Use of Dendrimers to Control Nanoparticle Size in Polymer-Metal Nanocomposites for Embedded Capacitor Application

摘要

Nanoparticles have been an object of constant interest due to many exotic properties they exhibit due to their small size. The small size results in extremely high surfaces of nanoparticles, which in turn may lead to unique physical (solubility, optical, electronic, magnetic, physical and mechanical) and/or chemical behavior. Polymer metal nanocomposites have been previously used as high dielectric constant materials in embedded capacitor applications. Yang Rao and C.P.Wong (52{sub}ndECTC, 2002) have already shown that a very high dielectric constant (～1000) can be achieved by incorporating metal fillers into epoxy. Previous study by these authors (paper in submission for publication) focused on an in-situ reduction of metal precursor in a polymer matrix. But through that method it is not possible to specifically tailor the size and control the position of the nanoparticles in the cured polymer. To overcome this drawback and also to achieve self assembled structures it is advantageous to use dendrimers. By this approach, the dielectric properties of the polymer nanocomposite could be tailored exactly, in the present study dendrimers are used as templates to pre-organize metal ions followed by an in-situ reduction, which will immobilize and stabilize atomic domains of the reaction products. Size, shape, size distribution and surface functionality of these nanocomposites are determined and controlled by the dendritic macromolecules and may also be influenced by the encapsulated compounds. Surface modified poly(amido-amine) (PAMAM) dendrimers are used to prepare {Ag(0)-PAMAM} dendrimer-metal nanocomposites containing stable zero valence metals. Characterization of the resulting nanocomposites would be done through TEM, FT-IR and LCR meter. The structure property relationship would be deduced.