Egyptian Petroleum Research Institute

An amphiphilic HEMA-co-AMPS copolymer was synthesized through microwave-assisted RAFT polymerization using a rapid and energy-efficient approach. Comprehensive characterization confirmed successful copolymer formation, high structural stability, and the presence of abundant negatively charged sulfonate groups. The copolymer exhibited excellent adsorption performance toward Cu2+ and Cr6+ ions, achieving maximum capacities of 165mg g⁻¹ and 115mg g⁻¹, respectively, within ≤ 3h. Adsorption followed a pseudo-second-order kinetic model, while equilibrium data were best described by the Langmuir model for Cu2+ and the Freundlich model for Cr6+. Thermodynamic analysis indicated spontaneous adsorption, with Cu2+ uptake occurring through an endothermic process and Cr6+ uptake proceeding exothermically. The copolymer retained more than 87% of its initial adsorption capacity after multiple cycles, demonstrating strong reusability. Overall, these findings highlight microwave-assisted RAFT polymerization as an efficient and sustainable strategy for producing high-performance polymeric adsorbents for water treatment applications.

The extant study introduces newly fabricated star-shaped polyamine surfactant (PAS) as a highly effective corrosion inhibitor for carbon steel (X-65) in 1.0 M HCl environment. The PAS was synthesized by reaction of dodecyl amine with maleic anhydride via ring-opening reaction forming a monomaleate amide that was esterified with triethanolamine to yield a star-shaped structure, followed by Michael addition reaction using diethylenetriamine. The chemical structures of PAS were confirmed by FT-IR and 1HNMR. Surface tension measurements were employed to quantify the key surface properties of PAS. The inhibition performance was comprehensively evaluated through electrochemical techniques, surface characterization, and theoretical computations. Electrochemical impedance spectroscopy (EIS) revealed an exceptional inhibition efficiency of ~ 96% at an optimal concentration of 1000 µM, with the charge transfer resistance increasing significantly to 348.56 Ωcm2. Potentiodynamic polarization (PDP) measurements demonstrated that PAS operated as a mixed-type inhibitor through suppressing both anodic and cathodic reactions. The inhibition mechanism was governed by the spontaneous adsorption of PAS molecules onto the X-65 surface, which follows the Langmuir adsorption isotherm suggesting a combination of physical and chemical adsorption. Surface morphology analysis utilizing scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM) provided direct evidence of the protective adsorbed film of PAS. Furthermore, theoretical assessments using density functional theory (DFT), and Monte Carlo simulations (MCs) successfully predicted the PAS active sites and its strong adsorption affinity onto the Fe surface, corroborating the experimental findings.

ABSTRACT Polylactide (PLA) and polycaprolactone (PCL) biocomposites were prepared with modified rice husk (RH). In this context, RH was treated with maleic anhydride (MA) and maleated PLA (i.e., coupling agent [CA]) forming modified RH (i.e., RH‐MA and RH‐CA, respectively). Several formulations were tested from biocomposites of PLA and PCL with different percentages of modified RH where the best results were obtained when using 5% with respect to the used mixing method. Pure PLA and PCL‐ modified RH biocomposites were first obtained, then each of them was further involved in cross blends' formation with each other. Different characteristics were studied for the prepared modified RH polymeric biocomposites for future expected applications in biomedical fields and packaging. Accordingly, several PLA and PCL‐ modified RH biocomposites were toxic on proliferation of cancer cells with inhibitory effect against biofilm formation of bacterial cells in case of MSSA or Pseudomonas aeruginosa . Also, the prepared biocomposites recorded low water vapor and oxygen transmission rates (WVTR, OTR) which indicated their possible application as packaging materials for food at low moisture level or for dry food.