Textural Porosity of Synthetic Clay Minerals

摘要

Recently an excellent review of the synthesis of smectite clay minerals, ncluding hectorite clays, was published (1). Efforts to create and control the ,ore size of clays continue intensively, including pillared clay (2) and nesoporous clay systems (3, 4). Concerning the latter, we recently reported he synthesis of mesoporous synthetic clays (MSCs) based on hectorites that Ire derived from polymer-containing silicate clay gels (3). In this technique, n situ interlayer intercalation of different polymers over broad molecular ~eight and concentration ranges is achieved. Upon removal of template by :alcination the individual interlayer spaces collapse, but astable and intact ,ore system remains from, it is speculated, the inter- and intra-tactoid Tolume. The use of polyvinylpyrrolidone (PVP) molecules or tetraethylam- nonium (TEA) cations yields materials with various porosity characteristics. ::onversion of dibenzothiophene to biphenyl and biphenyl selectivities lave been obtained from preliminary hydrodesulfurization tests, with en- 'ouraging results (5). The microstructure or extended network morphology 'or these materials has not yet been identified, however. An in-depth analy- iis of nitrogen adsorption-desorption behavior is undertaken toward this ;oal, along with transmission electron microscopy (TEM) measurements.