In order to overcome the problem of long-term stability of perovskite solar cells, the author proposes a method to study the effects of nanosemiconductor materials on the thermal stability of solar ...cells. In this method, n = 3 and n = 1 (C6H5(CH2)2NH3)2(CH3NH3)n-1Pbn I3n+1 two-dimensional nanoperovskite films were investigated on glass substrates and indium tin oxide (ITO) substrates, respectively, on the thermal stability. Experimental results show that the glass-based nanoperovskite PMPI3 film was partially decomposed into PbI2 after being heated at 160°C. When the temperature reaches 180°C, the film is completely decomposed into PbI2, and the perovskite PMPI3 film with ITO as the substrate is completely decomposed into PbI2 when the heating temperature reaches 140°C. The charge transfer between the perovskite film and the substrate is the physical reason for its easier thermal decomposition on the ITO substrate. Suggestions for improving the thermal stability of perovskite solar cell devices are given from the aspects of device design and fabrication process.
Three-dimensional Fe3O4 decorated carbon nanotubes/reduced graphene oxide foam/epoxy (3D Fe3O4-CNTs/rGF/EP) nanocomposites with highly oriented three-dimensional structures were fabricated by facile ...template method. Scanning electron microscope (SEM), transmission electron microscope (TEM), thermal gravimetric analyses (TGA), X-ray photoelectron spectroscopy (XPS) and Raman all proved the successfully graft of Fe3O4 onto the surface of CNTs and the formation of interconnected 3D highly aligned porous framework inner Fe3O4-CNTs/rGF. Owing to the presence of Fe3O4 and 3D nanohybrid framework, the obtained 3D Fe3O4-CNTs/rGF/EP nanocomposites with 0.24 wt% rGF and 2.76 wt% Fe3O4-CNTs showed remarkable electrical conductivity of 15.3 S/m and wonderful EMI SE value of 36 dB within the X-band range, almost 482% enhancement compared to physically blended Fe3O4-CNTs/EP nanocomposites without three-dimensional structure (∼6 dB). The excellent magnetic property and efficient 3D framework structures are considered as the main reasons for outstanding EMI shielding performances of the 3D Fe3O4-CNTs/rGF/EP nanocomposites.
Polymeric membranes, such as polyamide thin film composite membranes, have gained increasing popularity in wastewater treatment, seawater desalination, as well as the purification and concentration ...of chemicals for their high salt-rejection and water flux properties. Membrane biofouling originates from the attachment or deposition of organic macromolecules/microorganisms and leads to an increased operating pressure and shortened service life and has greatly limited the application of polymeric membranes. Over the past few years, numerous strategies and materials were developed with the aim to control membrane biofouling. In this review, the formation process, influence factors, and consequences of membrane biofouling are systematically summarized. Additionally, the specific strategies for mitigating membrane biofouling including anchoring of hydrophilic monomers, the incorporation of inorganic antimicrobial nanoparticles, coating/grafting of cationic bactericidal polymers, and the design of multifunctional material integrated multiple anti-biofouling mechanisms, are highlighted. Finally, perspectives on the challenges and opportunities in anti-biofouling polymeric membranes are shared, shedding light on the development of even better anti-biofouling materials in near future.
The boosting of consumer electronics and 5G technology cause the continuous increment of the power density of electronic devices and lead to inevitable overheating problems, which reduces the ...operation efficiency and shortens the service life of electronic devices. Therefore, it is the primary task and a prerequisite to explore innovative material for meeting the requirement of high heat dissipation performance. In comparison with traditional thermal management material (e.g., ceramics and metals), the polymer-based thermal management material exhibit excellent mechanical, electrical insulation, chemical resistance and processing properties, and therefore is considered to be the most promising candidate to solve the heat dissipation problem. In this review, we summarized the recent advances of two typical polymer-based thermal management material including thermal-conduction thermal management material and thermal-storage thermal management material. Furtherly, the structural design, processing strategies and typical applications for two polymer-based thermal management materials were discussed. Finally, we proposed the challenges and prospects of the polymer-based thermal management material. This work presents new perspectives to develop advanced processing approaches and construction high-performance polymer-based thermal management material.
Predicting the aggregation tendency of nanoscale zero-valent iron (nZVI), oxidized nZVI, in particular, is crucial for the risk assessment of nZVI in aquatic environments. In this study, the ...comprehensive effects of the pH and ionic strength (IS) on the aggregation behaviors of two highly oxidized nZVIs (HO-nZVI) were examined. Compared with hematite nanoparticles, HO-nZVI presented a sudden acceleration in aggregation under critical conditions; moreover, the morphology of the HO-nZVI aggregates at pH and IS values higher or lower than the critical conditions was significantly different. Furthermore, owing to the differences in magnetization between the two prepared HO-nZVI samples, their critical coagulation conditions were significantly different. The significant changes in the aggregation behavior of the HO-nZVI samples were analyzed using colloidal theories, and the aggregation tendency of HO-nZVI under specific conditions could be simulated by calculating the theoretical critical conditions of aggregation via a method that takes into account the hydrochemical properties, magnetization, and surface charge of HO-nZVI. To examine the correctness of the method, we compared the experimentally determined colloidal stability of HO-nZVI in water samples collected from nearby rivers with the theoretically predicted value. The results indicated that the method was adequate for most situations, except for those in which the hydrochemical properties of the water samples were close to the critical coagulation conditions. Our study proposes a theoretical approach that is viable for simulating the colloidal stability of magnetic nanoparticles in aquatic environments; we anticipate that it will further facilitate the risk assessment of nanoparticles.
The low-velocity impact finite element model of the carbon fiber-reinforced composite grid sandwich structure was established by ABAQUS. Its panels and grid are both carbon fiber-reinforced composite ...laminates. The constitutive relation of composite laminates is written into the VUMAT user subroutine using the Fortran language. Simulation of intralaminar failure behavior of composite laminates using the three-dimensional Hashin failure criterion. The quadratic stress criterion and the B-K energy criterion were used to simulate the interlaminar failure behavior, and the delamination damage of the composite panel and the interface debonding damage were simulated. The finite element models of four different types of composite grid sandwich structures, including quadrilateral configuration, triangular configuration, mixed configuration, and diamond configuration, were established. The influence of the single grid width and the height of the grid on the impact resistance of each composite grid configuration was studied. Compared with other geometric configurations, triangular grid sandwich structure provides the best energy absorption characteristics, and T-6-10 has the highest fracture absorption energy (15816.46 mJ). The damage propagation law of carbon fiber-reinforced composite grid sandwich structure under impact load is analyzed.
Solid composite polymer electrolytes are the optimal candidate for all solid-state lithium batteries, because of their enhanced ionic conductivities, long-life cycle ability and compatibility to ...lithium anode. Herein, we reported a kind of solid composite polymer electrolyte comprised of poly(ethylene oxide), graphitic-like carbon nitride and lithium perchlorate, which was prepared by a facile solution blending method. Microstructure of the solid composite polymer electrolyte was regulated by thermal annealing and interaction among components and was characterized by XRD, DSC, FTIR-ATR, and ROM. The obtained solid composite polymer electrolyte achieved an ionic conductivity as high as 1.76 × 10
S cm
at 25°C. And the electrochemical stable window and the lithium ion transference number, t
, were also obviously enhanced. LiFePO
/Li solid-state batteries with the annealed PEO-LiClO
-g-C
N
solid polymer electrolyte presented a high initial discharge capacity of 161.2 mAh g
and superior cycle stability with a capacity retention ratio of 81% after 200 cycles at 1C at 80°C. The above results indicates that the thermal annealing treatment and g-C
N
as a novel structure modifier is crucial for obtaining the high-performance solid composite polymer electrolytes used in the all solid-state lithium battery.
Hierarchically porous carbonaceous sponges and their magnetic nanocomposites were fabricated by a combined approach of hydrothermal carbonization and freeze drying. The resulting carbonaceous sponges ...have hierarchically porous structure and a large number of oxygen-containing functional groups. The unique structure enables carbonaceous sponges candidate materials for rapid and efficient organic molecules removal from water.
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•The CS is sustainable, inexpensive and hierarchically porous.•The CS exhibits excellent adsorption capacities toward organic molecules.•Convenient solid–liquid separation after removal of organic molecules is achieved by introducing Fe3O4 NPs into CS network.
This work describes the preparation, characterization and removal capability of a novel biomass derived carbonaceous sponges (CS) and their nanocomposites. The CS has hierarchically porous structure which is composed of lamellar structures and secondary porous structures. The pore size is on a scale from 1nm to 200μm. Utilizing the CS as adsorbents, rapid removal of model organic molecules, including methylene blue (MB), methyl orange (MO) and crystal violet (CV), from their aqueous solutions can be completed within 1min with the assistance of pressure and the removal efficiency reaches up to 100%, 81% and 98%, respectively. The removal capabilities for CS towards MB, MO and CV are 0.0769g/g, 0.2218g/g and 1.0384g/g, respectively and 0.0635g/g, 0.0977g/g and 0.8634g/g, respectively for CS nanocomposites.
The water pollution caused by heavy metals is bringing serious damage to public health and environment, and significant efforts have been devoted to explore advanced materials and technologies for ...eliminating toxic metal ions more efficiently. Herein, a phytic acid (PA)-incorporated polyamide thin-film composite nanofiltration (NF) membrane is constructed though traditional interfacial polymerization and electrostatic assembly of PA with polyethyleneimine. Owing to the high negative charges of PA, the resultant NF membrane exhibits ultrahigh binding affinity for heavy metals cations, and is highly capable of removing heavy metal ions from aqueous solution. As a result, the PA-functionalized NF membrane can reduce Cd2+ and Pb2+ concentrations from 500 ppm to the ultralow level of ~0 and 5 ppb, and achieve record-breaking remove rates of 100.000% for Cd2+ and 99.999% for Pb2+. Additionally, the as-prepared NF membrane also delivers excellent long-term stability in continuous 120-h operation, and can be easily regenerated and reused without remarkable fading of the initial Cd2+ removal rate even after six filtration cycles. This work demonstrates the potential usage of the PA-functionalized NF membrane for serving as a promising platform to eliminate heavy metal ions in waste water.
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•A PA-incorporated NF membrane was fabricated by molecular LbL assembly.•The prepared membrane can remove heavy metal ions from wastewater effectively.•The PA-incorporated NF membrane delivers high operation stability and reusability.•Coordination of PA is mainly responsible for excellent removing of heavy metals.
A new modeling method is presented in this study for optimizing the thermal and electrical energy scheduling for a multiple energy carrier microgrid (MECM) so as to minimize operations costs while ...meeting restrictions. A combination of microgrid (MG) network's thermal and electrical loads are supposed with the model using a day-ahead forecast (24 h). A digital twin of the MG incorporating different thermal and electrical devices is considered which can represent the real behavior of the MG, effectively. Electricity production from wind turbines has been estimated by using a day-ahead forecasting as well. Wind power production are estimated by a Monte Carlo simulation because of the uncertainty of day-ahead forecasting. Moreover, non-essential loads are shifted through the real-time demand response programs. The hybrid teacher learning with particle swarm optimization algorithm minimizes the operating costs of the MG. Using simulations, it is demonstrated that the suggested modeling method reduces operating costs and computing burden more than traditional centralized optimum scheduling methods found in other writing. Additionally, the outcomes will be examined and confirmed by scenarios test after implementing the suggested modeling structure.
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