Preparation and Preliminary Dielectric Characterization of Structured C\u3csub\u3e60\u3c/sub\u3e-Thiol-Ene Polymer Nanocomposites Assembled Using the Thiol-Ene Click Reaction

Fullerene-containing materials have the ability to store and release electrical energy. Therefore, fullerenes may ultimately find use in high-voltage equipment devices or as super capacitors for high electric energy storage due to this ease of manipulating their excellent dielectric properties and their high volume resistivity. A series of structured fullerene (C60) polymer nanocomposites were assembled using the thiol-ene click reaction, between alkyl thiols and allyl functionalized C60 derivatives. The resulting high-density C60-urethane-thiol-ene (C60-Thiol-Ene) networks possessed excellent mechanical properties. These novel networks were characterized using standard techniques, including infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermal gravimetric analysis (TGA). The dielectric spectra for the prepared samples were determined over a broad frequency range at room temperature using a broadband dielectric spectrometer and a semiconductor characterization system. The changes in thermo-mechanical and electrical properties of these novel fullerene-thiol-ene composite films were measured as a function of the C60 content, and samples characterized by high dielectric permittivity and low dielectric loss were produced. In this process, variations in chemical composition of the networks were correlated to performance characteristics

Role of Graphene Oxide in Bacterial Cellulose−Gelatin Hydrogels for Wound Dressing Applications

Biopolymer-based hydrogels have several advantages, including robust mechanical, high biocompatibility, and excellent properties. These hydrogels can be ideal wound dressing materials and advantageous to repair and regenerate skin wounds. In this work, we have reported fabricated of composite hydrogels from gelatin and graphene oxide-functionalized-bacterial cellulose (synthesized by hydrothermal method) (GO-f-BC) and crosslinked with tetraethyl orthosilicate (TEOS). The hydrogels were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy, and water contact angle analyses to explore functional groups and their interactions, surface morphology, and wetting behavior, respectively. The swelling, biodegradation, and water retention were tested to respond to biofluid. Maximum swelling was exhibited by samle with maximum amount of GO (GBG-4) in all media (aqueous = 1902.83%, PBS = 1546.63%, and electrolyte = 1367.32%). The hemolysis of all hydrogel samples is less than 0.5%, and the blood coagulation time decreased as the hydrogel concentration increased. The composite hydrogels were found to be hemocompatible as they have less than 0.5% hemolysis for all hydrogel samples under in vitro standard conditions. These hydrogels performed unusual antimicrobial activities against Gram (positive and negative) bacterial strains. The cell viability and proliferation were increased with an increased GO amount, and maximum values were found for GBG-4 against fibroblast (3T3) cell lines. The mature and well-adhered cell morphology of 3T3 cells was found against all hydrogel samples. Hence, based on these results findings, these hydrogels would be potential wound dressing skin materials for wound healing applications.We are grateful to the European Union's Horizon to support the research project. This project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement no. 951747 and acknowledge the NPRP award [NPRP 12S -0310-190276] from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu

3D Printing‐Enabled Design and Manufacturing Strategies for Batteries: A Review

Lithium-ion batteries (LIBs) have significantly impacted the daily lives, finding broad applications in various industries such as consumer electronics, electric vehicles, medical devices, aerospace, and power tools. However, they still face issues (i.e., safety due to dendrite propagation, manufacturing cost, random porosities, and basic & planar geometries) that hinder their widespread applications as the demand for LIBs rapidly increases in all sectors due to their high energy and power density values compared to other batteries. Additive manufacturing (AM) is a promising technique for creating precise and programmable structures in energy storage devices. This review first summarizes light, filament, powder, and jetting-based 3D printing methods with the status on current trends and limitations for each AM technology. The paper also delves into 3D printing-enabled electrodes (both anodes and cathodes) and solid-state electrolytes for LIBs, emphasizing the current state-of-the-art materials, manufacturing methods, and properties/performance. Additionally, the current challenges in the AM for electrochemical energy storage (EES) applications, including limited materials, low processing precision, codesign/comanufacturing concepts for complete battery printing, machine learning (ML)/artificial intelligence (AI) for processing optimization and data analysis, environmental risks, and the potential of 4D printing in advanced battery applications, are also presented

Hierarchical Porous Carbon Nitride-Crumpled Nanosheet-Embedded Copper Single Atoms: An Efficient Catalyst for Carbon Monoxide Oxidation

Rational design of metal single-site embedded porous graphitic carbon nitride (P-g-C3N4) nanostructures exploiting maximum atom utilization is warranted to enhance the thermal CO oxidation (COOx) reaction. Herein, a facile, green, one-pot, and template-free approach is developed to fabricate the hierarchical porous P-g-C3N4-crumpled ultrathin nanosheets atomically doped with copper single atoms (Cu–P-g-C3N4). Mechanistically, the quick protonation of melamine and pyridine under acidic conditions induces deamination to form melem, which is polycondensed under heating. The interconnected pores, high surface area (240 m2g–1), and maximized exposed isolated Cu atomic active sites (1.8 wt %) coordinated with nitrogen atom P-g-C3N4 are the salient features of Cu– P-g-C3N4 that endowed complete conversion to CO2 at 184 °C. In contrast, P-g-C3N4 only converted 3.8% of CO even at 350 °C, implying the electronic effect of Cu single atoms. The abundant Cu-nitrogen moieties can drastically weaken the binding affinity of the CO-oxidation (COOx) intermediates and products, thus accelerating the reaction kinetics at a low temperature. This study may promote the fabrication of P-g-C3N4 doped with various single atoms for the oxidation of CO.This work was supported by the Qatar National Research Fund (QNRF, a member of the Qatar Foundation) through a National Priority Research Program Grant (NPRP) NPRP13S-0117-200095 and the Qatar University through an International Research Collaboration Co-Fund grant, QUHI-22/23–550. The authors also gratefully thank the Synchrotron-light for Experimental Science and Applications in the Middle East (SESAME), Allan 19252, Jordan for the XANES and EXAF measurements of Cu/P-g-C3N4 and its reference samples CuO, Cu2O, and Cu metal. Statements made herein are solely the responsibility of the authors.Scopu

Synthesis of mesoporous carbons with controlled morphology and pore diameters from SBA-15 prepared through the microwave-assisted process and their CO2 adsorption capacity

Mesoporous carbon materials (CMK-3-T-MW) with high surface area, different pore diameters and rod shaped morphology were synthesized via nanocasting technique using the SBA-15 templates prepared by ultra-fast microwave-assisted process under static condition. The combined microwave and static approach offers the highly ordered rod shaped morphology to the SBA-15 template, which was successfully replicated into the mesoporous carbon materials. By tuning the synthesis temperature of the template, it is possible to fabricate mesoporous carbons with different pore diameters and specific surface areas. These excellent materials can be utilized for various applications and here we demonstrate their use as adsorbents for CO2 molecules. A significant enhancement in the adsorption of CO2 was achieved for the mesoporous carbon with rod shaped morphology, large pore diameter and high surface area. The adsorption capacity of CMK-3-T-MW was also compared with commercially available activated carbon, multi walled carbon nanotubes (MWCNTs) and 2D and 3D highly basic mesoporous carbon nitrides (MCNs). The CO2 adsorption capacity of mesoporous carbon with controlled morphology is 24.4 mmol/g at 273 K and 30 bar pressure which is much higher than that of mesoporous carbon CMK-3-HT (20.3 mmol/g at the same conditions) prepared by the conventional hydrothermal method, activated carbons, MWCNTs, and MCNs. 2016The authors extend their sincere appreciation to the Deanship of Scientific Research at King Saud University for funding the Prolific Research group (PRG- 436-14).Scopu

Cultivating STEM Interest in High School Students through Computer-assisted COVID-19 Pandemic Awareness Course

Due to the COVID-19 pandemic, students were sidetracked by the shift in the educational process, primarily in the field of STEM (science, technology, engineering, mathematics) education. Teachers were also besieged to find sustainable teaching solutions. During this chaos, many were subjected to various rumors and misinformation about the pandemic. Hence, we aimed to design a 3 week long computer-assisted STEM-based health awareness course. The course was designed and delivered to twenty high school students in various public schools in Qatar. The course creators utilized various innovative computer-based educational tools to involve and motivate students. In addition, students attended several synchronous and asynchronous sessions with experts in different fields to gain a better awareness of the crisis. A feedback mechanism was also operated to assess the effectiveness of the course delivery. The results revealed a 100% retention rate. The student questionnaire survey result showed higher post-test scores on pandemic awareness. A SWOT analysis depicted the strength, weaknesses, opportunities, and threats of the executed course. Thereby, we successfully investigated the effectiveness of the STEM-integrated pedagogical approach through the learning outcomes of the student’s awareness of the course. in different fields to gain a better awareness of the crisis. A feedback mechanism was also operated to assess the effectiveness of the course delivery. The results revealed a 100% retention rate. The student questionnaire survey result showed higher post-test scores on pandemic awareness. A SWOT analysis depicted the strength, weaknesses, opportunities, and threats of the executed course. Thereby, we successfully investigated the effectiveness of the STEM-integrated pedagogical approach through the learning outcomes of the student’s awareness of the course

Preparation and Preliminary Dielectric Characterization of Structured C60-Thiol-Ene Polymer Nanocomposites Assembled Using the Thiol-Ene Click Reaction

Fullerene-containing materials have the ability to store and release electrical energy. Therefore, fullerenes may ultimately find use in high-voltage equipment devices or as super capacitors for high electric energy storage due to this ease of manipulating their excellent dielectric properties and their high volume resistivity. A series of structured fullerene (C60) polymer nanocomposites were assembled using the thiol-ene click reaction, between alkyl thiols and allyl functionalized C60 derivatives. The resulting high-density C60-urethane-thiol-ene (C60-Thiol-Ene) networks possessed excellent mechanical properties. These novel networks were characterized using standard techniques, including infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermal gravimetric analysis (TGA). The dielectric spectra for the prepared samples were determined over a broad frequency range at room temperature using a broadband dielectric spectrometer and a semiconductor characterization system. The changes in thermo-mechanical and electrical properties of these novel fullerene-thiol-ene composite films were measured as a function of the C60 content, and samples characterized by high dielectric permittivity and low dielectric loss were produced. In this process, variations in chemical composition of the networks were correlated to performance characteristics