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Nanoarchitectonics of Silver/Poly (Methyl Methacrylate) Films: Structure, Optical Characteristics, Antibacterial Activity, and Wettability

Research Abstract

Functionalizing organic–inorganic materials for use in packaging technologies, such as polymers wrapped in thin metal, has proven to be one of the more successful strategies. In this study, the direct current (DC) sputtering technique under a vacuum of 3× 10−5 Torr was used to deposit silver (Ag) flms of thicknesses of 100 and 300 nm on poly (methyl methacrylate) (PMMA) polymer. The structural, optical, antibacterial activity, and wettability properties of Ag/PMMA were carried out using X-ray difraction (XRD), Fourier-transform infrared spectroscopy (FTIR), feld emission scanning electron microscope (FE-SEM), atomic force microscopy (AFM), UV spectrophotometer, and contact angle. The cubic crystal structure phase of Ag was confrmed by the XRD. The Ag coating layer has consistent nanomorphology, according to AFM, and the PMMA substrate surface was well coated with Ag nanoparticles. As the Ag flm thickness rose, the optical band gap values of Ag/PMMA slightly increased. In addition, it has been found that these optical characteristics such as extension coefcient, optical density, and optical surface resistance essentially depend on the thickness of the Ag layers. Both samples of pure PMMA and Ag/PMMA polymers show no activity against E. coli. In the meantime, S. aureus activity is detected in the Ag/PMMA samples, and the antibacterial activity is slightly infuenced by the Ag thickness. The contact angle rose as the Ag flm thickness grew over the PMMA, resulting in a decrease in the wettability of the liquid which is required for food packaging technology.

Research Authors
Asmaa N. Mohammed Ali, Nadia A. Ali, Seenaa I. Hussein, A. Hakamy, Bahaaudin Rafah, Ayman S. Alof, Alaa M. Abd‑Elnaiem
Research Date
Research Department
Research Journal
Journal of Inorganic and Organometallic Polymers and Materials
Research Member
Research Pages
694-706
Research Publisher
Springer
Research Vol
33(3)
Research Website
https://doi.org/10.1007/s10904-022-02525-4
Research Year
2023

Optical basicity, polarizability and spectroscopic investigations of CuO doped TeO2–B2O3 glass system

Research Abstract

A study of the spectroscopic properties, as well as polarizability and optical basicity of TeO2–B2O3 glasses doped with CuO using density, XRD, and UV–Vis analysis, is presented in this paper. The TeO2–B2O3 – CuO glasses are fabricated using the melt-quenching method. The glasses proved to be amorphous in nature from the XRD which was confirmed by the UV–Vis spectra. The peak observed in the pattern of the 0% CuO sample represents the presence of a crystalline phase of α-TeO2 and/or γ-TeO2. Important optical and physical parameters are discussed such as the refractive index (2.318–2.378), metallization criterion (0.4069–0.3919), optical basicity (0.7995–0.8057), electronic polarizability (0.2358–0.2410), linear dielectric susceptibility (0.3480–0.3704 esu), and third order non-linear dielectric susceptibility (1.466 × 1012–1.882 × 1012 esu). Based on the refractive index, metallization criterion, electronic polarizability, optical basicity, and dielectric susceptibility values, the glasses could present great potential applications in fiber optics and laser applications.

Research Authors
S.A. Umar, Nazrin S.N, I.G. Geidam, R. El-Mallawany, Alaa M. Abd-Elnaiem, Ahmad Hakamy, F.U. Muhammad
Research Date
Research Department
Research Journal
Materials Chemistry and Physics
Research Member
Research Pages
127309
Research Publisher
Elsevier
Research Vol
297
Research Website
https://doi.org/10.1016/j.matchemphys.2023.127309
Research Year
2023

Optical properties of functional Al2O3 nano-filler in eco-friendly PVA polymer for flexible optoelectronic devices

Research Abstract

This article has attempted to establish eco-friendly organic PVA/Al2O3 nanocomposite membranes and estimate the effectiveness of different additives (1, 2, and 3 wt%) of alumina (Al2O3) nano-filler in PVA matrix on their structural and optical properties for establishing their suitability in photonic applications. Al2O3 nano-filler dispersed in the PVA matrix has been synthesized via the solvent casting technique. The structure of synthesized PVA/Al2O3 nanocomposite membranes has been characterized by Fourier transform-infrared (FTIR), Raman spectroscopy, and X-ray diffraction (XRD). Upon introducing the Al2O3 nano-filler in the PVA matrix, the self-hydrogen bonding between the PVA chains was weakened while hydrogen bonding with Al2O3 was generated. In addition, optical, dielectric, and dispersion analysis suggested that even though the Al2O3 nano-filler in PVA/Al2O3 nanocomposite membranes aided in regularly folding the PVA polymer chains. Moreover, formed new structural defects, disorders, and impurities can be used for tuning the PVA/Al2O3 nanocomposites for optoelectronic applications and for making efficient absorbents for environmental treatments.

Research Authors
M. Rashad, Alaa M. Abd-Elnaiem, T.A. Hanafy, N.M. Shaalan, A.M.A. Shamekh
Research Date
Research Department
Research Journal
Optical Materials
Research Pages
113990
Research Publisher
Elsevier
Research Vol
141
Research Website
https://doi.org/10.1016/j.optmat.2023.113990
Research Year
2023

Numerous defects induced by exfoliation of boron-doped g-C3N4 towards active sites modulation for highly efficient solar-to-fuel conversion

Research Abstract

Graphitic carbon nitride (CN) has emerged as a highly promising material in the photocatalysis field. However, its bulk structure suffers from a lack of active sites, limiting its practical application. Herein, a boron-doped CN (BCN) was prepared by a green gas-blowing-assisted thermal polymerization and then subjected to different exfoliation processes in order to delaminate the layered structure and tune the surface-active sites. A thorough comparative study shows that thermal exfoliation creates unsaturated nitrogen sites and induces the formation of interconnected layers that act as an electron diffusion channel for better charge transport. Furthermore, the thermally exfoliated BCN is rich in structural disorders that serve as dissociation defects for photoinduced charge carriers with a low exciton binding energy of 27 meV. Experimental results supported by theoretical calculations show that the nitrogen adjacent to 

Research Authors
Mahmoud Kamal Hussien, Amr Sabbah, Mohammad Qorbani, Mohamed Hammad Elsayed, Shaham Quadir, Putikam Raghunath, Der-Lii M Tzou, Shu-Chih Haw, Ho-Hsiu Chou, Nguyen Quoc Thang, M-C Lin, Li-Chyong Chen, Kuei-Hsien Chen
Research Date
Research Department
Research Journal
Materials Today Sustainability
Research Member
Research Year
2023

Metal-free four-in-one modification of g-C3N4 for superior photocatalytic CO2 reduction and H2 evolution

Research Abstract

Utilization of g-C3N4 as a single photocatalyst material without combination with other semiconductor remains challenging. Herein, we report a facile green method for synthesizing a metal free modified g-C3N4 photocatalyst. The modification process combines four different strategies in a one-pot thermal reaction: non-metal doping, porosity generation, functionalization with amino groups, and thermal oxidation etching. The as-prepared amino-functionalized ultrathin nanoporous boron-doped g-C3N4 exhibited a high specific surface area of 143.2 m2 g−1 which resulted in abundant adsorption sites for CO2 and water molecules. The surface amino groups act as Lewis basic sites to adsorb acidic CO2 molecules, which can also serve as active sites to facilitate hydrogen generation. Besides, the simultaneous use of ammonium chloride as a dynamic gas bubble template along with thermal oxidation etching …

Research Authors
Mahmoud Kamal Hussien, Amr Sabbah, Mohammad Qorbani, Mohamed Hammad Elsayed, Putikam Raghunath, Tsai-Yu Lin, Shaham Quadir, Hong-Yi Wang, Heng-Liang Wu, Der-Lii M Tzou, Ming-Chang Lin, Po-Wen Chung, Ho-Hsiu Chou, Li-Chyong Chen, Kuei-Hsien Chen
Research Date
Research Department
Research Journal
Chemical Engineering Journal
Research Member
Research Year
2022

Design of sculptured SnS/g-C3N4 photocatalytic nanostructure for highly efficient and selective CO2 conversion to methane

Research Abstract

Here, we demonstrate the SnS/g-C3N4 crystallized and nanostructured photocatalysts for efficient and selective CO2 conversion to CH4 by engineered thermal evaporation and the decoration of g-C3N4 through a simple dipping method, overcoming the limitation of bulk SnS-based photocatalysts. The SnS/g-C3N4 nanostructured photocatalysts exhibit a superior methane production rate of 387.5 μmol∙m−2∙h−1 (= c.a. 122.33 μmol∙g−1∙h−1) with an apparent quantum yield of c.a. 9.7% at 520 nm with engineered lengths. Moreover, 100% selective production toward CH4 is also measured from the SnS/g-C3N4 photocatalysts, with > 10 h stable operation. These performances are, to the best of our knowledge, the highest production rate among reported photocatalytic films and metal sulfide/g-C3N4 composite-based photocatalysts. These highly improved performances are attributed to synergistic effects by the …

Research Authors
Hossam AE Omr, Raghunath Putikam, Mahmoud Kamal Hussien, Amr Sabbah, Tsai-Yu Lin, Kuei-Hsien Chen, Heng-Liang Wu, Shien-Ping Feng, Ming-Chang Lin, Hyeonseok Lee
Research Date
Research Department
Research Journal
Applied Catalysis B: Environmental
Research Year
2022

Novel Thiazolidine-2, 4-dione-trimethoxybenzene-thiazole Hybrids as Human Topoisomerases Inhibitors

Research Abstract

Cancer is a complex and heterogeneous disease and is still one of the leading causes of morbidity and mortality worldwide, mostly as the population ages. Despite the encouraging advances made over the years in chemotherapy, the development of new compounds for cancer treatments is an urgent priority. In recent years, the design and chemical synthesis of several innovative hybrid molecules, which bring different pharmacophores on the same scaffold, have attracted the interest of many researchers. Following this strategy, we designed and synthetized a series of new hybrid compounds that contain three pharmacophores, namely trimethoxybenzene, thiazolidinedione and thiazole, and tested their anticancer properties on two breast cancer (MCF-7 and MDA-MB-231) cell lines and one melanoma (A2058) cell line. The most active compounds were particularly effective against the MCF-7 cells and did not affect the viability of the normal MCF-10A cells. Docking simulations indicated the human Topoisomerases I and II (hTopos I and II) as possible targets of these compounds, the inhibitory activity of which was demonstrated by the mean of direct enzymatic assays. Particularly, compound 7e was proved to inhibit both the hTopo I and II, whereas compounds 7c,d blocked only the hTopo II. Finally, compound 7e was responsible for MCF-7 cell death by apoptosis. The reported results are promising for the further design and synthesis of other analogues potentially active as anticancer tools.

Research Date
Research Department
Research Year
2023

N‐Heterocyclic Carbene (NHC) Silver Complexes as Versatile Chemotherapeutic Agents Targeting Human Topoisomerases and Actin

Research Abstract

In recent years, the number of people suffering from cancer has risen rapidly and the World Health Organization and U.S. and European governments have identified this pathology as a priority issue. It is known that most bioactive anticancer molecules do not target a single protein but exert pleiotropic effects, simultaneously affecting multiple pathways. In our study, we designed and synthesized a new series of silver N‐heterocyclic carbene (NHC) complexes [(NHC)2Ag]+[AgX2] (X=iodide or acetate). The new complexes were active against two human breast cancer cell lines, MCF‐7 and MDA‐MB‐231. These compounds showed multiple target actions as anticancer, by inhibiting in vitro the activity of the human topoisomerases I and II and interfering with the cytoskeleton dynamic, as also confirmed by in silico studies. Moreover, the antimicrobial activity of these silver complexes was studied against Gram …

Research Authors
hussein el kashef
Research Date
Research Department
Research Year
2022

Metal complexes with Schiff bases: Data collection and recent studies on biological activities

Research Abstract

Metal complexes play a crucial role in pharmaceutical sciences owing to their wide and significant activities. Schiff bases (SBs) are multifaceted pharmacophores capable of forming chelating complexes with various metals in different oxidation states. Complexes with SBs are extensively studied for their numerous advantages, including low cost and simple synthetic strategies. They have been reported to possess a variety of biological activities, including antimicrobial, anticancer, antioxidant, antimalarial, analgesic, antiviral, antipyretic, and antidiabetic ones. This review summarizes the most recent studies on the antimicrobial and antiproliferative activities of SBs-metal complexes. Moreover, recent studies regarding mononuclear and binuclear complexes with SBs are described, including antioxidant, antidiabetic, antimalarial, antileishmanial, anti-Alzheimer, and catecholase activities.

Research Authors
hussein el kashef
Research Date
Research Department
Research Year
2022

An Update of Carbazole Treatment Strategies for COVID-19 Infection

Research Abstract

The Coronavirus disease 2019 (COVID-19) outbreak was declared by the World Health Organization (WHO) in March 2020 to be a pandemic and many drugs used at the beginning proved useless in fighting the infection. Lately, there has been approval of some new generation drugs for the clinical treatment of severe or critical COVID-19 infections. Nevertheless, more drugs are required to reduce the pandemic’s impact. Several treatment approaches for COVID-19 were employed since the beginning of the pandemic, such as immunomodulatory, antiviral, anti-inflammatory, antimicrobial agents, and again corticosteroids, angiotensin II receptor blockers, and bradykinin B2 receptor antagonists, but many of them were proven ineffective in targeting the virus. So, the identification of drugs to be used effectively for treatment of COVID-19 is strongly needed. It is aimed in this review to collect the information so far known about the COVID-19 studies and treatments. Moreover, the observations reported in this review about carbazoles as a treatment can signify a potentially useful clinical application; various drugs that can be introduced into the therapeutic equipment to fight COVID-19 or their molecules can be used as the basis for designing new antivirals.

Research Authors
hussein el kashef
Research Date
Research Department
Research Year
2023
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