Patent US3788818A successfully refreshed from Google Patents.
US3788818A
Expired / Lapsed
US
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Method for growing crystals using a semipermeable membrane
Assignee: Pennsylvania Research Corp
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Filing: 1971-04-22
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Granted: 1974-01-29
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Expires: 1991-04-22
Abstract
Abstract A PROCESS FOR GROWING CRYSTALS WHEREIN A FIRST SOLVENT IS LOADED WITH A CRYSTALLIZABLE SOLUTE OR CRYSTAL PRECURSOR AND SEPARATED FROM A SECOND SOLVENT IN WHICH THE CRYSTALS ARE LESS SOLUBLE, BY A DIFFUSION BOUNDARY, SUCH THAT CRYSTALS ARE GROWN FROM NUCLEATION SITES AT THE DIFFUSION BOUNDARY AS THE SECOND SOLVENT DIFFUSES INTO THE FIRST SOLVENT. THIS PROCESS IS HIGHLY SUITABLE FOR GROWING A WIDE VARIETY OF CRYSTALS, INCLUDING MANY WHICH HAVE BEEN HERETOFORE DIFFICULTY OBTAINABLE BY OTHER CRYSTALLIZATION METHODS.
Inventors
- 👤 A Madjid
- 👤 J Pedulla
- 👤 A Vaala
- 👤 W Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:48
CPC Classifications
C; C30; C30B; C30B7/00; C30B7/14; B; B01; B01D; B01D9/00; B01D9/005; C30B29/00; C30B29/54; C30B29/58; C30B35/00; C30B35/002
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |