Process for the production of nan-sized zeolite A
AssigneesE. I. DuPont de Nemours and Company, Northeastern University, University of Connecticut
InventorsDavid Richard Corbin, Albert J. Sacco, Steven L. Suib, Qiuhua Zhang
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Abstract
Described is a process to synthesize nano-size Zeolite A from an amorphous gel precursor which can be synthesized via reaction of NaAlO2, NaOH, and tetraethoxysilane (TEOS). Zeolite A with particle sizes of ˜150 nm was made by transformation of the amorphous precursor in (CH3)4NOH solution with Zeolite A seeding. The nano-sized Zeolite A can be part of processes for making non-phosphate detergent where the as-synthesized Zeolite A used as builders, for making thin films for separation and/or catalysis, for making secondary ordered patterns.
Claims14
A process to prepare nano-size Zeolite A comprising the steps of:
- a. preparing a precursor mixture comprising sodium, silica, and alumina, wherein the proportions of sodium, silica, and alumina are those required to produce Zeolite A, to form a solid precursor;
- b. isolating the solid precursor from step a);
- c. combining the solid precursor from step b) with seed crystals of Zeolite A having particle sizes of less than 500 nm, with agitation in an aqueous alkaline solution containing hydroxide ions at a temperature of about 18° C. to about 85° C. to form a mixture containing nano-sized Zeolite A crystals;
- and
- d. optionally separating the nano-sized Zeolite A crystals from the mixture of step c).
A process to prepare nano-size Zeolite A comprising the steps of:
- a. preparing a precursor mixture comprising sodium, silica, and alumina, wherein the proportions of sodium, silica, and alumina are those required to produce Zeolite A, to form a solid precursor;
- b. isolating the solid precursor from step a);
- c. combining the solid precursor from step b) with seed crystals of Zeolite A with agitation in an aqueous alkaline solution containing hydroxide ions at a temperature of about 18° C. to about 85° C. to form a mixture containing nano-sized Zeolite A crystals;
- d. optionally separating the nano-sized Zeolite A crystals from the mixture of step c);
- e. adding the nano-sized Zeolite A crystals with agitation from step d) to an aqueous solution of a Na+ salt to form a mixture containing nano-sized Zeolite A crystals;
- and
- f. optionally isolating the nano-sized Zeolite A crystals.
Dependencies are inferred from the claim text.