Publications by authors named "Mohamed Hammad Elsayed"

Conjugated microporous polymers (CMPs) feature extended excellent porosity properties and fully conjugated electronic systems, making them highly effective for several uses, including photocatalysis, dye adsorption, CO capture, supercapacitors, and so on. These polymers are known for their high specific surface area and adjustable porosity. To synthesize DHTP-CMPs (specifically TPE-DHTP CMP and Anthra-DHTP CMP) with abundant nitrogen (N) and oxygen (O) adsorption sites and spherical structures, we employed a straightforward Schiff-base [4 + 2] condensation reaction.

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Introduction: The treatment of acute ischemic stroke due to large artery vessel occlusion experienced a dramatic development within the last decade. This meta-analysis investigates the effectiveness of bridging therapy (BT) versus mechanical thrombectomy (MT) alone in treating acute ischemic stroke.

Methods: Two independent reviewers assessed two-arm clinical trials from Scopus, PubMed, Web of Science, and the Cochrane Library up to January 2024.

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Article Synopsis
  • The study addresses challenges in photocatalytic CO reduction reactions, specifically the need for intrinsic active sites and the fast recombination of charge carriers.
  • Researchers developed a novel phosphorus and boron binary-doped graphitic carbon nitride material, which shows significantly enhanced photocatalytic activity for selective CO generation due to its unique structural properties.
  • The combination of dual dopants and porous structure activates specific nitrogen atoms, stabilizes reaction intermediates, and enhances light absorption, leading to a CO yield that is approximately 12 times greater than traditional graphitic carbon nitride.
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Article Synopsis
  • Designing efficient organic polymer photocatalysts for hydrogen production using visible and near-infrared (NIR) light remains challenging.
  • Researchers developed a new series of polymer nanoparticles (Pdots) using ITIC and BTIC units with different π-linkers, which work effectively alone without needing to combine with other materials.
  • The difluorothiophene (ThF) π-linker improves charge transfer between donor and acceptor components in the polymers, resulting in significantly enhanced hydrogen production rates of 279 µmol/h with visible light and 20.5 µmol/h with NIR light, and an apparent quantum yield of 4.76% at 700 nm.
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In this study, we used effective and one-pot Heck coupling reactions under moderate reaction conditions to construct two new hybrid porous polymers (named OVS-P-TPA and OVS-P-F HPPs) with high yield, based on silsesquioxane cage nanoparticles through the reaction of octavinylsilsesquioxane (OVS) with different brominated pyrene (P-Br), triphenylamine (TPA-Br), and fluorene (F-Br) as co-monomer units. The successful syntheses of both OVS-HPPs were tested using various instruments, such as X-ray photoelectron (XPS), solid-state C NMR, and Fourier transform infrared spectroscopy (FTIR) analyses. All spectroscopic data confirmed the successful incorporation and linkage of P, TPA, and F units into the POSS cage in order to form porous OVS-HPP materials.

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Organic semiconducting polymers exhibited promising photocatalytic behavior for hydrogen (H) evolution, especially when prepared in the form of polymer dots (Pdots). However, the Pdot structures were formed using common nonconjugated amphiphilic polymers, which have a negative effect on charge transfer between photocatalysts and reactants and are unable to participate in the photocatalytic reaction. This study presents a new strategy for constructing binary Pdot photocatalysts by replacing the nonconjugated amphiphilic polymer typically employed in the preparation of polymer nanoparticles (Pdots) with a low-molecular-weight conjugated polyelectrolyte.

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