In this paper, we use a ball milling process, but it will lead to a broad particle size range. I think a better method should be in-situ synthesis by hydrothermal method, which has a relatively uniform particle size range.

Ball milling can reduce the size but will lead to large particle size distribution then you should use sieves to fractionate the particles but it is tds job. In some cases this technique will also damage the porous structure and produce defects.

Instead of post synthesis size reduction it is better to use hydrothermal synthesis and carefully maipulate the conditions (slow hydrolysis rate or use of in situ stabilizers etc.) to produce nanozeolites.

ball milling

ball milling

I think usage of template method is good manner for the synthesis of nanozeolite. Meanwhile the template ratio such as TMABr/TMAOH (S) ratio is an effective method for the controlling of zeolite size.In addition, crystallization time is effective in determining the size of the zeolite.

Brett A. Holmberg, Huanting Wang, Yushan Yan, Microporous and Mesoporous Materials 74 (2004) 189–198.

please see this review:

Rev Chem Eng 2014; 30(3): 289–322

This review aims at investigating the effect of the different synthetic parameters on the crystallinity and crystal size of nanosized ZSM-5 zeolite. The influence of the different parameters, such as the material of the synthesis source, the material ratio to each other, crystallization time and temperature, aging time and temperature, microwave treatment, seeding, and sonication, on the size of the final product is studied and the reason for each phenomenon is explained.

I recommend to see this paper, the authors propose a simple method for preparing nanoparticle zeolites.

Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 453, 5 July 2014, Pages 86-93

In this reference (Thesis):

www.theses.ulaval.ca/2006/24114/24114.pdf

You can find an hydrothermal procedure to obtain silicate-1 and FAU (nanosized).

I think a method called Resin-gel method is ideal. It is a modification of the Pechini method. It has several advantages over hydrothermal method. More notable is the fact that you don't form hydroxides that will have a bearing on the morphology of your zeolite. The suspension of ions in the resin give access to the proportions of metal percentage weight compositions you can tailor. The pyrolysis of the resin allows rapid ionic interaction to give the desired zeolite. 

It is possible to make nano-sized zeolite A using traditional synthesis method. You can check this paper:

http://www.sciencedirect.com/science/article/pii/S0306261913000263

Thank you so much 

I synthesize zeolite LTA in a very simple and inexpensive method. You can change the size from 400nm to 11 micrometer. You can read this paper " http://pubs.acs.org.ezproxy1.lib.asu.edu/doi/abs/10.1021/acs.cgd.6b00133", if need more detail information please let me know.

If you need to make zeolite LTA smaller than 300 nm, please let me know. I will send the procedure to you.

Thank you so much for sharing 

Its really helpful , 

Regards 

Shariat