Effects of silica on the synthesis of AFI molecular sieve in acid and base conditions under microwave irradiation

The AFI molecular sieve has been synthesized under microwave irradiation in various conditions including the pH and Si/Al ratio. In acidic conditions, silica accelerates the crystallization, whereas in alkaline conditions, silica hinders the crystallization to form plate-like hexagonal crystals. The plate-like hexagonal crystal of AFI molecular sieve can be synthesized from an alkaline gel in very limited conditions. (C) 2004 Elsevier Inc. All rights reserved.