Chemical Lasers
The laser, an acronym for light amplification by stimulated emission of radiation, is a source of nearly monochromatic, coherent, electromagnetic radiation that propagates as a beam. The chemical laser is a type of laser system that is driven by the release of energy during a chemical reaction. Chemical lasers are usually large, high power devices that integrate chemical delivery systems, a supersonic flow apparatus, and an optical resonator.
An electronic transition chemical laser
cw laser action was achieved on the 2P1/2→2P3/2 transition of the iodine atom by energy transfer from the 1Δ metastable state of O2. The excited oxygen was generated chemically by flowing chlorine gas through a basic solution of 90% H2O2. The effluent from the oxygen generator was mixed with molecular iodine at the entrance of a longitudinal flow laser cavity where the I2 was dissociated by a small amount of O2(1Σ) that was present in the flow due to energy pooling processes. The measured output power was greater than 4 mW.
Electrochemical detection of copper(II) at a gold electrode modified with a self-assembled monolayer of penicillamine
A penicillamine (PCA) self-assembled monolayer (SAM) was prepared on a gold electrode. It has been found that the modified electrode exhibited a selective response to copper ions. As demonstrated by cyclic voltammetric experiments, the SAM-based electrode showed an attractive ability to preconcentrate efficiently traces of copper(II) from solutions. Under optimum conditions, the anodic peak current was proportional to the concentration of Cu(II) in the range from 8.0 × 10−7 to 1.0 × 10−4 M with a detection limit of 4.0 × 10−7 M. Moreover, this modified gold electrode is also characterized by excellent repeatability, showing a relative standard deviation of 3.2% for nine successive measurements of 1.0 × 10−5 M Cu(II). The PCA/Au SAM gold electrode was used for the determination of Cu(II) in a tap water sample and the results showed a good agreement with the data obtained by atomic emission spectrometry.