Optical sensing of organic vapor using blue phase liquid crystals

ABSTRACT

This study presents the investigation of the use of blue phase liquid crystals (BPLCs) for the sensing of toxic gas vapours of toluene, phenol and 1,2 dichloropropane. The vapours of these three toxic solvents were obtained by evaporating at different temperatures within the different times, and BPLC was separately exposed to these gas vapours. The diffusion and adsorption of these vapours on the BPLCs were investigated depending on the dimensions and polarity of the molecules. The optical response of BPLC exposed to gas vapours of toluene, phenol and 1,2 dichloropropane was determined with Bragg reflection wavelength as a function of temperature and time. We found that BPLC produced a remarkable change to the red side of the spectrum due to diffusion of toluene gas vapour by the BPLC sample and itsBragg reflection wavelength change within the time showed a good linearity correlation. Moreover, the diffusion coefficient of the toluene gas vapour in BPLC sample was calculated, and it was determined as 8.224 × 10⁻¹² (cm²/s) by using a least-squares method.

Graphical Abstract

KEYWORDS:

• Liquid crystal sensor
• blue phase sensor
• toxic gas
• Bragg reflection
• gas sensor

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was funded by the Scientific and Technological Research Council of Turkey (TUBITAK) ARDEB 1001, under grant 119F117.