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Drake AD, He Y, Ladipo F, Knutson BL, Rankin SE. Effect of Pore Confinement of Ionic Liquids on Solute Diffusion within Mesoporous Silica Microparticles. J Phys Chem B 2024. [PMID: 38478906 DOI: 10.1021/acs.jpcb.4c01018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
The transport properties of the ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) confined within silica microparticles with well-ordered, accessible mesopores (5.4 or 9 nm diameter) were investigated. [BMIM][PF6] confinement was confirmed by using differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. The transport properties of the confined IL were studied using the neutral and cationic fluorescent probes 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) and rhodamine 6G, respectively, through fluorescence recovery after photobleaching (FRAP) in confocal microscopy. The diffusivity of DCM in 9 nm pores is 0.026 ± 0.0091 μm2/s, which is 2 orders of magnitude less than in the bulk ionic liquid. The pore size did not affect the diffusivity of DCM in unmodified silica nanopores. The diffusivity of the cationic probe is reduced by 63% relative to that of the neutral probe. Diffusivity is increased with water content, where equilibrium hydration of the system leads to a 37% increase in DCM diffusivity. The most dramatic impact on diffusivity was caused by tethering an IL-like methylimidazolium chloride group to the pores, which increased the pore hydrophobicity and resulted in 3-fold higher diffusivity of DCM compared to bare silica pores. Subsequent exchange of the chloride anion from the tethering group with PF6- decreased the diffusivity to half that of bare silica. The diffusion of probe molecules is affected most strongly by the pore wall effects on probe interactions rather than by the pore size itself, which suggests that understanding pore wall diffusion is critical to the design of nanoconfined ILs for separations, catalysis, and energy storage.
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Affiliation(s)
- Andrew D Drake
- Department of Chemical and Materials Engineering, University of Kentucky, 177 F.P. Anderson Tower, Lexington, Kentucky 40506-0046, United States
| | - Yuxin He
- Department of Chemical and Materials Engineering, University of Kentucky, 177 F.P. Anderson Tower, Lexington, Kentucky 40506-0046, United States
| | - Folami Ladipo
- Department of Chemistry, University of Kentucky, 125 Chemistry/Physics Building, Lexington, Kentucky 40506-0055, United States
| | - Barbara L Knutson
- Department of Chemical and Materials Engineering, University of Kentucky, 177 F.P. Anderson Tower, Lexington, Kentucky 40506-0046, United States
| | - Stephen E Rankin
- Department of Chemical and Materials Engineering, University of Kentucky, 177 F.P. Anderson Tower, Lexington, Kentucky 40506-0046, United States
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Qin L, Liu W, Su J, Yang Z, Liang Z, Li X, Luan P, Wang DK, Lu ZH, Zhu Q. Influence of Volatile Organic Compound Adsorption on the Characteristics of Organic Field-Effect Transistors and Rules for Gas-Sensing Measurements. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:15756-15765. [PMID: 37883782 DOI: 10.1021/acs.langmuir.3c02334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
Owing to the advantages of organic field-effect transistors (OFETs) in the versatility of organic synthesis, multiparameter measurement, and signal amplification, sensors based on OFETs have received increasing attention for detecting volatile organic compounds (VOCs). However, false device operation and gas-sensing measurements often occur to vitiate the advantages of OFETs and even output error gas-sensing signals. In this work, by experimentally and theoretically studying the effects of VOC adsorption on the operational characteristics of the OFET, the proper operations of OFETs in gas-sensing measurements were clarified. The multiparameter measurements of OFETs showed that the source-drain current was the optimized parameter for achieving high responsivity, and other OFET parameters could be used for fingerprint analysis. By operating OFETs in the near-threshold region, the amplification effect was switched to enhance the responsivity by orders of magnitude to VOCs, while in the overthreshold region, the OFETs had a low signal-to-noise ratio. Besides, a counteraction effect and an uncertainty effect were discovered, leading to error gas-sensing signals. A theoretical study was carried out to reveal the dependency of the gas-sensing properties of OFETs on VOC adsorption. A series of rules were proposed for guiding the measurements of OFET sensors by taking full advantage of transistors in gas-sensing applications.
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Affiliation(s)
- Lingping Qin
- Key Laboratory of Yunnan Provincial Higher Education Institutions for Optoelectronics Device Engineering, School of Physics and Astronomy, Yunnan University, Kunming 650504, China
| | - Wei Liu
- Clinical Medical Laboratory, Mengzi People's Hospital, Yunnan University of Chinese Medicine, Mengzi 661100, China
| | - Jiale Su
- Key Laboratory of Yunnan Provincial Higher Education Institutions for Optoelectronics Device Engineering, School of Physics and Astronomy, Yunnan University, Kunming 650504, China
| | - Zhenxin Yang
- Key Laboratory of Yunnan Provincial Higher Education Institutions for Optoelectronics Device Engineering, School of Physics and Astronomy, Yunnan University, Kunming 650504, China
| | - Zheng Liang
- Key Laboratory of Yunnan Provincial Higher Education Institutions for Optoelectronics Device Engineering, School of Physics and Astronomy, Yunnan University, Kunming 650504, China
| | - Xiaoliang Li
- Key Laboratory of Yunnan Provincial Higher Education Institutions for Optoelectronics Device Engineering, School of Physics and Astronomy, Yunnan University, Kunming 650504, China
| | - Pengyan Luan
- Key Laboratory of Yunnan Provincial Higher Education Institutions for Optoelectronics Device Engineering, School of Physics and Astronomy, Yunnan University, Kunming 650504, China
| | - Deng-Ke Wang
- Key Laboratory of Yunnan Provincial Higher Education Institutions for Optoelectronics Device Engineering, School of Physics and Astronomy, Yunnan University, Kunming 650504, China
| | - Zheng-Hong Lu
- Key Laboratory of Yunnan Provincial Higher Education Institutions for Optoelectronics Device Engineering, School of Physics and Astronomy, Yunnan University, Kunming 650504, China
- Department of Materials Science and Engineering, University of Toronto, Toronto M5S 3E4, Canada
| | - Qiang Zhu
- Key Laboratory of Yunnan Provincial Higher Education Institutions for Optoelectronics Device Engineering, School of Physics and Astronomy, Yunnan University, Kunming 650504, China
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Zheng Z, Jiang N, Liang R, Chi H, Wu J, Jiang J, Ye Z, Zhu L. Enhanced Acetone-Sensing Properties of Pt-Decorated In 2O 3 Hollow Microspheres Derived from Pt-Embedded Template. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:10178-10188. [PMID: 37439034 DOI: 10.1021/acs.langmuir.3c01096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Pt-decorated In2O3 hollow microspheres were prepared using a template and reflux method. The size of the prepared carbon templates was adjusted from 200 nm to 1.3 μm by introducing chloroplatinic acid during the hydrothermal process. At the same time, Pt nanoparticles inside the carbon layer were protected from oxidation and agglomeration. Also, the folds created on the surface of the hollow sphere during shrinkage led to a substantial increase in specific surface area. The response of the In2O3-based sensor toward acetone was significantly enhanced by the addition of Pt decoration. This improvement can be attributed to the increased availability of active sites for the target gas and the consequential alteration of the energy band structure. In addition, high response sensitivity, rapid dynamic processes, long-term reliability, and selectivity have all been achieved. The detectable limit is less than 1 ppm, which might satisfy the 1.8 ppm threshold value in the exhaled breath of patients with diabetes. Consequently, the proposed sensor has great sensitivity and can detect low-concentration of acetone, making it an ideal choice for applications such as monitoring daily dietary intake, managing diabetes, and inspecting industrial production processes.
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Affiliation(s)
- Zicheng Zheng
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
- Wenzhou Key Laboratory of Novel Optoelectronic and Nano Materials, Institute of Wenzhou, Zhejiang University, Wenzhou 325006, PR China
| | - Nan Jiang
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
- Wenzhou Key Laboratory of Novel Optoelectronic and Nano Materials, Institute of Wenzhou, Zhejiang University, Wenzhou 325006, PR China
| | - Rong Liang
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
- Wenzhou Key Laboratory of Novel Optoelectronic and Nano Materials, Institute of Wenzhou, Zhejiang University, Wenzhou 325006, PR China
| | - Hanwen Chi
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
- Wenzhou Key Laboratory of Novel Optoelectronic and Nano Materials, Institute of Wenzhou, Zhejiang University, Wenzhou 325006, PR China
| | - Jingmin Wu
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
- Wenzhou Key Laboratory of Novel Optoelectronic and Nano Materials, Institute of Wenzhou, Zhejiang University, Wenzhou 325006, PR China
| | - Jie Jiang
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
- Wenzhou Key Laboratory of Novel Optoelectronic and Nano Materials, Institute of Wenzhou, Zhejiang University, Wenzhou 325006, PR China
| | - Zhizhen Ye
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
- Wenzhou Key Laboratory of Novel Optoelectronic and Nano Materials, Institute of Wenzhou, Zhejiang University, Wenzhou 325006, PR China
| | - Liping Zhu
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
- Wenzhou Key Laboratory of Novel Optoelectronic and Nano Materials, Institute of Wenzhou, Zhejiang University, Wenzhou 325006, PR China
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Su Y, Wang T, Zhang F, Huang J, Zhu Z, Shah FU, Xu F, An R. Effect of Electrode Surface Chemistry on Ion Structuring of Imidazolium Ionic Liquids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37289976 DOI: 10.1021/acs.langmuir.3c00710] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Surface chemistry plays a critical role in the ion structuring of ionic liquids (ILs) at the interfaces of electrodes and controls the overall energy storage performance of the system. Herein, we functionalized the gold (Au) colloid probe of an atomic force microscope with -COOH and -NH2 groups to explore the effect of different surface chemical properties on the ion structuring of an IL. Aided by colloid-probe atomic force microscopy (AFM), the ion structuring of an imidazolium IL, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6], abbreviated as BP hereafter), on the Au electrode surface and the ion response to the change in the surface chemistry are investigated. AFM morphologies, contact angles, and approaching force-distance curves of the BP IL on the functionalized Au surfaces exhibited that the IL forms a more obvious layering structure on the -COOH-terminated Au surface (Au-COOH), while it forms heterogeneous and aggregating droplets on the -NH2 surface (Au-NH2). The formed uniform and aggregation-free ion layers in the vicinity of the Au-COOH surface are due to the π-π+ stacking interaction between the delocalized π+ electrons from the imidazolium ring in the IL [BMIM]+ cation and the localized π electrons from the sp2 carbon on the -COOH group. The in situ observation of nano-friction and torsional resonance frequency at the IL-electrode interfaces further demonstrated the ion structuring of the IL at Au-COOH, which results in a more sensitive electrochemical response associated with a faster capacitive process.
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Affiliation(s)
- Yiqun Su
- School of Materials Science and Engineering/Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Tiantian Wang
- School of Materials Science and Engineering/Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Fan Zhang
- Department of Engineering and Design, School of Engineering and Information, University of Sussex, Brighton BN1 9RH, U.K
| | - Junsen Huang
- School of Materials Science and Engineering/Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Zhehang Zhu
- School of Materials Science and Engineering/Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Faiz Ullah Shah
- Chemistry of Interfaces, Luleå University of Technology, 97187 Luleå, Sweden
| | - Feng Xu
- School of Materials Science and Engineering/Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Rong An
- School of Materials Science and Engineering/Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing 210094, China
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