Amino-functionalized Fe3O4@SiO2 core–shell magnetic nanomaterial as a novel adsorbent for aqueous heavy metals removal

A review with ca. 400 references is provided dealing with the use of mesoporous silica and organically-modified silica-based materials for removal of inorganic and organic pollutants from aqueous solutions. After having briefly discussed the interest of functionalized mesoporous silica for environmental remediation purposes, the various synthetic methods to prepare such nanoengineered adsorbents are described. Then, their application to the removal of heavy metal species, toxic anions, radionuclides, and a wide range of organic pollutants is presented in a comprehensive way with the help of extensive tables and some illustrating figures.

Mesoporous organosilica adsorbents: nanoengineered materials for removal of organic and inorganic pollutants

Synergistic effect of iron doped ordered mesoporous carbon on adsorption-coupled reduction of hexavalent chromium and the relative mechanism study

Mesoporous molecular sieves with size-tunable mesopores have been well developed and have attracted a great deal of attention because of their controllable structures and compositions, which make them suitable for a wide range of applications in catalysis, adsorption, separation, chromatography, etc. The pore size of mesoporous silica is large enough to accommodate a variety of large molecules, and the high density of silanol groups on the pore wall is beneficial to the introduction of functional groups with a high coverage. Actually, various kinds of surface modifications have been conducted for providing new functions for the surfaces. Among various functional groups, the introduction of the amino groups onto the mesopores has enabled us to use amino-functionalized mesoporous materials as solid-base catalysts and adsorbents. Meanwhile, “anionic surfactant templated mesoporous silica (AMS)” has been synthesized via a novel templating route for preparing mesoporous silicas based on the self-assembly of anionic surfactants and inorganic precursors in the presence of aminosilane or quaternized aminosilane as a co-structure-directing agent. AMSs are synthetically interesting not only for their structural diversity, including chiral properties, but also for the chance of functionalizing the pore surface by removing the surfactant by solvent extraction, resulting in the formation of the mesoporous silica with aminopropyl groups intact. Thus obtained amino-functionalized AMS can be applied to solid-base catalysis, adsorption, drug delivery, etc. This review gives an overview on the recent development of amino-functionalized mesoporous silica. In particular, the difference in the state and catalytic activity of amino groups between the functionalized mesoporous silicas synthesized via anionic and cationic surfactants templating routes is featured. Interesting applications of amino-functionalized mesoporous silica besides solid-base catalyst are also described.

Amino-functionalized mesoporous silica as base catalyst and adsorbent

Porous polysilsesquioxane gels derived from sol–gel systems based on trifunctional silanes are reviewed. Although it is well known that trifunctional silanes possess inherent difficulties in forming homogeneous gels, increasing attention is being paid on these precursors and resultant porous polysilsesquioxanes because of hydrophobicity, functionality, and versatile mechanical properties. Much effort has been made to overcome the difficulties for homogeneous gelation, and a number of excellent porous materials with various pore properties have been explored. In this critical review, we put special emphasis on the formation of a well-defined macroporous structure by making use of phase separation, which in turn is a serious problem in obtaining homogeneous gels though. Porous polysilsesquioxane monoliths with the hierarchical structure and transparent aerogels with high mechanical durability are particularly highlighted (169 references).

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Controlled pore formation in organotrialkoxysilane-derived hybrids: from aerogels to hierarchically porous monoliths

Synthesis, amino-functionalization of mesoporous silica and its adsorption of Cr(VI)

The present invention discloses ordered mesoporous silica and its fast preparation process in an acid system with high concentration solution of three block copolymer P123 as the template agent and ethyl silicate (TEOS) as silicon source The ordered mesoporous silica has the features of high degree of order, complete spatial group structure, great pore size, thick pore wall and high hydrothermalstability Its preparation process is simple, fast, easy in operation, environment friendly and low in cost It may be post-treated properly to prepare excellent adsorbent as one kind of environment protecting material or inorganic separating film with high flux, high selectivity and broad application range

Xiaoyu Miao

Papers

Synthesis, amino-functionalization of mesoporous silica and its adsorption of Cr(VI)

Ordered meso-porous silicon oxide and rapid preparation method thereof