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Differential data on the thermodynamics and kinetics of water-vapor sorption and desorption in the acrylamide−water system at room temperature and 0 < n < 74 (n is the number of sorbed water molecules per amido group) are obtained. Water-vapor sorption from air of 100% humidity appears to be limitless. The magnitude of the differential molar enthalpy of sorption is about 25 kJ/mol for n ≪ 1, passes through a maximum of 42 kJ/mol in the vicinity of n = 1 and a minimum of 24 kJ/mol in the vicinity of n = 2, and then approaches the level of the heat of water-vapor condensation on the pure water surface. The probability for a water molecule to desorb from the system into vacuum per unit time is observed to monotonically increase with n up to n = 44, with a small minimum for n = 15−17. In the system, a slight tendency for clathratization reveals itself in nonmonotonic dependences of ΔH(n) and P(n), but no stable clathratization, as such, is identified. The results are compared with the corresponding data for the polyacrylamide−water system. The mechanisms of the sorption−desorption process are discussed.

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