Response Characteristics of Thermoresponsive Polymers Using Nanomechanical Cantilever Sensors
✍ Scribed by Calvin Bradley; Nader Jalili; Sebastian K. Nett; Liqiang Chu; Renate Förch; Jochen S. Gutmann; Rüdiger Berger
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 461 KB
- Volume
- 210
- Category
- Article
- ISSN
- 1022-1352
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✦ Synopsis
Abstract
We investigated coatings of thermally responsive thin polymer films prepared on nanomechanical cantilever sensor (NCS): (i) a PNIPAM brush, and (ii) an interlinked ppDEA polymer. Upon heating from 22 to 50 °C in water, a minimum in the differential deflection between 31.9 ± 1.7 °C (PNIPAM) and 47.7 ± 1.9 °C (ppDEA) was measured. The minimum in differential deflection can be associated with the lower critical solution temperature (LCST) of the films. Below the LCST the NCS deflection corresponds to a bending toward the thermally responsive polymer film side, associated to dehydration. At higher temperature, the deflection was reversed, i.e., away from the polymer coating. This response is mainly attributed to a bimaterial effect between the collapsed polymer and the NCS material. The LCST of the PNIPAM brush layer and the ppDEA film were close to that reported for the bulk polymers.
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