Deposition of Nanocomposites by Plasmas

Abstract

Recently, there is much interest in nanocomposites consisting of metal nanoparticles dispersed in a dielectric matrix due to their novel functional properties offering hosts of new applications. Polymers are particularly attractive as matrix. Consequently, various approaches have been reported to incorporate metal nanoparticles into polymers. The present review is mainly concerned with the preparation of polymer-based nanocomposites by co-and tandem sputtering of metallic and organic components and the resulting functional properties. Different from typical wet chemical approaches, this vapor phase deposition technique allows the preparation of composites which contain alloy clusters of well defined composition. Emphasis is placed on soft-magnetic high frequency materials with cut-off frequencies well above 1 GHz and optical composites with tuned plasmon resonances suitable for ultrathin color filters, Bragg reflectors, and other devices. In addition, antibacterial coatings are addressed.

Effect of gold alloying on stability of silver nanoparticles and control of silver ion release from vapor-deposited Ag–Au/polytetrafluoroethylene nanocomposites

“…The sputtering process of PTFE results in the deposition of a highly crosslinked flouropolymer film where surface structure and contact angle determination were shown in our group's previous work of Schürmann et al [18] and Hassel et al [19]. The detailed procedure of polymer vapor deposition is described in our previous work [20]. The experiment was done in a homemade stainless steel vacuum chamber, which was initially evacuated to a pressure below 10 −6 mbar.…”

Metal‐Polymer Nanocomposites for Functional Applications

“…While extensive research has been carried out in the field of structural polymer-based nanocomposites [1][2][3] much less investigations have been concerned with polymer nanocomposites for functional applications. [4][5][6][7] Among the functional nanomaterials, nanocomposites consisting of metal nanoparticles dispersed in a dielectric matrix are of particular interest due to their novel properties offering hosts of new applications. [4,8,9] Functional properties obtained by embedding metallic nanoparticles in a dielectric matrix include electronic conductivity ranging from single-electron hopping and tunneling to percolation, [10] particle surface plasmon resonances giving rise to characteristic optical features [11] explored in the new field of plasmonics, [12] magnetic properties governed by ferromagnetic single domain behavior or superparamagnetism, [13] granular giant magnetoresistance, [14] and enhancement of catalytic activity owing to the large effective surface area of the nanoparticles and the marked contribution of the surface energy to the chemical potential.…”

Metal-polymer nanocomposite with stable plasmonic tuning under cyclic strain conditions

“…[14][15][16] An alternative approach is based on the mixing of preformed nanoparticles in a solvent subsequently used to prepare the polymer. 17,18 These methods present several weaknesses such as the poor control of spatial distribution and aggregation of the dispersed nanoparticles, not to mention the limited amount of nanoparticles that can be dispersed without negatively affecting the polymerization process of the matrix.…”

“…17,18 These methods present several weaknesses such as the poor control of spatial distribution and aggregation of the dispersed nanoparticles, not to mention the limited amount of nanoparticles that can be dispersed without negatively affecting the polymerization process of the matrix. 15 The functionalization of elastomeric surfaces with noble metal nanoparticles has been proposed as an alternative to obtain stretchable plasmonic nanocomposites: this approach allows a very precise control of nanoparticle size and reciprocal distance; however, surface-functionalized elastomers are quite fragile and their stability has not yet been characterized. [11][12][13] In view of applications, a fundamental issue is the stability of the nanocomposite optical properties upon cyclic strain conditions; to date, no characterization of this aspect is reported in the literature, although there are clear evidences that nanoparticles in an elastomeric matrix are a dynamic system undergoing rearrangement and reorganization upon stretching.…”