Emergence of Macroporous Materials

Ordered macroporous materials have special optical features due to their pore diameters. Since the synthesis of macroporous materials has just started, there are no general synthetic strategies for this type of materials at present, and hence only a few examples will be mentioned here. 

By using modified colloidal particles as templates, silicon oxide macroporous materials with uniform submicrometer-sized pores can be synthesized.[14] Modified polystyrene emulsion microspheres (200 1000 nm) can be electronegative (sulfates) or electropositive (amidines). After these microspheres are packed in an orderly fashion, they can interact with surfactants and silicon oxides to form macroporous solid composites, and further to form macroporous materials after the removal of the templates by calcination. The sizes of the macropores in the products range from 150 to 1000 nm. Macroporous Ti02 can also be prepared in a similar way. 

Mineralization on hyphae can also generate macroporous materials.[15] Using this method in the synthesis of mesoporous materials, mesoporous and macroporous composites can be obtained. The long channels in these composites are parallel to each other. The pores are at a micron level, and the thickness of the walls ranges from 50 to 200 nm. 

By using colloid as the template, inorganic oxides can be deposited on the outer surface of the colloidal droplet to form macroporous materials with apertures of 50 nm 

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