Fabrication and characterizationof new Co(II)-MOF/polyvinylidenefluoride (PVDF) bead composites as visual sensors for detection of industrialacid vapors

Visual sensors based on Metal-Organic Frameworks (MOFs) in the detection of gases andvapors are known as vapochromic systems. The color change of MOFs is easily visible with thenaked eye and is the simplest answer in sensing and detecting gaseous species [۱]. In this work, acobalt-organic framework (Co(II)-MOF) has been perpared by the reaction of mixed bispyridylanddicarboxylate linkers under ultrasound irradiation.The composite mixture of thesenanocrystals with organic polymer polyvinylidene fluoride (PVDF) was prepared using phaseinversion method and the resulting mixture was shaped into composite beads.The sensingproperties of the prepared bead composites toward vapors of concentrated industrial acids suchas hydrochloric acid (HCl), nitric acid (HNO۳), and sulfuric acid (H۲SO۴), as well as thionylchloride (SOCl۲) vapors were investigated. The color change of nanoparticles was observed frompurple to green, yellow, blue-violet and dark green, respectively.

Keywords:

Metal‒ organic framework (MOF) , Sensing , Bead composite