Durable graphene-based alkyd nanocomposites for surface coating applications.

Recently, the scientific community's main goal is the long-term sustainability. Vegetable oils are easily accessible, non-depletable, and cost-effective materials. Vegetable oils are used to prepare polymeric alkyd surfaces. Novel and exciting designs of alkyd/graphene nanocomposites have provided eco-friendly thermal stability and protective coating surfaces. This review has briefly described important graphene-based alkyd nanocomposites along with their applications as protective coatings. These alkyd composites have high hydrophobicity, corrosion resistance, and durability. Graphene-based alkyd nanocoatings have many industrial and research interests because of their exceptional thermal and chemical properties. This work introduces an advanced horizon for developing protective nanocomposite coatings. The anti-corrosion properties and coatings' longevity may be improved by combining the synergistic effects of hybrid nanofillers introduced in this work.

Synthesis and Characterization of New Polymeric Ionic Liquids as Corrosion Inhibitors for Carbon Steel in a Corrosive Medium: Experimental, Spectral, and Theoretical Studies.

A novel series of polymeric ionic liquids (ILs) based on benzimidazolium chloride derivatives, namely, 1,3-diheptyl-2-(2-phenyl-propyl)-3H-benzimidazol-1-ium chloride (IL1), 1,3-dioctyl-2-(2-phenyl-propyl)-3H-benzimidazol-1-ium chloride (IL2), and 1,3-Bis-decyl-2-(2-phenyl-propyl)-3H-benzoimidazol-1-ium chloride (IL3), were synthesized and chemically elucidated by Fourier transform infrared spectroscopy, 1H NMR, 13C NMR, and elemental analysis. Their influence as corrosion suppressors were investigated for C-steel corrosion in 1 M HCl, by weight loss (WL), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) methods, revealing that their exclusive addition decreased corrosion with mounting concentrations. These assays demonstrated that novel ILs are efficient inhibitors at relatively low dosages. The efficacy of the synthesized ILs reached 79.7, 92.2 and 96.9%, respectively, at 250 ppm and 303 K. Parameters for activation and adsorption were calculated and are discussed. The Tafel polarization results demonstrated that the investigated ILs support the suppression of both cathodic and anodic reactions, acting as mixed type inhibitors. Langmuir's adsorption isotherm was confirmed as the best fitted isotherm, describing the physical-chemical adsorption capability of used ILs on the C-steel surface with the change in the free energy of adsorption, ΔG°ads = 32.6-37.2 kJ mol-1. The efficacy of the synthesized ILs was improved by increasing the doses, and the temperature reached 86.6, 96.1, and 98.4%, respectively, at 318 K. Surface morphology was proved by Fourier Transform Infrared spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy (AFM), and then, changes in test solutions were checked by Ultraviolet-visible spectroscopy. Theoretical modeling (density functional theory and Monte Carlo) revealed the correlation between the IL's molecular chemical structure and its anticorrosive property.

Effect of Polymer Waste Mix Filler on Polymer Concrete Composites.

The hazards of polymer waste and emitted gas on the environment pose a global challenge. As a trial to control this, the current work aims to reuse the polymer waste mix (PM) as fillers in calcium silicate to prepare new composites of environmentally friendly polymer concrete. PM was first subjected to treatment to obtain treated PM (TPM) and then was filled in new dicalcium silicate cement with different concentrations. The microstructural characterizations declare the successful preparation of the dicalcium silicate base material. After the curing reaction, the precipitated carbonate main product is responsible for the gained properties. The CO2 uptake% in the proposed composites reached 16.6%, referring to the successful storage of CO2 gas during curing. The treatment reaction led to an increase in the flexural and compression strengths due to the strengthening of the polymer waste mix-cement interface; the strengths were increased gradually with more contents of TPM fillers. 7% TPM-cement concentration achieved the highest flexural strength and compression strength of10.2 and 12.7%, respectively, compared with blank cement. The used polymer improved slightly the pull-off force of the prepared cement, and 7 and 5% TPM-cement composites have the maximum values. All the proposed composites passed the impact testing without failure, where the combination between the polymer waste and silicate cement resulted in a stable composite surface. Compared with the blank, the different concentrations of TPM-cement composites show more stability against water absorption. In addition, the proposed composites and blank cement have a very low carbon dioxide emission. The ability to recycle the polymer waste, form new type of low-energy silicate, improve the mechanical and surface properties, uptake CO2 gas, and reduce gas emission makes the proposed polymer waste mix-cement composites as environmentally friendly construction products.

Environmentally Friendly Polymer Concrete: Polymer Treatment, Processing, and Investigating Carbon Footprint with Climate Change.

Climate change is being currently faced globally; controlling the plastic waste and gas emission is aimed to reduce their hazardous effects. In this work, polyethylene terephthalate (PET) and polyvinyl chloride (PVC) polymer wastes are used as fillers to calcium silicate. Chemical treatment was performed to get the best efficiency of the binder material with the treated PET (TPET) and treated PVC (TPVC). The used silicate, new nonhydraulic dicalcium silicate, was synthesized by sintering. A new environmentally friendly polymer concrete, based on different concentrations of PET-/TPET-/PVC-/TPVC-dicalcium silicate composites, was prepared and cured by carbonation. FTIR analysis confirms that the treatment gave functional groups on the polymer surface; also, the hydrophilicity was increased after treatment. SEM photos show that the treated polymers have a rougher surface, which led to improved attachment with cement. The structures of the prepared and cured cement materials are proved by XRD, FTIR analysis, and SEM, through the change of calcium silicate to carbonate. Carbon footprint is used to analyze the environmental implications of the prepared composites. After the treatment reaction, the TPET-cement and TPVC-cement composites showed improved compression and flexural properties and more stability against water absorption. The novelty arises from recycling this plastic waste in the proposed low-energy dicalcium silicate cement, for the first time, to give improved environmentally friendly composites after converting CO2 gas to carbonates, with the reduced carbon footprint.

Methylene blue removal from aqueous solutions using a biochar/gellan gum hydrogel composite: Effect of agitation mode on sorption kinetics.

Hydrogel membranes are prepared by casting a mixture of gellan gum (associated with PVA) and biochar produced from a local Egyptian plant. The mesoporous material is characterized by a specific surface area close to 134 m2 g-1, a residue of 28 % (at 800 °C), and a pHPZC close to 6.43. After grinding, the material is tested for Methylene Blue sorption at pH 10.5: sorption capacity reaches 1.70 mmol MB g-1 (synergistic effect of the precursors). The sorption isotherms are fitted by both Langmuir and Sips eqs. MB sorption increases with temperature: the sorption is endothermic (∆H°: 12.9 kJ mol-1), with positive entropy (∆S°: 125 J mol-1 K-1). Uptake kinetics are controlled by agitation speed (optimum ≈200 rpm) and resistance to intraparticle diffusion. The profiles are strongly affected by the mode of agitation: the equilibrium time (≈180 min) is reduced to 20-30 min under sonication (especially at frequency: 80 kHz). The mode of agitation controls the best fitting equation: pseudo-first order rate agitation for mechanical agitation contrary to pseudo-second order rate under sonication. The sorption of MB is poorly affected by ionic strength (loss <6 % in 45 g L-1 NaCl solution). Desorption (faster than sorption) is completely achieved using 0.7 M HCl solution. At the sixth recycling, the loss in sorption is close to 5 % (≈ decrease in desorption efficiency). The process is successfully applied for the treatment of MB-spiked industrial solution: the color index decreases by >97 % with a sorbent dose close to 1 g L-1; a higher dose is required for maximum reduction of the COD (60 % at 3 g L-1).

Green Hydrogel-Biochar Composite for Enhanced Adsorption of Uranium.

Uranium is the backbone of the nuclear fuel used for energy production but is still a hazardous environmental contaminant; thus, its removal and recovery are important for energy security and environmental protection. So far, the development of biocompatible, efficient, economical, and reusable adsorbents for uranium is still a challenge. In this work, a new orange peel biochar-based hydrogel composite was prepared by graft polymerization using guar gum and acrylamide. The composite's structural, morphological, and thermal characteristics were investigated via Fourier transform infrared (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) methods. The composite's water absorption properties were investigated in different media. The performance of the prepared composite in adsorbing uranium (VI) ions from aqueous media was systematically investigated under varying conditions including solution's acidity and temperature, composite dose, contact time, and starting amount of uranium. The adsorption efficiency increased with solution pH from 2 to 5.5 and composite dose from 15 to 50 mg. The adsorption kinetics, isotherms, and thermodynamics parameters were analyzed to get insights into the process's feasibility and viability. The equilibrium data were better described through a pseudo-second-order mechanism and a Langmuir isotherm model, indicating a homogeneous composite surface with the maximum uranium (VI) adsorption capacity of 263.2 mg/g. The calculated thermodynamic parameters suggested that a spontaneous and endothermic process prevailed. Interference studies showed high selectivity toward uranium (VI) against other competing cations. Desorption and recyclability studies indicated the good recycling performance of the prepared composite. The adsorption mechanism was discussed in view of the kinetics and thermodynamics data. Based on the results, the prepared hydrogel composite can be applied as a promising, cost-effective, eco-friendly, and efficient material for uranium (VI) decontamination.

Multifunctional Aspects of the Synthesized Pyrazoline Derivatives for AP1 5L X60 Steel Protection Against MIC and Acidization: Electrochemical, In Silico, and SRB Insights.

The inhibitory impact of low-cost synthesized pyrazoline derivatives named Pz series (Pz1 and Pz2) on the corrosion of API 5L X60 carbon steel in 5 M HCl was inspected to serve as corrosion inhibitors against such a solution for its usage in the oilfield well acidization process. Also, the same compounds were unitized as biocides for sulfate-reducing bacteria (SRBs) to inhibit the microbial-induced corrosion effect. This study was conducted via several electrochemical techniques, namely, electrochemical potentiodynamic polarization (EP) and electrochemical impedance spectroscopy (EIS), in addition to computational density functional theory (DFT). The inhibition efficiency (IE) of Pz series on the corrosion of 5L X60 carbon steel in 5 M HCl was found to increase whenever the Pz series molecule concentration was increased. EP measurements revealed that Pz1 and Pz2 have both cathodic and anodic features (mixed inhibitor) and their corrosion IEs were around 90%. The physicochemical properties of the Pz1 and Pz2 compounds were studied using Langmuir adsorption isotherms, where the equilibrium adsorption data were found to follow it accurately. EIS outputs were found to comply with the values obtained from EP. Scanning electron microscopy was used to examine the topographic anisotropy between the inhibited and uninhibited 5L X60 carbon steel samples to double-check the electrochemical findings. DFT calculations and Monte Carlo simulations were utilized to predict the behavior of inhibitors and to rationalize the experimental results. The serial dilution bioassay technique was used to assess the Pz series as potential biocides to counter the effect of SRBs in compliance with the TM0194-2014-SG standard test method, and the results showed the potency of Pz series in inhibiting such bacterial growth.

Polymeric Ionic Liquids Based on Benzimidazole Derivatives as Corrosion Inhibitors for X-65 Carbon Steel Deterioration in Acidic Aqueous Medium: Hydrogen Evolution and Adsorption Studies.

Ionic liquids have significantly enhanced ecofriendly benefits compared to the traditional inhibitors. In the present work, new four polymeric ionic liquids based on benzoimidazole derivatives were synthesized through the reaction of 2-styryl-1H-benzo[d]imidazole with alkyl halide to form PIL1. Then, Cl- anions were exchanged with different anions through the neutralization reaction to form other investigated polymers. Their structures were chemically elucidated using Fourier transform infrared spectroscopy, 1H NMR, and 13C NMR. Their influence on carbon steel (CS) as corrosion inhibitors has been checked with dielectric spectroscopy in addition to potentiodynamic polarization curves. It was found that the percentage of inhibition efficiency increases as inhibitor's concentrations increase, suggesting a decrease in the rate of CS corrosion. Additionally, the hydrogen evolution rate controlled by the four polymers was monitored. Addition of the prepared polymers lessened the rate of generation of hydrogen as the inhibitor's concentrations augmented. Scanning electric electron microscopy in addition to energy-dispersive X-ray diffraction has proved the morphology of the CS surface as well as the formed protective film.

A novel 99m Tc-diester complex as tumor targeting agent: Synthesis, radiolabeling, and biological distribution study.

The target of this study is the synthesis of a new diester derivative and radiolabeling with one of the most effective diagnostic radioisotopes to be investigated as a novel targeting radiotracer for tumor imaging. 10-[2-(9-Carboxynonanoyloxy)propoxy]-10-oxodecanoic acid was synthesized in excellent yield and characterized by Fourier-transform infrared spectroscopy, mass, 1 H-NMR, and 13 C-NMR spectra. The diester was technetium-99m (99m Tc) radiolabeled by direct technique using sodium dithionite as a reducing agent. The labeling parameters such as diester amount, reducing agent amount, pH of the medium, and reaction time were optimized. High radiochemical yield of 95.10 ± 0.41% and in vitro stability in serum up to 12 h have been obtained on complexation of the synthesized diester with Tc-99m. Evaluation of the diester anticancer activity against breast cancer cell line (MCF-7) showed high percent of inhibition about 61.5% at 100 µg/ml. The rhenium complex of the diester was synthesized and characterized by liquid chromatography-mass spectrometry (ESI) and elemental analysis depending on the strong chemical resemblance between Tc and Re. Biodistribution studies of 99m Tc-diester complex showed high target to nontarget ratio (T/NT) equals 6.24 ± 0.09 in tumor-bearing mice at 30-min postinjection, suggesting this complex could be used as hopeful solid tumor-imaging agent.