Abstract
An oil-based composite is employed to monitor the exposure to oxygen inside food packaging, aiming at evaluating the package integrity and the freshness of food. The composite is an oxygen-sensitive printable ink consisting of electrically conductive silver microflakes, embedded in a vegetable oil matrix. The sensitivity of the oil to oxygen is driven by its high content of unsaturated fatty acids that polymerize and shrink upon exposure to atmospheric oxygen. Shrinkage increases the silver concentration and induces percolation, manifested by a steep increase in the electrical conductivity of the composite. We found that the electrical conductivity of the composite is related to its exposure time to air. Employing linseed oil as a matrix demonstrates an increase in electrical conductivity from 10-11 to 10-3 S/cm after only 6 days of exposure to air. We also show that this time span could be modified by changing the oil type to fit various expiration periods of food products.
Original language | English |
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Pages (from-to) | 3274-3280 |
Number of pages | 7 |
Journal | ACS Sensors |
Volume | 5 |
Issue number | 10 |
DOIs | |
State | Published - 23 Oct 2020 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2020 American Chemical Society.
Funding
This work was supported by the Israel Ministry of Defense under the project “Sensing and Monitoring Food Quality”.
Funders | Funder number |
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Ministry of Defense |
Keywords
- Electrical conductivity
- Food
- Ink
- Oil
- Oxygen
- Sensor