The permittivity and conductivity relaxation processes of polyethylene oxide (PEO) composite along with potassium hexachloroplatinate (K2PtCl6) electrolytes additive forming PEO/K2PtCl6 complex ...composite have been investigated. The complex composite has been used as a model for dry‐polymer electrolytes (PEs) due to the fact that, the anion is large enough for mimicking the immobilized anion in real dry‐polymer electrolytes. Stand‐free composite films with 0%, 1%, 3%, and 5% concentrations of K2PtCl6 have been studied using broadband dielectric spectroscopy in the temperatures range from 150 K until 345 K. The microstructural dynamics revealed the α‐, β‐, and σ‐relaxations and their salient spectral characteristics at various concentrations of K2PtCl6 in PEO. The experimental ε” master curves were fitted to HN function for one and/or two relaxation peaks with and without the electrical conductivity contribution in order to investigate the relaxation time (τ), dielectric strengths (Δε), modulus formalism (M”) and the electrical conductivitie (σ). The translational and reorientational degrees of freedom of PEO/K2PtCl6 complex composites are responsible for the relaxation behavior which is predicted to be correlated to the relaxation behavior of the polymer electrolyte below and above the glass transition temperature (Tg). The relaxation time (τ) deduced from β‐relaxation follows Arrhenius‐like behavior while that deduced from α‐relaxation process follows Vogel–Tamman–Fulcher (VTF) behavior.
Hybrid material of poly-methyle-methacrylate (PMMA)-benzyl-dimethyl-ketal-azo dye methyl red (MR) thin film composites doped by various concentrations of ZnO NPs have been dip coated on glass ...substrates. The existence of azo dye (MR) in the composite was intentional to give the solution the desired pH level and to induce the
cis ↔ trans
cycles through illumination
↔
thermal relaxation. The optical and structural properties of the as-prepared thin films are investigated in relevance to ZnO NPs contents and the period of UV light illumination (short- and long-wavelength UV light). We found that the PMMA-BDK-MR doped by 1% ZnO NPs could be successfully used in optical data storage by implementing this composite in the WRITE/READ/ERASE cycle repeatedly. Specifically, it was found that the absorption band of the PMMA-BDK-MR doped by 1% ZnO NPs thin film lies between 350 and 600 nm upon illumination with 366 nm UV light for 10 s. Thermogravimetric analysis (TGA) was used to investigate the thermal stability of PMMA-BDK-MR/ZnO NPs. The TGA results are presented and interpreted. Furthermore, we investigated annealed poly-methyle-methacrylate-benzyl-dimethyl-ketal-methyl-red (PMMA-BDK-MR) doped by 1% ZnO NPs thin films. The
trans
–
cis
cycle has been repeated sequentially to confirm the hysteresis behavior for possible data READ/WRITE or ERASE memory applications.
Metal oxide nanoparticles (MONPs) (ZnO, TiO
2
, SiO
2
, and CuO NPs) were synthesized with an average size of around 50 nm. The synthesized MONPs were incorporated into Poly(methyl methacrylate) ...(PMMA) matrix deposited on glass substrate led to form PMMA/MONPs nanocomposite films. Fourier-Transform Infrared (FTIR) spectroscopy was employed to investigate the vibrational bands of pure PMMA and the incorporated PMMA/MONPs nanocomposite films. SEM micrographs showed the amorphous morphology of PMMA/MONPs nanocomposite films indicating the excellent dispersion of the MONPs on the surface. PMMA and PMMA/MONPs were exposed to the UV light for a period of 1, 3, and 5 min to investigate the impact on their refractive index (
n
). The UV-light exposure led to cause an increase in the refractive index of the PMMA in the visible region and decrease in the UV region and the opposite way around in the PMMA/MONPs nanocomposite films. Applying Maxwell–Garnett and Bruggeman's effective medium approximation models to investigate the distribution of the MONPs in the PMMA matrix shows a transfer from continuous aggregated nanoparticles to spherical or ellipsoidal distribution.
Polyethylene oxide (PEO) complexed with molecular iodine (
I
2
) forming PEO/
I
2
complex composites stand‐free films were investigated using dielectric relaxation, X-ray photoelectron spectroscopy ...(XPS), UV–Vis spectrophotometry, structural and morphological techniques. Scanning electron microscopy was used to monitor the variation in the surface morphology and the related roughness. 2D Energy-dispersive X-ray spectroscopy (EDX) measurements enabled to observe the distribution of iodine on the film surface. High resolution XPS measurements were used to define the iodine anion types and the metallic iodine existence, as well as the relevant concentrations based on the binding energies. The dielectric relaxation measurements were carried out over the frequency range from 0.1 to 10
7
Hz and temperature range from 155 to 330 K. Dielectric loss (ε′′) curves were fitted to the Havriliak–Negami (HN) model for one and/or two relaxation peaks (α and β), with and without the electrical conductivity contribution term, in order to deduce the relaxation time (τ) and the dielectric strengths (Δ
ε
), in addition to the electrical conductivities (
σ
). The temperature-dependent data of β- and σ- relaxations follow the law of Arrhenius thermal activation indicating the presence of typical glass-forming polymers. Δ
ε
of α-relaxation obeys the curvature pattern of Vogel-Tammann-Fulcher (VTF) thermal activation law. The electrical conductivity of the system increases 6000 folds by doping PEO with 5 wt% of iodine at the same temperature (293 K).
Radon is one of the sources that negatively affect dwellings air quality and is ranked as a main cause of lung cancer after cigarette smoking. The indoor radon concentrations usually affected by the ...conditions of the environment surrounding the dwellings. Seasonal variations can have a significant impact on the indoor radon concentrations. In this article, we studied the seasonal variations of indoor radon concentration in a desert climate, particularly in gulf countries that usually leave the windows and doors closed all over the time. Four hundred dosimeters containing CR-39 detectors were planted for three months to measure the variation in radon concentration between winter and summer seasons. Our measurements showed that a building with a basement revealed a significant variation between radon concentration in winter (44.3 ± 3.1Bqm−3) and in summer (26.1 ± 1.7Bqm−3). Buildings without basements showed that the indoor radon concentration in winter (16.1 ± 1.7Bqm−3) is very much close to that in summer (16.7 ± 1.8Bqm−3). Our results indicated that seasonal variations can significantly affect indoor radon concentration for buildings established with basements. However; in the study region, the average indoor radon concentration as well as the annual effective dose rate are found to be below the action level recommended by ICRP.
•In this article, we studied the seasonal variation of indoor radon concentration in a desert climate.•We showed that the building with a basement revealed a big difference between indoor radon concentration in winter and summer.•We showed the desert climate doesn't have an impact on the seasonal variation of radon levels for buildings without basement.•For building with a basement, the indoor radon concentration was 44.3Bq m−3 in winter and 26.1 Bqm−3 in summer.•For buildings without a basement, the indoor radon levels in winter and summer were closed and the annual radon level was 16.4Bqm−3.
•Cichorium Pumilum was encapsulated by silica nanoparticles to support the photodynamic therapy.•Photodynamic therapy was applied on Osteosarcoma cells by activate the encapsulated Cichorium ...Pumilum.•Optimal CP-SiNPs concentration and exposure time were measured and compared with naked CP.
Silica nanoparticles (SiNPs) have been promising vehicles for drug delivery. Cichorium Pumilum (CP), a natural photosensitizer (PS), has been reported to have many useful effects in cancer treatment. However, the poor water solubility and its low bioavailability have confined its use as a suitable photosensitizer for photodynamic therapy. Therefore, a subtle approach is required to overcome these drawbacks.
We have synthesized a silica nanoparticles loaded with Cichorium Pumilum. The nanoparticles structural morphologies have been charectrized by Transmission Electron Microscopy (TEM). The cytotoxicity for different concentrations of naked and encapsulated CP was evaluated. Moreover, the optimal concentration of naked and encapsulated CP with exposure time to a light (Maximum intensity at 350nm ∼0.27mW/cm2) required to eliminate the used cells (Osteosarcoma cells) were also measured.
The results showed that encapsulated CP in SiNPs exhibited relatively higher efficacy than the naked CP by + 157.14 % of exposure time efficacy and + 49.45% of concentration efficacy, and encapsulated CP was also confirmed to be effective in eradicating osteosarcoma cells.
The engineered silica nanoparticles loaded with CP enhanced the photodynamic therapy by increasing the CP bioavailability.
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The structural alterations that may arise in boiled and nonboiled bones are often overlooked despite their critical importance in the development of defleshing techniques across various scientific ...disciplines. To elucidate the microstructural characteristics of bones following the removal of soft tissue through conventional methods, attenuated total reflectance Fourier-transform infrared (ATR-FTIR) and X-ray diffraction (XRD) spectroscopies were employed. Our findings indicate that the boiled water method resulted in higher crystallinity, as evidenced by the FTIR data, whereas the XRD data revealed the opposite. This underscores the notion that a direct comparison between these two techniques is unfeasible as they measure distinct crystallinity parameters. In addition, the cold water maceration method caused a significant reduction in collagen crosslinking, as evidenced by the lower index observed.
Nanocomposite films of hosted protonated polyaniline (PANI/CSA) in polyethylene oxide (PEO) and incorporated with silver nanoparticles and silver nitrate (AgNPs-AgNO3) were deposited on activated ...quartz substrates by spin coating technique. Deduced refractive index from UV–Vis spectrophotometry experiments falls in the range of 1.5–2.0 for undoped films, while for the nanocomposite films ranges between 1.7 and 2.1 due to the effect of AgNPs-AgNO3 incorporation. Scanning electron microscopy observations reveal that the typical PANI crystalline structure vanishes gradually with increasing AgNPs-AgNO3 content and the nanocomposite optical band-gap decreases with increasing concentration of AgNPs-AgNO3. An amorphous state is dominant in all nanocomposite films. The electrical conductivity increases with increasing dopant content due to polaron formation and increased concentration of Ag ions at concentrations below 60 wt.% of AgNPs-AgNO3 with respect to PANI/CSA. From fitting the data to a Sigmodial/Gomperz function for concentrations in the range of 100–360 wt.% it was found that the nanoparticles percolation was the dominant electrical conduction mechanism.
Photodynamic therapy (PDT) is a cutting-edge cancer treatment that utilizes both light and photosensitizers (PSs) to attack cancer cells. Methylene blue (MB) has emerged as a highly promising ...photosensitizer (PS) in PDT therapy due to its exceptional ability to produce singlet oxygen, which is attributed to its high quantum yield. However, the main challenge in utilizing MB in photodynamic therapy is its effective delivery to the target tissue. This challenge can be addressed by utilizing silica nanoparticles (SiNPs) as a drug delivery agent. Silica nanoparticles encapsulate MB and prevent its leakage, offering a novel approach to improving PDT therapy by reducing the toxicity of MB and increasing its bioavailability at the target cell. In this study, an extensive analysis of the size and shape evolution of the synthesized silica nanoparticles loaded with MB was conducted using TEM. Various encapsulated and bare MB concentrations were tested for cytotoxicity against osteosarcoma cells. Moreover, the optimal concentration and exposure time under light (with an intensity of approximately 8.9 mW/cm2 in the visible range) were determined to achieve maximum cell elimination. The results revealed that encapsulated MB in SiNPs exhibited a higher efficacy compared to naked MB, with a 50% increase in concentration effectiveness and a 90% increase in exposure time efficacy. This confirms that encapsulated MB in SiNPs is more effective in killing osteosarcoma cells than bare MB, thereby enhancing photodynamic therapy through increased bioavailability of MB in target cells. The enhanced bioavailability of MB in target cells as a result of its encapsulation in SiNPs makes it a highly promising drug delivery candidate for significantly enhancing the efficacy of photodynamic therapy against osteosarcomas.
•Fluoroquinolone (PyridoPyrrole Quinoxaline, PPQ) and gold nanoparticles (AuNPs) to create a synergistic anticancer compound.•1H-NMR chemical shifts with increasing AuNPs content confirms the ...intermolecular tethering primarily via fluorine atoms in (PyridoPyrrole Quinoxaline, PPQ).•The most common coordination mode is bidentate, with one oxygen atom from the deprotonated carboxylic group.
The tethering mechanism between Pyrido Pyrrole Quinoxaline (PPQ) anticancer agent and gold nanoparticles (AuNPs) to form the PPQ/AuNPs complex as a promising anticancer reagent was investigated. Physicochemical properties, including viscosity, self-diffusion coefficients, and local molecular dynamics, of both PPQ and the PPQ/AuNPs complex were systematically examined using advanced techniques such as high-resolution 1H Nuclear Magnetic Resonance (1H-NMR), spin-lattice relaxation time (T1), and self-diffusion coefficient (D) analysis. Various PPQ/AuNPs systems were prepared and analyzed, encompassing concentrations of 0, 1.5, 4, 6.5, 8.3, 10.15, and 11.15 mg of PPQ. The results of T1demonstrated that the predominant intermolecular bonding occurs between AuNPs and fluorine atoms, particularly involving the neighboring proton to the fluorine and nitrogen atoms. Remarkably, the curve of self-diffusion coefficients displayed notable peaks at PPQ concentrations of approximately 4 mg and 8.3 mg. The interaction between PPQ molecules and AuNPs revealed a pronounced affinity for the fluorine sites and hydrogen atoms within the hydroxyl group of PPQ molecules when dissolved in aqueous solutions.
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