Nanoparticles, conductive silver

To compare the bactericidal efficacy of silver nanoparticles and silver ions, the minimum inhibitory concentration (MIC) assays were conducted for gram-negative bacterium E. coli, gram-positive bacteria S. aureus and B. subtilis and fungus P. phoeniceum. The data on MICs are summarized in Table 18.1. The results demonstrated that the antimicrobial activity of silver ions was superior to that of silver nanoparticles against all microbes tested. 

Conductive silver tracks on a poly (imide) (PI) substrate have been prepared using microwave radiation in order to sinter silver nanoparticles that have been printed on the substrate (12). Such a method shortens the sintering time. In addition, the process is independent of the substrate. When the polymer substrate, i.e., PI, is basically transparent to microwave radiation, only a negligible amount of energy is absorbed in the substrate. On the other hand, the conducting silver nanoparticles that have a high dielectric loss factor, strongly absorb the microwaves. 

Sondi I, Salopek-Sondi B (2004) Silver nanoparticles as antimicrobial agent a case study on E. coli as a model for Gramnegative bacteria. J Colloid Int Sci 275 177-182 Southward RE, Thompson DW (2001) Reflective and conductive silvered polyimide films for space applications prepared via a novel single-stage self-metallization technique. Mat Des 22 565-576... 

Fig. 17. Variation of conductivity of Ag-starch nanocomposites with temperature. Inset shows variation with concentration of silver nanoparticles.

Figure 12.8. A photograph of a traditional roto-gravure label press that has a web width of 4 in. The press consists of a single gravure head that can be used to apply conductive inks, such as nanoparticle silver suspensions, onto surface-treated polymer substrates to generate patterned interconnects and electrodes.

Li Y, Wu X, Ong BS (2005) Facile synthesis of silver nanoparticles useful for fabrication of high-conductivity elements for printed electronics. J Am Chem Soc 127 3266-3267... 

Percolation threshold pc corresponding transition to metal conductivity in composite films from Teflon with Au nanoparticles is 30 vol.% [36]. The similar transition to semiconductor conductivity in films of polyvinyl alcohol containing nanocrystals CuS takes place at pc 15-20 vol.% [88]. In cryochemically synthesized films PPX with Ag nanocrystals conductivity of metal type is achieved already in films with Ag content 7 vol.% conductivity of these composite films increases with the lowering temperature proportional to (1 — j.Ty1 similarly to that of block metals, but coefficient a is 2.5 times less than value x0, characteristic for block silver [86]. 

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