Layered Clay Mineral Modifications for Functional Material Preparations

Characteristics of the layered clay minerals are the presence of tetrahedral and octahedral sheets with or without isomorphic substitution, an interlayer space with or without different fillers, and surface hydroxide groups. These structural characteristics recommend different clay modification methods for advanced material synthesis. Thus, the purpose of this review is to study the effects of modification methods on changes in clay mineral properties and their performance in various applications. The reference study of the individual different modification methods showed that generally intercalation, thermal activation, acid activation, and triple pillarization generated the largest improvements of the clay mineral basal distance (2.5 ×), SBET (9.8 ×), Vp (7.7 ×), and Total Organic Carbon (TOC) removal by catalytic reaction (9.3 ×), respectively. In other side, the reference study of the modification method comparison research confirmed that intercalation generated larger basal distance (1.1 ×), SBET (1.2 ×), and Zn2+ adsorption (1.13) than pillarization, acid activation enlarged the I2 surface area 1.03 × and 1.05 ×, also improved the naphthalene adsorption 1.1 × and 1.3 × higher than base and salt activation, respectively, thermal activation induced 1.1 × higher thermal stability and 1.1 × larger particle size, but 0.67 X lower compresive strength than mechanical activation. The conclusion is that intercalation is the best modification method for synthesis of the functional clay minerals.