Acid Polymer Research Articles

Unmatched resilience and fatigue resistance in a novel cellulose-derived ionic gel with hierarchical superstructured synergy for advanced human-computer interaction

Unlike traditional hydrogels, solvent-free ionic gels eliminate leakage and solvent volatilization, making them suitable for applications in electronic skin, sensing, and other fields due to their excellent conductivity and flexibility. However, designing solvent-free ionic gels with exceptional fatigue resistance, high ionic conductivity, and toughness remains a significant challenge. We address this challenge by employing small molecule/polymer heating self-assembly to regulate the synergistic effects of various components on the hierarchical superstructure. A multi-stage network was formed through the free radical polymerization of 3-Ethyl-1-vinyl-1H-imidazol-3-ium bromide ([C2VIm]Br), lipoic acid (LA), acrylic acid (AA), and hydroxypropyl cellulose (HPC), stabilized by dense hydrogen bonding and polymer chain entanglement. The resulting HPC/LA/AA/iLs (HLAI) ionic gel exhibits exceptional properties: excellent flexibility (with an elongation at break of 4222 %), toughness (1.03 MJ/m3), high ionic conductivity (3.29 × 10−2 S/m), and outstanding fatigue resistance (with a resilience of 91.9 % after 1000 load-unloading cycles at 50 % strain). Additionally, it shows low sensitivity to crack propagation (50 % notched sample can be stretched to 9 times without breaking) and good environmental stability, demonstrating excellent sensing sensitivity and stability (GF=3.23). The conductive ionic gel features a sophisticated hierarchical superstructure that synergistically enhances its properties at the molecular level. The integration of dynamic disulfide bonds, achieved through the polymerization of Lipoic acid, imparts remarkable self-healing capabilities and superior fatigue resistance. Additionally, the incorporation of a rigid HPC structure with dense cross-linking points bolsters elasticity, fracture resistance, and resilience. The gel’s ionic conductivity and sensing sensitivity are significantly enhanced by the inclusion of ionic liquids with polymerizable double bonds, making it an ideal material for applications requiring both flexibility and conductivity. This work presents a novel strategy for designing high-performance multi-stage network solvent-free ionic gels, opening up exciting possibilities for biomimetic electronic skin applications.

(Invited) Novel Polymer and Membrane Development Strategies for Water Electrolysis

Water electrolysis processes play a crucial role in transitioning to a climate-friendly society. They facilitate the integration of renewable energy, offer a clean and versatile energy carrier, decarbonize industries, improve energy storage and grid stability, and support the development of sustainable transportation solutions. As technology advances and economies of scale are realized, electrolysis is expected to play an increasingly significant role in the clean energy landscape, contributing to a more sustainable and resilient future.Various water-splitting electrolysis processes currently exist, including alkaline, solid oxide, proton exchange membrane (PEM), anion exchange (AEM), acidic-alkaline amphoteric, microbial, and photoelectrochemical methods [1]. In our research group, we are actively involved in membrane development for both PEM and AEM water electrolysis.In PEM electrolysis membrane development, our group explores several approaches, such as (a) aromatic main-chain block copolymers[2],(b) acid-base blend membranes using sulfonated and partially fluorinated aromatic polyether, polybenzimidazole, and a PSU-derived basic polymer[2], (c) poly(fluorene)-based sulfonated ionomers, (d) sulfonated and phosphonated poly(pentafluorostyrene) polymers with flexible side groups, and (d) nanophase-separated block copolymers based on phosphonated[3] or sulfonated pentafluorostyrene and octylstyrene. Additionally, we investigate (e) H+-conductive fiber-mat reinforced perfluorosulfonic acid (PFSA) polymers[4].The development of anion exchange membranes in our research group includes (a) polystyrene-based side chain anion exchange polymers and their blends with polybenzimidazole[5], (b) polynorbornene-based optionally ionically and covalently crosslinked anion exchange polymers and membranes, (c) side chain anion exchange polymers and membranes prepared by polyhydroxyalkylation[6], and (d) anion exchange blend membranes made from polydiallyldimethylammonium salts and polybenzimidazole.This contribution highlights the application of two polymer types in PEM and AEM membrane water electrolysis, respectively:(A) PEM Water Electrolysis (PEMWE): Membranes from PEM types (a) and (b) demonstrated good performance. PEM (a) achieved 2.2 V@6 A/cm2, and PEM (b) reached 2.26 V@6 A/cm2 (compared to Nafion212: 2.26 V@6 A/cm2)[2]. These performances were accomplished with non-optimized membrane-electrode assemblies using Nafion as the electrode ionomer. Further performance improvements are expected with optimized electrodes containing the same ionomers as used in the membrane.(B) AEM Water Electrolysis (AEMWE): Blend membranes from AEM type (a) exhibited excellent alkali stability (no conductivity decrease after 1000 hrs of storage in 1M KOH@85°C) and good AEMWE performance (CuCo anode catalyst, 1M KOH, 70°C, 2 V@3 A/cm2)[5]. Type (c) AEMs were applied to a seawater electrolysis cell at 60°C, achieving a performance of 2 V@1 A/cm2 using completely noble metal-free catalysts in both the anode and cathode[6].[1] M. F. Ahmad Kamaroddin, N. Sabli, T. A. Tuan Abdullah, S. I. Siajam, L. C. Abdullah, A. Abdul Jalil, A. Ahmad, Membranes 2021, 11.[2] J. Bender, B. Mayerhöfer, P. Trinke, B. Bensmann, R. Hanke-Rauschenbach, K. Krajinovic, S. Thiele, J. Kerres, Polymers 2021, 13.[3] S. Auffarth, M. Wagner, A. Krieger, B. Fritsch, L. Hager, A. Hutzler, T. Böhm, S. Thiele, J. Kerres, ACS Materials Lett. 2023, 5, 2039.[4] M. S. Mu'min, M. Komma, D. Abbas, M. Wagner, A. Krieger, S. Thiele, T. Böhm, J. Kerres, Journal of Membrane Science 2023, 685, 121915.[5] L. Hager, M. Hegelheimer, J. Stonawski, A. T. S. Freiberg, C. Jaramillo-Hernández, G. Abellán, A. Hutzler, T. Böhm, S. Thiele, J. Kerres, J. Mater. Chem. A 2023.[6] M. L. Frisch, T. N. Thanh, A. Arinchtein, L. Hager, J. Schmidt, S. Brückner, J. Kerres, P. Strasser, ACS Energy Lett. 2023, 8, 2387.

Confocal Raman Microscopy – Shedding Light on the Ionomer Properties of PFSA Membranes

Perfluorinated sulfonic acid (PFSA) polymers are the state-of-the-art material for the proton exchange membrane (PEM) in various electrochemical energy conversion devices, e.g., PEM fuel cells, PEM water electrolyzers, or redox flow batteries, combining chemical and mechanical durability with high proton conductivity.The most prominent example of a PFSA material is NafionTM, which is a so-called long side chain (LSC) ionomer due to its comparably long side chain between the polymer backbone and the charged sulfonyl end group. On the other hand, short side chain (SSC) ionomers like Aquivion® and 3M Ionomer or composite membranes are promising approaches to improve performance in harsh conditions, such as low humidity or high operating temperatures.1 SSC PEMs feature increased water uptake, proton conductivity,2 and crystallinity3 compared to LSC PEMs. Composite PEMs can be specifically tailored to the required operating conditions by carefully designing the interlayers or additives. As the performance and longevity of electrochemical cells are a delicate convolution of various (composite) membrane properties and parameters, a method for evaluating ionomer membrane properties is crucial for rationally engineering optimized PEMs.Here, we use confocal Raman microscopy (CRM) to investigate application-relevant properties of PFSA PEMs and for high-resolution imaging of composite membranes.4 Thus, the high spatial resolution of confocal optical microscopy and the chemical sensitivity of Raman scattering are combined in a single measurement approach. NafionTM, 3M Ionomer, and Aquivion® at varying equivalent weights (EW) feature distinctive Raman spectra (Fig. 1) that show characteristic spectral changes depending on the ionomer’s side chain structure and EW. We show that the EW of these PFSA types can be reliably measured using Raman spectroscopy. Further, parameters such as swelling, ionizable group content, and water uptake can be quantified by CRM non-destructively and contact-free. The diffraction-limited resolution of CRM of less than 2 µm enables a view of the local distribution of these properties and, therefore, allows to image and analyze composite membranes. In summary, we comprehensively study ionomer properties of (composite) membranes and establish CRM as a powerful platform for characterizing advanced PEMs for electrochemical energy deviceReferences A. S. Aricò, A. Di Blasi, G. Brunaccini, F. Sergi, G. Dispenza, L. Andaloro, M. Ferraro, V. Antonucci, P. Asher, S. Buche, D. Fongalland, G. A. Hards, J. D. B. Sharman, A. Bayer, G. Heinz, N. Zandonà, R. Zuber, M. Gebert, M. Corasaniti, A. Ghielmi and D. J. Jones, Fuel Cells, 10(6), 1013–1023 (2010).Y.-C. Park, K. Kakinuma, H. Uchida, M. Watanabe and M. Uchida, Journal of Power Sources, 275, 384–391 (2015).K. D. Kreuer, M. Schuster, B. Obliers, O. Diat, U. Traub, A. Fuchs, U. Klock, S. J. Paddison and J. Maier, Journal of Power Sources, 178(2), 499–509 (2008).M. Maier, D. Abbas, M. Komma, M. S. Mu'min, S. Thiele and T. Böhm, Journal of Membrane Science, 669, 121244 (2023). Figure 1

Enhancing Impregnability in Reinforced Composite Membrane Using Greener Dispersion

Perfluorosulfonic acid (PFSA) polymer commonly offer high ionic conductivity, chemical and physical properties, and rapid response, making them widely used in energy conversion technologies like fuel cell and water electrolysis. Industrial commercialization of the polymer electrolyte membranes for water electrolysis depends not only on sufficient electrochemical performance but also requires gas barrier properties and high dimensional stability. To improve the properties of these polymer electrolyte membranes selection of an appropriate dispersion solvent and optimization of its composition ratio are very important. However, PFSA polymer limits the types of dispersion solvents due to its unique structure, which consist of combining a hydrophilic perfluorovinyl ether side chain with sulfonate groups onto a hydrophobic tetrafluoroethylene backbone.Here, we have introduced a new greener mixture system for the fabrication of PFSA-reinforced composite membranes for water electrolysis and compared it with conventional solvent systems. Our solvent system not only produced a more densely packed support layer but also relaxed the anisotropy of the reinforced composite membrane. As a result, the compressive strength and tensile strain increased, making it possible to compensate for the shortcomings caused by the support. Also, this increased impregnability resulted in relatively low gas permeability and high ionic conductivity. The water electrolysis performance was comparable with those prepared using an NMP-based solvent. These results demonstrate a method for preparing PFSA dispersions for reinforced composite membrane and their potential to replace hazardous solvents used in fabrication processes.

(Invited) Recycling of Perfluorosulfonic-Acid Polymers, into Commercial Viable Second-Use Applications

This presentation will describe our efforts to commercialize our technology to re-deploy spent perfluorosulfonic acid (PFSA) polymer materials from end-of-life Hydrogen Economy energy conversion systems into second-use applications.The challenge in any recycling effort for the PFSA materials is to find a marketable application for the recovered polymer. This is in stark contrast to the situation for the precious group metals; where any recycling/recovery effort for PGM materials can be quickly and easily brought back to the market and converted to cash. This is why so much of the current end-of-life PGM bearing scrap is currently incinerated in order to recover the PGM value only. We will report on the development of several applications from polymer that we have purified and recovered from end-of-life Hydrogen Economy systems.

Biodegradable Biobased Polymers: A Review of the State of the Art, Challenges, and Future Directions.

Biodegradable biobased polymers derived from biomass (such as plant, animal, marine, or forestry material) show promise in replacing conventional petrochemical polymers. Research and development have been conducted for decades on potential biodegradable biobased polymers such as polylactic acid (PLA), polyhydroxyalkanoates (PHAs), and succinate polymers. These materials have been evaluated for practicality, cost, and production capabilities as limiting factors in commercialization; however, challenges, such as the environmental limitations on the biodegradation rates for biodegradable biobased polymer, need to be addressed. This review provides a history and overview of the current development in the synthesis process and properties of biodegradable biobased polymers, along with a techno-commercial analysis and discussion on the environmental impacts of biodegradable biobased polymers. Specifically, the techno-commercial analysis focuses on the commercial potential, financial assessment, and life-cycle assessment of these materials, as well as government initiatives to facilitate the transition towards biodegradable biobased polymers. Lastly, the environmental assessment focuses on the current challenges with biodegradation and methods of improving the recycling process and reusability of biodegradable biobased polymers.

Carbon-Interconnected Sodium Vanadium Phosphate Microparticles: Material Characterizations and Na+-Storage Performances

Sodium vanadium phosphate (Na3V2(PO4)3) with continuous carbon-coating (NVP/C) has been regarded as one of the most promising cathode materials for sodium-ion batteries (SIBs) owing to the three-dimensional sodium superionic conductor (NASICON) structure for fast sodium-ion migrations, high theoretical energy density (ca. 400 Wh/kg), and good thermal stability (450°C). In this study, carbon-interconnected NVP/C microparticles (C@NVP/C MPs) were successfully synthesized by employing ascorbic acid and sodium-containing polymer as dual carbon sources, followed by calcination at 750°C in an argon atmosphere. The resulting C@NVP/C MPs not only exhibited great crystallinity, high purity, and size of 5-10 μm but also possessed carbon amounts of 9.9 wt. %, as confirmed through the X-ray diffractometer, scanning electron microscope, and thermogravimetric analyzer, respectively. The cyclic voltammogram revealed that the potential difference between oxidation and reduction peaks of C@NVP/C (174 mV at 0.1 mV/sec and 382 mV at 1.0 mV/sec) was less than that of the NVP/C nanoparticles (197 mV at 0.1 mV/sec and 391 mV at 1.0 mV/sec) that were synthesized without adding the sodium-containing polymer. Moreover, the same reversible capacity was delivered from C@NVP/C, i.e., 75 mAh/g at 0.1 C. Those improved electrochemical performances could be attributed to the well-interconnection between NVP/C and carbon originating from the pyrolysis of sodium-containing polymer, creating additional electronic transportation pathways. Accordingly, the C@NVP/C MPs synthesized in the present study are reasonably anticipated to be promising cathode materials for SIBs.

Development of Next Generation Membranes for PEM Water Electrolysis in AGC

AGC’s FORBLUETM product family has over 70 years of experience in ion-exchange membranes (IEMs). S-SERIES, a FORBLUETM member, is a per-fluorinated sulfonic acid polymer (PFSA) membrane utilized in various electrochemical devices and industrial electrolysis. AGC’s IEM technology had a lot of experience in the chlor-alkali application and was further developed for the PEM water electrolysis industry.AGC R&D has developed S-SERIES membranes with a smaller thickness, improved reinforcement, and high ion exchange capacity (IEC) that enhanced not only an electrochemical performance but also dimensional stability.A membrane electrode assembly (MEA) was fabricated using a developed membrane with high IEC polymer (IEC 1.25 meq/g). As a result, IV characterization of a single cell with 25 cm2 electrode area at 80°C showed a significant voltage reduction compared to a commercial membrane in the PEM water electrolysis market. In addition, H2 crossover during the electrolysis was evaluated in a single cell with a 25 cm2 electrode area at 80°C and ambient pressure, and the H2 concentration in O2 at the anode side was compared at a current density of 1.0 A/cm2. The developed membrane showed 0.3 vol% H2 crossover, whereas the commercial membrane showed 0.5 vol%.Furthermore, next-generation membranes with gas recombination catalysts (GRC) and radical scavengers leading to lower gas crossover and higher chemical stability are under development. Recently, high-pressure electrolyzers have been getting more attention and the increase of H2 crossover is a concern against the lower explosive limit (LEL) for hydrogen in oxygen. In general, PFSA membranes are considered to have high chemical durability, however, F ion release is observed, that indicate that this PFSA polymer is attacked by OH radicals generated in the PEM water electrolysis system. AGC has been investigating the application of GRC and radical scavengers to the newly developed membranes. It was evaluated in a single cell with 25 cm2 electrode area at 80°C and 2.0 A/cm2. As a result, the H2 crossover and F ions release rate (FRR) were reduced compared to the membrane without both additives. The data will be presented on these improved performances.

Laser-rewritable room temperature phosphorescence based on in-situ polymerized tartaric acid

Laser-rewritable room temperature phosphorescence based on in-situ polymerized tartaric acid

Multiple Chirality Switching of a Dye-Grafted Helical Polymer Film Driven by Acid & Base.

A stimuli-responsive multiple chirality switching material, which can regulate opposed chiral absorption characteristics, has great application value in the fields of optical modulation, information storage and encryption, etc. However, due to the rareness of effective functional systems and the complexity of material structures, developing this type of material remains an insurmountable challenge. Herein, a smart polymer film with multiple chirality inversion properties was fabricated efficiently based on a newly-designed acid & base-sensitive dye-grafted helical polymer. Benefited from the cooperative effects of various weak interactions (hydrogen bonds, electrostatic interaction, etc.) under the aggregated state, this polymer film exhibited a promising acid & base-driven multiple chirality inversion property containing record switchable chiral states (up to five while the solution showed three-state switching) and good reversibility. The creative exploration of such a multiple chirality switching material can not only promote the application progress of current chiroptical regulation technology, but also provide a significant guidance for the design and synthesis of future smart chiroptical switching materials and devices.

3D Printed and Electrospun, Transparent, Hierarchical Polylactic Acid Mask Nanoporous Filter.

Face masks are becoming one of the most useful personal protective equipment with the outbreak of the coronavirus (CoV) pandemic. The entire world is experiencing shortage of disposable masks and melt-blown non-woven fabrics, which is the raw material of the mask filter. Recyclability of the discarded mask is also becoming a big challenge for the environment. Here, we introduce a facile method based on electrospinning and three-dimensional printing to make changeable and biodegradable mask filters. We printed polylactic acid (PLA) polymer struts on a PLA nanofiber web to fabricate a nanoporous filter with a hierarchical structure and transparent look. The transparent look overcomes the threatening appearance of the masks that can be a feasible way of reducing the social trauma caused by the current CoV disease-19 pandemic. In this study, we investigated the effects of nozzle temperature on the optical, mechanical, and morphological and filtration properties of the nanoporous filter.

Synthesis of Polypeptides by Ring-opening Polymerization: A Concise Review

Abstract: The most economical and efficient route to prepare polypeptides from synthetic chemistry is through the Ring-opening Polymerization (ROP) of amino acids using Ncarboxyanhydride (NCA) monomers. Peptide polymers, in contrast to proteins, consist of repeated amino acid units and are comparatively simpler macromolecules. Despite their simplicity, these polypeptides offer a unique combination of beneficial traits found in both synthetic polymers (such as solubility, processability, and rubber elasticity) and natural proteins (including secondary structure, functionality, and biocompatibility). Nevertheless, NCA polymerization faces significant challenges, including intricate monomer purification and the necessity for processing toxic solvents. In this context, this review presents the fundamental principles of this polymer chemistry, the synthesis of NCA monomers, and the different methodologies to access polypeptides by ROP. It also explores the most recent advances in this field of research, with a focus on how new methods enable the use of more reactive initiators and the development of original processes, including the use of aqueous solvents.

Self-Assembly of Three-Dimensional Hyperbranched Magnetic Composites and Application in High-Turbidity Water Treatment.

In order to improve dispersibility, polymerization characteristics, chemical stability, and magnetic flocculation performance, magnetic Fe3O4 is often assembled with multifarious polymers to realize a functionalization process. Herein, a typical three-dimensional configuration of hyperbranched amino acid polymer (HAAP) was employed to assemble it with Fe3O4, in which we obtained three-dimensional hyperbranched magnetic amino acid composites (Fe3O4@HAAP). The characterization of the Fe3O4@HAAP composites was analyzed, for instance, their size, morphology, structure, configuration, chemical composition, charged characteristics, and magnetic properties. The magnetic flocculation of kaolin suspensions was conducted under different Fe3O4@HAAP dosages, pHs, and kaolin concentrations. The embedded assembly of HAAP with Fe3O4 was constructed by the N-O bond according to an X-ray photoelectron energy spectrum (XPS) analysis. The characteristic peaks of -OH (3420 cm-1), C=O (1728 cm-1), Fe-O (563 cm-1), and N-H (1622 cm-1) were observed in the Fourier transform infrared spectrometer (FTIR) spectra of Fe3O4@HAAP successfully. In a field emission scanning electron microscope (FE-SEM) observation, Fe3O4@HAAP exhibited a lotus-leaf-like morphological structure. A vibrating sample magnetometer (VSM) showed that Fe3O4@HAAP had a relatively low magnetization (Ms) and magnetic induction (Mr); nevertheless, the ferromagnetic Fe3O4@HAAP could also quickly respond to an external magnetic field. The isoelectric point of Fe3O4@HAAP was at 8.5. Fe3O4@HAAP could not only achieve a 98.5% removal efficiency of kaolin suspensions, but could also overcome the obstacles induced by high-concentration suspensions (4500 NTU), high pHs, and low fields. The results showed that the magnetic flocculation of kaolin with Fe3O4@HAAP was a rapid process with a 91.96% removal efficiency at 0.25 h. In an interaction energy analysis, both the UDLVO and UEDLVO showed electrostatic repulsion between the kaolin particles in the condition of a flocculation distance of <30 nm, and this changed to electrostatic attraction when the separation distance was >30 nm. As Fe3O4@ HAAP was employed, kaolin particles could cross the energy barrier more easily; thus, the fine flocs and particles were destabilized and aggregated further. Rapid magnetic separation was realized under the action of an external magnetic field.

Determination of the true density and the filler content of pinus sylvestris wood particles in polymer‐wood‐composites

AbstractMeasuring the natural fiber content in fiber‐filled polymers remains challenging. Conventional methods, such as density calculations based on the specific bulk densities of the mixed components or determining the remaining fiber weights after calcination, often yield inaccurate results. Even helium pycnometer measurements tend to overestimate the true density of natural fibers. This study introduces a novel and potentially more cost‐effective method to accurately determine the true density of natural filler materials. The approach involves mixing these fillers into plastic melts and injection molding them under pressures up to 1000 bar. Using this method, the true density of Pinus sylvestris heartwood chips combined with a lactic acid polymer was precisely calculated as 1.40092 g/cm3 ± 0.0102 g/cm3. Knowing the true density of material like Pinus sylvestris heartwood offers an accurate calculation of filler content in unknown recycled mixtures. This method can calculate the amount of wood fillers in polymer compounds, such as those from former decking, fences, privacy screens or soundproof wall claddings.Highlights Precise method to determine specific actual densities of biofillers High‐resolution CT measurements of polymers filled with wood fibers Localization of density fluctuations in wood fiber filled polylactide Methodology for measuring the biofiber content of recyclates

Preparation of poly(methacrylic acid) grafted on SiO2-NH2/PSF composite membranes for amlodipine removal

Firstly, the SiO2 microspheres were prepared by Stӧber method, and then modified by 3-Aminopropyltrimethoxysilane (KH-540) to introduce –NH2 onto the microspheres. Then, SiO2-NH2 microspheres were mixed into polysulfone casting solution, and SiO2-NH2/PSF composite membrane was prepared by the phase conversion method. On this basis, the functional adsorbent SiO2-NH2/PSF-g-PMAA was prepared by grafting polymerization of methacrylic acid (MAA) as a functional monomer using –NH2/S2O8 2− surface initiation system. The samples were characterized by Fourier infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), the Brunauer–Emmett–Teller (BET) and weighing method. The adsorption properties of amlodipine (ADP) by functional adsorbents were investigated, and the adsorption mechanism was further studied. The results show that the adsorption reaches equilibrium at 180 min, and the adsorption kinetics can be well fitted by the pseudo-second-order model. The adsorption capacity of SiO2-NH2/PSF-g-PMAA for amlodipine in methanol with 1.4 mg/mL at 15 °C is 137 mg/g. The adsorption ability increases with the decrease of ionic strength and temperature via the hydrogen bond and ionic interactions, and the adsorption of ADP by SiO2-NH2/PSF-g-PMAA is consistent with the D-R adsorption isotherm model. Thermodynamic parameters imply that adsorption is a spontaneous and exothermic process.

Petrocella pelovolcani sp. nov., an Alkaliphilic Anaerobic Bacterium Isolated from Terrestrial Mud Volcano

Diversity of extremophilic microorganisms in mud volcanoes is largely unexplored. Here we report the isolation of a novel alkaliphilic, mesophilic, fermentative bacterium (strain FN5sucT) from a terrestrial mud volcano located at the Taman Peninsula, Russia. Cells of strain FN5sucT are gram-stain-positive, non-sporeforming, motile rods. The temperature range for growth is 10–37°C, with an optimum at 30°C. The pH range for growth is 7.5–10.0, with an optimum at pH 9.0. The isolate utilizes various organic polymeric substances, organic acids, carbohydrates, and proteinaceous compounds. The end products of carbohydrates fermentation are acetate, CO2 and trace amounts of H2 and formate. The major cellular fatty acid compounds are C16:0, C16:1 ω7c, and monounsaturated dimethyl acetal C14:1. Phylogenetic analysis reveals that strain FN5sucT is most closely related to Petrocella atlantisensis = DSM 105309T (98.4% 16S rRNA gene identity). The total size of the genome of strain FN5sucT is 3.35 Mb, and a genomic DNA G+C content is 37.0 mol %. The genome contains complete glycolisis/glyconeogenesis pathway. We propose to assign strain FN5sucT to the genus Petrocella, as a new species, Petrocella pelovolcani sp. nov. The type strain is FN5sucT (=DSM 113898T = UQM 41591T).

AI-guided few-shot inverse design of HDP-mimicking polymers against drug-resistant bacteria

Host defense peptide (HDP)-mimicking polymers are promising therapeutic alternatives to antibiotics and have large-scale untapped potential. Artificial intelligence (AI) exhibits promising performance on large-scale chemical-content design, however, existing AI methods face difficulties on scarcity data in each family of HDP-mimicking polymers (<102), much smaller than public polymer datasets (>105), and multi-constraints on properties and structures when exploring high-dimensional polymer space. Herein, we develop a universal AI-guided few-shot inverse design framework by designing multi-modal representations to enrich polymer information for predictions and creating a graph grammar distillation for chemical space restriction to improve the efficiency of multi-constrained polymer generation with reinforcement learning. Exampled with HDP-mimicking β-amino acid polymers, we successfully simulate predictions of over 105 polymers and identify 83 optimal polymers. Furthermore, we synthesize an optimal polymer DM0.8iPen0.2 and find that this polymer exhibits broad-spectrum and potent antibacterial activity against multiple clinically isolated antibiotic-resistant pathogens, validating the effectiveness of AI-guided design strategy.

Hydrophobic Mesoporous Polymeric Acid Catalysts for Glycerol Coetherification with Isobutene and tert-Butanol

Hydrophobic Mesoporous Polymeric Acid Catalysts for Glycerol Coetherification with Isobutene and <i>tert</i>-Butanol

Tough and Elastic Cellulose Composite Hydrogels/Films for Flexible Wearable Sensors.

Cellulose and its composites, despite being abundant and sustainable, are typically brittle with very low flexibility/stretchability. This study reports a solution processing method to prepare porous, amorphous, and elastic cellulose hydrogels and films. Native cellulose dissolved in a water-ZnCl2 mixture can form ionic gels through in situ polymerization of acrylic acid (AA) to poly(acrylic acid) (PAA). The addition of up to 30 vol % AA does not change the solubility of cellulose in the water-ZnCl2 mixture. After polymerization, the formation of interpenetrated networks, resulting from the chemical cross-linking of PAA and the ionic/coordination binding among cellulose/PAA and ZnCl2, gives rise to strong, transparent, and ionically conductive hydrogels. These hydrogels can be used for wearable sensors to detect mechanical deformation under stretching, compression, and bending. Upon removal of ZnCl2 and drying the gels, semitransparent amorphous cellulose composite films can be obtained with a Young's modulus of up to 4 GPa. The rehydration of these films leads to the formation of tough, highly elastic composites. With a water content of 3-10.5%, cellulose-containing films as strong as paper also show typical characteristics of elastomers with an elongation of up to 1300%. Such composite films provide an alternative solution to resolving the material sustainability of natural polymers without compromising their mechanical properties.

Thiol-polyethylene glycol-folic acid (HS-PEG-FA) induced aggregation of Au@Ag nanoparticles: A SERS and extinction UV–Vis spectroscopy combined study

Plasmonic colloidal nanoparticles (NPs) functionalised with polymers are widely employed in diverse applications, offering advantages demonstrated over non-functionalised NPs such as enhanced colloidal stability or increased biocompatibility. However, functionalisation with polymers does not always increase the stability of the colloidal system. This work explores the intricate relationship between the functionalisation of plasmonic core@shell Au@Ag nanoparticles (NPs) with thiol-polyethylene glycol-folic acid (HS-PEG-FA) polymer chains and the resulting stability and spectral characteristics of Surface-Enhanced Raman Scattering (SERS) nanotags based on these NPs. We demonstrate that varying levels of HS-PEG-FA grafting influence nanotag stability, with a low level of grafting causing aggregation and subsequently affecting the spectral signature of Raman-reporter molecules attached to the surface of the NP. Electrostatic destabilisation is identified as the primary mechanism driving aggregation, impacting the SERS spectrum of Malachite Green isothiocyanate (MGITC) whose spectral shape is different between the aggregated and non-aggregated NPs. The findings provide valuable insights into NPs stability under different conditions, offering essential considerations for the design and optimisation of SERS nanotags in bio-analytical applications, particularly those involving data processing based on spectral shape, such as in multiplex approaches where experimental spectra are decomposed with several reference components.