Encapsulation of polymers in CTA-MCM-41 via microemulsion

• The synthesis of a new type of MCM-41 material, based on the polymerization in microemulsion technique was succeeded.
• The presence of the monomers and polymers inside the MCM-41 channels was confirmed by X-ray Diffraction.
• The channel diameter and the degree of organization of the hybrid silicas depend on the monomer/surfactant ratio.
• The polymers inside the CTA-MCM-41channels increase the cation stability.

This work presents the synthesis of a new type of MCM-41 material, based on the polymerization in microemulsion technique. This type of synthesis, which has not been previously reported, uses microemulsion as a means of inserting polymers into the interior of the CTA-MCM-41 channels. The main difference between the traditional synthesis and that described here is in the initial step, involving formation of emulsified polymers derived from the microemulsions. The monomers used in the synthesis were butyl acrylate, butyl methacrylate, and styrene. Samples of monomers and polymers emulsified in aqueous media were characterized by small-angle X-ray scattering (SAXS) and X-ray diffractometry (XRD) was used to determine the degree of organization of the solid samples. These techniques showed the presence of the monomers and polymers in the interior of the cetyltrimethylammonium (CTA) micelles; the shift of the peak corresponding to the (100) diffraction plane to smaller 2θ angles showed that there was an increase in the diameter of the silica channels resulting from the insertion of the polymers. Infrared absorption spectroscopy and elemental analysis were also used to characterize the solids.

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