Catalytic effectiveness of azobisisobutyronitrile/[SiMes)Ru(PPH3)(Ind)Cl2 initiating system in the polymerization of methyl methacrylate and other vinylic monomers

The catalytic system of azo-bis-isobutyronitrile (AIBN) combined with (SiMes)Ru(PPH3)(Ind)Cl-2 [M-20] was investigated for the controlled radical polymerization of methyl methacrylate (MMA) in solution. Various factors that may influence the catalytic polymerization process, such as the aging time of the initiating system, AIBN/M-20 ratio, concentration of monomer, polymerization time, temperature, and the nature of solvent were examined. The results showed that the yield, molecular weight, and molecular distribution are practically unaffected by these parameters; however, the syndiotactic stereo-structure tendency that characterizes the produced poly(methyl methacrylate) (PMMA) varied with temperature. The optimum conditions for PMMA synthesis were determined to produce an essentially syndiotactic material with uniformly high molecular weights. It was also revealed that the kinetics of MMA polymerization is of first order with respect to the concentration of monomer. A comparison was also made for some vinylic polymers synthesized either with the AIBN alone or with the AIBN/M-20 initiating system under the same conditions

Assessment of groundwater quality for irrigation purpose using irrigation water quality index (IWQI)

Groundwater represents an important natural resource for sustaining life. This study was conducted to evaluate groundwater in the Doukkala region in Morocco, using the Irrigation Water Quality Index (IWQI) and uses Inverse Distance Weighting (IDW) in GIS was to show the spatial distribution of water quality parameters. It collected 97 of samples from groundwater and were estimated the sodium concentration (Na%), and sodium absorption rate (SAR), Also, Residual sodium carbonate (RSC), Kelly index (KI), magnesium content (MR), salinity potential (PS), and permeability index (PI). According to the distribution map of the Irrigation Water Quality Index (IWQI) for the study area, about 22.7% of samples fall into the severe restriction (SR) category, which can be used to irrigate plants with high salinity tolerance, 34.02 of samples fall under the high restriction (HR) category, 23.7% of samples fall into the moderate restrictions (MR) category, 17.52% of samples fall under the low restriction (LR) category, and 2.06% of samples fall under the no restriction (NR) category. The results of (IWQI) indicated that the groundwater quality in the study area is mostly suitable for irrigation purposes

Green Synthesis of ZnO/SnO₂ Hybrid Nanocomposite for Degradation of Cationic and Anionic Dyes under Sunlight Radiation

The aim of this work was to biosynthesize SnO2-decorated ZnO (ZT) nanocomposites (NCs) of different Sn content (10, 20, and 30 mol%), namely, ZT10, ZT20, and ZT30, using Olea europaea leaf aqueous extract-based phytocompounds as nanoparticle facilitating agents for application as effective photocatalyst in the removal of dyes from polluted water. The obtained ZT NCs were characterized using various techniques, including FTIR, XRD, TGA, TEM, EDS, UV–Vis, PL, and BET surface area. X-ray diffraction patterns show that rutile SnO2 and hexagonal ZnO coexist in the composites, and their crystallite size (D) is affected by the SnO2 ratio; the obtained D-values were 17.24, 19.07, 13.99, 6.45, and 12.30 nm for ZnO, SnO2, ZT10, ZT20, and ZT30, respectively. The direct band gaps of the ZT heterostructure increase with increasing SnO2 ratio (band gap = 3.10, 3.45, 3.14, 3.17, and 3.21 eV, respectively). TEM spectroscopy revealed nanorod and spherical grain morphologies of the composites, while EDS confirmed the elemental composition, the element ratio, and the composite’s purity. All catalysts exhibit type III isotherm with macropore structure. The photocatalytic efficiency against cationic (methylene blue (MB), rhodamine B (RB)), and anionic (methyl orange (MO)) dyes, under sunlight, was optimal with ZT20. The results revealed almost complete degradation at 55, 65, and 55 min, respectively. Hence, it is evident that incorporating SnO2 improves the photocatalyst’s performance, with an apparent optimal enhancement at 20 mol% Sn decorating ZT NCs. More interestingly, the catalyst stability and activity remained unaffected even after four activating cycles

Nitrogen-Rich Polyaniline-Based Activated Carbon for Water Treatment: Adsorption Kinetics of Anionic Dye Methyl Orange

In the present work, a nitrogen-rich activated carbon (PAnAC) was prepared using polyaniline (PAn) as a precursor to represent one possible conversion of nitrogen-containing polymeric waste into a valuable adsorbent. PAnAC was fabricated under the chemical activation of KOH and a PAn precursor (in a 4:1 ratio) at 650 °C and was characterized using FTIR, SEM, BET, TGA, and CHN elemental composition. The structural characteristics support its applicability as an adsorbent material. The adsorption performance was assessed in terms of adsorption kinetics for contact time (0–180 min), methyl orange (MO) concentration (C0 = 50, 100, and 200 ppm), and adsorbent dosages (20, 40, and 80 mg per 250 mL batch). The kinetic results revealed a better fit to a pseudo-second-order, specifically nonlinear equation compared to pseudo-first-order and Elovich equations, which suggests multilayer coverage and a chemical sorption process. The adsorption capacity (qe) was optimal (405.6 mg/g) at MO C0 with PAnAC dosages of 200 ppm and 40 mg and increased as MO C0 increased but decreased as the adsorbent dosage increased. The adsorption mechanism assumes that chemisorption and the rate-controlling step are governed by mass transfer and intraparticle diffusion processes

Chromium and copper dual-doped zinc sulfide nanoparticles: Synthesis, structural, morphological and optical properties

Copper (Cu) and chromium (Cr) dual-doped zinc sulfide (ZnS) nanoparticles (NPs) were fabricated via a chemical co-precipitation technique at 24±°C without any capping agent used. The obtained metal sulfides were characterize using transmission electron microscope (TEM), scanning electron microscope (SEM),energy-dispersive X-ray (EDX), X-ray diffraction (XRD), ultra-violet/visible (UV–Vis), and thermogravimetric analysis (TGA). The results revealed a Cr, Cu in ZnS lattice, grain size less than 5 nm, and unequal, aggregated spherical particles. Moreover, XRD analyses indicated that the dual ions penetrated the zinc sulfide without changing its cubic structure, the average size was nearly in the range 2.035–1.959 nm. Optical analysis displayed blue-shift after doping. The band gap values(Eg) were in the range of 4.79–4.89 eV. Thermal analysis shows that the synthesized sample is more stable in range 434–1029 °C. Based on these featured, it could be concluded that the synthesized Cu and Cr dual-doped ZnS NPs are beneficial for opto-electronic devices, and photocatalytic applications

Quinoline- and Isoindoline-Integrated Polycyclic Compounds as Antioxidant, and Antidiabetic Agents Targeting the Dual Inhibition of α-Glycosidase and α-Amylase Enzymes

Novel analogs of quinoline and isoindoline containing various heterocycles, such as tetrazole, triazole, pyrazole, and pyridine, were synthesized and characterized using FT-IR, NMR, and mass spectroscopy, and their antioxidant and antidiabetic activities were investigated. The previously synthesized compound 1 was utilized in conjugation with ketone-bearing tetrazole and isoindoline-1,3-dione to synthesize Schiff’s bases 2 and 3. Furthermore, hydrazide 1 was treated with aryledines to provide pyrazoles 4a–c. Compound 5 was obtained by treating 1 with potassium thiocyanate, which was then cyclized in a basic solution to afford triazole 6. On the other hand, pyridine derivatives 7a–d and 8a–d were synthesized using 2-(4-acetylphenyl)isoindoline-1,3-dione via a one-pot condensation reaction with aryl aldehydes and active methylene compounds. From the antioxidant and antidiabetic studies, compound 7d showed significant antioxidant activity with an EC50 = 0.65, 0.52, and 0.93 mM in the free radical scavenging assays (DPPH, ABTS, and superoxide anion radicals). It also displayed noteworthy inhibitory activity against both enzymes α-glycosidase (IC50: 0.07 mM) and α-amylase (0.21 mM) compared to acarbose (0.09 mM α-glycosidase and 0.25 mM for α-amylase), and higher than in the other compounds. During in silico assays, compound 7d exhibited favorable binding affinities towards both α-glycosidase (−10.9 kcal/mol) and α-amylase (−9.0 kcal/mol) compared to acarbose (−8.6 kcal/mol for α-glycosidase and −6.0 kcal/mol for α-amylase). The stability of 7d was demonstrated by molecular dynamics simulations and estimations of the binding free energy throughout the simulation session (100 ns)

Synthesis of trimetallic oxide (Fe2O3–MgO–CuO) nanocomposites and evaluation of their structural and optical properties

Abstract In this paper, tri-phase Fe2O3–MgO–CuO nanocomposites (NCs) and pure CuO, Fe2O3 and MgO nanoparticles (NPs) were prepared using sol–gel technique. The physical properties of the prepared products were examined using SEM, XRD, and UV–visible. The XRD data indicated the formation of pure CuO, Fe2O3 and MgO NPs, as well as nanocomposite formation with Fe2O3 (cubic), MgO (cubic), and CuO (monoclinic). The crystallite size of all the prepared samples was calculated via Scherrer's formula. The energy bandgap of CuO, Fe2O3 and MgO and Fe2O3–MgO–CuO NCs were computed from UV–visible spectroscopy as following 2.13, 2.29, 5.43 and 2.96 eV, respectively. The results showed that Fe2O3–MgO–CuO NCs is an alternative material for a wide range of applications as optoelectronics devices due to their outstanding properties

Preparation and Characterization of Poly(δ-Valerolactone)/TiO₂ Nanohybrid Material with Pores Interconnected for Potential Use in Tissue Engineering

Titanium dioxide/poly(δ-valerolactone) (TiO2/Pδ-VL) nanohybrid material containing interconnected pores with sizes in the range 80⁻150 μm were prepared by the solvent casting and polymer melting routes, and the dispersion of the TiO2 nanofiller in the Pδ-VL matrix and its adhesion were characterized by X-ray diffraction, differential scanning calorimetry, and scanning electron microscopy. A significant depression in the glass transition temperature (Tg) and melting temperature (Tm) values were revealed for the polymer nanocomposites prepared by the solvent casting technique. For the potential application of the prepared materials in the biomedical domain, complementary analyses were performed to examine the dynamic mechanical properties, and cell adhesion (using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay), and the results obtained for the samples prepared by the two methods were compared. Interconnected pores were successively produced in the new material by employing naphthalene microparticles as a porogen for the first time, and the results obtained were very promising

Thermal Properties and Non-Isothermal Crystallization Kinetics of Poly (δ-Valerolactone) and Poly (δ-Valerolactone)/Titanium Dioxide Nanocomposites

New poly (δ-valerolactone)/titanium dioxide (PDVL/TiO2) nanocomposites with different TiO2 nanoparticle loadings were prepared by the solvent-casting method and characterized by Fourier transform infra-red, differential scanning calorimetry, X-ray diffraction and scanning electron microscopy, and thermogravimetry analyses. The results obtained reveal good dispersion of TiO2 nanoparticles in the polymer matrix and non-formation of new crystalline structures indicating the stability of the crystallinity of TiO2 in the composite. A significant increase in the degree of crystallinity was observed with increasing TiO2 content. The non-isothermal crystallization kinetics of the PDVL/TiO2 system indicate that the crystallization process involves the simultaneous occurrence of two- and three-dimensional spherulitic growths. The thermal degradation analysis of this nanocomposite reveals a significant improvement in the thermal stability with increasing TiO2 loading

Poly (2-hydroxyethylmethacrylate –<i>co</i>–methylmethacrylate)/Lignocaine Contact Lens Preparation, Characterization, and in vitro Release Dynamic

2-hydroxyethyl methacrylate, methylmethacrylate, ethylene glycol dimethyl methacrylate, and lignocaine (drug) were mixed together and the monomers were copolymerized at 60 &#176;C through a free radical polymerization in the presence of &#945;,&#945;&#8242;-Azoisobutyronitrile in tetrahydrofuran. A series of copolymer/drug composites with different monoacrylate monomer compositions were prepared by solvent evaporation and characterized by different methods such as nuclear magnetic resonance, differential scanning calorimetry, Fourier transform infrared, X-ray diffraction, and mechanical and optical testing. The water content in the copolymers and the cell viability test on the samples were also examined in this investigation. The results of the analyses of the properties of this drug-carrier system are promising, indicating that this material may be a potential candidate for contact lens applications. The release dynamic of this medication from the prepared drug-carrier systems was investigated in neutral pH media. The results obtained revealed that the diffusion of lignocaine through the copolymer matrix obeys the Fick model and the dynamic release can be easily controlled by the methyl methacrylate content in the copolymer