Flowerlike CeO2 microspheres coated with Sr2Fe1.5Mo0.5Ox nanoparticles for an advanced fuel cell.
Ontology highlight
ABSTRACT:
SUBMITTER: Liu Y
PROVIDER: S-EPMC4495617 | biostudies-other | 2015
REPOSITORIES: biostudies-other
Similar Datasets
Project description:The synthesis of organic-inorganic hybrid particles with highly controlled particle sizes in the micrometer range is a major challenge in many areas of research. Conventional methods are limited for nanometer-scale fabrication because of the difficulty in controlling the size. In this study, we present a microfluidic method for the preparation of organic-inorganic hybrid microparticles with poly (1,10-decanediol dimethacrylate-co-trimethoxysillyl propyl methacrylate) (P (DDMA-co-TPM)) as the core and silica nanoparticles as the shell. In this approach, the droplet-based microfluidic method combined with in situ photopolymerization produces highly monodisperse organic microparticles of P (DDMA-co-TPM) in a simple manner, and the silica nanoparticles gradually grow on the surface of the microparticles prepared via hydrolysis and condensation of tetraethoxysilane (TEOS) in a basic ammonium hydroxide medium without additional surface treatment. This approach leads to a reduction in the number of processes and allows drastically improved size uniformity compared to conventional methods. The morphology, composition, and structure of the hybrid microparticles are analyzed by SEM, TEM, FT-IR, EDS, and XPS, respectively. The results indicate the inorganic shell of the hybrid particles consists of SiO2 nanoparticles of approximately 60?nm. Finally, we experimentally describe the formation mechanism of a silica-coating layer on the organic surface of polymeric core particles.
| S-EPMC5986865 | biostudies-literature
Project description:Rapid degradation of cell performance still remains a significant challenge for proton exchange membrane fuel cell (PEMFC). In this work, we develop novel CeO2 nanocubes-graphene oxide nanocomposites as durable and highly active catalyst support for proton exchange membrane fuel cell. We show that the use of CeO2 as the radical scavenger in the catalysts remarkably improves the durability of the catalyst. The catalytic activity retention of Pt-graphene oxide-8 wt.% CeO2 nanocomposites reaches as high as 69% after 5000 CV-cycles at a high voltage range of 0.8-1.23 V, in contrast to 19% for that of the Pt-graphene oxide composites. The excellent durability of the Pt-CeO2 nanocubes-graphene oxide catalyst is attributed to the free radical scavenging activity of CeO2, which significantly slows down the chemical degradation of Nafion binder in catalytic layers, and then alleviates the decay of Pt catalysts, resulting in the excellent cycle life of Pt-CeO2-graphene oxide nanocomposite catalysts. Additionally, the performance of single cell assembled with Nafion 211 membrane and Pt-CeO2-graphene oxide catalysts with different CeO2 contents in the cathode as well as the Pt-C catalysts in the anode are also recorded and discussed in this study.
| S-EPMC4261163 | biostudies-other
Project description:Driven by the demand for the commercialization of fuel cell (FC) technology, we describe the design and fabrication of a highly durable FC electrocatalyst based on double-polymer-coated carbon nanotubes for use in polymer electrolyte membrane fuel cells. The fabricated electrocatalyst is composed of Pt-deposited polybenzimidazole-coated carbon nanotubes, which are further coated with Nafion. By using this electrocatalyst, a high FC performance with a power density of 375?mW/cm(2) (at 70??C, 50% relative humidity using air (cathode)/H2(anode)) was obtained, and a remarkable durability of 500,000 accelerated potential cycles was recorded with only a 5% loss of the initial FC potential and 20% loss of the maximum power density, which were far superior properties compared to those of the membrane electrode assembly prepared using carbon black in place of the carbon nanotubes. The present study indicates that the prepared highly durable fuel cell electrocatalyst is a promising material for the next generation of PEMFCs.
| S-EPMC4655398 | biostudies-literature
Project description:A major challenge in tissue engineering is the formation of vasculature in tissue and organs. Recent studies have shown that positively charged microspheres promote vascularization, while also supporting the controlled release of bioactive molecules. This study investigated the development of gelatin-coated pectin microspheres for incorporation into a novel bioink. Electrospray was used to produce the microspheres. The process was optimized using Design-Expert® software. Microspheres underwent gelatin coating and EDC catalysis modifications. The results showed that the concentration of pectin solution impacted roundness and uniformity primarily, while flow rate affected size most significantly. The optimal gelatin concentration for microsphere coating was determined to be 0.75%, and gelatin coating led to a positively charged surface. When incorporated into bioink, the microspheres did not significantly alter viscosity, and they distributed evenly in bioink. These microspheres show great promise for incorporation into bioink for tissue engineering applications.
| S-EPMC8512326 | biostudies-literature
Project description:Convenient strategies to provide cell membrane-coated nanoparticles (CM-NPs) with multi-functionalities beyond the natural function of cell membranes would dramatically expand the application of this emerging class of nanomaterials. We have developed a facile approach to functionalize CM-NPs by chemically modifying live cell membranes prior to CM-NP fabrication using a bifunctional linker, succinimidyl-[(N-maleimidopropionamido)-polyethyleneglycol] ester (NHS-PEG-Maleimide). This method is particularly suitable to conjugate large bioactive molecules such as proteins on cell membranes as it establishes a strong anchorage and enable the control of linker length, a critical parameter for maximizing the function of anchored proteins. As a proof of concept, we show the conjugation of human recombinant hyaluronidase, PH20 (rHuPH20) on red blood cell (RBC) membranes and demonstrate that long linker (MW: 3400) is superior to short linker (MW: 425) for maintaining enzyme activity, while minimizing the changes to cell membranes. When the modified membranes were fabricated into RBC membrane-coated nanoparticles (RBCM-NPs), the conjugated rHuPH20 can assist NP diffusion more efficiently than free rHuPH20 in matrix-mimicking gels and the pericellular hyaluronic acid matrix of PC3 prostate cancer cells. After quenching the unreacted chemical groups with polyethylene glycol, we demonstrated that the rHuPH20 modification does not reduce the ultra-long blood circulation time of RBCM-NPs. Therefore, this surface engineering approach provides a platform to functionlize CM-NPs without sacrificing the natural function of cell membranes.
| S-EPMC4876625 | biostudies-literature
Project description:We have achieved performance enhancement of polymer electrolyte membrane fuel cell (PEMFC) though crack generation on its electrodes. It is the first attempt to enhance the performance of PEMFC by using cracks which are generally considered as defects. The pre-defined, cracked electrode was generated by stretching a catalyst-coated Nafion membrane. With the strain-stress property of the membrane that is unique in the aspect of plastic deformation, membrane electrolyte assembly (MEA) was successfully incorporated into the fuel cell. Cracked electrodes with the variation of strain were investigated and electrochemically evaluated. Remarkably, mechanical stretching of catalyst-coated Nafion membrane led to a decrease in membrane resistance and an improvement in mass transport, which resulted in enhanced device performance.
| S-EPMC4876450 | biostudies-literature
Project description:Ceria nanoparticles (CeO2 NPs) are generally considered in various functional applications, such as catalysts in fuel cells, sensors, and antioxidant and oxidase-like enzymes in the biological environment. The CeO2 NPs were synthesized using the E. globulus leaf extract-mediated hydrothermal technique. The synthesized NPs were characterized by various analytical instruments including powder X-ray diffractometer (PXRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and dynamic light scattering (DLS) analysis. The XRD results showed an average NPs sizes of 13.7 nm. Cytotoxic study results showed an IC50 value of 45.5 µg/L for A549 and 58.2 µg/L for HCT 116, indicating that CeO2 NPs are more toxic to A549 compared to HCT116 cell lines. The generation of ROS was responsible for its cytotoxic activity against cancer cell lines. Specific surface area (40.96 m2/g) and pore diameter (7.8 nm) were measured using Brunauer-Emmett-Teller (BET) nitrogen adsorption-desorption isotherms. CeO2 NPs with a high surface area were used as photocatalyst in degrading sunset yellow (SY) dye under UV-irradiation and 97.3% of the dye was degraded within 90 min. These results suggest that the synthesized CeO2 NPs could be used as a good photocatalyst as well as a cytotoxic agent against human cancer cell lines.
| S-EPMC7148453 | biostudies-literature
Project description:Biomimetic microspheres containing alginate/carboxymethylcellulose/gelatin and coated with 0%, 1%, 3%, and 6% berberine (BACG, BACG-1B, BACG-3B, BACG-6B) were prepared by the oil-in-water emulsion method combined with spray drying. Through a series of physicochemical parameters and determination of hemostatic properties in vitro and in vivo, the results indicated that BACG and BACG-Bs were effective in inducing platelet adhesion/aggregation and promoting the hemostatic potential due to their biomimetic structure and rough surface. In addition, BACG-6B with high berberine proportion presented better hemostatic performance compared with the commercial hemostatic agent compound microporous polysaccharide hemostatic powder (CMPHP). BACG-6B also showed strong antibacterial activity in the in vitro test. The hemolysis test and cytotoxicity evaluation further revealed that the novel composite biomaterials have good hemocompatibility and biocompatibility. Thus, BACG-6B provides a new strategy for developing a due-functional (hemostat/antibacterial) biomedical material, which may have broad and promising applications in the future.
| S-EPMC7865669 | biostudies-literature
Project description:We report the gene expression profile in BV2 murine microglia cell line after treatment of silica coated magnetic nanoparticles with low dose (0.01 µg/µl) and high dose (0.1 µg/µl) for 12 h.
2021-08-18 | GSE154250 | GEO
Project description:A novel polypyrrole nanowires coated by graphene oxide (PPy-NWs/GO) has been successfully synthesized by one-step electrochemical method, whose structure was different from previously reported PPy/GO composites. The microbial fuel cell equipped with PPy-NWs/GO as anode was fabricated and compared with PPy-NWs ones. The SEM images show that the synthesized PPy-NWs/GO materials possess more surface areas than PPy-NWs. The electrochemical analysis indicated that PPy-NWs/GO anode had lower charge transfer resistance, which may be attributed to synergistic effect of them. The MFC equipped with PPy-NWs/GO anode have higher circle voltages and the power density is about 22.3 mW/m2, which is great higher than that of PPy-NWs about 15.9 mW/m2. These improvements of the MFCs may be due to more bacteria on the larger biofilms based on GO nanosheets, indicating that the PPy-NWs/GO is more effective anode for improving electricity generation.
| S-EPMC6087702 | biostudies-literature