Application Of Molecularly Imprinted Polymers Based On Silicon Materials

Because of its simple preparation, good stability and molecular recognition function, it has been widely applied in chromatographic separation, solid-phase extraction, chemical sensing, mimetic enzyme catalysis and so on.

In recent years, molecularly imprinted polymers based on silicon materials have developed rapidly.

In this paper, the preparation and molecular recognition properties of molecularly imprinted polymers for silicon materials are introduced, and their applications are classified. Based on this, the future development of the molecularly imprinted polymers is prospected.

Molecular recognition plays a very important role in organisms. Some biomolecules in nature, such as enzymes, antigens and hormones, have specific molecular recognition on substrates, antibodies and receptors, thus determining whether organisms can grow normally.

However, these biomolecules have disadvantages such as complex preparation, poor stability, inconvenience in storage and operation.

Molecularly imprinted technology (MIP) is a technology of artificial synthesis of polymers with specific recognition sites since 1970s. Molecularly imprinted polymers with good stability, simple synthesis and molecular recognition function can be prepared by molecular imprinting technology.

At present, there are fewer kinds of crosslinking agents for preparing molecularly imprinted polymer matrix materials, which are mainly olefin compounds that can participate in free radical polymerization, such as vinyl glycol methyl methacrylate, trimethoxy propane three methacrylate and two vinyl benzene.

These crosslinking agents can only be used in organic solvents, which greatly limits the development of imprinted polymers.

It means that the imprinted molecules and functional monomers first form a complex through reversible reaction, and then polymerize to form highly crosslinked rigid polymer in the presence of crosslinking agent. After removing the imprinted molecule, a functional group with binding ability is left in the network structure of the polymer, which can be used as a molecular receptor to selectively identify imprinted molecules in many imprinted molecular structure analogues.

Molecularly imprinted technology can be divided into two basic types according to the different mechanism of interaction between imprinted molecules and functional monomers.

The first is the covalent method, created by Wulff.

Molecularly imprinted molecules and functional monomers are covalently bonded to form polymerizable monomers. After cross-linking polymerization, the covalent bonds are broken by chemical methods and the imprinted molecules are removed.

The advantage of this method is that the interaction between imprinted molecules and functional monomer molecules is strong, so that polymerization can be carried out in strong polar solvents, and the imprinted sites are precisely determined.

However, there are fewer kinds of reversible chemical reactions, and the rate of elution and binding of imprinted molecules is very slow.

The second is the non covalent method. This polymerization is simple, and the recognition and recognition process of imprinted molecules is faster than that of natural molecular recognition systems.

In addition, these two methods are combined to prepare imprinted polymers and study their properties. That is, the interaction between imprinted molecules and functional monomers is covalent during polymerization, and the way of action is non covalent.

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Preparation of molecularly imprinted polymers.

In 1949, Dickey and other imprinted silica gel with dye methyl orange as the imprinted molecule and acidified silicate solution were prepared. The adsorption material for methyl orange adsorbed on ethyl orange was two times higher than that of ethyl orange, and the preparation and research of molecularly imprinted polymers based on silicon began.

At present, a lot of beneficial progress has been made in this area. The preparation of imprinted polymers was carried out by using silane as the parent material in the early stage, and the preparation of imprinted polymers on the surface of silicon materials with different morphologies was developed.