Electrical characterization of leaf-based wires & supercapacitors.

Electronic waste (e-waste) is a growing problem in the world due to increasing consumption and subsequent discarding of electronic devices. One of the ways to address this problem is to develop electronics made up of biodegradable components. Leaves are readily available, biodegradable and can be found with various types of architecture of the vascular conduits within. We investigated the possibility of developing electronic components based on leaves of a monocotyledon plant by introducing a conducting polymer inside the vascular conduits. We were able to construct conducting wires in those conduits extending to centimeters in length within a leaf. Furthermore, we were able to demonstrate the construction of a supercapacitor within a leaf by using the conducting conduits as electrodes. These results suggest the possibility of constructing embedded electronic components within leaves which may provide an alternative towards the development of biodegradable electronics.

Rate constants for hydrogen abstraction from alkoxides by a perfluoroalkyl radical. An oxyanion accelerated process.

A combination of laser flash photolysis and competitive kinetic methods has been used to measure the absolute bimolecular rate constants for hydrogen atom abstraction in water from a series of fluorinated alkoxides and aldehyde hydrates by the perfluoroalkyl radical, *CF2CF2OCF2CF2SO3- Na+. The bimolecular rate constants observed for the beta-fluorinated alkoxides were in the 10(5) M(-1) s(-1) range, such rates representing enhancements (relative to the respective alcohols) of between 100 and almost 1000-fold, depending on the reactivity of the alkoxide. Likewise, the monobasic sodium salts of chloral and fluoral hydrate exhibit similar rate enhancements, relative to their respective hydrates.

Large primary kinetic isotope effects in the abstraction of hydrogen from organic compounds by a fluorinated radical in water.

Isotope effects have been measured for the abstraction of hydrogen from a series of organic substrates by the perfluoro radical, Na+ -O3SCF2CF2OCF2CF2*, in water. Both primary and secondary deuterium isotope effects were measured, with the primary isotope effects ranging in value from 4.5 for isopropanol to 19.6 for acetic acid. The values for the alpha- and beta-secondary deuterium isotope effects were 1.06 and 1.035, respectively. It was concluded that tunneling contributes significantly to the production of the observed, large primary kinetic isotope effects in these C-H abstraction reactions.

Absolute rate constants for some hydrogen atom abstraction reactions by a primary fluoroalkyl radical in water.

A combination of laser flash photolysis and competitive kinetic methods have been used to measure the absolute bimolecular rate constants for hydrogen atom abstraction in water from a variety of organic substrates including alcohols, ethers, and carboxylic acids by the perfluoroalkyl radical, *CF(2)CF(2)OCF(2)CF(2)SO(3)(-) Na(+). Comparison, where possible, of these rate constants with those previously measured for analogous reactions in the non-polar organic solvent, 1,3-bis(trifluoromethyl)benzene (J. Am. Chem. Soc, 1999, 121, 7335) show that the alcohols react 2-5 times more rapidly in the water solvent and that the ethers react at the same rate in both solvents. A transition state for hydrogen abstraction that is more reminiscent of an "intimate ion pair" than a "solvent separated ion pair" is invoked to explain these modest solvent effects.