------------------- GENERAL INFORMATION ------------------- Name: Johannes Gmeiner (0009-0006-8241-6545) Role/Function: Data collector (main contact person) Institution: Institute for Technical and Macromolecular Chemistry, University of Hamburg Address: Bundesstrasse 45, 20146 Hamburg, Germany Email: johannes.gmeiner@uni-hamburg.de Name: Jonah Hasse (0009-0008-9086-8239) Role/Function: Data collector Institution: Institute for Technical and Macromolecular Chemistry, University of Hamburg Address: Bundesstrasse 45, 20146 Hamburg, Germany Email: jonah.hasse@uni-hamburg.de Name: Kathrin Marina Eckert (ORCID: 0000-0002-8454-4886) Role/Function: Data collector Institution: Institute of Thermal Separation Processes, Hamburg University of Technology Address: Eißendorfer Straße 38, 21073 Hamburg, Germany Email: kathrin.eckert@tuhh.de Name: Irina Smirnova (ORCID: 0000-0003-4503-4039) Role/Function: Principal Investigator Institution: Institute of Thermal Separation Processes, Hamburg University of Technology Address: Eißendorfer Straße 38, 21073 Hamburg, Germany Email: irina.smirnova@tuhh.de Name: Andreas Liese (0000-0002-4867-9935) Role/Function: Principal Investigator Institute of Technical Biocatalysis, Hamburg University of Technology Address: Denickestr. 15, 21073 Hamburg, Germany Email: irina.smirnova@tuhh.de Name: Gerrit A. Luinstra (ORCID: 0000-0003-4602-8319) Role/Function: Principal Investigator (alternative contact person) Institution: Institute for Technical and Macromolecular Chemistry, University of Hamburg Address: Bundesstrasse 45, 20146 Hamburg, Germany Email: gerrit.albert.luinstra@uni-hamburg.de Date of data collection: November 2025 - Februar 2026 Location of data collection: Institute for Technical and Macromolecular Chemistry, University of Hamburg Funding: This project is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – SFB 1615 – 503850735. Update to Version 02: - The supporting information has been added --------------------------- SHARING/ACCESS INFORMATION --------------------------- Title of data set: "Esterification in an Autonomously Controlled Reactor: Exploiting the Chemo-Mechanical Properties of a Smart Organogel" DOI of data set: Related publication: Yi Luo et al. Tough, Stretchable, and Thermoresponsive Smart Hydrogels. (2023) DOI of related article: https://doi.org/10.3390/gels9090695 Please cite the accepted version of this publication in case you use the data. Keywords: Smart reactors, autonomous flow control, chemoresponsive organogel, P(NiPAAm-co-AA), esterification, kinetics --------------------- DATA & FILE OVERVIEW --------------------- ### 1. Chemicals.csv (creation date: 01.03.2026, version: 01) - **Description:** List of chemicals used in the study. - **Columns:** - Chemical: Name of the chemical used - Supplier: Supplier of the chemical used - Location: Location of the Supplier - CAS-Nr.: CAS-Nr. of the chemical used ### 2. PUMPRATE_TIME_BALANCE.csv (creation date: 01.03.2026, version: 01) - **Description:** Raw data of valve experiments using P(NIPAAm-co-AA) organogel beads - **Columns:** - Time (clock) - Balance (g) - PI Controller (g) - Pump Frequency (stroke/min) - Time (s) ### 3.PUMPRATE_TIME_BALANCE_VALVE_LOOP_VALIDATION.csv (creation date: 01.03.2026, version: 01) - **Description:** Raw data on the swelling kinetics of the organogel in a 2:1 mixture of ethanol and acetic acid. - **Columns:** - **Columns:** - Time (clock) - Balance (g) - PI Controller (g) - Pump Frequency (stroke/min) - Time (s) ### 4.RATIO_4_1_SWELLING_EXPERIMENTS.csv (creation date: 01.03.2026, version: 01) - **Description:** Raw data on the swelling kinetics of the organogel in a 2:1 mixture of ethanol and acetic acid. - **Columns:** - Time (s) - Diameter (pixels) ### 5.RATIO_2_1_SWELLING_EXPERIMENTS.csv (creation date: 01.03.2026, version: 01) - **Description:** Raw data on the swelling kinetics of the organogel in a 4:1 mixture of ethanol and acetic acid. - **Columns:** - Time (s) - Diameter (pixels) ### 6. CONVERSION_ESTERFICATION_MOLAR_RATIO.csv (creation date: 01.03.2026, version: 01) - **Description:** Data of esterfication conversion with different ratios of ethanol to acetic acid. - **Columns:** - Time (h) - Molar Ratios --------------------------- METHODOLOGICAL INFORMATION --------------------------- The methodological information can be found in the publication. 1. Experimental Methods The autonomous loop reaction system was built around a 500 ml double-walled glass reactor (Rettberg GmbH, Germany) with a central bottom outlet (Figure 1). The reactor was modified with an integrated glass frit (porosity 0) to serve as a retention barrier for a heterogeneous catalyst Amberlite IRC120H. This design allowed for the continuous mechanical agitation of the solid catalyst beads within the reactor. Temperature control was achieved using a thermostat (Julabo EH5, Seelbach, Germany), which circulated water through the jacket of the vessel to maintain a constant reaction temperature of 50 °C (±0.1 °C). The mixture in the reactor was stirred with an electronic overhead stirrer (IKA EUROSTAR digital, Staufen, Germany). The propeller stirrer was operated at 1000 rpm. The smart valve consisted of a custom-made stainless steel flange valve (25 mm high, 25 mm inner diameter) attached directly to the reactor outlet. An additional custom-made glass flange valve (70 mm height, 25 mm inner diameter) was manufactured to allow for direct observation of the hydrogel behavior. The iron(III)-functionalized organogel beads were filled into this casing and are retained there by a chemically inert stainless steel mesh with a pore size of 1 mm. The bead size was 6.4 ± 0.6 mm (conditioned in ethanol). The reaction mixture was allowed to leave the reactor through the organogel valve into a collection container placed on a precision balance (Mettler Toledo, Giessen, Germany). A diaphragm metering pump (ProMinent Delta optoDrive, Heidelberg, Germany) with a maximum delivery rate of 160 strokes per minute and a maximum flow rate of 30 L∙h-1 continuously fed the reaction mixture from this container back into the main reactor vessel. A proportional-integral control algorithm implemented in the software regulated the pump frequency in real time to maintain a constant mass in the intermediate container. The entire process automation was controlled by a LabManager system (LM-LABBM2B, HiTec Zang GmbH, Herzogenrath, Germany). The pump stroke frequency was monitored to serve as a flow meter for the valve. The esterification reactions were carried out in sealed glass vessels containing a total volume of 15 ml of the ethanol/acetic acid reactant mixture at molar feed ratios of 1:1 and 2:1. The temperature of the mixture was set to 50 °C and the reaction was initiated by adding 10 wt% of the dried Amberlite catalyst (relative to the total liquid mass). The mixture was stirred at 600 rpm. Conversion was monitored by taking and evaluating of proton nuclear magnetic resonance spectra of samples (1H-NMR obtained from a Bruker 300 MHz spectrometer). Samples (0.05 mL) were withdrawn from the reaction supernatant at hourly intervals for the first 5 hours, followed by a final measurement after 24 hours. Each aliquot was immediately diluted with 0.5 mL of deuterated dimethyl sulfoxide (DMSO-d6), and the 1H NMR spectrum recorded. The molar conversion was calculated from the integrated signals of the methyl group of ethyl acetate and acetic acid. The swelling kinetics of beads were monitored using the optical tracking setup previously established.37 Image sequences of the beads were recorded at 30 s intervals (Canon EOS R50) and processed via a custom Python algorithm to determine their diameter. The distinct deep orange coloration of the Fe³⁺- loaded beads facilitated a robust segmentation against a black background by applying color thresholding. Hydrodynamic radii were calculated from the detected contours using a metric calibration scale. ----------------- RESEARCH CONTEXT ----------------- This research explores the transition toward autonomous "smart reactors" in chemical engineering, aiming to reduce reliance on complex external control infrastructures. The study focuses on a self-regulating reactor loop for the equilibrium-limited esterification of acetic acid and ethanol. Central to this design is a chemo-mechanical valve utilizing iron(III)-reinforced poly(N-isopropylacrylamide-co-acrylic acid) organogel beads. The investigation evaluates the beads' ability to act as an intrinsic feedback mechanism, swelling to restrict flow in the presence of polar reactants and autonomously shrinking to release the product mixture as the reaction approaches thermodynamic equilibrium.