Mercury porosimetry:: applicability of the buckling-intrusion mechanism to low-density xerogels

被引:35
作者
Alié, C [1 ]
Pirard, R [1 ]
Pirard, JP [1 ]
机构
[1] Univ Liege, Inst Chim B6A, Lab Genie Chim, B-4000 Liege, Belgium
关键词
D O I
10.1016/S0022-3093(01)00881-X
中图分类号
TQ174 [陶瓷工业]; TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
Mineral materials can be either crushed or invaded by mercury during mercury porosimetry experiments. It has been shown here that many low-density xerogels exhibit the two volume variation mechanisms successively, compaction followed by intrusion. when submitted to mercury porosimetry and that a unimodal pore size distribution can be obtained by applying Pirard's collapse model below the pressure of transition P-1 and Washburn's intrusion theory above P-t. To confirm the validity of the use of the buckling law, one low-density xerogel was wrapped in a tight membrane (intrusion is prevented and the sample is crushed during the whole porosimetry experiment). The analysis of the mercury porosimetry data of the wrapped sample by the buckling law leads to a continuous unimodal distribution similar to the distribution of the unwrapped sample obtained by applying the buckling law below P-t and the intrusion law above P-t. The position of P-t is characteristic of the tested material: when submitted to mercury pressure. aerogels and low-density xerogels only collapse in case of very small aggregates whereas they are crushed and then intruded in case of larger silica aggregates. The fact that compacted slabs of monodisperse non-aggregated silica spheres (of the same size range as the xerogels and aerogels) show only intrusion during mercury porosimetry experiments implies that the particles need to be aggregated so that the compaction mechanism takes place. The position of the change of mechanism from crushing to intrusion is not directly related to the size of the elementary particles but is linked to the size of the aggregates of silica particles. (C) 2001 Elsevier Science B.V. All rights reserved.
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页码:138 / 149
页数:12
相关论文
共 29 条
[1]   Preparation of low-density xerogels through additives to TEOS-based alcogels [J].
Alié, C ;
Pirard, R ;
Lecloux, AJ ;
Pirard, JP .
JOURNAL OF NON-CRYSTALLINE SOLIDS, 1999, 246 (03) :216-228
[2]   STUDIES ON PORE SYSTEMS IN CATALYSTS .14. CALCULATION OF CUMULATIVE DISTRIBUTION FUNCTIONS FOR SLIT-SHAPED PORES FROM DESORPTION BRANCH OF A NITROGEN SORPTION ISOTHERM [J].
BROEKHOFF, JC ;
DEBOER, JH .
JOURNAL OF CATALYSIS, 1968, 10 (04) :391-+
[3]   STUDIES ON PORE SYSTEMS IN CATALYSTS .13. PORE DISTRIBUTIONS FROM DESORPTION BRANCH OF A NITROGEN SORPTION ISOTHERM IN CASE OF CYLINDRICAL PORES .B. APPLICATIONS [J].
BROEKHOFF, JC ;
DEBOER, JH .
JOURNAL OF CATALYSIS, 1968, 10 (04) :377-+
[4]   STUDIES ON PORE SYSTEMS IN CATALYSTS .11. PORE DISTRIBUTION CALCULATIONS FROM ADSORPTION BRANCH OF A NITROGEN ADSORPTION ISOTHERM IN CASE OF INK-BOTTLE TYPE PORES [J].
BROEKHOFF, JC ;
DEBOER, JH .
JOURNAL OF CATALYSIS, 1968, 10 (02) :153-+
[6]   STUDIES ON PORE SYSTEMS IN CATALYSTS .X. CALCULATIONS OF PORE DISTRIBUTIONS FROM ADSORPTION BRANCH OF NITROGEN SORPTION ISOTHERMS IN CASE OF OPEN CYLINDRICAL PORES .B. APPLICATIONS [J].
BROEKHOFF, JC ;
DEBOER, JH .
JOURNAL OF CATALYSIS, 1967, 9 (01) :15-+
[8]  
BRUNAUER S, 1969, CHEM ENG PROG S SER, V65, P1
[10]   ADSORPTION IN MICROPORES [J].
DUBININ, MM .
JOURNAL OF COLLOID AND INTERFACE SCIENCE, 1967, 23 (04) :487-&