Effect of Polymer Hydrophobicity in the Performance of Hybrid Gel Gas Sensors for E-Noses
Relative humidity (RH) is a common interferent in chemical gas sensors, influencing their baselines and sensitivity, which can limit the performance of e-nose systems. Tuning the composition of the sensing materials is a possible strategy to control the impact of RH in gas sensors. Hybrid gel materi...
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MDPI AG
2023-03-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/23/7/3531 |
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| author | Ana Rita Oliveira Henrique M. A. Costa Efthymia Ramou Susana I. C. J. Palma Ana Cecília A. Roque |
| author_facet | Ana Rita Oliveira Henrique M. A. Costa Efthymia Ramou Susana I. C. J. Palma Ana Cecília A. Roque |
| author_sort | Ana Rita Oliveira |
| collection | DOAJ |
| description | Relative humidity (RH) is a common interferent in chemical gas sensors, influencing their baselines and sensitivity, which can limit the performance of e-nose systems. Tuning the composition of the sensing materials is a possible strategy to control the impact of RH in gas sensors. Hybrid gel materials used as gas sensors contain self-assembled droplets of ionic liquid and liquid crystal molecules encapsulated in a polymeric matrix. In this work, we assessed the effect of the matrix hydrophobic properties in the performance of hybrid gel materials for VOC sensing in humid conditions (50% RH). We used two different polymers, the hydrophobic PDMS and the hydrophilic bovine gelatin, as polymeric matrices in hybrid gel materials containing imidazolium-based ionic liquids, [BMIM][Cl] and [BMIM][DCA], and the thermotropic liquid crystal 5CB. Better accuracy of VOC prediction is obtained for the hybrid gels composed of a PDMS matrix combined with the [BMIM][Cl] ionic liquid, and the use of this hydrophobic matrix reduces the effect of humidity on the sensing performance when compared to the gelatin counterpart. VOCs interact with all the moieties of the hybrid gel multicomponent system; thus, VOC correct classification depends not only on the polymeric matrix used, but also on the IL selected, which seems to be key to achieve VOCs discrimination at 50% RH. Thus, hybrid gels’ tunable formulation offers the potential for designing complementary sensors for e-nose systems operable under different RH conditions. |
| first_indexed | 2024-03-11T05:25:00Z |
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| id | doaj.art-a155e217833b40d39167981cea8f46b4 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-11T05:25:00Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-a155e217833b40d39167981cea8f46b42023-11-17T17:33:55ZengMDPI AGSensors1424-82202023-03-01237353110.3390/s23073531Effect of Polymer Hydrophobicity in the Performance of Hybrid Gel Gas Sensors for E-NosesAna Rita Oliveira0Henrique M. A. Costa1Efthymia Ramou2Susana I. C. J. Palma3Ana Cecília A. Roque4Associate Laboratory i4HB—Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, PortugalAssociate Laboratory i4HB—Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, PortugalAssociate Laboratory i4HB—Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, PortugalAssociate Laboratory i4HB—Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, PortugalAssociate Laboratory i4HB—Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, PortugalRelative humidity (RH) is a common interferent in chemical gas sensors, influencing their baselines and sensitivity, which can limit the performance of e-nose systems. Tuning the composition of the sensing materials is a possible strategy to control the impact of RH in gas sensors. Hybrid gel materials used as gas sensors contain self-assembled droplets of ionic liquid and liquid crystal molecules encapsulated in a polymeric matrix. In this work, we assessed the effect of the matrix hydrophobic properties in the performance of hybrid gel materials for VOC sensing in humid conditions (50% RH). We used two different polymers, the hydrophobic PDMS and the hydrophilic bovine gelatin, as polymeric matrices in hybrid gel materials containing imidazolium-based ionic liquids, [BMIM][Cl] and [BMIM][DCA], and the thermotropic liquid crystal 5CB. Better accuracy of VOC prediction is obtained for the hybrid gels composed of a PDMS matrix combined with the [BMIM][Cl] ionic liquid, and the use of this hydrophobic matrix reduces the effect of humidity on the sensing performance when compared to the gelatin counterpart. VOCs interact with all the moieties of the hybrid gel multicomponent system; thus, VOC correct classification depends not only on the polymeric matrix used, but also on the IL selected, which seems to be key to achieve VOCs discrimination at 50% RH. Thus, hybrid gels’ tunable formulation offers the potential for designing complementary sensors for e-nose systems operable under different RH conditions.https://www.mdpi.com/1424-8220/23/7/3531electronic nosegas sensingionogelshumidityPDMSgelatin |
| spellingShingle | Ana Rita Oliveira Henrique M. A. Costa Efthymia Ramou Susana I. C. J. Palma Ana Cecília A. Roque Effect of Polymer Hydrophobicity in the Performance of Hybrid Gel Gas Sensors for E-Noses Sensors electronic nose gas sensing ionogels humidity PDMS gelatin |
| title | Effect of Polymer Hydrophobicity in the Performance of Hybrid Gel Gas Sensors for E-Noses |
| title_full | Effect of Polymer Hydrophobicity in the Performance of Hybrid Gel Gas Sensors for E-Noses |
| title_fullStr | Effect of Polymer Hydrophobicity in the Performance of Hybrid Gel Gas Sensors for E-Noses |
| title_full_unstemmed | Effect of Polymer Hydrophobicity in the Performance of Hybrid Gel Gas Sensors for E-Noses |
| title_short | Effect of Polymer Hydrophobicity in the Performance of Hybrid Gel Gas Sensors for E-Noses |
| title_sort | effect of polymer hydrophobicity in the performance of hybrid gel gas sensors for e noses |
| topic | electronic nose gas sensing ionogels humidity PDMS gelatin |
| url | https://www.mdpi.com/1424-8220/23/7/3531 |
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