Mesoporous material synthesis through

The history of mesoporous material synthesis is unintentionally or intentionally duplicating the development of zeolites and microporous molecular sieve. It starts from silicate and aluminosilicate, through heteroatom substitution, to other oxide compounds and sulfides. It is worth mentioning that many unavailable compositions for zeolite (e.g., certain transition metal oxides, even pure metals and carbon) can be made in mesoporous material form. 

An artificial neural network (ANN) model was developed to predict the structure of the mesoporous materials based on the composition of their synthesis mixtures. The predictive ability of the networks was tested through comparison of the mesophase structures predicted by the model and those actually determined by XRD. Among the various ANN models available, three-layer feed-forward neural networks with one hidden layer are known to be universal approximators [11, 12]. The neural network retained in this work is described by the following set of equations that correlate the network output S (currently, the structure of the material) to the input variables U, which represent here the normalized composition of the synthesis mixture ... 

A desire to design high capacity adsorbents resulted in the synthesis of hybrid materials with multifunctional groups introduced via direct co-condensation of proper organosilanes instead of less effective post-synthesis si lanization.19,20 One-pot synthesis through self-assembly mechanism allows the creation of active sites inside mesopores, that after template removal become accessible for adsorption.21 An alternative method for chemical grafting of OMSs, known as template displacement synthesis, permits a simultaneous template removal and attachment of functional groups.22... 

The main difference between the synthesis of MCM-41 mesoporous material and traditional synthesis of zeolite or silica molecular sieve is the use of different templates. An individual organic molecule or metal cation is used for the traditional synthesis of silica microporous molecular sieve. For example, the typical template for ZSM-5 synthesis is tetrapropylammonium ion the crystal is formed through the condensation of silicate species around the template molecule, while for the formation of MCM-41, the typical template is the assembly of large molecules containing one hydrophobic chain with more than 10 carbons. 

In order to avoid this limitation, the interest in synthesising mesoporous materials is nowadays increasing in catalysis as the high pore dimension (10-150 A) allows the access to bulky organic molecules. In 1991, the Mobil Oil Company synthesised a mesoporous alumino-silicate through a basic synthesis using alumino-silica gel and alkyl-... 

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