As an alternative energy source to fossil fuels, biobutanol has received increasing attention. In this work, new mixed matrix membranes (MMMs) incorporating zeolitic imidazolate frameworks (ZIF-71) ...particles into polyether-block-amide (PEBA) were prepared for biobutanol recovery from acetone–butanol–ethanol (ABE) fermentation broth by pervaporation (PV). FESEM, EDS, XRD, FT-IR, DSC and contact angle measurements were conducted to study the morphologies, physical and chemical properties and surface properties of the MMMs. The PV performance of the prepared MMMs with various ZIF-71 loadings for separating n-butanol from its aqueous solution was investigated. As a result, both separation factor and thickness-normalized flux of the PEBA membranes were improved by incorporating appropriate amount of ZIF-71 (≤20wt%). The membrane with 20wt% ZIF-71 was evaluated in ABE model solution and ABE fermentation broth, and exhibited high n-butanol separation performance. ZIF-71 particles were confirmed as promising fillers to enhance the separation performance for butanol recovery because of their excellent compatibility with polymer and organophilicity. This work demonstrated the ZIF-71/PEBA MMMs could be potential candidates for practical biobutanol production.
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•Hydrophobic ZIF-71 particles were introduced into PEBA to prepare MMMs.•The MMMs improved separation factor and flux simultaneously in aqueous butanol.•The MMMs showed high butanol recovery performance in ABE fermentation broth.
In this work, ceramic hollow fiber supported polydimethylsiloxane (PDMS) composite membranes were developed by dip-coating PDMS layer on the surface of macroporous ceramic hollow fiber support. By ...controlling the properties of polymer solution and ceramic hollow fiber, high-quality ceramic hollow fiber supported PDMS composite membranes were fabricated for pervaporation (PV) recovery of bio-butanol. It was found both the viscosity of PDMS dip-coating solution and pore size and structure of ceramic support played critical roles in determining the microstructures, the mass transport and the PV performance of PDMS composite membrane. The optimized composite membrane with defect-free PDMS layer and low transport resistance of support showed a total flux of 1282g/m2h and separation factor of 42.9 for 1wt% n-butanol–water mixtures at temperature of 40°C during 200h continuous operation. In addition, the membrane PV performance and stability in acetone–butanol–ethanol (ABE) fermentation broth were investigated. The results showed the PDMS composite membrane exhibited high and stable performance for butanol recovery from ABE systems. Compared with literatures, our work demonstrated that the ceramic hollow fiber supported PDMS composite membrane could be a competitive PV membrane for recovering organic compounds from fermentation broth to produce renewable biofuels.
•Ceramic hollow fiber supported PDMS composite membrane is developed.•Coating solution viscosity and supports are critical for forming PDMS layer.•PDMS composite membrane is used for ABE recovery from fermentation broth.•PDMS composite membrane shows high performance for PV of n-butanol–water mixture.
•GO/ceramic composite membrane was prepared by facile dip-coating method.•Interfacial adhesion of the membrane was improved by silane-modification.•GO/ceramic composite membrane shows potential for ...small molecule separation.
Graphene oxide (GO) composite membrane was fabricated on a silane-modified ceramic support via dip-coating method. The modification of ceramic support by saline improves the interfacial adhesion with GO membrane layer. Meanwhile, the automatic capillary filtration process of ceramic support enables the preparation simple. SEM, EDS, XRD, FT-IR, AFM, nanoindentor and contact angle measurements were conducted to study the morphologies, physical and chemical properties and surface properties of the GO/ceramic composite membrane. The membrane exhibits good integrity, continuity and strong interfacial adhesion, and the surface of GO/ceramic composite membrane is hydrophilic. Additionally, the pervaporation performance of the GO/ceramic composite membrane for separation water from ethanol/water mixtures was investigated, showing a total flux of 461.86g/(m2h) and a water concentration enhancement from 5wt% to 39.92wt% at 40°C.
Cancer deaths are mainly caused by tumor metastases. However, tumor ablation therapies can only target the primary tumor but not inhibit tumor metastasis. Herein, a multifunctional covalent organic ...framework (COF)-based nanocomposite is designed for synergetic photo-, chemodynamic- and immunotherapies. Specifically, the synthesized COF possesses the ability to produce singlet oxygen under the 650 nm laser irradiation. After being metallized with FeCl3, p-phenylenediamine is polymerized on the surface of COF with Fe3+ as the oxidant. The obtained poly(p-phenylenediamine) can be used for photothermal therapy. Meanwhile, the overexpressed H2O2 in the tumor would be further catalyzed and decomposed into hydroxyl radicals (•OH) by the Fe3+/Fe2+ redox couple via Fenton reaction. Intriguingly, the increase of temperature caused by photothermal therapy can accelerate the production of •OH. Moreover, the tumor-associated antigen induced a robust antitumor immune response and effectively inhibited tumor metastasis in the presence of anti-PD-L1 checkpoint blockade. Such a COF-based multifunctional nanoplatform provides an efficacious treatment strategy for both the primary tumor and tumor metastasis.
The bismuth nanosheets grown on carbon fiber cloth were designed. For sodium-ion batteries, the Bi/CFC electrode exhibited a high reversible capacity of 350 and 240mAhg−1 after 300cycles at 50 and ...200mAg−1, as well as a good rate capability. Besides, the electrode displayed two flat potential profiles during the charge/discharge process. The results suggest that the Bi/CFC electrode has excellent potential as an anode for sodium-ion batteries.
•Bismuth (Bi) grown on carbon fiber cloth (Bi/CFC) is prepared.•The Bi/CFC is investigated as flexible anode for sodium-ion batteries.•The Bi/CFC exhibits high specific capacity and good cycling performance.
Hybrid supercapacitors (HSCs), which are expected to possess the good characteristics of both lithium batteries and supercapacitors, have become a hot research topic in recent years for catering to ...the growing market for electric vehicles (EVs) and hybrid electric vehicles (HEVs). Herein, we demonstrate an advanced hybrid material construction by the orthorhombic Nb2O5 quantum dots embedded in nitrogen-doped porous carbon derived from ZIF-8 dodecahedrons, referred to as NQD-NC. Then the applications of this material in LIBs and HSCs are studied in-depth. The LIB test reveals that the novel Nb2O5-based material shows excellent high-rate capability and long-term cyclic stability. Importantly, by assembling a HSC device using a NQD-NC anode and a commercial activated carbon cathode with an organic electrolyte, the HSC shows superior electrochemical performance including ultra-high energy and power density (76.9 W h kg-1 and 11 250 W kg-1, respectively) and superior cyclic stability (capacity retention of similar to 85% at 5 A g-1 after 4500 cycles in a voltage range of 0.5-3.0 V). The excellent electrochemical performance of the HSCs indicates combining the advantages of lithium-ion batteries and supercapacitors, which is promising for the next generation of energy storage systems.
Vanadium oxides with a layered structure are promising candidates for both lithium-ion batteries and sodium-ion batteries （SIBs）. The self-template approach, which involves a transformation from ...metal-organic frameworks （MOFs） into porous metal oxides, is a novel and effective way to achieve desirable electrochemical performance. In this stud~ porous shuttle-like vanadium oxides （i.e., V205, V203/C） were successfully prepared by using MIL-88B （V） as precursors with a specific calcination process. As a proof-of-concept application, the as- prepared porous shuttle-like VaOdC was used as an anode material for SIBs. The porous shuttle-like V203/C, which had an inherent layered structure with metallic behavior, exhibited excellent electrochemical properties. Remarkable rate capacities of 417, 247, 202, 176, 164, and 149 mAh.g-1 were achieved at current densities of 50, 100, 200, 500, 1,000, and 2,000 mA.g-1, respectively. Under cycling at 2 A.g-1, the specific discharge capacity reached 181 mAh.g-1, with a low capacity fading rate of 0.032% per cycle after 1,000 cycles. Density functional theory calculation results indicated that Na ions preferred to occupy the interlamination rather than the inside of each layer in the V203. Interestingly, the special layered structure with a skeleton of dumbbell-like V-V bonds and metallic behavior was maintained after the insertion of Na ions, which was beneficial for the cycle performance. We consider that the MOF precursor of MIL-88B （V） can be used to synthesize other porous V-based materials for various applications.
The process of full-thickness skin regeneration is complex and has many parameters involved, which makes it difficult to use a single dressing to meet the various requirements of the complete ...regeneration at the same time. Therefore, developing hydrogel dressings with multifunction, including tunable rheological properties and aperture, hemostatic, antibacterial and super cytocompatibility, is a desirable candidate in wound healing. In this study, a series of complex hydrogels were developed via the hydrogen bond and covalent bond between chitosan (CS) and alginate (SA). These hydrogels exhibited suitable pore size and tunable rheological properties for cell adhesion. Chitosan endowed hemostatic, antibacterial properties and great cytocompatibility and thus solved two primary problems in the early stage of the wound healing process. Moreover, the sustained cytocompatibility of the hydrogels was further investigated after adding FGF and VE-cadherin via the co-culture of L929 and EC for 12 days. The confocal 3D fluorescent images showed that the cells were spherical and tended to form multicellular spheroids, which distributed in about 40-60 μm thick hydrogels. Furthermore, the hydrogel dressings significantly accelerate defected skin turn to normal skin with proper epithelial thickness and new blood vessels and hair follicles through the histological analysis of in vivo wound healing. The findings mentioned above demonstrated that the CS/SA hydrogels with growth factors have great potential as multifunctional hydrogel dressings for full-thickness skin regeneration incorporated with hemostatic, antibacterial, sustained cytocompatibility for 3D cell culture and normal skin repairing.
Lithium-sulfur (Li-S) batteries have received extensive attention due to their numerous advantages, including a high theoretical specific capacity, high energy density, abundant reserves of sulfur in ...cathode materials, and low cost. Li-S batteries also face several challenges, such as the insulating properties of sulfur, volume expansion during charging and discharging processes, polysulfide shuttling, and lithium dendritic crystal growth. In this study, a composite of a porous multi-site diatomite-loaded graphene oxide material and a PAN fiber membrane is developed to obtain a porous and high-temperature-resistant GO/diatomite/polyacrylonitrile functional separator (GO/DE/PAN) to improve the electrochemical performance of Li-S batteries. The results show that the use of GO/DE/PAN helps to inhibit lithium phosphorus sulfide (LPS) shuttling and improve the electrolyte wetting of the separator as well as the thermal stability of the battery. The initial discharge capacity of the battery using GO/DE/PAN is up to 964.7 mAh g
at 0.2 C, and after 100 cycles, the reversible capacity is 683 mAh g
with a coulombic efficiency of 98.8%. The improved electrochemical performance may be attributed to the porous structure of diatomite and the layered composite of graphene oxide, which can combine physical adsorption and spatial site resistance as well as chemical repulsion to inhibit the shuttle effect of LPS. The results show that GO/DE/PAN has great potential for application in Li-S batteries to improve their electrochemical performance.
As traditional cancer treatment methods, photodynamic therapy (PDT) and photothermal therapy (PTT) can eliminate primary tumors, but they cannot inhibit extensive tumor metastasis and local ...recurrence. Herein, in order to prevent intermolecular accumulation and improve photostability, indocyanine green (ICG) is spontaneously adsorbed onto a covalent organic framework (COF) with high affinity through π-π conjugation, and then chicken ovalbumin (OVA) is coated on the surface of COF@ICG
via
an electrostatic interaction force. The resultant COF@ICG@OVA can ablate primary tumors under 650 nm and 808 nm laser irradiation due to its high photothermal conversion efficiency (
η
= 35.75%) and ability to produce reactive oxygen species (ROS). Tumor-associated antigens are also produced after combinational PTT/PDT therapy. By further combining with anti-PD-L1 checkpoint blockade therapy, it can effectively eliminate primary tumors and inhibit the metastasis of cancer cells by generating strong immune responses. Taken together, COF@ICG@OVA nanoparticles offer an efficient synergistic therapeutic modality for the treatment of tumor metastasis.
As traditional cancer treatment methods, photodynamic therapy (PDT) and photothermal therapy (PTT) can eliminate primary tumors, but they cannot inhibit extensive tumor metastasis and local recurrence.
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