One-step Polymerization Research Articles

State-of-the-art of Synthesized PANI/NiCo2O4/CeO2 Nanocomposites by One-Step Polymerization for Use in Photodetectors

State-of-the-art of Synthesized PANI/NiCo2O4/CeO2 Nanocomposites by One-Step Polymerization for Use in Photodetectors

Facile Preparation of Raspberry-Like SiO2@Polyurea Microspheres with Tunable Wettability and Their Application for Oil-Water Separation.

Raspberry-like microspheres have been widely used as superhydrophobic materials, photonic crystals, drug carriers, etc. Nevertheless, their preparation methods, usually consisting of multiple steps, are generally time- and energy-consuming. Herein raspberry-like SiO2@polyurea microspheres (SiO2@PUM) are readily prepared via a one-step precipitation polymerization of isophorone diisocyanate in a H2O/acetone mixture with the presence of SiO2 particles. The sphere size, surface roughness, and SiO2 content of SiO2@PUM are easily adjustable by varying the experimental conditions. TEM and SEM observations reveal that the final SiO2@PUM exhibits a core-shell structure, with polyurea (PU) in the core and SiO2 particles as the shell. In the process, the SiO2 particles were initially located on the PUM surface as a monolayer. With the reaction proceeding, the monolayer of SiO2 particles became thicker, forming a thicker layer of SiO2 particles on PUM due to the accumulation of SiO2 particles, leading to a multilayer structure of SiO2 particles on the shell of SiO2@PUM. The formation mechanism of the raspberry-like SiO2@PUM was thoroughly discussed and ascribed to electrostatic attraction between the positively charged PU and negatively charged SiO2 particles. Once dried, SiO2@PUM was superhydrophobic and turned hydrophilic if water-wetted. Using a layer of SiO2@PUM, effective separation with good reusability for a variety of oil-water mixtures was achieved regardless of the oil density and types of oil-water emulsions. This work presents a novel protocol for the preparation of raspberry-like microspheres with tunable wettability via a rapid and green process, and the resulting microspheres are highly effective for the separation of diverse types of oil-water mixtures.

Preparation of Disulfide/Trisulfide Core-Cross-Linked Polycarbonate Nanocarriers for Intracellular Reduction-Triggered Drug Release.

Polymeric nanocarriers have attracted significant attention in the field of anticancer drug delivery due to their unique advantages. However, designing nanocarriers that can maintain stability in the bloodstream while achieving specific drug release within tumor cells remains a major challenge. To address this issue, constructing reversible cross-linked polymeric nanocarriers that are sensitive to the intracellular reducible glutathione (GSH) characteristic of the tumor microenvironment is a promising strategy. Based on this, we designed and synthesized two novel six-membered bicyclic carbonate monomers containing disulfide (DSBC) and trisulfide (TSBC) bonds. Through a one-step ring-opening polymerization, a series of reduction-sensitive polycarbonate copolymers (i.e., PEG-PDSBC and PEG-PTSBC) were prepared, and doxorubicin (DOX)-loaded nanoparticles were fabricated using a nanoprecipitation method. The in vitro drug release behaviors of these nanoparticles were systematically investigated. The results showed that these polymers, due to the cross-linked structure formed by the ring-opening polymerization of their bicyclic monomers, could self-assemble into stable nanoparticles. Under different concentrations of glutathione, DOX-loaded PEG-PTSBC nanoparticles demonstrated faster drug release, indicating more optimized intracellular drug release properties. Further cytotoxicity experiments revealed that both types of blank nanoparticles exhibited good biocompatibility with the 4T1 and NIH-3T3 cells. Fluorescence microscopy and flow cytometry results further indicated that DOX-loaded PEG-PTSBC nanoparticles released more drugs in 4T1 cells, significantly inhibiting tumor cell growth compared with DOX-loaded PEG-PDSBC nanoparticles, with no noticeable difference in NIH-3T3 normal cells. In conclusion, this study suggests that trisulfide cross-linked polycarbonate-based nanocarriers hold promise as an anticancer drug delivery system that combines stability in the bloodstream with specific intracellular drug release, offering new insights for the development of novel, efficient, and safe anticancer nanomedicines.

Polyester Adhesives via One-Pot, One-Step Copolymerization of Cyclic Anhydride, Epoxide, and Lactide.

Polyesters (PEs) are sustainable alternatives for conventional polymers owing to their potential degradability, recyclability, and the wide availability of bio-based monomers for their synthesis. Herein, we used a one-pot, one-step self-switchable polymerization linking the ring-opening alternating copolymerization (ROAC) of epoxides/cyclic anhydrides with the ring-opening polymerization (ROP) of L-lactide (LLA) to synthesize PE-based hot-melt adhesives with a high bio-based content. In the cesium pivalate-catalyzed self-switchable polymerization of glutaric anhydride (GA), butylene oxide (BO), and LLA using a diol initiator, the ROAC of GA and BO proceeded whereas the ROP of LLA simultaneously proceeded very slowly, resulting in a copolyester consisting of poly(GA-alt-BO) and poly(L-lactide) (PLLA) segments with tapered regions, that is, PLLA-tapered block-poly(GA-alt-BO)-tapered block-PLLA (PLLA-tb-poly(GA-alt-BO)-tb-PLLA). Additionally, a series of tapered-block or real-block copolyesters consisting of poly(anhydride-alt-epoxide) (A segment) and PLLA (B segment) with AB-, BAB-, (AB)3-, and (AB)4-type architectures of different compositions and molecular weights were synthesized by varying the monomer combinations, alcohol initiators, and initial feed ratios. The lap shear tests of these copolyesters revealed an excellent relationship between the adhesive strength and polymer structural parameters. The (AB)4-type star-block copolyester (poly(GA-alt-BO)-tb-PLLA)4 exhibited the best adhesive strength (6.74 ± 0.64 MPa), comparable to that of commercial products, such as PE-based and poly(vinyl acetate)-based hot-melt adhesives.

Highly Stretchable, Transparent, Solvent-Resistant Multifunctional Ionogel with Underwater Self-Healing and Adhesion for Wearable Strain Sensors and Barrier-Free Information Transfer.

Ionogels with excellent deformability, high ionic conductivity, and a sensitive stimulus response have been widely used and rapidly developed in flexible wearable systems. However, previously reported ionogels are mainly limited to atmospheric environments applications and have difficulty meeting the requirements of solvent-resistant, self-healing, and adhesion properties in underwater environments. Herein, a multifunctional ionogel capable of underwater applications is prepared by one-step photoinitiated polymerization of a fluorine-containing monomer (2,2,3,4,4,4-hexafluorobutyl acrylate, HFBA) and acrylic acid (AA) in a hydrophobic ionic liquid ([EMIM][TFSI]). The dynamic physical interactions of hydrogen bonds and ionic dipoles endow the ionogel with remarkable transparency, tunable mechanical properties, and underwater self-healing properties. Moreover, the fluoropolymer matrix offers high resistance to water and various solvents and exhibits strong underwater adhesion on different substrates. Thus, the sensor based on the ionogel exhibits excellent sensing properties, including high sensitivity, fast response, and superior durability. In particular, the ionogel can be used as a wearable underwater sensor to perform barrier-free information transfer. This study provides a design idea for the development of underwater flexible strain sensors.

Advancement in Soft Hydrogel Grippers: Comprehensive Insights into Materials, Fabrication Strategies, Grasping Mechanism, and Applications.

Soft hydrogel grippers have attracted considerable attention due to their flexible/elastic bodies, stimuli-responsive grasping and releasing capacity, and novel applications in specific task fields. To create soft hydrogel grippers with robust grasping of various types of objects, high load capability, fast grab response, and long-time service life, researchers delve deeper into hydrogel materials, fabrication strategies, and underlying actuation mechanisms. This article provides a systematic overview of hydrogel materials used in soft grippers, focusing on materials composition, chemical functional groups, and characteristics and the strategies for integrating these responsive hydrogel materials into soft grippers, including one-step polymerization, additive manufacturing, and structural modification are reviewed in detail. Moreover, ongoing research about actuating mechanisms (e.g., thermal/electrical/magnetic/chemical) and grasping applications of soft hydrogel grippers is summarized. Some remaining challenges and future perspectives in soft hydrogel grippers are also provided. This work highlights the recent advances of soft hydrogel grippers, which provides useful insights into the development of the new generation of functional soft hydrogel grippers.

Eutectogel adhesives with underwater-enhanced adhesion to hydrophilic surfaces and strong adhesion in harsh environments

It has been a challenge to achieve strong adhesion strength for gel adhesives in water. In this study, a novel eutectogel adhesive is synthesized via one-step photoinitiated polymerization of N-vinylpyrrolidone (NVP) in deep eutectic solvent (DES). The abundant hydrogen bonding interactions and the hydrophilic polyvinylpyrrolidone network structure endow the eutectogel with excellent adhesion to both hydrophilic and hydrophobic surfaces in air and underwater. Moreover, for hydrophilic substrates, the underwater adhesion strength of the eutectogel adhesives is 1.3 times larger than that in air, demonstrating an underwater-enhanced adhesion effect. In contrast, for hydrophobic substrates, the underwater adhesion strength is lower than in air. Furthermore, strong adhesion performance is maintained even in boiling water, strong acidic medium, strong basic medium, and organic solvents. The experimental and simulation results have unveiled the underwater adhesion enhancement mechanism of the eutectogel. It is believed that the designed eutectogel will show great promise in the development of the next-generation of gel adhesives with underwater adhesion capabilities and high environmental adaptability.

Facile Synthesis of Soft Core-Shell Nanospheres for Constructing Multiresponsive Photonic Crystal Security Patterns.

Responsive photonic crystals (RPCs) presenting tunable structural colors under external stimuli are widely applied in the fields of dynamic displays, sensors, and anticounterfeiting. However, the development of multiresponsive photonic crystal (MRPC) films possessing versatile variable optical properties remains a significant challenge due to the tedious synthetic procedure of multifunctional building blocks and complex assembly processes, thereby constraining their extensive applications. In the present work, a series of soft nanospheres with a hydrophobic cores and responsive hydrophilic shells have been synthesized by a facile one-step surfactant-free emulsion polymerization method. The MRPC patterns were then prepared by depositing soft nanosphere emulsions onto the 3D-printed substrates with a topological structure followed by drying at room temperature. The shells of soft nanospheres deformed and fused with each other, resulting in the formation of transparent MRPC film patterns. The MRPC patterns exhibited brilliant structural color in a wet state but lost the color again after complete drying. Such a reversible structural color was ascribed to the change of the refractive index (RI) of the hydrophilic shell layers of nanospheres according to wetting/drying state shifting. Moreover, the on-demand designed MRPC patterns could rapidly respond to external stimuli of temperature, pH, and organic solvents in a reversible manner, and multichannel encrypted security labels were also demonstrated. We postulate that our facile and feasible approach can be applied to the systematic design and large-scale production of MRPC patterns for a variety of applications.

Construction of chlorogenic acid nanoparticles for effective alleviation of ulcerative colitis.

The onset and progression of ulcerative colitis (UC) are intricately linked to the worsening of intestinal inflammation, an imbalance in oxidative stress, and impairment of the intestinal mucosal barrier. Although chlorogenic acid (CA) shows potential in effectively alleviating the symptoms of UC, its clinical application is hindered by its poor bioavailability, stability, rapid metabolism, and quick excretion. This study utilized a one-step enzyme-catalyzed polymerization technique to create chlorogenic acid nanoparticles (CA NPs), aiming to improve the bioavailability and stability of CA. The CA NPs exhibited an optimal nanosize (106.65 ± 4.12 nm) and showed increased cellular uptake over time. Importantly, CA NPs significantly prolonged retention time in inflamed colonic tissues, enhancing accumulation and providing a targeted therapy for UC. Animal studies confirmed the substantial benefits of CA NPs, including reduced weight loss, lessened reduction in colon length, and a lowered disease activity index (DAI) score in DSS-induced UC mice. Moreover, CA NPs effectively reduced oxidative stress and levels of inflammatory factors in the colonic tissues of UC mice, thus mitigating tissue damage and restoring the integrity of the intestinal mucosal barrier. In conclusion, our research proposes a novel approach to increase the bioavailability and stability of CA, offering a promising avenue for its effective application in preventing UC.

Synthesis of metal-phenanthroline-modified hypercrosslinked polymer for enhanced CO2 capture and conversion via chemical and photocatalytic methods under ambient conditions

Catalytic conversion of CO2 into valuable chemicals is a promising approach to mitigate the greenhouse effect and alleviate energy shortages. Hypercrosslinked polymers (HCPs) offer a scalable and stable platform for this conversion, but they often suffer from low CO2 adsorption and activation capabilities, necessitating high temperatures and pressures for effectiveness. To overcome these limitations, nitrogen-based CO2-philic active sites have been integrated into the structure of HCPs, enhancing CO2 attraction and leading to superior adsorption performance. The incorporation of cobalt ions further bolsters CO2 affinity, with HCP-PNTL-Co-B achieving the highest observed adsorption heat of 33.0 kJ·mol-1 alongside a substantial 2.0 mmol·g-1 CO2 uptake. These modified HCPs exhibit higher yields and reaction rates in cycloaddition reactions with cocatalyst tetrabutylammonium bromide at room temperature and atmospheric pressure, while HCP-1,10-phenanthroline (PNTL)-Co-B demonstrates a higher CO production rate (2,173 μmol·g-1·h-1) and selectivity (84%) in photocatalytic reduction reaction. This research has successfully achieved outstanding carbon dioxide capture and conversion performance at room temperature and atmospheric pressure by introducing CO2-philic active sites and cobalt ions into HCPs via facile one-step polymerization. This study provides a new method to design highly efficient organic catalysts for CO2 conversion.

Synthesis Of Ce/Cu/Nb Catalysts, by the One-Step Polymerization Method, Applied in the Selective Oxidation Reaction of Acetonitrile

Objective: The objective of this study is to investigate the catalytic capacity of cerium, copper and niobium oxide catalysts in the oxidation reaction of acetonitrile, in order to test the catalytic behavior, conversion and selectivity of the catalysts; evaluate the different proportions of niobium used (0, 15, 30, 50 and 75% m.m) and compare the catalytic performance of the synthesized materials with other studies present in the literature. Method: The catalysts were synthesized using the one-step polymerization method and were characterized using XRD and H2-TPR techniques. Then, they were applied in the acetonitrile oxidation reaction to be evaluated for conversion and selectivity. Results and Discussion: The results obtained revealed that the catalysts played a significant role in the proposed reaction, obtaining good conversion and selectivity values, including the production of N2 as the majority. Research Implications: Considering that the oxidation of acetonitrile generates polluting gases from nitrogen compounds, the research presents a method that produces an extremely low quantity of these pollutants. This method ensures better product quality, reduces energy consumption due to the lower reaction temperature and uses cheaper and more viable catalysts. Originality/Value: This study contributes to the literature by being based on compounds not yet used together as catalysts and also for the proposed reaction. The relevance of the use of the catalyst is demonstrated through the results obtained, such as high conversions and selectivities to desirable products.

The Impact of Polymerization Atmosphere on the Microstructure and Photocatalytic Properties of Fe-Doped g-C3N4 Nanosheets

Peroxymonosulfate (PMS, SO52−)-based oxidation is an efficient pathway for degrading organic pollutants, but it still suffers from slow degradation efficiency and low PMS utilization. In this work, we report the preparation of porous Fe-doped g-C3N4 catalysts by one-step thermal polymerization using urea and transition metal salts as precursors and investigate the effect of atmosphere conditions (air and nitrogen) on the catalytic performance. Systematic characterizations show that Fe-doped g-C3N4 prepared in air (FeNx-CNO) has a larger specific surface area (136.2 m2 g−1) and more oxygen vacancies than that prepared in N2 (FeNx-CNN, 74.2 m2 g−1), giving it more active sites to participate in the reaction. Meanwhile, FeNx-CNO inhibits the recombination of photogenerated carriers and improves the light utilization. The redox cycling of Fe(III) and Fe(II) species in the photocatalytic system ensures the continuous generation of SO5•− and SO4•−. Therefore, FeNx-CNO can remove CBZ up to 96% within 20 min, which is 3.4 times higher than that of CNO and 3.1 times higher than that of FeNx-CNN, and the degradation efficiency can still retain 93% after 10 cycles of reaction. This study provides an economical and efficient method for photocatalysis in the degradation of medicines in contaminated water.

Highly porous P(DVB-AMPS) copolymer with tailored surface engineering for efficient fluoride capture from water

Surface engineering, especially surface hydrophilicity and active binding sites are crucial for porous polymers in the removal of fluoride ions from water. Herein, a novel P(DVB-AMPS) copolymer with tailored surface engineering was designed through a one-step polymerization method by incorporating diethylene-benzene (DVB) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). AMPS endows abundant active binding sites and provides P(DVB-AMPS) with both hydrophilicity and affinity for fluoride ions, while the monomer DVB acting as a crosslinker, facilitating pore generating. The surface hydrophilicity of P(DVB-AMPS) could be easily tuned by increasing the amounts of AMPS with the contact angle decreased from 126° (PDVB) to 52°. Furthermore, P(DVB-AMPS) material maintains a large specific surface area of 428 m2 · g[Formula: see text] and preserves its highly porous structure. P(DVB-AMPS) exhibits an efficient adsorption capacity (51.9 mg · g[Formula: see text]) and a rapid adsorption rate (6.83 mg · g[Formula: see text] · min[Formula: see text]), which demonstrates competitive performance compared with previous reports. Importantly, the material possesses highly selective adsorption toward fluoride. The excellent adsorption performance of P(DVB-AMPS) is attributed to the high porosity, improved surface hydrophilicity and active binding sites. This work not only provides a new strategy for designing high-performance adsorbents but also offers a novel polymer material for the efficient capture of fluoride ions from water.

Single proton anti-freezing hydrogel electrolyte with enhanced ion migration number enabling high-performance supercapacitor

Compared with traditional binary ion electrolytes, single-ion electrolytes have higher ion migration number and can avoid concentration polarization. In this work, single proton hydrogel electrolytes were prepared by one-step free radical polymerization of acrylamide and 2-acrylaminoamido-2-methyl-1-propane sulfonic acid in ethylene glycol (EG)/water binary solvent. The electrolyte possesses good mechanical strength and excellent anti-freezing ability. A high conductivity of 1.28 mS cm−1 at −40 °C is achieved by adjusting monomer ratio and EG content. The proton hopping along the ion channel formed by the anionic polymer chain and the Grotthuss transport are responsible for the high conductivity. An extremely high ion migration number of 0.87 is obtained. The fixed anionic group endows the hydrogel electrolyte with good anticorrosion ability. The hydrogel electrolyte assembled supercapacitor (SC) exhibits excellent electrochemical performance in a wide temperature range from −40 °C to 60 °C and can be stored at −30 °C for 10 months without capacitance attenuation. The capacitance retention rate of the SC is as high as 92% after 15,000 cycles at both room temperature and − 40 °C. The single proton hydrogel electrolyte provides a new route for the further development of storage device based proton transport.

Charge reconstruction from simultaneous Fe coordination and P/O co-doping in g-C3N4 for efficient photo-reductive recovery of uranium(VI)

The risk of radionuclide leakage always threats ecological security and human health, making the recovery of uranium from nuclear wastewater a meaningful and urgent issue. However, the low-cost and efficient capture of uranium remains a challenge at present. In this study, a homemade photocatalyst of iron coordinated graphitic carbon nitride (g-C3N4) co-doped with phosphorus and oxygen (OPFCN), which was facilely synthesized through a novel one-step thermal polymerization method, exhibited superior photoelectric efficiency and photocatalytic activity towards the photo-reductive capture of uranium(VI). The simultaneous Fe coordination and P/O co-doping in framework of g-C3N4 played a synergistic effect in charge reconstruction, in which electrons migration driven by coordinated Fe and lone electron pairs delocalization from doped P/O enormously increased electron density and enhanced charge transfer, thus effectively promoting the separation of photogenerated charge carriers. The specific surface area, pore volume and average pore size of OPFCN reached 70.2 m2·g−1, 0.157 cm3·g−1 and 7.78 nm, respectively, exhibiting a trend increasingly beneficial for photocatalytic adsorption and mass transfer with successive introduction of Fe, P and O into original g-C3N4. With the simultaneous introduction of Fe, P and O, the optical absorption edge underwent a significant redshift and fluorescence emission intensity dropped by 75 % compared to that of CN, demonstrating the enhanced visible light capturing ability and significantly inhibited recombination of photogenerated charge carriers in OPFCN. As a result, a uranium capture rate of over 98 % was achieved with catalyst dosage of only 5:1 at pH 5 with OPFCN, demonstrating its competitive photo-reductive activity towards uranium(VI) uptake compared with previously reported g-C3N4-based photocatalysts. Meanwhile, OPFCN exhibited remarkable reusability and stability with even over 65 % uranium recovery rate and almost unchanged peak patterns in XRD and FT-IR in fifth reuse recycle. Additionally, it was demonstrated that e− and O2•− were the direct active species to realize the photoreduction of uranium(VI) over OPFCN, in which e− played the dominant role. The modification method of simultaneous Fe coordination and P/O co-doping would be expected to effectively promote the utilization of g-C3N4-based photocatalysts towards photo-reductive recovery of uranium(VI) from radioactive wastewater.

Energy-Efficient Smart Window Based on a Thermochromic Hydrogel with Adjustable Critical Response Temperature and High Solar Modulation Ability.

Thermochromic smart windows realize an intelligent response to changes in environmental temperature through reversible physical phase transitions. They complete a real-time adjustment of solar transmittance, create a livable indoor temperature for humans, and reduce the energy consumption of buildings. Nevertheless, conventional materials that are used to prepare thermochromic smart windows face challenges, including fixed transition temperatures, limited solar modulation capabilities, and inadequate mechanical properties. In this study, a novel thermochromic hydrogel was synthesized from 2-hydroxy-3-butoxypropyl hydroxyethyl celluloses (HBPEC) and poly(N-isopropylacrylamide) (PNIPAM) by using a simple one-step low-temperature polymerization method. The HBPEC/PNIPAM hydrogel demonstrates a wide response temperature (24.1-33.2 °C), high light transmittance (Tlum = 87.5%), excellent solar modulation (ΔTsol = 71.2%), and robust mechanical properties. HBPEC is a functional material that can be used to adjust the lower critical solution temperature (LCST) of the smart window over a wide range by changing the degree of substitution (DS) of the butoxy group in its structure. In addition, the use of HBPEC effectively improves the light transmittance and mechanical properties of the hydrogels. After 100 heating and cooling cycles, the hydrogel still has excellent stability. Furthermore, indoor simulation experiments show that HBPEC/PNIPAM hydrogel smart windows have better indoor temperature regulation capabilities than traditional windows, making these smart windows potential candidates for energy-saving building materials.

Monolithic conjugated microporous polymers with antibacterial activity for air filtration

The air pollution caused by particulate matters (PMs) poses a severe threat to the human health. In particular, the fine particles with diameter smaller than 2.5 μm (PM2.5) can be carriers of various bacteria and viruses, accelerating spread of epidemic. In this work, we synthesized two robust and flexible conjugated microporous polymer (CMP) aerogels for PMs removal, via one-step coupling polymerization of arylethynylenes and aryl halides with different molecular configuration. The resulting CMP aerogels comprise of hollow nanotubes with 3D porous network and high surface areas up to 660 m2/g. The efficiency of CMP aerogels for PM2.5 and PM10 was 99.5 ± 0.3 % and 99.8 ± 0.1 % with a long-term durability. In combination with their physicochemical stability and inherent surface hydrophobicity, a high efficiency for PM2.5 filtration more than 99.6 ± 0.1 % also can be obtained at a high humidity at room temperature both for the two CMP aerogels. In addition, benefiting from the rich alkynyl groups in skeletons, post-modification of the resulting CMP aerogels with thiol-yne chemistry followed by silver ion uptake gives rise to antibacterial materials with outstanding activity for gram-positive strains far superior to other porous organic polymer materials. This work provides a new avenue to fabricate bifunctional CMPs derived porous aerogels for air filtration with high performance and antibacterial activity, and is expected to expand the application of CMPs in environmental purification.

Emulsion-Templated Gelatin/Amino Acids/Chitosan Macroporous Hydrogels with Adjustable Internal Dimensions for Three-Dimensional Stem Cell Culture.

The demand for macroporous hydrogel scaffolds with interconnected porous and open-pore structures is crucial for advancing research and development in cell culture and tissue regeneration. Existing techniques for creating 3D porous materials and controlling their porosity are currently constrained. This study introduces a novel approach for producing highly interconnected aspartic acid-gelatin macroporous hydrogels (MHs) with precisely defined open pore structures using a one-step emulsification polymerization method with surface-modified silica nanoparticles as Pickering stabilizers. Macroporous hydrogels offer adjustable pore size and pore throat size within the ranges of 50 to 130 μm and 15 to 27 μm, respectively, achieved through variations in oil-in-water ratio and solid content. The pore wall thickness of the macroporous hydrogel can be as thin as 3.37 μm and as thick as 6.7 μm. In addition, the storage modulus of the macroporous hydrogels can be as high as 7250 Pa, and it maintains an intact rate of more than 92% after being soaked in PBS for 60 days, which is also good performance for use as a biomedical scaffold material. These hydrogels supported the proliferation of human dental pulp stem cells (hDPSCs) over a 30 day incubation period, stretching the cell morphology and demonstrating excellent biocompatibility and cell adhesion. The combination of these desirable attributes makes them highly promising for applications in stem cell culture and tissue regeneration, underscoring their potential significance in advancing these fields.

Interplanar spacing and nanosheet thickness regulation of carbon nitride and its “cold” catalytic hydrogen production performance under 10 W LED irradiation

Investigation of hydrogen production catalysis under low-temperature and low-power light irradiation, such as LEDs, is important for energy conservation in cold natural conditions. Interlayer charge transfer in g-C3N4 nanosheets is influenced by the crystal face spacing and nanosheet thickness, due to rapid photogenerated carrier recombination and slow charge transfer, thus enhancing hydrogen production capabilities. Few studies have controlled both crystal face spacing and nanosheet thickness simultaneously. In this research, copper-phosphorus co-doped g-C3N4 was synthesized through one-step thermal polymerization, achieving both control over nanosheet thickness and crystal surface spacing. The hydrogen production rate of 0.5 %Cu/1 %P doped g-C3N4 was increased by 5.25 times and reached 958.98 μmol/g/h under 10 °C and 10 W LED illumination. Copper and phosphorus doping that reduced (002) surface spacing of g-C3N4, resulting in thinner nanosheets. This structural modification facilitated interlayer charge transfer and suppressed photogenerated carrier recombination. This research provides a novel insight and strategy for designing hydrogen production photocatalyst at low temperatures and with low energy consumption.

Co2+ coordination-assisted molecularly imprinted covalent organic framework for selective extraction of ochratoxin A

Covalent organic frameworks (COFs) are attractive materials for sample pretreatment due to their tunable structures and functions. However, the precise recognition of contaminant in complex environmental matrices by COFs remains challenging owing to their insufficient specific active sites. Herein, we report Co2+ coordination-assisted molecularly imprinted flexible COF (MI-COF@Co2+) for selective recognition of ochratoxin A (OTA). The MI-COF@Co2+ was prepared via one-step polymerization of 3,3-dihydroxybenzidine, 2,4,6-tris(4-formylphenoxy)− 1,3,5-triazine, Co2+ and template. The flexible units endowed COFs with the self-adaptable ability to regulate the molecular conformation and coordinate with Co2+ to locate the imprinted cavities. The coordination interaction greatly improved the adsorption capacity and selectivity of MI-COF@Co2+ for OTA. The prepared MI-COF@Co2+ was used as solid phase extraction adsorbent for high-performance liquid chromatography determination of OTA with the detection limit of 0.03 ng mL−1 and the relative standard deviation of < 2.5 %. In addition, this method permitted interference-free determination of OTA in real samples with recovery from 89.5 % to 102.8 %. This work provides a simple way to improve the selectivity of COFs for the determination of hazardous compounds in complex environments.