Eastern Mediterranean Chemical Engineering Conferences 9, Ankara, Türkiye, 30 Ağustos - 01 Eylül 2018, ss.1
Polymeric materials have gained a recent interest
especially in sensor technology. Optical properties of polymeric sensors can be
tuned by templating the polymer network by liquid crystals (LCs).[1]
LCs are stable fluid phases that possess molecular ordering. When a chiral
dopant is added, helical twisting of the molecular directional order (n) can be
induced leading to a cholesteric liquid crystalline (CLC) phase.[2] CLCs
exhibit a wavelength and polarization selective reflection due to their
periodic helical structure. The periodic helical structure, therefore the wavelength
of the reflected light, has been shown to be influenced by various external
stimuli, such as temperature, electricity and chemicals.[3]
Therefore, the presence of the chemical vapors can be identified according to
extend of the change in the color appearance of the polymeric films templated
from CLCs. In this study, CLC-templated polymeric films were fabricated in the
presence of strain orthogonal to the molecular director and tested for sensor
applications in a controlled experimental system where the concentration of the
volatile organic compound (VOC) is controlled. Upon exposure to VOC vapor, we
observed a color change that is influenced by the amount of strain on the
cholesteric axis of the polymeric sensor.
Polymeric materials have gained a recent interest
especially in sensor technology. Optical properties of polymeric sensors can be
tuned by templating the polymer network by liquid crystals (LCs).[1]
LCs are stable fluid phases that possess molecular ordering. When a chiral
dopant is added, helical twisting of the molecular directional order (n) can be
induced leading to a cholesteric liquid crystalline (CLC) phase.[2] CLCs
exhibit a wavelength and polarization selective reflection due to their
periodic helical structure. The periodic helical structure, therefore the wavelength
of the reflected light, has been shown to be influenced by various external
stimuli, such as temperature, electricity and chemicals.[3]
Therefore, the presence of the chemical vapors can be identified according to
extend of the change in the color appearance of the polymeric films templated
from CLCs. In this study, CLC-templated polymeric films were fabricated in the
presence of strain orthogonal to the molecular director and tested for sensor
applications in a controlled experimental system where the concentration of the
volatile organic compound (VOC) is controlled. Upon exposure to VOC vapor, we
observed a color change that is influenced by the amount of strain on the
cholesteric axis of the polymeric sensor.