@article{malhotra2025quantification,

title = {Quantification of Methane in Water at Parts Per Billion Sensitivity Using a Metal–Organic Framework-Functionalized Quartz Crystal Resonator},

author = {Jaskaran Singh Malhotra and Clara Dávila Duarte and Per Reichert and Deepthy Krishnan and Jonas Sundberg},

url = {https://pubs.acs.org/doi/abs/10.1021/acsanm.4c06883},

doi = {https://doi.org/10.1021/acsanm.4c06883},

year  = {2025},

date = {2025-02-26},

urldate = {2025-02-26},

journal = {ACS Applied Nano Materials},

publisher = {ACS Publications},

abstract = {Wetlands and water bodies are essential sources of methane emissions, a greenhouse gas that is roughly 25 times more potent than carbon dioxide. However, the biological production, fluxes, and interplay between methane and carbon dioxide due to microbial activity must be better understood. This is primarily attributed to the lack of sensor technology to provide the required spatial and temporal resolution. Herein, we demonstrate how a porous metal–organic framework material can create a sensor to quantify dissolved methane. The sensor is based on a quartz crystal microbalance, which measures methane adsorption using a quartz resonator functionalized with the material. Combining the quartz crystal microbalance and the nanoporous material yields fast response times and high sensitivity. This is due to a favorable partitioning coefficient between the empty pores of the material and the aqueous phase, promoting rapid migration of dissolved methane into the material. The result is a sensor system that achieves equilibration and response times under 60 s with parts per billion sensitivity. The high sensor performance is based on microporous pore size distribution, surface hydrophobicity, and crystallite size, yielding strong synergy. A fully functioning prototype has been designed, built, and evaluated to demonstrate real-life applicability and obtain a response from methane-spiked lake water. The modular nature of metal–organic frameworks opens possibilities for creating materials for selective sensing of other aqueous species. Thus, our study showcases the importance of materials for methane sensing and environmental monitoring in general.},

keywords = {chemical sensors, greenhouse gas emissions, hydrocarbons, Metal organic frameworks, methane monitoring, openQCM NEXT, QCM, Quartz Crystal Microbalance, Thin films, wetlands},

pubstate = {published},

tppubtype = {article}

}

@article{dedecker2025selective,

title = {Selective Adsorption and Separation of C 6 Hydrocarbons: The Role of Structural Flexibility and Functionalization in Zeolitic Imidazolate Frameworks},

author = {Kevin Dedecker and Martin Drobek and Anne Julbe},

url = {https://pubs.rsc.org/en/content/articlehtml/2025/lf/d4lf00388h},

doi = {https://doi.org/10.1039/D4LF00388H},

year  = {2024},

date = {2024-12-19},

urldate = {2024-12-19},

journal = {RSC Applied Interfaces},

publisher = {Royal Society of Chemistry},

abstract = {This study investigates the selective adsorption and separation of C6 hydrocarbons (benzene, cyclohexane, and n-hexane) by zeolitic imidazolate frameworks (ZIFs), focusing on their structural flexibility and functionalization. ZIF-8_CH3 and ZIF-8_Br were synthesized and compared, indicating distinct adsorption behaviors. ZIF-8_CH3 showed higher uptake for benzene (9.5 molecules per unit cell) and n-hexane (8.0 mlc uc−1) compared to cyclohexane (1.0 mlc uc−1). In contrast, ZIF-8_Br exhibited enhanced adsorption for cyclohexane (5.0 mlc uc−1) and reduced n-hexane uptake (0.5 mlc uc−1). Computational simulations supported these findings, identifying the involved host–guest interactions. Ideal adsorbed solution theory analysis confirmed that ZIF-8_CH3 demonstrated virtually zero uptake of cyclohexane from binary mixtures containing either n-hexane or benzene, while ZIF-8_Br exhibited negligible adsorption of n-hexane from its mixtures with cyclohexane or benzene. It was concluded that bromine functionalization in ZIF-8_Br increased structural rigidity and selectivity for aromatic compounds. These results highlight the crucial role of functionalization and gate-opening phenomena in ZIFs to achieve efficient volatile organic compound capture and separation where traditional adsorbents may not be effective.},

keywords = {Adsorption, benzene, cyclohexane, hydrocarbons, n-hexane, openQCM, QCM, Quartz Crystal Microbalance},

pubstate = {published},

tppubtype = {article}

}