Thin films of poly(vinylidene fluoride-: Co -hexafluoropropylene)-ionic liquid mixtures as amperometric gas sensing materials for oxygen and ammonia
© The Royal Society of Chemistry 2020. Gas sensors are important devices used to monitor the type and amount of gas present. Amperometric gas sensors-based on measuring the current upon an applied potential-have been progressing towards miniaturised designs that are smaller, lower cost, faster r...
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| Format: | Journal Article |
| Language: | English |
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ROYAL SOC CHEMISTRY
2020
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| Subjects: | |
| Online Access: | http://purl.org/au-research/grants/arc/FT170100315 http://hdl.handle.net/20.500.11937/79832 |
| _version_ | 1848764113167056896 |
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| author | Lee, Juni Hussain, Ghulam López-Salas, N. Macfarlane, D.R. Silvester-Dean, Debbie |
| author_facet | Lee, Juni Hussain, Ghulam López-Salas, N. Macfarlane, D.R. Silvester-Dean, Debbie |
| author_sort | Lee, Juni |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | © The Royal Society of Chemistry 2020.
Gas sensors are important devices used to monitor the type and amount of gas present. Amperometric gas sensors-based on measuring the current upon an applied potential-have been progressing towards miniaturised designs that are smaller, lower cost, faster responding and more robust compared to commercially available sensors. In this work, a planar thin-film electrode device is employed for gas sensing with a thin layer of gel polymer electrolyte (GPE). The GPE consists of a room temperature ionic liquid (RTIL, with two different imidazolium cations and the tetrafluoroborate [BF4]- anion) mixed with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). The polymer acts as a scaffold, with the RTIL ions able to flow within the porous percolated channels, resulting in a highly robust gel with high conductivity. The chemical nature of the polymer allows thin-films (ca. 6 μm) to be evenly dropcast onto planar electrode devices, using minimal amounts of material. Remarkably, no significant effect of resistance was observed in the voltammetric response with such thin films. Oxygen (O2) and ammonia (NH3) gases were detected in the concentration ranges 1-20% O2 and 1-10 ppm NH3 in the two GPEs using both linear sweep voltammetry (LSV) and long-term chronoamperometry (LTCA). LTCA was the preferred detection method for both gases due to the steady-state current response compared to the sloping current response from LSV. The thin nature of the film gave fast response times for both gases-less than 10 seconds for O2 and ca. 40 seconds for NH3-easily rivaling the commercially available porous electrode designs and allowing for continuous monitoring of gas concentrations. These materials appear to be highly promising candidates as gas detection electrolytes in miniaturised devices, with accurate and fast responses in both the cathodic and anodic potential regions. |
| first_indexed | 2025-11-14T11:14:11Z |
| format | Journal Article |
| id | curtin-20.500.11937-79832 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:14:11Z |
| publishDate | 2020 |
| publisher | ROYAL SOC CHEMISTRY |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-798322020-08-14T07:16:27Z Thin films of poly(vinylidene fluoride-: Co -hexafluoropropylene)-ionic liquid mixtures as amperometric gas sensing materials for oxygen and ammonia Lee, Juni Hussain, Ghulam López-Salas, N. Macfarlane, D.R. Silvester-Dean, Debbie Science & Technology Physical Sciences Chemistry, Analytical Chemistry TEMPERATURE IONIC LIQUIDS ELECTROCHEMICAL NO2 SENSOR POLYMER GEL ELECTROLYTES STATE REDUCTION VOLTAMMETRY SUPEROXIDE ELECTRODES MEMBRANES MONOMERS © The Royal Society of Chemistry 2020. Gas sensors are important devices used to monitor the type and amount of gas present. Amperometric gas sensors-based on measuring the current upon an applied potential-have been progressing towards miniaturised designs that are smaller, lower cost, faster responding and more robust compared to commercially available sensors. In this work, a planar thin-film electrode device is employed for gas sensing with a thin layer of gel polymer electrolyte (GPE). The GPE consists of a room temperature ionic liquid (RTIL, with two different imidazolium cations and the tetrafluoroborate [BF4]- anion) mixed with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). The polymer acts as a scaffold, with the RTIL ions able to flow within the porous percolated channels, resulting in a highly robust gel with high conductivity. The chemical nature of the polymer allows thin-films (ca. 6 μm) to be evenly dropcast onto planar electrode devices, using minimal amounts of material. Remarkably, no significant effect of resistance was observed in the voltammetric response with such thin films. Oxygen (O2) and ammonia (NH3) gases were detected in the concentration ranges 1-20% O2 and 1-10 ppm NH3 in the two GPEs using both linear sweep voltammetry (LSV) and long-term chronoamperometry (LTCA). LTCA was the preferred detection method for both gases due to the steady-state current response compared to the sloping current response from LSV. The thin nature of the film gave fast response times for both gases-less than 10 seconds for O2 and ca. 40 seconds for NH3-easily rivaling the commercially available porous electrode designs and allowing for continuous monitoring of gas concentrations. These materials appear to be highly promising candidates as gas detection electrolytes in miniaturised devices, with accurate and fast responses in both the cathodic and anodic potential regions. 2020 Journal Article http://hdl.handle.net/20.500.11937/79832 10.1039/c9an02153a English http://purl.org/au-research/grants/arc/FT170100315 http://purl.org/au-research/grants/arc/FL120100019 ROYAL SOC CHEMISTRY restricted |
| spellingShingle | Science & Technology Physical Sciences Chemistry, Analytical Chemistry TEMPERATURE IONIC LIQUIDS ELECTROCHEMICAL NO2 SENSOR POLYMER GEL ELECTROLYTES STATE REDUCTION VOLTAMMETRY SUPEROXIDE ELECTRODES MEMBRANES MONOMERS Lee, Juni Hussain, Ghulam López-Salas, N. Macfarlane, D.R. Silvester-Dean, Debbie Thin films of poly(vinylidene fluoride-: Co -hexafluoropropylene)-ionic liquid mixtures as amperometric gas sensing materials for oxygen and ammonia |
| title | Thin films of poly(vinylidene fluoride-: Co -hexafluoropropylene)-ionic liquid mixtures as amperometric gas sensing materials for oxygen and ammonia |
| title_full | Thin films of poly(vinylidene fluoride-: Co -hexafluoropropylene)-ionic liquid mixtures as amperometric gas sensing materials for oxygen and ammonia |
| title_fullStr | Thin films of poly(vinylidene fluoride-: Co -hexafluoropropylene)-ionic liquid mixtures as amperometric gas sensing materials for oxygen and ammonia |
| title_full_unstemmed | Thin films of poly(vinylidene fluoride-: Co -hexafluoropropylene)-ionic liquid mixtures as amperometric gas sensing materials for oxygen and ammonia |
| title_short | Thin films of poly(vinylidene fluoride-: Co -hexafluoropropylene)-ionic liquid mixtures as amperometric gas sensing materials for oxygen and ammonia |
| title_sort | thin films of poly(vinylidene fluoride-: co -hexafluoropropylene)-ionic liquid mixtures as amperometric gas sensing materials for oxygen and ammonia |
| topic | Science & Technology Physical Sciences Chemistry, Analytical Chemistry TEMPERATURE IONIC LIQUIDS ELECTROCHEMICAL NO2 SENSOR POLYMER GEL ELECTROLYTES STATE REDUCTION VOLTAMMETRY SUPEROXIDE ELECTRODES MEMBRANES MONOMERS |
| url | http://purl.org/au-research/grants/arc/FT170100315 http://purl.org/au-research/grants/arc/FT170100315 http://hdl.handle.net/20.500.11937/79832 |