• Reaction and Process Monitoring Using Benchtop NMR Spectroscopy

Monitoring chemical reactions and processes is a central aspect of process engineering. Compact benchtop NMR spectrometers enable direct, non-invasive online analysis, allowing real-time information on reaction kinetics and the composition of mixtures to be obtained. Quantitative measurement in continuous flow poses a challenge, particularly for ¹³C nuclei due to their low sensitivity. The goal of this project is to shorten relaxation times through paramagnetic relaxation enhancement (PRE), thereby enabling quantitative NMR measurements even at high flow rates.

• Acceleration of NMR Experiments Through Spatially Decoupled Paramagnetic Relaxation

NMR spectroscopic measurements are time-consuming because long waiting periods are required between individual scans to allow the nuclear spins to return to equilibrium polarization (T₁ relaxation). This leads to inefficient use of measurement time, particularly in measurements involving many scans, such as two-dimensional experiments, or when dealing with low-sensitivity nuclei and dilute samples. A typical example is ¹³C NMR spectroscopy, which is particularly time-consuming due to the low gyromagnetic ratio, low natural frequency, and long T₁ times. At the same time, it provides information-rich spectra due to the high chemical shift and is therefore of great importance. The goal of this project is to specifically shorten the T₁ times through the use of spatially separated paramagnetic relaxation enhancement (PRE), thereby accumulating the required number of scans more efficiently. This should significantly speed up NMR measurements and improve the utilization of the instruments.

Teaching Assistance

• Anwendungen der Magnetresonanz für Naturwissenschaftler und Ingenieure (WiSe 2021)
• Laborpraktikum Anwendungen der Magnetresonanz für Naturwissenschaftler und Ingenieure (WiSe 2021, WiSe 2022, WiSe 2024)
• chemCar Wettbewerb I (WiSe 2021)
• Labor Thermische Verfahrenstechnik I (WiSe 2021, WiSe 2022, SoSe 2023, SoSe2024)
• chemCar Wettbewerb II (SoSe 2022)
• Grenzflächenthermodynamik (SoSe 2022)
• Grundlagenlabor für das Schwerpunktfach I (SoSe 2022, SoSe 2023, SoSe2024)
• Thermodynamik I (WiSe 2022)
• Elektrochemische Energiespeicherung (SoSe 2023)

• Thermodynamik der Transportprozesse (WiSe 2024)

   

Appointments

Inquire by E-Mail

 Publications

• R. Kircher, S. Mross, H. Hasse, K. Münnemann: Functionalized Controlled Porous Glasses for Producing Radical-Free Hyperpolarized Liquids by Overhauser DNP, Molecules 27 (2022) 6402 [DOI]
• R. Kircher, S. Mross, H. Hasse, K. Münnemann: Quantitative Analysis in Continuous‑Flow ¹H Benchtop NMR Spectroscopy by Paramagnetic Relaxation Enhancement, Applied Magnetic Resonance 54 (2023) 1555-1569 [DOI]
• J. Phuong, S. Mross, D. Bellaire, H. Hasse, K. Münnemann: Determination of self-diffusion coefficients in mixtures with benchtop ¹³C NMR spectroscopy via polarization transfer, Magn. Reson. Chem. (2023) 1-12 [DOI]
• S. Mross, S. Schmitt, S. Stephan, K. Münnemann, H. Hasse: Diffusion Coefficients in Mixtures of Poly(oxymethylene) Dimethyl Ethers with Alkanes, Ind. Eng. Chem. Res. 63 (2024) 1662–1669 [DOI]
• P.Zittlau, S.Mross, D. Gond, M. Kohns: Molecular modeling and simulation of organic electrolyte solutions for lithium ion batteries, J. Chem. Phys. 161 (2024) 124118 [DOI]
• J. Phuong, R.Kircher, S. Mross, B. Salgado, H. Hasse, K. Münnemann: Quantitative Nuclear Magnetic Resonance Spectroscopy with Overhauser Dynamic Nuclear Polarization, ChemPhysChem 26 (2025)  [DOI]
• S. Mross, J.Peter, A. Izadi, F. de Meyer, K. Münnemann, H. Hasse: NMR Study on the Reactivity of Hydrogen Sulfide in Aqueous Amine Solutions, Ind. Eng. Chem. Res. 64 (2025) 15958-15964 [DOI]
• L. Stubbe, Y. Stiemcke, S. Mross, S. Staub, K. Steiner, K. Münnemann, O. Koch, S. Thielen: A new rubber-lubricant compatibility test on a tribometer for radial shaft seals, Tribologie + Schmierungstechnik 71 (2025) 38-44 [DOI] 
• S. Mross, H. Hasse, K. Münnemann: Enabling Quantitative Benchtop ¹³C NMR Spectroscopy in Fast Continuous Flow, Magn. Reson. Chem. (2026) 1-10 [DOI]
• O. Großmann, S. Mross, J. Wagner, K. Münnemann, F. Jirasek, H. Hasse: Measurements of Diffusion Coefficients of CO₂ in 1-Butanol with a New Laminar Jet Apparatus and PFG-NMR, Pointing to Interfacial Mass Transfer Effects, Ind. Eng. Chem. Res. 65 (2026) 19333-19345 [DOI] 

Presentations

• M. Dyga, S. Schmitt, S. Mross, A. Keller, S. Maurer, S. Stephan, H. Hasse: The unexpected liquid−liquid equilibrium behavior of mixtures of water and isoprenol, Thermodynamik-Kolloquium, Chemnitz, 26.09.-28.09.2022.
• J. Phuong, R. Kircher, S. Mross, H. Hasse, K. Münnemann: Overhauser DNP for Online NMR Spectroscopy, 19th European Magnetic Resonance Congress (EUROMAR), Glasgow, 09.07.-13.07.2023.
• S. Mross, S. Schmitt, B. Kunstmann, D. Bellaire, K. Münnemann, H. Hasse: Diffusion Coefficients in Mixtures of OME and Alkanes by NMR Spectroscopy, 14^th European Congress of Chemical Engineering and 7^th European Congress of Applied Biotechnology (ECCE&ECAB), Berlin, 17.09.-21.09.23.
• S. Mross, Z. Romero, K. Münnemann, F. Jirasek, H. Hasse: Measurement and Prediction of Self-Diffusion Coefficients with NMR Spectroscopy and Active Learning Strategies, Thermodynamik-Kolloquium, Hannover, 25.09.-27.09.2023.
• S. Mross, S. Schmitt, S. Stephan, K. Münnemann, H. Hasse: Measurement and Modeling of Diffusion Coefficients in Mixtures of Poly(oxymethylene) Dimethyl Ethers with Alkanes by NMR Spectroscopy and Entropy Scaling, 20^th International Conference on Diffusion in Solids and Liquids (DSL), Barcelona, 24.06.-28.06.2024.
• S. Mross, R. Kircher, H. Hasse, K. Münnemann: Quantitative Analysis in Continuous Flow Benchtop ¹H NMR with Paramagnetic Relaxation Enhancement, 6th qNMR Summit, Buchs SG, 18.09.-20.09.2024.
• S. Mross, H. Hasse, K. Münnemann: Quantitative Analysis of Flowing Mixtures using Benchtop NMR Spectroscopy with Paramagnetic Relaxation Enhancement, Quantitative NMR Methods for Reaction and Process Monitoring (NMRPM), Kaiserslautern, 31.03.-02.04.2025.
• B. Salgado, J. Phuong, S. Mross, H. Hasse, K. Münnemann: ODNP-Enhanced Benchtop ¹³C NMR Spectroscopy for Continuous-Flow Applications. µscale NMR and MRI Conference, Ettlingen, 29.06-02.07.2025.
• S. Mross, H. Hasse, K. Münnemann: Improving Process Monitoring by ¹³C Benchtop NMR Spectroscopy with Paramagnetic Relaxation Enhancement, Small Molecule NMR Conference 2025 (SMASH), Porto, 21.09-24.09.2025.
• B. Salgado, J. Phuong, S. Mross, H. Hasse, K. Münnemann: Quantitative Analysis using ODNP-Enhanced ¹³C Benchtop NMR Spectroscopy for Continuous-Flow Applications. qNMR Summit, Bari, 19.11-21.11.2025.
• S. Mross, H. Hasse, K. Münnemann: Quantitative Analysis of Flowing Mixtures using ¹³C Benchtop NMR Spectroscopy with Paramagnetic Relaxation Enhancement. qNMR Summit, Bari, 19.11-21.11.2025.

Posters

• S. Mross, D. Bellaire, K. Münnemann, H. Hasse: Self-Diffusion Coefficients in Mixtures of OME with Alkanes, (Bio)Process Engineering 2022 - A Key to Sustainable Development, Aachen, 12.09.-15.09.2022.
• J. Phuong, S. Mross, D. Bellaire, H. Hasse, K. Münnemann: Determination of Self-Diffusion Coefficients in Mixtures with Benchtop ¹³C NMR-Spectroscopy. Thermodynamik-Kolloquium, Chemnitz, 26.09.-28.09.2022.
• S. Mross, D. Bellaire, M. Kohns, K. Münnemann, H. Hasse: Self-Diffusion Coefficients in Mixtures of OME with Alkanes, Thermodynamik-Kolloquium, Chemnitz, 26.09.-28.09.2022.
• S. Mross, R. Kircher, H. Hasse, K. Münnemann: Quantitative Analysis in Continuous Flow Benchtop ¹H NMR by Paramagnetic Relaxation Enhancement, Quantitative NMR Methods for Reaction and Process Monitoring (NMRPM), Kaiserslautern, 24.05.-26.05.2023.
• S. Mross, D. Bellaire, K. Münnemann, H.Hasse: Mutual Diffusion Coefficients by NMR spectroscopy. 19^th European Magnetic Resonance Congress (EUROMAR), Glasgow, 09.07.-13.07.2023.
• J. Phuong, S. Mross, H.Hasse, K. Münnemann: A New Method to Determine Self-Diffusion Coefficients in Complex MIxtures with Benchtop ¹³C NMR Spectroscopy. Small Molecule NMR Conference 2023 (SMASH), Baveno, Italien, 17.09.-20.09.2023.
• S. Mross, R. Kircher, H. Hasse, K. Münnemann: Quantitative Analysis in Continuous Flow Benchtop ¹H NMR with Paramagnetic Relaxation Enhancement and Overhauser Dynamic Nuclear Polarization, 45th FGMR Annual Discussion Meeting, Rostock, 09.09.-13.09.2024.
• P.Zittlau, S.Mross, D. Gond, M. Kohns: Molecular Models for Lithium Ion Battery Electrolytes: Cyclic Carbonate Solvents and Lithium Salts, Thermodynamik-Kolloquium, Stuttgart, 25.09.-27.09.2024.
• S. Mross, R. Kircher, H. Hasse, K. Münnemann: Quantitative Analysis in Online Benchtop NMR Spectroscopy by Paramagnetic Relaxation Enhancement, Reaction Monitoring Symposium 2025, Bath, 28.01.2025.
• S. Mross, B. Gizatullin, B. Salgado, F. Casanova, H. Hasse, K. Münnemann: Accelerating NMR by Reduction of Scan Accumulation Time using PRE Shuttle, EUROMAR Conference 2026, Göteborg, Schweden, 28.06.2026.