Decanephosphonic acid

The lower concentration limit of existence of some phases may be found by plotting the enthalpy per gram of sample against concentration and extrapolating to zero enthalpy. In n-decanephosphonic acid-water and n-dodecanephosphonic acid-water systems, the lower limit of existence of the waxy solid was determined by plotting the enthalpy associated with the hydrated crystals-waxy solid transition, and that of the low-temperature lamellar mesophase (La) by plotting the enthalpy associated with the waxy solid-L transition [54]. 

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