Stable supersaturated solns. of sparingly soluble salts - formed in the presence of polyanionic polyelectrolyte of at least 900 daltons

摘要

Supersatd. aq. solns. of sparingly soluble inorganic alkali metal salts are made by forming a supersatd. soln. of the salt in an aq. medium in the presence of a polyanionic polyelectrolyte (I) of at least 900 daltons and having at least 5 ionisable gps. concn. of (I) is pref. 0.5- 5 g/l and is pref. a polyphosphate or polycarboxylate. Used esp. in applications where metered addn. of the salt is required within narrow concn. limits, hemodialysis systems; a specific use is in the prodn. of NaHCO3 concentrates for hemodialysis systems. The solns. may also be useful as enhanced sources of CO2 and as a means for enhancing crystal growth. The solns. are stable and have long shelf lives.