustment,No polymer network No particle network,Polymer network + local particle network,Interpenetrating polyme

2、r and particle networks,Contribution to CTE and mechanical properties,Low,High,(1) Structural adjustment,(2) Low CTE Nanoparticles,Montmorillonite,Attapulgite,MWCNT,Polyoxometalate,研究思路,固体颗粒表面改性,(2) Attapulgite (ATT),(1) Montmorillonite (MMT),(3) Multiwall Carbon Nanotubes (MWCNT),(4) Polyoxometalat

3、e (POM),Na+,Na+,Na+,Na+,Na+,Na+,Ion Exchange,-OH,-OH,-OH,Activation, Covalently Bonding,Oxidation, Functionalization,Coordination/Anion Exchange,蒙脱土/环氧纳米复合材料-受限松弛 （1）,相同条件下的纯树脂和复合材料的DSC 曲线：10 oC/min,相同过冷度下的不同材料的焓松弛比较：Tg-20 oC 退火372小时,Anastasiadis, S.H., Phys. Rev. Lett. 2000, 84(5):915-918 (Greece);

4、,Hongbin Lu, Steven Nutt, Macromolecules, 2003, 36(11):4010-4016,蒙脱土/环氧纳米复合材料-受限松弛 （2）,受限松弛的唯象解释 (1),Dh*,x,b,Tf=Tg,Temperature, T,Heat capacity or enthalpy, Cp or Sc,Non-equilibrium glass,Equilibrium liquid,Non-Debye relaxation process,Sc, Tf,Segmental Relaxation,Nonlinearity:,Nonexponentiality:,（TN

5、M Model）,受限松弛的唯象解释 (2),Using cooperatively rearranging concept to elucidate the change in configurational entropy during segmental motions.,High surface area + Good interface adhesion,Lower configurational entropy,Slower segmental motion,Good stability and mechanical properties,Results,Overview,Adam

6、-Gibbs model:,Hongbin Lu, Steven Nutt, Macromol. Chem. Phys. 2003, 204: 1832-1841,(C. A. Angell et al, Nature, 2001, 410, 663-667),玻璃化转变的热力学动力学相关性,玻璃化转变的构象熵模拟,Configurational Entropy Model:,(Gomez Ribelles, J. L. et al. Macromolecules, 1995, 28, 5867; 1995, 28, 5878. ),构象熵模拟结果,热力学和动力学脆性之间：反相关,热力学和动力

7、学之间的联系,我们的建议：,然而,m 16 ?,Hongbin Lu, Steven Nutt, Macromolecules, submitted,棒状硅酸盐/环氧纳米复合材料,棒状硅酸盐/环氧纳米复合材料-实验结果,Hongbin Lu, Steven Nutt et al., Adv. Mater., submitted,Discovered by Iijima in 1991 Outstanding properties: Tensile modulus SWNT: 1.25 TPa ; 56 times higher than steel wire 1.7 times higher

8、than silicon carbide nanonods Electrical conductivity 104 S/cm; higher than amorphous metal Calcium-Aluminum (103 S/cm) Thermal conductivity MWNT: 3000 W/m-K; higher than graphite (2000 W/m-K) Thermal expansion coefficient SWNT: -1.5 ppm K-1,多壁碳纳米管/环氧纳米复合材料,Two critical issues Uniform dispersion Goo

9、d interfacial adhesion Current strategy (Covalent bonding and Noncovalent bonding) Covalent Functionalization Sonication,Acylchloride:,Fluorination:,多壁碳纳米管/环氧纳米复合材料,Advantages: (1) rather mild reaction conditions (reflux at 80 oC) (2) shorter reaction time ( 1 h) (3) higher functionalization efficie

10、ncy ( 4 wt %),Simple Functionalization Method with Commercial Potential,多壁碳纳米管/环氧纳米复合材料,Only characteristic adsorptions of amine groups, no isocyanate groups 3.7 0.9 % weight loss of organic molecules,多壁碳纳米管/环氧纳米复合材料,MWNTs,MWNTs-epoxy Composites,多壁碳纳米管/环氧纳米复合材料,MWNT-Epon 862-DDM Nanocomposites (DMA)

11、,多壁碳纳米管/环氧纳米复合材料,Two important factors: Exclusive volume effect below Tg Confined segmental motions above Tg,多壁碳纳米管/环氧纳米复合材料,(Wei, Nano Letters, 2002, 2, 647),Dynamics simulation for SWNT-PS: CTE increases, whether in rubber state or in glass state,Neutron reflectivity experiments: CTE decreases in

12、the rubber state, due to the boundary confinement of polymer films,(Pochan, Macromolecules, 2001, 34, 3041),多壁碳纳米管/环氧纳米复合材料,即将开展的工作,零膨胀有机高分子材料 有机热电材料 受限链段动力学 聚合物纳米复合材料流变学,DSPN Components: Low CTE Inorganic Nanoparticles,1. Mesoporous nanoparticles:,ZrW2O8 (CTE = -8.510-6 K-1) HfW2O8 (CTE = -5.310-6

13、K-1),2. Nanobuilding blocks:,(SiW10O36(RPO)2)4-) Zr10O6(OH)4(OPr)18(AAA)6,(Inorganic clusters with low CTE),Mesoporous particle,Polymer molecules,New Concepts and New Materials,零膨胀材料,应用前景、研究现状,加电制冷绿色冰箱，红外传感器制冷，电脑芯片制冷等; 温差发电太阳能热电转换电池，热机式原子能电池，人 造卫星电源等。,Brian C. Sales, Science, 2002, 295, 1248,有机热电材料,

14、家用冰箱的能量转换效率（卡诺系数）：30 大型中央空调设备的卡诺系数： 90 现有热电材料(ZT 1.0)的卡诺系数： 10,基本原理、性能参数,Seebeck 效应：温差产生电流 Peltier 效应： 电场导致冷却,热电优值 ZT = S2sT/k,热电性能表征,S Seebeck 系数；s 电导率；k 热导率。,有机热电材料,最好的热电材料PbSeTe/PbTe QDSL,ZT = 2.0 at 300 K, k = 3.3 W/m.K, DT = 42.7 K,T. C. Harman, P. J. Taylor, M. P. Walsh, B. E. LaForge Science, 2002,