Mass spectrometric study of the deterioration of polystyrene-based ion-exchangers.
A mass spectrometric study of the aging effects in polystyrene-based ion-exchangers has been made. Fragments in the m/e range 10-70 were examined and attributed to OH(+), H(2)O(+), CO(+), CO(+)(2), supplemented by SO(+) and SO(+)(2) from sulphonic-acid cation-exchangers. Ion-current intensities were found to be dependent on the state of the resin.
Ion Exchanger-Solvent Interactions: Properties and Methodology
I. INTRODUCTION The phenomenon of ion exchange has been scientifically recognized since the middle of the 19th century.1,2 Many of these early scientific investigations were carried out with naturally occurring clays and minerals, such as the zeolites. The zeolites which attracted most of the attention contain alumino-silicate skeletons with exchangeable alkali metal or alkaline earth cations. Artificial silicates were also prepared and successfully used.
A preliminary report on a new laparoscopic sterilization approach: the silicone rubber band technique.
Abstract A preliminary report is given of a new laparoscopic sterilization approach with the use of silicone rubber bands. A description of the laparoscope silicone rubber band applicator, as well as its operative utilization, is provided. One hundred cases have been completed without any major problems. No statement can be made at this time as to the incidence of failure. The described technique eliminates the need for the thermoenergy which is used in tubal occlusion and thus removes the cause of intestinal burns. The potential for successful future tubal reopening procedures should be greater with this procedure.