@article{64873, abstract = {{Continuous flow catalysis utilizing gel-bound organocatalysts within a microfluidic reactor represents a compelling strategy in the realm of organic synthesis. In this study, a quinuclidine-based catalytic monomer (QMA) was synthesized to create polymer gel dots through the process of photopolymerization that serve as a support for the catalyst. The resulting gel-bound organocatalysts were assembled within a continuous microfluidic reactor to facilitate the Baylis–Hillman reaction between various aldehydes and acrylonitrile at a temperature of 50 °C. The conversion of the product was assessed using 1H NMR spectroscopy as an offline analytical method over a duration of 8 h. The findings indicated that highly reactive aldehydes achieved conversion rates exceeding 90%, in contrast to their less reactive counterparts. Furthermore, these results were juxtaposed with previously published data derived from alternative synthetic methodologies, revealing that the continuous microfluidic reactions employing integrated organocatalysts within polymer networks exhibited significantly higher conversions with reduced reaction times (8 h) at the same temperature (50 °C). Additionally, the influence of different geometries (round, triangular, and square) of the gel dots on catalytic activity was investigated, with round and square gel dots demonstrating slightly superior performance compared with triangular gel dots, attributed to their increased surface area. Moreover, an extended reaction period of 6 days was conducted using 4-bromobenzaldehyde and acrylonitrile, resulting in a conversion rate exceeding 70%, which remained stable for 5 days before experiencing a slight decline due to product accumulation on the gel dots.}}, author = {{Killi, Naresh and Kumar, Amit and Nebhani, Leena and Obst, Franziska and Richter, Andreas and Reineke Matsudo, Bernhard and Zentgraf, Thomas and Kuckling, Dirk}}, issn = {{2470-1343}}, journal = {{ACS Omega}}, number = {{9}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Integrating an Organocatalyst into a Polymeric Gel Framework for the Continuous Microflow Baylis–Hillman Reaction}}}, doi = {{10.1021/acsomega.5c09476}}, volume = {{11}}, year = {{2026}}, } @article{59510, abstract = {{The use of organo-catalysis in continuous-flow reactor systems is gaining attention in medicinal chemistry due to its cost-effectiveness and reduced chemical waste. In this study, bioactive curcumin (CUM) derivatives were synthesized in a continuously operated microfluidic reactor (MFR), using piperidine-based polymeric networks as catalysts. Piperidine methacrylate and piperidine acrylate were synthesized and subsequently copolymerized with complementary monomers (MMA or DMAA) and crosslinkers (EGDMA or MBAM) via photopolymerization, yielding different polymeric networks. Initially, batch reactions were optimized for the organo-catalytic Knoevenagel condensation between CUM and 4-nitrobenzaldehyde, under various conditions, in the presence of polymer networks. Conversion was assessed using offline 1H NMR spectroscopy, revealing an increase in conversion with enhanced swelling properties of the polymer networks, which facilitated greater accessibility of catalytic sites. In continuous-flow MFR experiments, optimized polymer gel dots exhibited superior catalytic performance, achieving a conversion of up to 72%, compared to other compositions. This improvement was attributed to the enhanced swelling in the reaction mixture (DMSO/methanol, 7:3 v/v) at 40 °C over 72 h. Furthermore, the MFR system enabled the efficient synthesis of a series of CUM derivatives, demonstrating significantly higher conversion rates than traditional batch reactions. Notably, while batch reactions required 90% catalyst loading in the gel, the MFR system achieved a comparable or superior performance with only 50% catalyst, resulting in a higher turnover number. These findings underscore the advantages of continuous-flow organo-catalysis in enhancing catalytic efficiency and sustainability in organic synthesis.}}, author = {{Killi, Naresh and Rumpke, Katja and Kuckling, Dirk}}, issn = {{2310-2861}}, journal = {{Gels}}, keywords = {{flow chemistry, heterogeneous catalysis, sustainable synthesis, organo-catalysis, polymeric gel dots}}, number = {{4}}, publisher = {{MDPI AG}}, title = {{{Synthesis of Curcumin Derivatives via Knoevenagel Reaction Within a Continuously Driven Microfluidic Reactor Using Polymeric Networks Containing Piperidine as a Catalyst}}}, doi = {{10.3390/gels11040278}}, volume = {{11}}, year = {{2025}}, } @article{59511, abstract = {{AbstractTo minimize or avoid the use of antibiotics, antimicrobial polymers have emerged as a promising option to fight biomaterial‐associated infections, e.g., on titanium‐based implants. However, the challenge is to develop active polymers that exhibit an antimicrobial effect and are compatible with human cells. Different studies aiming for biocidal polymers active in soluble mode, focused on the ratio of cationic to hydrophobic groups, while only marginal knowledge is available for immobilized components. Here a strong hydrophilic electrolyte 4‐vinylbenzyltrimethylammonium chloride (TMA) is chosen as the cationic component. The block composition of the polycationic segment is modified with styrene (Sty) regarding the amphiphilic balance. To adsorb such polymers onto titanium surfaces they are equipped with a polyphosphonic acid anchor block by sequential reversible‐addition‐fragmentation chain‐transfer polymerization (RAFT) polymerization. The polymer composition affected the wetting behavior of adsorbed coatings with water contact angles ranging from 17° to 72°, while zetapotential measurements confirmed high extent of positive charges for all adsorbed polymer coatings. The fundamentally modified block composition resulted in significantly improved cytocompatibility. Antimicrobial efficacy in early bacterial adhesion is still retained from slightly antiadhesive coatings to combined antiadhesive/biocidal activity depending on Sty/TMA ratio in random polymers while a block copolymer revealed lowest antimicrobial effect.}}, author = {{Wolf‐Brandstetter, Cornelia and Methling, Rafael and Kuckling, Dirk}}, issn = {{1438-7492}}, journal = {{Macromolecular Materials and Engineering}}, keywords = {{antiadhesive surfaces, antimicrobial polymers, grafting to, polymerbrushes}}, publisher = {{Wiley}}, title = {{{Adsorbable and Antimicrobial Amphiphilic Block Copolymers with Enhanced Biocompatibility}}}, doi = {{10.1002/mame.202500078}}, year = {{2025}}, } @article{64884, abstract = {{To address the challenges associated with poor drug solubility and uncontrolled drug release in conventional dosage forms, a combination of polymer design and advanced drug delivery approaches has been employed. The development of pH-responsive nanoparticles for controlled and selective drug release represents a notable advance in adaptive nanomedicine. This study explores the design of a pH-responsive polymer, poly(1,4-phenyleneacetone dimethylene ketal) (PPADK). Additionally, the incorporation of light-responsive ortho-nitrobenzyl groups (o-NB-PPADK) enhanced the degradation upon exposure to light. Based on the polymer, nanoparticles were prepared using the solvent displacement method. The fluorescence dye Lumogen® Red was incorporated as a model substance. The nanoparticles were characterized by dynamic light scattering to determine their hydrodynamic diameter and size distribution, and the surface charge was analyzed. Atomic force microscopy was used to visualize the surface morphology. The nanoparticles remained stable under physiological pH conditions while exhibiting accelerated degradation and substance release in acidic environment, a property potentially exploitable for tumor targeting. Further enhanced degradation and correspondingly increased release was achieved by incorporating light-responsive elements in the polymer structure. The cytotoxicity of these newly designed nanoparticles was evaluated in cell culture using a breast cancer cell line. These results support the potential of o-NB-PPADK nanoparticles as a possible candidate for selective and effective cancer therapy, combining stimuli-responsive degradation mechanisms for improved therapeutic outcomes.}}, author = {{Kramer, Maurice and van der Linde, Matthias and Hönscheid, Lisa and Horky, Corinna and Völlmecke, Katharina and Mulac, Dennis and Herrmann, Fabian and Kuckling, Dirk and Langer, Klaus}}, issn = {{0378-5173}}, journal = {{International Journal of Pharmaceutics}}, keywords = {{Nanoparticles, Drug delivery, Controlled release, Stimuli-responsiveTumor targeting}}, publisher = {{Elsevier BV}}, title = {{{Enlightening release strategies: Accelerated nanoparticle degradation and substance release utilizing light- and pH-responsive polymers}}}, doi = {{10.1016/j.ijpharm.2025.126127}}, volume = {{684}}, year = {{2025}}, } @article{64885, abstract = {{The tribological behavior of thermo‐responsive poly(N‐isopropylacrylamide) (PNIPAAm)‐based microgels is investigated for use as water‐dispersible lubricant additives. Two types of microgels are synthesized using a surfactant‐free emulsion polymerization method: MG0, consisting of pure PNIPAAm with a volume phase transition temperature (VPTT) of ≈33 °C, and MG16, consisting of PNIPAAm copolymerized with hydrophobic tert‐butyl acrylamide, exhibiting a lower VPTT of around 23 °C. Swelling and lubrication performance are evaluated at 20 and 40 °C. Both microgels significantly reduce friction and wear compared to water alone. At 20 °C, MG0 remains fully swollen and provides effective wear protection through hydrated microgel lubrication. MG16, being near its VPTT, exhibits partial collapse and slightly higher wear. At 40 °C, MG16 demonstrates improved wear resistance, attributed to enhanced film compaction in the collapsed state. Raman spectroscopy and scanning electron microscopy–energy‐dispersive X‐ray spectroscopy confirm that carbon‐rich tribofilms are formed via tribochemical reactions. MG0 produces more graphitic films, while MG16 generates amorphous carbon structures. These findings highlight the tunability of microgel composition for designing adaptive, water‐based lubricants for temperature‐sensitive applications.}}, author = {{Syed, Junaid and Dyck, Florian and Herberg, Artjom and Kuckling, Dirk and Gosvami, Nitya Nand}}, issn = {{1438-1656}}, journal = {{Advanced Engineering Materials}}, number = {{1}}, publisher = {{Wiley}}, title = {{{Microgel Additives for Aqueous Lubrication: Tailoring Friction and Wear via Composition and Thermal Responsiveness}}}, doi = {{10.1002/adem.202501673}}, volume = {{28}}, year = {{2025}}, } @article{52541, abstract = {{AbstractWe conducted an investigation into the palladium‐catalyzed carbon‐sulfur cross‐coupling reaction involving a 2‐bromothiophene derivative and potassium thioacetate as a substitute for hydrogen sulfide. This investigation utilized kinetic and computational methods. We synthesized two palladium complexes supported by the bisphosphane ligands bis(diphenylphosphino)ferrocene (DPPF) and bis(diisopropylphosphino)ferrocene (DiPPF), as well as their tentative intermediates in the catalytic cycle. Reaction rates were measured and then compared to computational predictions.}}, author = {{Peschtrich, Sebastian and Schoch, Roland and Kuckling, Dirk and Paradies, Jan}}, issn = {{1434-193X}}, journal = {{European Journal of Organic Chemistry}}, keywords = {{Organic Chemistry, Physical and Theoretical Chemistry}}, number = {{8}}, publisher = {{Wiley}}, title = {{{A Comparative Kinetic and Computational Investigation of the Carbon‐Sulfur Cross Coupling of Potassium Thioacetate and 2‐Bromo Thiophene Using Palladium/Bisphosphine Complexes}}}, doi = {{10.1002/ejoc.202301207}}, volume = {{27}}, year = {{2024}}, } @article{53163, abstract = {{An SPR-based dually crosslinked gel sensor for adiponitrile bearing pillar[5]arene responsive sites with a low limit of detection was developed.}}, author = {{Rodin, Maksim and Helle, David and Kuckling, Dirk}}, issn = {{1759-9954}}, journal = {{Polymer Chemistry}}, keywords = {{Organic Chemistry, Polymers and Plastics, Biochemistry, Bioengineering}}, number = {{7}}, pages = {{661--679}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{Pillar[5]arene-based dually crosslinked supramolecular gel as a sensor for the detection of adiponitrile}}}, doi = {{10.1039/d3py01354e}}, volume = {{15}}, year = {{2024}}, } @article{59509, abstract = {{AbstractA strategy for multifunctional biosurfaces exploiting multiblock copolymers and the antipolyelectrolyte effect is reported. Combining a polyzwitterionic/antifouling and a polycationic/antibacterial block with a central anchoring block for attachment to titanium oxide surfaces affords surface coatings that exhibit antifouling properties against proteins and allow for surface regeneration by clearing adhering proteins by employing a salt washing step. The surfaces also kill bacteria by contact killing, which is aided by a nonfouling block. The synthesis of block copolymers of 4‐vinyl pyridine (VP), dimethyl 4‐vinylbenzyl phosphonate (DMVBP), and 4‐vinylbenzyltrimethyl ammonium chloride (TMA) is achieved on the multigram scale via RAFT polymerization with good end group retention and narrow dispersities. By polymer analogous reactions, poly(4‐vinyl pyridinium propane sulfonate‐block‐4‐vinylbenzyl phosphonic acid‐block‐4‐vinylbenzyl trimethylammonium chloride) (P(VSP64‐b‐PA14‐b‐TMA64)) is obtained. The antifouling properties against the model protein pepsin and the salt‐induced surface regeneration are shown in surface plasmon resonance (SPR) experiments, while independently the antibacterial and antifouling properties of coated titanium substrates are successfully tested in preliminary microbiological assays against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). This strategy may contribute to the development of long‐term effective antibacterial implant surface coatings to suppress biomedical device‐associated infections.}}, author = {{Methling, Rafael and Greiter, Michael and Al‐Zawity, Jiwar and Müller, Mareike and Schönherr, Holger and Kuckling, Dirk}}, issn = {{1616-5187}}, journal = {{Macromolecular Bioscience}}, keywords = {{antibacterial coatings, antipolyelectrolyte effect, salt switchable polymers, zwitterionic brushes}}, number = {{1}}, publisher = {{Wiley}}, title = {{{Salt‐Responsive Switchable Block Copolymer Brushes with Antibacterial and Antifouling Properties}}}, doi = {{10.1002/mabi.202400261}}, volume = {{25}}, year = {{2024}}, } @article{59508, abstract = {{Over the last few decades, nanotechnology has established to be a promising field in medicine. A remaining dominant challenge in today's pharmacotherapy is the limited selectivity of active pharmaceutical ingredients and associated undesirable side effects. Controlled drug release can be promoted by smart drug delivery systems, which release embedded API primarily depending on specific stimuli. Consequently, also the microenvironment of tumor tissue can be used advantageously. Dithiothreitol (DTT) based self-immolative polydisulfides were synthesized that preferentially respond to pathologically increased glutathione (GSH) concentrations, as found in solid tumors. The synthesis with different degrees of polymerisation was investigated as well as the synthesis of a copolymer consisting of dithiothreitol and butanedithiol (BDT). Toxicity tests were carried out on pure polymers and their degradation products. The ability to degrade was examined at pathological and physiological glutathione concentrations in order to test the suitability of the polymer as a matrix for nanoparticulate carrier systems. In addition, the processability of one polymer into nanoparticles was investigated as well as the degradation behaviour with glutathione.}}, author = {{Völlmecke, Katharina and Kramer, Maurice and Horky, Corinna and Dückmann, Oliver and Mulac, Dennis and Langer, Klaus and Kuckling, Dirk}}, issn = {{2046-2069}}, journal = {{RSC Advances}}, number = {{48}}, pages = {{35568--35577}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{Self-immolative polydisulfides and their use as nanoparticles for drug delivery systems}}}, doi = {{10.1039/d4ra07228f}}, volume = {{14}}, year = {{2024}}, } @article{35657, abstract = {{The controlled delivery of active pharmaceutical ingredients to the site of disease represents a major challenge in drug therapy. Particularly when drugs have to be transported across biological barriers, suitable drug delivery systems are of importance. In recent years responsive delivery systems have been developed which enable a controlled drug release depending on internal or external stimuli such as changes in pH, redox environment or light and temperature. In some studies delivery systems with reactivity against two different stimuli were established either to enhance the response by synergies of the stimuli or to broaden the window of possible trigger events. In the present review numerous exciting developments of pH-, light- and redox-cleavable polymers suitable for the preparation of smart delivery systems are described. The review discusses the different stimuli that can be used for a controlled drug release of polymer-based delivery systems. It puts a focus on the different polymers described for the preparation of stimuli-sensitive systems, their preparation techniques as well as their stimuli-responsive degradation. © 2022 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry.}}, author = {{Rust, Tarik and Jung, Dimitri and Langer, Klaus and Kuckling, Dirk}}, issn = {{0959-8103}}, journal = {{Polymer International}}, keywords = {{drug delivery system, stimuli, polymer, cleavable}}, number = {{1}}, pages = {{5--19}}, publisher = {{Wiley}}, title = {{{Stimuli‐accelerated polymeric drug delivery systems}}}, doi = {{10.1002/pi.6474}}, volume = {{72}}, year = {{2023}}, } @article{53170, abstract = {{AbstractCoating medical implants with antibacterial polymers may prevent postoperative infections which are a common issue for conventional titanium implants and can even lead to implant failure. Easily applicable diblock copolymers are presented that form polymer brushes via “grafting to” mechanism on titanium and equip the modified material with antibacterial properties. The polymers carry quaternized pyridinium units to combat bacteria and phosphonic acid groups which allow the linear chains to be anchored to metal surfaces in a convenient coating process. The polymers are synthesized via reversible‐addition‐fragmentation‐chain‐transfer (RAFT) polymerization and postmodifications and are characterized using NMR spectroscopy and SEC. Low grafting densities are a major drawback of the “grafting to” approach compared to “grafting from”. Thus, the number of phosphonic acid groups in the anchor block are varied to investigate and optimize the surface binding. Modified titanium surfaces are examined regarding their composition, wetting behavior, streaming potential, and coating stability. Evaluation of the antimicrobial properties revealed reduced bacterial adhesion and biofilm formation for certain polymers, albeit the cell biocompatibility against human gingival fibroblasts is also impaired. The presented findings show the potential of easy‐to‐apply polymer coatings and aid in designing next‐generation implant surface modifications.}}, author = {{Methling, Rafael and Dückmann, Oliver and Simon, Frank and Wolf‐Brandstetter, Cornelia and Kuckling, Dirk}}, issn = {{1438-7492}}, journal = {{Macromolecular Materials and Engineering}}, keywords = {{Materials Chemistry, Polymers and Plastics, Organic Chemistry, General Chemical Engineering}}, number = {{8}}, publisher = {{Wiley}}, title = {{{Antimicrobial Brushes on Titanium via “Grafting to” Using Phosphonic Acid/Pyridinium Containing Block Copolymers}}}, doi = {{10.1002/mame.202200665}}, volume = {{308}}, year = {{2023}}, } @article{53166, abstract = {{The Knoevenagel reaction is a classic reaction in organic chemistry for the formation of C-C bonds. In this study, various catalytic monomers for Knoevenagel reactions were synthesized and polymerized via photolithography to form polymeric gel dots with a composition of 90% catalyst, 9% gelling agent and 1% crosslinker. Furthermore, these gel dots were inserted into a microfluidic reactor (MFR) and the conversion of the reaction using gel dots as catalysts in the MFR for 8 h at room temperature was studied. The gel dots containing primary amines showed a better conversion of about 83–90% with aliphatic aldehyde and 86–100% with aromatic aldehyde, compared to the tertiary amines (52–59% with aliphatic aldehyde and 77–93% with aromatic aldehydes) which resembles the reactivity of the amines. Moreover, the addition of polar solvent (water) in the reaction mixture and the swelling properties of the gel dots by altering the polymer backbone showed a significant enhancement in the conversion of the reaction, due to the increased accessibility of the catalytic sites in the polymeric network. These results suggested the primary-amine-based catalysts facilitate better conversion compared to tertiary amines and the reaction solvent had a significant influence on organocatalysis to improve the efficiency of MFR.}}, author = {{Killi, Naresh and Bartenbach, Julian and Kuckling, Dirk}}, issn = {{2310-2861}}, journal = {{Gels}}, keywords = {{Knoevenagel reaction, organocatalysis, polymeric gel dots, microfluidic reactions, polymeric networks}}, number = {{3}}, publisher = {{MDPI AG}}, title = {{{Polymeric Networks Containing Amine Derivatives as Organocatalysts for Knoevenagel Reaction within Continuously Driven Microfluidic Reactors}}}, doi = {{10.3390/gels9030171}}, volume = {{9}}, year = {{2023}}, } @article{35642, abstract = {{There is an increasing interest in sensing applications for a variety of analytes in aqueous environments, as conventional methods do not work reliably under humid conditions or they require complex equipment with experienced operators. Hydrogel sensors are easy to fabricate, are incredibly sensitive, and have broad dynamic ranges. Experiments on their robustness, reliability, and reusability have indicated the possible long-term applications of these systems in a variety of fields, including disease diagnosis, detection of pharmaceuticals, and in environmental testing. It is possible to produce hydrogels, which, upon sensing a specific analyte, can adsorb it onto their 3D-structure and can therefore be used to remove them from a given environment. High specificity can be obtained by using molecularly imprinted polymers. Typical detection principles involve optical methods including fluorescence and chemiluminescence, and volume changes in colloidal photonic crystals, as well as electrochemical methods. Here, we explore the current research utilizing hydrogel-based sensors in three main areas: (1) biomedical applications, (2) for detecting and quantifying pharmaceuticals of interest, and (3) detecting and quantifying environmental contaminants in aqueous environments.}}, author = {{Völlmecke, Katharina and Afroz, Rowshon and Bierbach, Sascha and Brenker, Lee Josephine and Frücht, Sebastian and Glass, Alexandra and Giebelhaus, Ryland and Hoppe, Axel and Kanemaru, Karen and Lazarek, Michal and Rabbe, Lukas and Song, Longfei and Velasco Suarez, Andrea and Wu, Shuang and Serpe, Michael and Kuckling, Dirk}}, issn = {{2310-2861}}, journal = {{Gels}}, keywords = {{Polymers and Plastics, Organic Chemistry, Biomaterials, Bioengineering}}, number = {{12}}, publisher = {{MDPI AG}}, title = {{{Hydrogel-Based Biosensors}}}, doi = {{10.3390/gels8120768}}, volume = {{8}}, year = {{2022}}, } @article{32416, abstract = {{In recent years, sequence-defined oligomers (SDOs) gained increasing interest due to their perfectly controlled molecular structure, thus providing defined properties. In order to tune the properties, different functionalities need to be incorporated into the oligomers and the chain tacticity needs to be controlled. Beside the synthesis of SDOs, suitable methods need to be found to analyze the molecular structure. In this work, oligomers exhibiting an alternating or block-wise sequence of side chain functionalities were analyzed using a hyphenation of ultra-high-performance liquid chromatography and electrospray ionization mass spectrometry enhanced by ion mobility separation (IMS). Moieties in the side chains were varied according to polarity and bulkiness. Moreover, chain tacticity was varied. Drift times in the IMS cell and the corresponding collision cross section (CCS) values were shown to be individual parameters allowing the identification of SDOs, even in the case that SDO structures only differ in sequence or tacticity of side chain functionalities. Thus, a library of CCS values was obtained as reference used for the analysis of complex mixtures of SDOs.}}, author = {{Berg, Marie-Theres and Herberg, Artjom and Kuckling, Dirk}}, issn = {{1023-666X}}, journal = {{International Journal of Polymer Analysis and Characterization}}, keywords = {{Ultra-high-performance liquid chromatography, ion mobility separation, mass spectrometry, LC-MS hyphenation, sequence-defined oligomers}}, pages = {{1--12}}, publisher = {{Informa UK Limited}}, title = {{{Hyphenation of ultra-high-performance liquid chromatography and ion mobility mass spectrometry for the analysis of sequence-defined oligomers with different functionalities and tacticity}}}, doi = {{10.1080/1023666x.2022.2100968}}, year = {{2022}}, } @article{35645, abstract = {{Poly(quinuclidin-3-yl methacrylate-co-divinylbenzene) microparticles having porous as well as nonporous morphology and varying contents of quinuclidine functionality were synthesized by distillation–precipitation polymerization. Further, the synthesized microparticles were explored to catalyze the Baylis–Hillman reaction between 4-nitrobenzaldehyde and acrylonitrile. Porous and nonporous microparticles functionalized with a catalytic moiety with a loading of 70% (labeled as P70 and NP70) were employed to optimize reaction parameters such as water content, solvent, and temperature for the Baylis–Hillman reaction between 4-nitrobenzaldehyde and acrylonitrile. Using optimal conditions, the catalytic efficiency of porous and nonporous microparticles at different feed compositions was determined. Porous microparticles containing 70% of quinuclidine (P70) displayed 100% conversion within 16 h at 50 °C, while nonporous microparticles containing 70% of quinuclidine (NP70) displayed a relatively less catalytic conversion, which is attributed to their lower surface area. Furthermore, the catalytic activity of porous microparticles containing 70% of quinuclidine (P70) for the Baylis–Hillman reaction involving a variety of aryl aldehyde derivatives was determined, where the microparticles displayed impressive catalytic efficiency. In addition, the reusability of the microparticles functionalized with a catalytic moiety was evaluated for five cycles of catalytic reaction.}}, author = {{Kumar, Amit and Kuckling, Dirk and Nebhani, Leena}}, issn = {{2637-6105}}, journal = {{ACS Applied Polymer Materials}}, keywords = {{distillation−precipitation polymerization, porous microparticles, heterogeneous catalysis Baylis−Hillman reaction, reusable catalyst}}, number = {{12}}, pages = {{8996--9005}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Quinuclidine-Immobilized Porous Polymeric Microparticles as a Compelling Catalyst for the Baylis–Hillman Reaction}}}, doi = {{10.1021/acsapm.2c01330}}, volume = {{4}}, year = {{2022}}, } @article{32865, abstract = {{For the first time, poly(N-isopropylacrylamide) (PNIPAAm) star polymers with a β-cyclodextrin core are characterized in detail by size-exclusion chromatography (SEC) with triple detection to experimentally verify the number of arms. A combination of a refractive index detector, multi-angle laser light scattering detector, and an online-viscosimeter was used for branching analysis. At first, the SEC system was calibrated and the detector setup was validated using linear polystyrene reference polymers. The applicability of the established triple detection SEC for branching analysis was shown by the analysis of two commercially available polystyrene star polymers. Due to the high molar masses of the star polymers, both the contraction ratio g and g′ could be determined independently, thus allowing the calculation of the viscosity shielding ratio ε. Finally, the branching analysis of the PNIPAAm star polymers could experimentally confirm the assumed arm number of up to 21 arms. Moreover, an increasingly compact molecular structure and the influence of the arm number on the viscosity shielding ratio could be shown.}}, author = {{Herberg, Artjom and Kuckling, Dirk}}, issn = {{1023-666X}}, journal = {{International Journal of Polymer Analysis and Characterization}}, keywords = {{Size-exclusion chromatography, triple detection, branching analysis, star polymers, poly(N-isopropylacrylamide), β-cyclodextrin}}, pages = {{1--19}}, publisher = {{Informa UK Limited}}, title = {{{Branching analysis of β-cyclodextrin-based poly(N-isopropylacrylamide) star polymers using triple detection SEC}}}, doi = {{10.1080/1023666x.2022.2110133}}, year = {{2022}}, } @article{59617, abstract = {{There is an increasing interest in sensing applications for a variety of analytes in aqueous environments, as conventional methods do not work reliably under humid conditions or they require complex equipment with experienced operators. Hydrogel sensors are easy to fabricate, are incredibly sensitive, and have broad dynamic ranges. Experiments on their robustness, reliability, and reusability have indicated the possible long-term applications of these systems in a variety of fields, including disease diagnosis, detection of pharmaceuticals, and in environmental testing. It is possible to produce hydrogels, which, upon sensing a specific analyte, can adsorb it onto their 3D-structure and can therefore be used to remove them from a given environment. High specificity can be obtained by using molecularly imprinted polymers. Typical detection principles involve optical methods including fluorescence and chemiluminescence, and volume changes in colloidal photonic crystals, as well as electrochemical methods. Here, we explore the current research utilizing hydrogel-based sensors in three main areas: (1) biomedical applications, (2) for detecting and quantifying pharmaceuticals of interest, and (3) detecting and quantifying environmental contaminants in aqueous environments.}}, author = {{Völlmecke, Katharina and Afroz, Rowshon and Bierbach, Sascha and Brenker, Lee Josephine and Frücht, Sebastian and Glass, Alexandra and Giebelhaus, Ryland and Hoppe, Axel and Kanemaru, Karen and Lazarek, Michal and Rabbe, Lukas and Song, Longfei and Velasco Suarez, Andrea and Wu, Shuang and Serpe, Michael and Kuckling, Dirk}}, issn = {{2310-2861}}, journal = {{Gels}}, number = {{12}}, publisher = {{MDPI AG}}, title = {{{Hydrogel-Based Biosensors}}}, doi = {{10.3390/gels8120768}}, volume = {{8}}, year = {{2022}}, } @article{23701, author = {{Schoppa, Timo and Jung, Dimitri and Rust, Tarik and Mulac, Dennis and Kuckling, Dirk and Langer, Klaus}}, issn = {{0378-5173}}, journal = {{International Journal of Pharmaceutics}}, publisher = {{Elsevier}}, title = {{{Light-responsive polymeric nanoparticles based on a novel nitropiperonal based polyester as drug delivery systems for photosensitizers in PDT}}}, doi = {{10.1016/j.ijpharm.2021.120326}}, volume = {{597}}, year = {{2021}}, } @article{23662, author = {{Rust, Tarik and Jung, Dimitri and Hoppe, Axel and Schoppa, Timo and Langer, Klaus and Kuckling, Dirk}}, issn = {{2637-6105}}, journal = {{ACS Applied Polymer Materials}}, number = {{8}}, pages = {{3831--3842}}, publisher = {{ACS}}, title = {{{Backbone-Degradable (Co-)Polymers for Light-Triggered Drug Delivery}}}, doi = {{10.1021/acsapm.1c00411}}, volume = {{3}}, year = {{2021}}, } @article{23699, author = {{Schmiegel, Carsten J. and Baier, Rene and Kuckling, Dirk}}, issn = {{1434-193X}}, journal = {{European Journal of Organic Chemistry}}, pages = {{2578--2586}}, publisher = {{Wiley-VCH}}, title = {{{Direct Asymmetric Aldol Reaction in Continuous Flow Using Gel‐Bound Organocatalysts}}}, doi = {{10.1002/ejoc.202100268}}, year = {{2021}}, }