Determination of pore size distribution for mesoporous materials and polymeric gels by means of DSC measurements: thermoporometry

The determination of porous structure of fragile materials from classical m ethods such as mercury porosimetry and nitrogen adsorption-desorption metho ds is often delicate and can be source of false structure interpretation. T he thermoporometry is an alternative method, sometimes the unique method, a llowing a better characterization of porous fragile and soft materials and hydrogels. In this paper we report on the use of thermoporometry as a technique allowi ng the determination of pore size distribution in mesoporous materials. Fir st, the reliability of the technique was tested on rigid mesoporous silica with known pore size distribution. The expected pore radius distribution cu rve was obtained. Thereafter, the technique was applied to characterize the mesoporous structure of poly(N-(2-hydroxypropyl) methacrylamide) (PHPMA) g els swollen in aqueous medium. The pore size distributions determined were compared to those obtained from nitrogen physisorption isotherms. (C) 2000 Elsevier Science Ltd. All rights reserved.