Size Control for Nano-Sized Zeolite A by Bottom-Up Process.

Abstract

The fabrication of nano-sized zeolites with an average size of 200 to 400 nm was attempted by the bottom-up process such as the hydrothermal technique, in which zeolite nucleation and crystal growth were controlled during the hydrothermal synthesis. Effect of hydrothermal parameters like synthetic temperatures, holding times, and compositions of starting materials on the microstructures of zeolites were mainly investigated. In addition, influence of aging of mixture of starting materials at room temperature before hydrothermal treatments was examined. In this study, in special, homogeneous zeolite A (LTA type structure) nanocrystals without an average size less than 100 nm and coarse zeolites over 500 nm were successfully synthesized by the present bottom-up process under optimum hydrothermal conditions at 60 °C for 3 hr after aging at room temperature.