This README.txt file was generated on 2026-02-27 by Jonah Hasse (Jonah.hasse@uni-hamburg.de) ------------------- GENERAL INFORMATION ------------------- Name: Jonah Hasse (ORCID: 0009-0008-9086-8239) Role/Function: Data collector (main contact person) Institution: Institute for Technical and Macromolecular Chemistry, University of Hamburg Address: Bundesstrasse 45, 20146 Hamburg, Germany Email: Jonah.hasse@uni-hamburg.de Name: Johannes Gmeiner (ORCID: 0009-0006-8241-6545) Role/Function: Contributing Researcher Institution: Institute for Technical and Macromolecular Chemistry, University of Hamburg Address: Bundesstrasse 45, 20146 Hamburg, Germany Name: Andreas Liese (ORCID: 0000-0002-4867-9935) Role/Function: Principal Investigator Institution: Institute of Technical Biocatalysis, Hamburg University of Technology Address: Denickestr. 15, 21073 Hamburg, Germany 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: July 2024 - February 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. --------------------------- SHARING/ACCESS INFORMATION --------------------------- Title of data set: "Dataset on Solvent-Responsive HEA-Gels as Intrinsic Actuators in a Smart Reactor Concept" 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 Kathrin Marina Eckert et al. Exploring pNIPAM Lyogels: Experimental Study on Swelling Equilibria in Various Organic Solvents and Mixtures, Supported by COSMO-RS Analysis (2024) DOI of related article: https://doi.org/10.1016/j.fluid.2024.114182 Kathrin Marina Eckert et al. Enhancing Swelling Kinetics of pNIPAM Lyogels: The Role of Crosslinking, Copolymerization, and Solvent (2025) DOI of related article: https://doi.org/10.1016/j.fluid.2025.114462 Please cite the accepted version of this publication in case you use the data. Keywords: Organogels, swelling behavior, smart valve, oxidation, self-controlled reactor, HEA --------------------- DATA & FILE OVERVIEW --------------------- ### 1. chemicals.csv (creation date: 26.02.2026, version: 01) - **Description:** List of chemicals used for the synthesis and experiments. - **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. gel_formulations.csv (creation date: 27.02.2026, version: 01) - **Description:** Summary of the synthesis parameters and chemical compositions for all poly(2-hydroxyethyl acrylate) organogel formulations evaluated in this study. - **Columns:** - organogel: The name/identifier of the specific gel formulation. - monomer /wt%: The monomer used and its weight percentage in the aqueous precursor solution. - crosslinker /wt%: The specific crosslinker used and its weight percentage in the precursor solution. - dosing end diameter /mm: The inner diameter of the needle or tubing used during the cryo-dripping process to control the macroscopic bead size. ### 3. gravimetric_swelling_data_HEA-beads.csv (creation date: 27.02.2026, version: 01) - **Description:** Raw gravimetric data and the equilibrium degree of swelling (DoS). The dataset includes 5 measurement replicates per sample to ensure statistical reliability. - **Columns:** - probe ID: The name/identifier of the specific gel formulation. - dry weight 1 - 5 /g: The dry masses of 5 individual polymer beads. - benzyl alcohol weight 1 - 5 /g: The swollen masses of the same 5 beads equilibrated in benzyl alcohol. - DoS benzyl alcohol /g/g: The calculated mass-specific degree of swelling in benzyl alcohol, presented as mean ± standard deviation. - benzaldehyde weight 1 - 5 /g: The swollen masses of the same 5 beads equilibrated in benzaldehyde. - DoS benzaldehyde /g/g: The calculated mass-specific degree of swelling in benzaldehyde, presented as mean ± standard deviation. ### 4. size-distribution_HEA-20.csv (creation date: 27.02.2026, version: 01) - **Description:** Raw optical measurement data for determining the particle size distribution of the as-synthesized organogel beads. The dataset compares three different bead sizes of the HEA-20 formulation (S: small, standard, L: large). - **Columns:** - count: Consecutive numbering of the analyzed beads. - HEA-20S diameter /cm: The measured diameter of individual HEA-20S beads. - HEA-20 diameter /cm: The measured diameter of individual standard HEA-20 beads. - HEA-20L diameter /cm: The measured diameter of individual HEA-20L beads. ### 5. swelling_HEA-beads_BzOH-BzA_mixtures.csv (creation date: 27.02.2026, version: 01) - **Description:** Raw optical measurement data used to determine the equilibrium swelling behavior of various HEA organogel beads in binary/ternary solvent mixtures. The dataset tracks the bead diameters across varying volumetric ratios of benzyl alcohol and benzaldehyde. - **Columns:** - probe ID: The name/identifier of the specific gel formulation. - diameter in 0 % benzaldehyde /pixel: The measured bead diameter in 0 vol% benzaldehyde (pure benzyl alcohol). - diameter in 25 % benzaldehyde /pixel: The measured bead diameter in a mixture containing 25 vol% benzaldehyde. - diameter in 50 % benzaldehyde /pixel: The measured bead diameter in a mixture containing 50 vol% benzaldehyde. - diameter in 75 % benzaldehyde /pixel: The measured bead diameter in a mixture containing 75 vol% benzaldehyde. - diameter in 100 % benzaldehyde /pixel: The measured bead diameter in 100 vol% benzaldehyde (pure benzaldehyde). - comments: Additional notes regarding the specific sample. ### 6. swelling_kinetics_tau-and-volume_calculations_[Formulation].xlsx (creation date: 26.02.2026, version: 01) - **Description:** Process data from swelling/shrinkage experiments to determine the tau values of the swelling and shrinkage processes. There is one file per organogel formulation. All files share the following identical sheet structure: - **Sheets and Columns:** - **Sheet 'Data':** - Time [s]: The time of the experiment in seconds. - Diameter [pixels]: The raw optically measured bead diameter. - Diameter [cm]: The converted macroscopic bead diameter. - Volume [cm^-3]: The calculated spherical volume. - relative volume: The dimensionless volume normalized to the initial/equilibrium state. - **Sheet 'Calculation':** - Time [s]: The time of the experiment in seconds. - Diameter [cm]: The macroscopic bead diameter. - Simulation [cm]: The calculated diameter based on the kinetic simulation/model. - **Sheet 'Oversight':** - Summary sheet containing the final calculated kinetic parameters (such as the tau values) for the respective swelling and shrinkage processes. ### 7. rheology_compression_[Formulation].csv (creation date: 26.02.2026, version: 01) - **Description:** Raw rheological data from single-bead unconfined compression tests to determine the mechanical properties of the organogels. There is one file per formulation. Each file contains 5 measurement replicates (V1 to V5) for beads swollen in benzyl alcohol, followed by 5 replicates for beads swollen in benzaldehyde. - **Columns:** - V1 - V5 Gap /µm (benzyl alcohol): The measured gap distance during compression for 5 individual beads equilibrated in benzyl alcohol. - V1 - V5 Axial Force /N (benzyl alcohol): The corresponding recorded compressive force for the 5 beads in benzyl alcohol. - V1 - V5 Gap /µm (benzaldehyde): The measured gap distance during compression for 5 individual beads equilibrated in benzaldehyde. - V1 - V5 Axial Force /N (benzaldehyde): The corresponding recorded compressive force for the 5 beads in benzaldehyde. ### 8. rheology_elastic-modulus_HEA-beads.csv (creation date: 27.02.2026, version: 01) - **Description:** Summary of the calculated compressive elastic moduli for all analyzed organogel formulations. The dataset compares the mechanical stiffness of the beads fully swollen in the reactant (benzyl alcohol) versus the product (benzaldehyde). - **Columns:** - probe ID: The name/identifier of the specific gel formulation. - Young's Modulus in benzyl alcohol /kPa: The calculated elastic modulus of the beads equilibrated in benzyl alcohol, presented as mean ± standard deviation. - Young's Modulus in benzaldehyde /kPa: The calculated elastic modulus of the beads equilibrated in benzaldehyde, presented as mean ± standard deviation. ### 9. organogel_image_analysis.py (creation date: 26.02.2026, version: 01) - **Description:** Python script utilizing the OpenCV library to optically track the macroscopic bead diameter over time from a sequence of time-lapse images. - **Requirements:** Python 3.x, OpenCV (cv2), NumPy, Pandas, PIL (Pillow), re, os, glob. --------------------------- METHODOLOGICAL INFORMATION --------------------------- The methodological details of the distinct analyses. 1. Gel Synthesis: Macroscopic poly(2-hydroxyethyl acrylate) organogel beads were synthesized via UV droplet polymerization. An aqueous precursor solution of HEA, PEGDA/BIS crosslinker, and TPO-Li photoinitiator was degassed via ultrasonication. The solution was dropped into liquid nitrogen using a syringe pump (pump rates: 0.06 - 0.15 mL/min) to yield frozen droplets of varying diameters (0.57 - 4.0 mm). Polymerization was triggered in the frozen state using a UV-curing chamber (365 nm, 10 min, 880 mW/cm^2). 2. Size Distribution: The particle size distribution of the as-synthesized beads was determined optically. Images of a statistical population were acquired using a digital camera (CANON EOS R50) and the macroscopic diameters were quantified using ImageJ (version 1.54g). 3. Swelling Equilibria: The mass-specific equilibrium degree of swelling (DoS) was determined gravimetrically as the ratio of swollen to dry mass. Dry mass was obtained from lyophilized cryogel beads (-90 °C, 0.250 mbar, 48 h). Swollen mass was measured after equilibrating the beads in benzyl alcohol or benzaldehyde for 48 h. For solvent sensitivity in binary/ternary (With water) mixtures (0-100 vol%), beads were equilibrated for 45 min prior to optical diameter tracking. 4. Swelling Kinetics: Swelling and shrinkage rates were monitored optically. Pre-swollen beads were mounted on a metal skewer within a glass cuvette and exposed to the complementary solvent. Dimensional changes were recorded with a camera (CANON EOS R50) at 30 s intervals. The image series were analyzed using a Python script to detect bead boundaries and calculate diameters. Cyclic switching was performed by alternating solvent exposure for 30 min. 5. Mechanical Properties: Uniaxial compression tests were performed using a Discovery HR 30 rheometer with a parallel plate geometry (25 mm diameter). Individual equilibrated beads were compressed at a speed of 50 µm/s up to a maximum strain of 50% (n=5 replicates per condition). The elastic modulus was calculated from the force-displacement curves by fitting the Hertzian contact model for spherical objects, assuming a Poisson's ratio of 0.5. ----------------- RESEARCH CONTEXT ----------------- This dataset supports a study demonstrating the translation of a molecular volume phase transition into a macroscopic smart flow control application. Macroporous poly(2-hydroxyethyl acrylate) (PHEA) organogels were synthesized via a cryo-polymerization technique. The dataset includes the fundamental physicochemical characterization (equilibrium swelling, kinetics, mechanical properties) of these solvent-responsive beads. The gathered data elucidates how changes in solvent quality trigger drastic changes in the gel's volume, ultimately enabling the successful realization of an autonomous smart valve within a reactor system. This chemomechanical transduction was practically realized in a macroscopic valve configuration, enabling the gel to autonomously control fluid flow. ---------------------------------- EXPLANATION OF MEASURED VARIABLES ---------------------------------- DoS: Degree of swelling, describes the mass-specific swelling capacity of the gel (mass of swollen gel / mass of dry polymer). Normalized Volume: The dimensionless volume normalized to the fully swollen equilibrium volume, used to track relative size changes. Tau: The characteristic relaxation time constant describing the speed of the swelling/shrinkage process. E-Modulus: The compressive elastic modulus, describing the mechanical stiffness and rigidity of the organogel network. -------------- ABBREVIATIONS -------------- PHEA: Poly(2-Hydroxyethyl acrylate). HEA: 2-Hydroxyethyl acrylate. BzOH: Benzyl alcohol. BzA: Benzaldehyde DoS: Degree of Swelling. HEA-10, HEA-20, etc.: Denotes the specific formulation of the organogel, with the number indicating the crosslinker density or specific synthesis parameter.