Rich Porous Structure Research Articles

Green synthesis of a superhydrophobic porous organic polymer for the removal of volatile organic compounds at high humidity

Superhydrophobic porous organic polymers are potential sorbents for volatile organic compounds (VOCs) pollution control by suppressing the competition of water molecules on their surfaces. However, the synthesis of superhydrophobic reagents usually requires large amounts of organic solvents and a long reaction time (≥ 24 h). Herein, a green mechanochemical method was developed to synthesize a superhydrophobic polymer (MSHMP-1) with the advantages of using a small amount of organic solvents (5 mL/g) and a short reaction time (2 h). Meanwhile, MSHMP-1 with a water contact angle (WCA) of 162° exhibited a dramatically rich pore structure as revealed by its specific surface area (SSA) of 1780 m2/g. The decrease in the adsorption of benzene on MSHMP-1 due to the competition of water molecules, even at relative humidity of 90 %, was nonsignificant (<10 %), indicating the great application potential of MSHMP-1 in hydrophobic adsorption. Moreover, the adsorption capacity of MSHMP-1 was maintained after at least five adsorption–desorption cycles. Therefore, MSHMP-1 can be a remarkable adsorbent for the removal of hazardous VOCs, especially at high humidity levels.

Long-Term performance of composite Cu-Fe ore oxygen carrier by Extrusion-Spheronization in chemical looping combustion

High-performance and low-cost oxygen carrier is vital for engineering demonstration and industrial application of chemical looping combustion. In this work, binary-ore (copper ore and iron ore) oxygen carriers are prepared at a large scale (25 kg/h) by the extrusion-spheronization method, using montmorillonite as the inert support. The anti-sintering ability and long-term stability are systematically investigated through well-organized tests in a thermogravimetric analyzer (TGA) and batch fluidized bed reactor (BFB). Four kinds of low-cost composite oxygen carriers are prepared with montmorillonite content of 10 wt%∼40 wt%, and the montmorillonite loading ratio is optimized as 10 wt% through 100-cycle TGA tests, with the fastest reduction rate of 0.155 %/s. The results show that the CO2 yield is always beyond 90 %, suggesting the stable reactivity of FeCu-10 M, and the average attrition rate is 0.108 %/h. No significant sintering or agglomeration is detected in the inner surface or among the particles, as indicated by SEM images. The specific surface area is developed from 0.125 to 0.185 m2/g, and the rich pore structure remains in the 100-cycle test. Additionally, the crushing strength of FeCu-10 M is higher than 2 N throughout the cyclic experiment, and the lifetime is 2 ∼ 7 times longer than that of the original iron ore. The extrusion-spheronization method has the potential in the industrial-scale preparation of oxygen carriers, and the FeCu-10 M is a favorable oxygen carrier to the chemical looping combustion process.

Advanced Applications of Porous Materials in Triboelectric Nanogenerator Self-Powered Sensors.

Porous materials possess advantages such as rich pore structures, a large surface area, low relative density, high specific strength, and good breathability. They have broad prospects in the development of a high-performance Triboelectric Nanogenerator (TENG) and self-powered sensing fields. This paper elaborates on the structural forms and construction methods of porous materials in existing TENG, including aerogels, foam sponges, electrospinning, 3D printing, and fabric structures. The research progress of porous materials in improving TENG performance is systematically summarized, with a focus on discussing design strategies of porous structures to enhance the TENG mechanical performance, frictional electrical performance, and environmental tolerance. The current applications of porous-material-based TENG in self-powered sensing such as pressure sensing, health monitoring, and human-machine interactions are introduced, and future development directions and challenges are discussed.

Low-cost and green straw derived hierarchical porous carbon as support to phosphotungstic acid for efficient and clean production of α-terpineol

This study developed a novel reciprocal template method to prepare MgO@Carbon micrometre tubes directly from straw-based biomass. Biomass carbon with a rich hierarchical porous structure (MRSC30) was obtained by acid-washing the MgO@Carbon micrometre tubes. The pore formation mechanism of MRSC30 was systematically analyzed using Density Functional Theory calculations and various characterization methods. The in situ growth of Mg(OH)Cl/MgO inside the biomass promotes the polymerized carbon precursors to be tightly affixed to the templating agent and provides exfoliation, support, and catalysis (i.e., electrostatic attraction, nucleophilic substitution, and electrophilic addition), which effectively promotes the formation of hierarchical porous carbon. The continuous release of light gases from the inside out during the prolongation of the decomposition temperature of the biomass by Mg(OH)Cl or/and MgO helps to promote the formation of stomata in the biomass carbon. The results showed that the method minimized the consumption of chemicals, energy consumption, and the time required to prepare HPC by 35.75%, 67.57%, and 52.38%, respectively. The phosphotungstic acid-loaded MRSC30 was successfully prepared as a highly amphiphilic and highly acidic solid acid catalyst and applied to the hydration of α-pinene to prepare superior performance gasoline additives (α-terpineol). Under optimal process conditions obtained in a batch reactor, the catalytic performance of the catalyst could be further improved by alternating flow using a novel semi-batch unsteady-state reactor developed in this institute, and the α-pinene conversion and the α-terpineol selectivity reached a maximum of 95.53% and 65.75%, respectively. At the same time, the reactor was able to substantially reduce the time required for hydration and the amount of moderately toxic acetone used compared to the conventional batch reactor by 20.83% and 62.50%, respectively.

Synergistic effects of Co-pyrolysis on the immobilization and transformation of lead (Pb), chromium (Cr), nickel (Ni), and fluorine (F) in phosphogypsum-biomass mixtures

Co-pyrolysis of biomass with phosphogypsum (PG) presents an effective strategy for facilitating the recycling of PG resources. However, it is crucial to note the environmental threats arising from the presence of Pb, Cr, Ni, and F in PG. This study investigated the effect of immobilization and transformation of four elements during co-pyrolysis with biomass and its components. The co-pyrolysis experiments were carried out in a tube furnace with a mixture of PG and corn stover (CS), cellulose (C), lignin (L), glucose (G). Co-pyrolysis occurred at varying temperatures (600 °C, 700 °C, 800 °C, and 900 °C) and different addition ratios (10%, 15%, and 20%). The results indicated that an increase in co-pyrolysis temperature was more conducive to the immobilization and transformation of harmful elements in PG, demonstrating significant efficacy in controlling F. Additionally, the addition of biomass components exerts a significant impact on inhibiting product toxicity, with small molecules such as glucose playing a prominent role in this process. The mechanism underlying the control of harmful elements during co-pyrolysis of PG and biomass was characterized by three main aspects. Firstly, biomass components have the potential to melt-encapsulate the harmful elements in PG, leading to precipitation. Secondly, the pyrolysis gas produced during the co-pyrolysis process contributes to the formation of a rich pore structure in the product. Finally, this process aids in transforming hazardous substances into less harmful forms and stabilizing these elements. The findings of this study are instrumental in optimizing the biomass and PG blend to mitigate the environmental impact of their co-pyrolysis products.

Facile synthesis of Co3O4 with porous capsule–shaped structure and its lithium storage properties as anode materials for Li–ion batteries

In this work, a porous Co3O4 anode material with capsule–shaped morphology is prepared by a simple solvothermal method and subsequent heat treatment process in air. The as–synthesized CoCO3 precursor and Co3O4 sample are systematically studied and analyzed by a series of testing technologies, such as XRD, FTIR, FESEM, (HR)TEM, TGA, XPS and N2 adsorption/desorption measurement. As negative materials in Li–ion batteries, the Co3O4 active material exhibits high charge/discharge specific capacity, good rate performance and satisfactory cycle stability. The excellent electrochemical properties are inevitably related to the structural characteristics of the electrode material itself, including regular morphology, rich pore structure, large specific surface area, high crystallinity, nanoscale particle size, etc.

Photocatalytic and fouling resistant MXene/3D-S-COF for efficient oil-water emulsion separation

Three-dimensional sphere covalent organic framework (3D-S-COF) membranes have received increasing attention in the field of oily wastewater and industrial organic matter due to their rich pore structure as well as having many exposed functional group sites. However, the synthesis of conventional imine COF through the Schiff base method, which suffers from the easy hydrolysis under organic solvent conditions. Herein, a novel super-wettable MXene/3D-S-COF composite membrane for oil–water emulsion separation was prepared by depositing MXene nanosheets on oxidized amide COF from the imine COF. The hydroxyl groups of the COF membrane not only improved the water permeability but also formed hydrogen bonds with the MXene layer, which enhanced the interaction and formed the high stability composite membrane. The porous 3D-S-COF and the zigzag MXene layer work synergistically to enable emulsion fluxes up to 240 L·m−2h−1 bar−1 and the separation efficiency is more than 98 %. In addition, the residual mass of the composite membrane remained above 95 % after 10 days of immersion in various solvents, and it also has photocatalytic properties and good resistance to fouling. This study provides a brand new idea for the use of MXene/3D-S-COF based composite membrane for oil–water emulsion separation.

Dialdehyde starch cross-linked aminated gelatin sponges with excellent hemostatic performance and biocompatibility

Developing a hemostatic material suitable for rapid hemostasis remains a challenge. This study presents a novel aminated gelatin sponge cross-linked with dialdehyde starch, exhibiting excellent biocompatibility and hemostatic ability. This aminated gelatin sponge features hydrophilic surface and rich porous structure with a porosity of up to 80 %. The results show that the aminated gelatin sponges exhibit superior liquid absorption capacity and can absorb up to 30–50 times their own mass of simulated body fluid within 5 min. Compared with the commercial gelatin hemostatic sponge and non-aminated gelatin hemostatic sponge, the aminated gelatin hemostatic sponge can accelerate the hemostatic process through electrostatic interactions, demonstrating superior hemostatic performance in both in vitro and in vivo hemostasis tests. The aminated gelatin sponge can effectively control the hemostatic time within 80 s in the in vivo rat femoral artery injury model, significantly outperforming both commercial and non-aminated gelatin sponges. In addition, the aminated gelatin sponge also exhibits good biocompatibility and certain antibacterial properties. The proposed aminated gelatin sponge has very good application prospects for the management of massive hemorrhage.

Efficient removal of cadmium from aqueous solution by chitosan grafted pillared bentonite

Developing an environmentally friendly adsorbent with high adsorption capacity and economic advantages is crucial for the treatment of cadmium (Cd)-contaminated wastewater. In this study, Bentonite (Bt), which is widely distributed in nature, was used to prepare a new type of chitosan (CS)-grafted polymerized aluminum-pillared bentonite (i.e., Al@Bt): CS@Al@Bt. This new material effectively addresses the issues of chitosan’s poor mechanical strength, limited load capacity, and the weak adsorption properties of raw bentonite for Cd. The effects of synthesis conditions on Cd adsorption by modified bentonite were investigated through batch experiments. The adsorption mechanism was revealed by characterization tests such as X-ray diffraction (XRD), N2 adsorption-desorption experiments, Scanning and Transmission electron microscopy (SEM-TEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The results showed that compared to raw Bt, when the ratio of Al in polymerized aluminum to the cation exchange capacity (CEC) of Bt was increased to 5 (i.e., Al/CEC=5), the specific surface area (SSA) of Bt increased from 78.46 m²/g to 195.99 m²/g. Additionally, the interlayer spacing and total pore volume increased by 1.22 and 1.13 times, respectively. After grafting chitosan onto Al@Bt, CS@Al@Bt reached adsorption equilibrium rapidly within 15 min, achieving a removal rate of up to 99.82% (initial concentration of Cd(II) was 20 mg/L, and the solid-liquid ratio was 1 g/L). Additionally, CS@Al@Bt showed good adsorption performance over a wide pH range. The rich pore structure of CS@Al@Bt and the complexation between amino (-NH2) and hydroxyl (-OH) groups with Cd(II) were the main mechanisms for the removal of Cd(II) from the solution. The application showed that CS@Al@Bt effectively reduced Cd-containing mining wastewater from class V to class II quality, underscoring its significant potential for treating Cd(II)-contaminated wastewater.

Bimetallic-doped three-dimensional carbon skeleton porous material as efficient catalysts for oxygen reduction reaction

The slowness of the oxygen reduction reaction (ORR) kinetics of the fuel cell cathode has terrifically inhibited its development process. Now it is of considerable importance to research low-cost, multi-defect, high-performance non-noble metal ORR catalysts. Specifically, CuO nanosheets are grown in situ on ZIF-8 to form a composite material (zif-8@CuO), and then undergo a high-temperature carbonization process. Finally, the Zn-Cu codoped composite material Zn-xCu-N/C with a porous structure supported by a three-dimensional carbon skeleton can be obtained. The material has a 3D carbon skeleton support and a rich pore structure, which can expose more active sites. The combination of bimetallic Zn and Cu with carbon materials also increases the overall stability and conductivity of the material, which is beneficial to improvement of catalytic performance. The electrochemical performance test results show that the onset potential and half-wave potential of the Zn-0.1Cu-N/C material are 0.889 V and 0.803 V respectively, with a low Tafel slope of 62 mV dec−1 and excellent long-term stability. After 10000 cycles, the ORR curve only changed 18 mV, while the carbon skeleton can still maintain unchanged.

Synthesis of activated carbon from waste polyester fabric activated by ZnCl2 and its adsorption for organic dyes

In order to achieve the resource utilization of waste polyester (WPT), the WPT based activated carbon (WPT-AC) was prepared by ZnCl2 activation high-temperature pyrolysis method. The phase morphology, characteristic groups, pore structure of specific surface area and microstructure were characterized by TGA, XRD, FTIR, BET and SEM. The optimum preparation process of WPT-AC was determined by L9(34) orthogonal experiment, and the adsorption performance of WPT-AC for methylene blue (MB) was evaluated. WPT-AC showed a high specific surface area of 1037.62 m2/g, with rich pore structure, which provided the possibility for efficient adsorption. The pretreatment of ZnCl2 plays a key role in the formation of WPT-AC pore structure, and the abundant pore structure is conducive to improving the adsorption of pollutants. WPT-AC showed excellent performance in the field of organic dye adsorption, and the highest removal rate of MB reached 97.34%. The adsorption was mainly related to electrostatic attraction, hydrogen bonding and π–π conjugation. The analysis of adsorption kinetics and thermodynamics is conducive to a better understanding of the adsorption process.

Novel magnetic N-doped biochar derived from sugarcane bagasse and red mud for effective adsorption of tetracycline hydrochloride

In this work, with sugarcane bagasse (SB) and red mud (RM) as raw materials, magnetic nitrogen (N)-doped biochar (MNSB) was synthesized by a facile one-pot pyrolysis method and then applied as an efficient adsorbent to remove tetracycline hydrochloride (TC-HCl) from wastewater. The results of SEM, EDS, VSM, BET, FT-IR, and XPS demonstrated that the synthesized MNSB adsorbent had a large specific surface area, excellent superparamagnetic properties, and rich mesopore pore structures. The batch adsorption experiments revealed that the TC-HCl could be removed 96.3% with the optimal adsorption conditions: MNSB dosage of 0.25 g/L, initial pH of 6.58, TC-HCl initial concentration of 20 mg/L, and adsorption temperature of 30 °C. The analysis of adsorption kinetics and isotherms showed that the adsorption process was mainly controlled by chemisorption, and the theoretical maximum adsorption capacity of TC-HCl on MNSB was 143.9 mg/g. Mechanistic analysis revealed that the excellent adsorption process of MNSB for TC-HCl was mainly contributed by pore filling, π–π interaction, hydrogen bonding, and electrostatic attraction. The recycling and settlement experiments demonstrated that MNSB had good stability and settleability. This study successfully opened new prospects that utilizing RM and SB to prepare a low-cost adsorbent to remove TC-HCl from water.

Study on the adsorption mechanism of polar and non-polar VOCs by the activated carbon with surface oxygen

In this study, CO2 was converted to activated carbon by the molten salt CO2 capture and electrochemical conversion (MSCC-EC) method, and the surface oxygen content of the activated carbon was further modified for the adsorption of polar molecules (chlorobenzene) and nonpolar molecules (toluene), the role of the pore structure and surface O-containing functional groups of the adsorbents in contributing to the adsorption process was systematically investigated. The results showed that MS-AC500-10, MS-AC500-15, and MS-AC550-15 have rich pore structures with specific surface areas of 811.56 m2/g, 835.35 m2/g, 1249.104 m2/g, and surface oxygen contents of about 10 %, 15 %, 15 %, respectively. The toluene adsorption capacity of MS-AC500-10, MS-AC500-15, and MS-AC550-15 was 203.82 mg/g, 229.72 mg/g, and 358.97 mg/g, respectively, and was dominated by pore adsorption, which was positively proportional to the specific surface areas and pore volumes, the adsorption process belonged to the pseudo-first-order kinetic model. The adsorption amounts of chlorobenzene by MS-AC500-10, MS-AC500-15, and MS-AC550-15 were 287.98 mg/g, 363.11 mg/g, and 495.41 mg/g, respectively. In addition to the pore adsorption, the oxygen content on the surface of the adsorbents had a non-negligible promotion effect on the adsorption of chlorobenzene, mainly because chlorobenzene is a polar molecule, and the asymmetric electrons on its surface have strong interactions with the O-containing functional groups on the surface of the adsorbents. Moreover, the prepared adsorbents were thermally stable, and the decay rate of adsorption performance was less than 5 % after five adsorption–desorption cycles.

Preparation of porous materials by ultrasound-intensified acid leaching of high-carbon component in coal gasification fine slag

Coal gasification fine slag is one of the by-products from clean and efficient utilization of coal, and its resource utilization is extremely urgent. In this work, a high carbon fraction with a fixed carbon content higher than 60% was obtained by simple sieving of gasification fine slag, from which a porous material was prepared by ultrasonic acid leaching method. The adsorption performance of porous materials, being used as treatment of radioactive iodine in nuclear wastewater, is characterized by iodine adsorption value. The effects of ultrasound time, ultrasound power, acid concentration, and temperature on the iodine adsorption performance and compositional structure of the porous materials were systematically investigated by combining the results of SEM, BET, XRD, and FT-IR. The mechanisms of ultrasound-enhanced acid leaching on compositional structure of residual carbon and migration and transformation laws of the ash constituents were explored and summarized. The results show that the porous material prepared under conditions of acid concentration of 4 mol/L, acid immersion temperature of 50 °C, ultrasonic power of 210 W, and ultrasonic time of 1.5 h has the best iodine adsorption performance of 468.53 mg/g, with a specific surface area of 474.97 m2/g, and possesses a rich pore structure with predominant mesopores. The order of each factor on the iodine adsorption performance is: sonication time > acid concentration > sonication power > acid immersion temperature. The mechanism of ultrasonic enhanced acid leaching is that ultrasonic cavitation and mechanical wave action firstly enhance dissociation of carbon-ash adherent particles, thus making desorption of ash particles blocked in pore channels of the gasification slag to increase its connectivity; secondly, lead to generation of cracks on surface of the carbon and ash particles to enhance accessibility of inorganic components inside the carbon particles; and thirdly, enhance the acid leaching process by increasing mass transfer rate to strengthen leaching effect of inorganic components in the gasification slag.

A new strategy to increase compost carbon fixation: Shell powder reduced gaseous pollutant emissions in co-composting of cow manure and sawdust

To reduce gas emission and convert inorganic carbon into humus more efficiently has become a key research direction in composting. Microorganisms were the main factor affecting gas emissions. Because of its rich nutrients and porous structure, shell powder (SP) can change the succession of microorganisms during composting. The result showed that SP was found to reduce the emissions of CH4 (CK: 4.99 g; T: 3.21 g) and CO2 (CK: 114.48 g; T: 79.23 g) during composting, especially in the thermophilic phase. SP increased the DOM (CK: 20.91 mg/g; T: 26.92 mg/g) and HS (CK: 19.32 g/kg; T: 21.17 g/kg) content of the final compost product. SP increased the abundance of cbbL and Actinobacteria, and decreased mcrA abundance. cbbL and mcrA were identified as key genes for CO2 and CH4 metabolism, respectively. And Actinobacteria was identified as a key microorganism for carbon fixation and conversion during composting. This study can provide a new strategy for improving composting performances and compost quality.

Catalytic pyrolysis of rice husk to co-produce hydrogen-rich syngas, phenol-rich bio-oil and nanostructured porous carbon

How to achieve high value modification of biomass through simple process and low cost is an important bottleneck in the development of biomass energy. In this study, hydrogen-rich syngas, phenol-rich bio-oil and high specific surface area nanostructured porous carbon materials were synthesized by one-step in situ catalytic pyrolysis at 500 °C. Composition and physicochemical property tests of the three-phase products showed that KOH promotes ring opening and bond breaking of macromolecules in the bio-oil, improves the directional selectivity of phenolic compounds, and generates more small molecule gases. Molten K+ and water vapor etched the biomass to prepare porous carbon with high graphitization and rich pore structure and generate more H2. Further electrochemical characterization showed that the porous carbon material had good specific capacitance and cyclic stability. This study provides a new idea for the utilization of pyrolysis polygeneration technology of agroforestry biomass resources, and it is also of guiding significance for the research of high-value utilization of biomass resources.

SnO2 QDs sensitized ZnFe2O4 spheres with enhanced acetone sensing performance

Herein, SnO2 QDs (<10 nm) with small size instead of conventional nanoparticles was employed to modify ZnFe2O4 to synthesize porous and heterogeneous SnO2/ZnFe2O4 (ZFSQ) composites for gas sensing. By an immersion process combined with calcination treatment, the resultant porous ZFSQ composites with different contents of SnO2 QDs were obtained, and their sensing properties were investigated. Compared with bare ZnFe2O4 and SnO2 QDs, porous ZFSQ composites based-sensors showed much improved sensor response to acetone. For contrast, the sensor performance of ZFSQ composites was also compared with that of ZnFe2O4 sphere modified by SnO2 nanoparticles with different size. The porous ZFSQ composite with 5 wt% SnO2 QDs (ZFSQ-5) showed a better acetone sensing response than that of other ZFSQ composites, and it exhibited a high response value of 110–100 ppm of acetone and a low detection limit of 0.3 ppm at 240 °C. In addition to the rich heterojunctions and porous structure, the size effect of SnO2 QDs was other indispensable reasons for the improved sensor performance. Finally, the ZFSQ-5 composite sensor was attempted to be applied for acetone sensing in exhaled breath, suggesting its great potential in monitoring acetone.

MXene/Ag3PO4 modified PVDF composite membranes for efficient interfacial evaporation and photodegradation

Solar-powered interface evaporation is considered a promising technology to obtain freshwater from non-potable water by using sustainable solar energy. However, research on combining the photocatalytic effect with solar interfacial evaporation technology to go for photothermal conversion materials with full solar spectrum utilization for photothermal and photodegradation capabilities is still scarce. Due to the unique optical properties of MXene, a novel MXene/Ag3PO4-based membrane with synergistic photothermal and photocatalytic effects was developed from the perspective of practical applications such as water purification, photodegradation of organic dyes and antibacterial properties. In this paper, polyvinylidene fluoride (PVDF) and carbon black (CB) were used as the substrate, calcium carbonate (CaCO3) and hydrochloric acid (HCl) were selected as the pore-forming agent for hydrophilic modification, and MXene/Ag3PO4 serves as the photocatalyst. The prepared composite polyvinylidene fluoride membrane (PCC-MXene/Ag3PO4) with Schottky junction, possesses a rich pore structure, abundant water molecule transport channels, high light absorption ability, and low thermal conductivity, which lead to a good performance in solar interface evaporation, photodegradation and antibacterial. The superhydrophobicity and floatability of the nanosponges in water enable them to continuously pump water, which greatly promotes the dissolution of salt accumulation. With the help of porous nanosponges, PCC-MXene/Ag3PO4 exhibits excellent evaporation stability and salt resistance under 1 kW m−2 solar irradiation, as well as photodegradation of organic dyes. In addition, the PCC-MXene/Ag3PO4 membrane has the properties of self-buoyancy, electrical conductivity, and superior flexibility. Therefore, considering the simple preparation method and fine performances, the PCC-MXene/Ag3PO4 mixed membrane has great application potential in the study of interface evaporation, photodegradation of organic dyes, and antibacterial properties.

Intrinsically microporous polyimide membranes with synergistic aromatic and alicyclic linking groups for efficient molecular separation

Polymers of intrinsic microporosity (PIMs) are widely recognized for having great potential in reforming membrane technology for molecular separation within organic solvents, due to their rich and appropriate pore structures with a size < 2 nm. However, the swelling in organic solvents has a significant effect on their pore structures due to the amorphous and linear nature, resulting in the permeability and selectivity performances of developed PIM membranes being far from ideal. In this work, we synthesized an advanced polyimide of intrinsic microporosity by integrating a Tröger’s base (TB) structure with an synergistic structure of aromatic (naphthalenediimide, NDI) and alicyclic (bicyclooctenediimide, BCODI) linking groups. The TB with a rigid and twisted structure was used to furnish a basis for inhibiting chain packing for high overall free volume. The ultra-rigid NDI units maintained such a tailored high free volume and provided superior solvent resistance. The relatively flexible and polar BCODI units promoted local chain mobility to tailor uniform pore size distribution and increased affinity for polar solvents. The innovative design fostered the formation of stable, uniform, and highly solvent-accessible intrinsic micropores. The prepared TFC membrane exhibited good organic solvent separation capabilities, achieving an ethanol permeance of 7.6 L m-2 h−1 bar−1 and a low molecular weight cut-off (MWCO) of approximately 470 Da. This work contributes significantly to the strategic design of PIMs for preparing high-performance membranes for realistic chemical-related separation application scenarios.

A super hydrophilic and high strength chitosan hemostatic sponge prepared by freeze-drying and alkali treatment for rapid hemostasis

Excessive blood loss caused by natural accidents or major surgical procedures can be life-threatening and requires rapid hemorrhage management. Developing hemostatic materials with high water absorption capacity and high strength properties is still challenging. Super hydrophilic/high-strength chitosan hemostatic sponges (SHHS-CHS) were prepared by freeze-drying and alkali treatment. The freeze-drying technology formed a porous three-dimensional structure of sponges, and alkali treatment increased the hydrophilicity of sponges and the rigidity of the chitosan molecular chain, improving the hydrophilicity and mechanical properties of chitosan sponges. Characterization experiments revealed that SHHS-CHS had high water absorption capacity, rich pore structure, and excellent mechanical properties. The cytotoxicity and hemolysis experiments showed that SHHS-CHS had good biocompatibility. Compared to the commercial hemostatic gelatin sponges and chitosan hemostatic material, SHHS-CHS had better blood coagulation and red blood cell and platelet adhesion ability. Moreover, SHHS-CHS showed better hemostatic ability than gelatin sponges in rat-liver injury and rat leg vein rupture models, significantly reducing the hemostasis time and bleeding volume. In conclusion, SHHS-CHS has broad prospects for clinical application as a hemostatic material.