Zeolite nanocrystals have attracted much attention because of their potential uses as active catalysts, effective membranes, low-k thin films, and model systems for fundamental studies of zeolite crystal growth. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] For most of these applications, dispersible zeolite nanocrystals with controlled and uniform size are preferred. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] There are a number of examples of the preparation of zeolite nanocrystals. [21][22][23][24][25][26][27][28][29][30][31][32] For example, zeolite nanocrystals with small size and narrow distribution could be prepared by control of synthetic gel composition or crystallization temperature/time. [21][22][23][24][25] Addition of organic templates to synthetic gels can effectively reduce the size of the zeolites. [7, 8,[12][13][14][26][27][28][29][30] Space-confined synthesis by means of carbon black can be used to prepare zeolite nanocrystals, the sizes of which are generally controlled by the various types of carbon black. [31] Thermoreversible polymer hydrogels are novel media for the synthesis of zeolite nanocrystals, and the polymer hydrogels are recyclable. [32] However, design and size control of uniform zeolite nanocrystals is still not easy owing to the complexity of their synthesis and limitations of various synthetic routes.
Recently, uniform and monodisperse polymer spheres were synthesized, and there are voids between these polymer spheres in aqueous media. [33] Interestingly, these confined voids can be simply adjusted by the solid content and diameter of the polymer spheres. The adjustable confined voids formed by polymer spheres could potentially serve as micro-or nanoreactors for controlling zeolite growth. Moreover, these polymer spheres are stable in the temperature range 0-160 8C, [34] which is suitable for the synthesis of most types of zeolites. Furthermore, these polymer spheres can easily be transformed into polymer chains dissolved in an