A symbiotic-like biologically-driven regenerating fabric

Living organisms constantly maintain their structural and biochemical integrity by the critical means of response, healing, and regeneration. Inanimate objects, on the other hand, are axiomatically considered incapable of responding to damage and healing it, leading to the profound negative environmental impact of their continuous manufacturing and trashing. Objects with such biological properties would be a significant step towards sustainable technology. In this work we present a feasible strategy for driving regeneration in fabric by means of integration with a bacterial biofilm to obtain a symbiotic-like hybrid - the fabric provides structural framework to the biofilm and supports its growth, whereas the biofilm responds to mechanical tear by synthesizing a silk protein engineered to self-assemble upon secretion from the cells. We propose the term crossbiosis to describe this and other hybrid systems combining organism and object. Our strategy could be implemented in other systems and drive sensing of integrity and response by regeneration in other materials as well

Electroreduction of sulfur dioxide in some room-temperature ionic liquids

The mechanism of sulfur dioxide reduction at a platinum microelectrode was investigated by cyclic voltammetry in several room-temperature ionic liquids (RTILs) - [C2mim][NTf2], [C4mim][BF 4], [C4mim][NO3], [C4mim]-[PF 6], and [C6mim][Cl] where [C2mim] is l-ethyl-3- methylimidazolium, [C4mim] is l-butyl-3-methylimida-zolium, [C 6mim] is l-hexyl-3-methylimidazolium, and [NTf2] is bis(trifluoromethylsufonyl)imide - with special attention paid to [C 4mim][NO3] because of the well-defined voltammetry, high solubility, and relatively low diffusion coefficient of SO2 obtained in that ionic liquid. A cathodic peak is observed in all RTILs between -2.0 and -1.0 V versus a silver quasi-reference electrode. In [C4mim][NO 3], the peak appears at -1.0 V, and potential step chronoamperometry was used to determine that SO2 has a very high solubility of 3100 (±450) mM and a diffusion coefficient of 5.0 (±0.8) × 10-10 m2 s_1 in that ionic liquid. On the reverse wave, up to four anodic peaks are observed at ca. -0.4, -0.3, -0.2, and 0.2 V in [C4mim][NO3]. The cathodic wave is assigned to the reduction of SO2 to its radical anion, SO2-̇. The peaks at -0.4 and -0.2 V are assigned to the oxidation of unsolvated and solvated SO2-, respectively. The peak appearing at 0.2 V is assigned to the oxidation of either S2O 42- or S2O4-̇. The activation energy for the reduction of SO2 in [C4mim] [NO3] was measured to be 10 (±2) kJ mol-1 using chronoamperometric data at different temperatures. The stabilizing interaction of the solvent with the reduced species SO2-̇ leads to a different mechanism than that observed in conventional aprotic solvents. The high sensitivity of the system to SO2 also suggests that [C 4mim][NO3] may be a viable solvent in gas sensing applications. © 2008 American Chemical Society