Microcapsules adapted to rupture in a magnetic field
US8741804B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 2011 |
| Grant date | Jun 3, 2014 |
| Priority date | — |
| Expiry date | Oct 28, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC05G5/38
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Controlled release of one or more agricultural chemicals is provided by microcapsules adapted to rupture in a magnetic field. The microcapsules, which may be applied to soil, seeds and/or plants, each have a shell that encapsulates an agricultural chemical, such as a fertilizer, herbicide or insecticide. One or more organosilane-coated magnetic nanoparticles is/are covalently bound into the shell of each microcapsule. For example, (3-aminopropyl) trimethylsilane-coated magnetite nanoparticles may be incorporated into the shell of a urea-formaldehyde (UF) microcapsule during in situ polymerization. In one embodiment, microcapsules encapsulating a fertilizer are applied during seed planting. Controlled release is subsequently triggered after an appropriate period of dormancy by positioning a magnetic field generating device proximate the microcapsules to generate a magnetic field sufficient to rupture the microcapsule shells through magnetic stimulation of the organosilane-coated magnetic nanoparticles. The ruptured microcapsule shells release the fertilizer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.