Figure 7.
Time-dependent frequency response of the FBAR sensors coated with PEI flat film and different amounts of PEI nanofibers when exposed to 300 ppb formaldehyde vapor. All the tests were performed at room temperature and 40% relative humidity.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.