TY - JOUR
T1 - Seeing the Unseen: The Role of Liquid Crystals in Gas-Sensing Technologies
AU - Esteves, Carina
AU - Ramou, Efthymia
AU - Porteira, Ana Raquel Pina
AU - Moura Barbosa, Arménio Jorge
AU - Roque, Ana Cecília Afonso
N1 - SCENT-ERC-2014-STG-639123 (2015-2020)
UIDB/04378/2020
SFRH/BD/113112/2015
PY - 2020/6/1
Y1 - 2020/6/1
N2 - Fast, real-time detection of gases and volatile organic compounds (VOCs) is an emerging research field relevant to most aspects of modern society, from households to health facilities, industrial units, and military environments. Sensor features such as high sensitivity, selectivity, fast response, and low energy consumption are essential. Liquid crystal (LC)-based sensors fulfill these requirements due to their chemical diversity, inherent self-assembly potential, and reversible molecular order, resulting in tunable stimuli-responsive soft materials. Sensing platforms utilizing thermotropic uniaxial systems—nematic and smectic—that exploit not only interfacial phenomena, but also changes in the LC bulk, are demonstrated. Special focus is given to the different interaction mechanisms and tuned selectivity toward gas and VOC analytes. Furthermore, the different experimental methods used to transduce the presence of chemical analytes into macroscopic signals are discussed and detailed examples are provided. Future perspectives and trends in the field, in particular the opportunities for LC-based advanced materials in artificial olfaction, are also discussed.
AB - Fast, real-time detection of gases and volatile organic compounds (VOCs) is an emerging research field relevant to most aspects of modern society, from households to health facilities, industrial units, and military environments. Sensor features such as high sensitivity, selectivity, fast response, and low energy consumption are essential. Liquid crystal (LC)-based sensors fulfill these requirements due to their chemical diversity, inherent self-assembly potential, and reversible molecular order, resulting in tunable stimuli-responsive soft materials. Sensing platforms utilizing thermotropic uniaxial systems—nematic and smectic—that exploit not only interfacial phenomena, but also changes in the LC bulk, are demonstrated. Special focus is given to the different interaction mechanisms and tuned selectivity toward gas and VOC analytes. Furthermore, the different experimental methods used to transduce the presence of chemical analytes into macroscopic signals are discussed and detailed examples are provided. Future perspectives and trends in the field, in particular the opportunities for LC-based advanced materials in artificial olfaction, are also discussed.
KW - gas sensing
KW - liquid crystals
KW - self-assembly
KW - soft functional materials
KW - volatile organic compounds
UR - http://www.scopus.com/inward/record.url?scp=85083055673&partnerID=8YFLogxK
U2 - 10.1002/adom.201902117
DO - 10.1002/adom.201902117
M3 - Review article
C2 - 32612901
AN - SCOPUS:85083055673
SN - 2195-1071
VL - 8
JO - Advanced Optical Materials
JF - Advanced Optical Materials
IS - 11
M1 - 1902117
ER -