Bi-Functionalized Hybrid Materials as Novel Adsorbents for Heavy Metal Removal from Aqueous Solution: Batch and Fixed-Bed Techniques

In this study, two new mesoporous hybrid gels were synthesized. The structural order, morphology, and textural properties of the prepared hybrid materials have been studied by 13C CP MAS NMR, SEM, FTIR, and nitrogen adsorption–desorption analysis. The application for the heavy metal uptake from aqueous solution using the as-synthesized hybrid materials as an adsorbent is explored. Operating parameters influencing the adsorption procedure, for instance, solution pH, contact time, and temperature are contemplated. In order to gain an insight into the adsorption mechanism and reveal the rate-controlling steps, three models pseudo-first-order, pseudo-second-order, and intra-particle diffusion have been studied to fit. Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) models are assigned to portray the adsorption isotherms. Besides, the feasibility of the synthesized adsorbents for a continuous process in fixed-bed column was investigated. Prior tests produced on electroplating effluents reveal that the as-prepared xerogel could be strongly used for the heavy metal uptake from real wastewater

ELABORATION OF ORGANIC-INORGANIC HYBRID MATERIALS OBTAINED BY CHEMICAL REACTION OF POLYMETHYLHYDROSILOXANE AND BI-FUNCTIONAL HETEROCYCLIC MOLECULES

New organic-inorganic hybrid materials G1-G5 were obtained by chemical reaction of polymethylhydrosiloxane (PMHS) and bi-functional heterocyclic molecules under 2:1 stoechiometry, in tetrahydrofurane as solvant, using hexachloroplatinic acid (H2PtCl2, 6H2O) as catalyst at 60 °C. This reaction leads to the formation of transparent and monolithic gels. The xerogels have been caracterized by infrared, 29Si and 13C CP MAS NMR spectroscopy. The results show the formation of Si–N; Si – O; Si – S bridges in produced xerogels. The thermal analysis of the xerogels was determined by TGA and DTA. Xerogels morphology and texture of the obtained materials were studied by scanning electron microscopy (SEM) and Brunauer – Emmet – Teller method (BET)

Design, synthesis, antimicrobial evaluation, and molecular docking studies of novel symmetrical 2,5‐difunctionalized 1,3,4‐oxadiazoles

International audienceA series of novel symmetrical 2,5-difunctionalized 1,3,4-oxadiazole derivatives of pharmacological significance have been synthesized. The obtained compounds were screened for their in vitro antimicrobial activities against Gram-negative (Escherichia coli and Salmonella typhimurium) and Gram-positive bacteria (Staphylococcus aureus, Enterococcus feacium and Streptococcus agalactiae or group B Streptococcus), as well as against the fungus Candida albicans. Although the synthesized compounds showed moderate antifungal activity against C. albicans, they exhibited good to excellent antibacterial activities against several strains, compared with standard drugs Ampicillin and Nystatin. In silico molecular docking in FabI enzyme active site, gave information regarding the binding mode of the drug candidate at molecular level

Synthesis of new silica xerogels based on bi-functional 1,3,4-thiadiazole and 1,2,4-triazole adducts

<p>New transparent Silica-based hybrid materials were synthesized by reaction of polymethylhydrosiloxane (PMHS) and organic compounds: 1,3,4-thiadiazole-2,5-diamine <b>(1)</b>, 1,3,4-thiadiazole-2,5-dithiol <b>(2)</b> and 1H-1,2,4-triazole-3-thiol <b>(3)</b>, in tetrahydrofuran as solvant using hexachloroplatinic acid (H₂PtCl₆.6H₂O) as a catalyst. PMHS was used as a principal network forming agent, it has been cross-linked via hydrosilylation reaction with bi-functional heterocyclic compounds, leading to the formation of colored gels. These later dried (xerogels) were characterized by numerous techniques, including spectroscopy of (FT–IR) and ¹³C and ²⁹Si CP MAS NMR. The xerogels morphology and texture were studied by scanning electron microscopy and Brunauer–Emmet–Teller method. According to N₂-physisorption results, isotherms are classified as type IV with H₂ type hysteresis loop; then, the xerogels are mesoporous materials. The optic and magnetic properties of the obtained materials were studied by UV–VIS and EPR spectroscopies, respectively. This study showed that all materials are paramagnetic semiconductors.</p

New silica hybrids elaborated by sol-gel process from bifunctional thiadiazole and 1,2,4-triazole precursors

<p>New hybrid materials were synthesized from an inorganic precursor, (tetraethoxysilane: TEOS) and bifunctional organic precursors through the sol-gel process. Indeed, monolithic and transparent hybrid gels were obtained by the reaction of tetraethoxysilicate (TEOS) with 1,2,4-thiadiazole-3,5-diamine <b>(1)</b>, 5-amino-1,3,4-thiadiazole-2-thiol <b>(2)</b>, and 1H-1,2,4-triazole-3-thiol <b>(3)</b> in ethanol as solvent, using chloric acid (HCl 10⁻¹M) as catalyst. It is shown that TEOS has been cross-linked with bi-functional heterocyclic compounds: <b>(1), (2)</b> and <b>(3)</b> leading to the formation of transparent and colorous gels. The characterization was realized by infrared, ²⁹Si and ¹³C CP MAS NMR. The xerogels morphology and texture were studied by scanning electron microscopy (SEM) and Brunauer – Emmet – Teller method (BET). The obtained results show that organic adducts <b>(1), (2)</b> and <b>(3)</b> react with TEOS leading to gels in which Si–N and Si–S bridges were formed. According to N₂-physisorption results, xerogels are mesoporous with specific surface area varied from 105 to 312 m²g⁻¹ and their isotherms are classified as type IV. The optic and magnetic properties of hybrids were studied respectively by UV-Vis spectroscopy and RPE. This study showed that all materials are paramagnetic semiconductors.</p

New silica-based hybrid materials (Nouveaux matériaux hybrides à base de silicium)

<p></p> <p>New hybrid organic-inorganic materials have been obtained by reactions at room temperature of polymethylhydrosiloxane (PMHS) with different organic bi-functional molecules, in tetrahydrofuran (THF) using hexachloroplatinic acid (H₂PtCl₆.6H₂O) as a catalyst. These reactions have led to the formation of monolithic colored and transparent polymeric gels. The characterization of xerogels has been carried by infrared, ²⁹Si and ¹³C CP MAS NMR and thermal analysis DTA-TGA. Xerogels morphology and texture were studied by scanning electron microscopy (SEM) and Brunauer–Emmet–Teller method (BET). The obtained results show that organic molecules react with PMHS leading to gels in which Si–N and Si–O covalent bridges are formed. The optic and magnetic properties of hybrid gels are studied respectively by UV-Vis spectroscopy and RPE. The obtained results show that materials are paramagnetic semiconductors.</p