MERCURY POROSIMETRY OF ORDERED SPHERE COMPACTS - INVESTIGATION OF INTRUSION AND EXTRUSION PORE-SIZE DISTRIBUTIONS
MERCURY POROSIMETRY OF ORDERED SPHERE COMPACTS - INVESTIGATION OF INTRUSION AND EXTRUSION PORE-SIZE DISTRIBUTIONS
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DOI：
10.1016/0032-5910(88)80103-7
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发表时间：
1988-07-01
影响因子：
5.2
通讯作者：
ROSS, SB
中科院分区：
文献类型：
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作者：
CIFTCIOGLU, M;SMITH, DM;ROSS, SB
水银孔隙率测定法中的侵入-挤出滞后被认为是由汞接触角滞后引起的，或者是由孔体的挤出和喉道对孔隙网络的侵入的支配引起的。大多数情况下，只有在汞侵入过程中获得的信息才用于通过汞孔隙率测定法表征材料的孔结构。使用挤出过程中获得的数据已成为最近几项研究的主题，试图获得更完整的孔隙结构图。在这项工作中，研究了侵入和挤出用于孔隙结构表征的可能用途。合成了二氧化硅和碱式碳酸钇的亚微米单尺寸球形颗粒，并制备了这些粉末的有序压块。对这些高密度压块（通常为球体密度的 68 – 70%）进行的水银孔隙率测试表明，除了一个压块之外，存在两个用于侵入和挤出的孔峰。侵入孔径与有序球体填料的理论收缩尺寸的比较显示出合理的一致性。球体填料的空腔尺寸与挤出孔径之间的类似比较并未显示出相同的一致性。一个样品的结果即使在非常大的孔径下也没有显示出明显的挤出孔径，这很可能是由于样品中存在的很少的大孔主导了汞的挤出。对于所有其他样品，挤出孔径接近实际球体尺寸，并且挤出很可能由有序结构中的一些空球位点主导。这项工作的结果表明，使用挤压数据确定孔体尺寸分布的可能性值得严重怀疑。多孔体中极少数较大孔隙的存在可能主导整个挤出过程，并可能导致从挤出数据中提取不准确的孔径信息。
Intrusion—extrusion hysteresis in mercury porosimetry is thought to be caused either by mercury contact angle hysteresis or by the domination of extrusion by pore bodies and intrusion by throats to the pore network. Mostly, only the information obtained during the intrusion of mercury has been used in the pore structure characterization of materials via mercury porosimetry. The use of the data obtained during extrusion has been the subject of several recent studies in an attempt to reach a more complete picture of pore structure.In this work, the possible use of both intrusion and extrusion for pore structure characterization have been investigated. Submicron monosize spherical particles of silica and yttrium hydroxycarbonate were synthesized and ordered compacts of these powders have been prepared. Mercury porosimetry tests on these high-density compacts (typically 68 – 70% of sphere density) have shown the presence of two pore peaks for intrusion and extrusion with the exception of one compact. Comparisons of intrusion pore sizes with the theoretical sizes of the constrictions for ordered sphere packings have shown reasonable agreements. Similar comparisons between the sizes of cavities in sphere packings and the extrusion pore sizes did not show the same agreement. Results for one sample did not show a distinct extrusion pore size even at very large pore sizes, most probably due to the domination of mercury extrusion by very few large pores present in the sample. For all other samples, the extrusion pore sizes were close to the actual sphere size and the extrusion was most probably dominated by a few vacant sphere sites in the ] ordered structures. The results of this work have shown that the possibility of using extrusion data for pore body size distribution determination is in serious doubt. The presence of very few larger pores in the porous body may dominate the whole extrusion process and can cause the extraction of inaccurate pore size information from the extrusion data.