Immobilization of Actinides by Electropolymerization of Acrylonitrile : Application to the Preparation of Alpha Spectroscopy Sources

Abstract

Electrochemistry / Electropolymerization / Organic media / Uranium / Neptunium / a Spectrometry sources / Polyacrylonitrile SummaryThe electrochemical reduction of uranium and neptunium ions is achieved in aprotic solvents in presence of acrylonitrile. The cathodic deposit on a usual metal consists of a grafted polyacrylonitrile layer in which actinide oxide or actinide metal has been inserted as a consequence of the overall cathodic reaction. As polyacrylonitrile is an insulating material, the electrochemical polymerization reaction is stopped when the polymer layer thickness reaches 1000 A at maximum.The material we thus produced may be used as an alpha spectroscopy source and we report here the results originating from the preparation of more than hundred samples. -ECI V) Fig. 1. Voltammetric two-step reduction of acrylonitrile (0.1 M) in AN with Et 4 NC10 4 , 0.05 M; Ni electrode, total surface: 2 cm 2 ; υ = 50 mV s" 1 .

Electrochemical Strategies for the Strengthening of Polymer−Metal Interfaces

“…As direct applications of the fine control of the AN electrografting, specific achievements have been reported, for example, preparation of thin α‐emitting sources by simultaneous electroreduction of AN and uranium salts,77 preparation of electrical connectors by an adequate thermal post‐treatment of electrografted PAN thin films78 and protection of art pieces 68,79…”

Immobilization of actinide ions in thin layers of polypyrrole/polyacrylamidoglycolic acid (PPy/PAGA) composite. Application to the preparation of alpha spectrometry sources

“…Stephan and Carrier [3], while preparing polypyrrole films functionalized by alkylammonium group in acetonitrile, evidenced 15 keV with 239 Pu under their best conditions. In those two papers, the activity fixed into the polymeric layers was much lower than the activity involved in this process: only 3.6 Bq for 237 Np (geometrical factor 0.83% of 4πsr; 1 cm 2 ) in polyacrylonitrile layer [12] and 15 Bq for 233 U (geometrical factor 8.2% of 4πsr; 1 cm 2 ) in alkylammonium polypyrrole [3]. Higher activities are fixed in our process with layers of comparable thickness and area; no energy straggling due to the self-absorption of the actinide nuclei is observed.…”

“…From our own experiments it appears that FWHM values below 10 keV are routinely obtained for various isotopes with an error < 1% on peak area (accuracy = 2σ). From isolating polymer layers of polyacrylonitrile (PAN) [12] prepared in organic solvent by electrochemical grafting on various electrodes, we reported FWHM values ranging from 13 to 16 keV for the 238 U and 234 U double peaks. Stephan and Carrier [3], while preparing polypyrrole films functionalized by alkylammonium group in acetonitrile, evidenced 15 keV with 239 Pu under their best conditions.…”

Electrodeposition of mixed adherent thin films of poly(ethyl acrylate) and polyacrylonitrile onto nickel

“…A surface area of 85 µm x 85 µm was analyzed for the samples. The data acquisition time was 5 min and the total ion dose per spectrum was c. 10 12 ions/cm 2 , which is lower than the usually accepted dose for static conditions [37]. No charge effect was detected for the investigated samples.…”

“…This conclusion has been assessed recently by coupling quartz crystal microbalance and cyclic voltammetry measurements [9]. This unusual coating technique has been successfully implemented for the preparation of thin α-emitter sources via simultaneous reduction of AN and uranium salts [10] and of electrical connectors by adequate thermal post treatment of electrografted PAN thin films [11].…”