Chemical Faraday cages

Due to the pyramidalization of the C atoms and the rigid cage structure of Cjq the outer convex surface is very reactive towards addition reactions but at the same time the inner concave surface is inert (chemical Faraday cage). This allows the encapsulation, observation and tuning of the wavefimction of extremely reactive species that otherwise would immediately form covalent bonds with the outer surface. 

Pietzak. B. Waiblinger M. Murphy, T.A. Weidinger. A. Hohne. M. Dietel, E. Hirsch. A. Buckminsterfullerene Ceo A chemical Faraday cage for atomic nitrogen. Chem. Phys. Lett. 1997. 279 (5-6). 259-263. 

The plasma polymerization of TFE by itself and mixed with inert gases has been studied in the field-free zone inside a Faraday cage by Buzzard et al. [737]. The chemical structure of the products were analyzed by XPS, revealing linear and branched molecules. Linear chains are formed by less energetic plasma and at low monomer residence times. 

Figure 25 Faraday cage used by Fasso et al. (1982) (With permission of Elsevier Science) (a) and examples of electrostatic probes of Soo et al. (1964) (Reprinted with permission from Ind. Eng. Chem. Fundam., 1964, 3, 98-106 Copyright 1964 American Chemical Society) (b) and Boland and Geldart (1971) (With permission of Elsevier Science) (c).

A specific problem related to enzyme sensors is their restricted shelf life, since enzymes are not very stable. In dry state, they can be stored for some time. Disposable sensors are activated when they are humidified but lose their activity soon after use. Efforts are being made to improve the stability of enzyme sensors by chemical treatment. It has been proposed that the active substance in polyelectrolytes be immobilized with polysugars (Gibson and Hulbert 1993). The enzyme-polyelectrolyte complex formed seems to be stabilized electrostatically by some kind of Faraday cage. In this way, the enzyme activity remains preserved somewhat longer. 

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