Internalization study of nanosized zeolite crystals in human glioblastoma cells.

While the use of nanozeolites for cancer treatment holds a great promise, it also requires a better understanding of the interaction between the zeolite nanoparticles and cancer cells and notably their internalization and biodistribution. It is particularly important in situation of hypoxia, a very common situations in aggressive cancers, which may change the energetic processes required for cellular uptake. Herein, we studied, in vitro, the kinetics of the internalization process and the intracellular localization of nanosized zeolite X (FAU-X) into glioblastoma cells. In normoxic conditions, scanning electron microscopy (SEM) showed a rapid cell membrane adhesion of zeolite nanoparticles (< 5 min following application in the cell medium), occurring before an energy-dependent uptake which appeared between 1 h and 4 h. Additionally, transmission electron microscopy (TEM) and flow cytometry analyzes, confirmed that the zeolite nanoparticles accumulate over time into the cytoplasm and were mostly located into vesicles visible at least up to 6 days. Interestingly, the uptake of zeolite nanoparticles was found to be dependent on oxygen concentration, i.e. an increase in internalization in severe hypoxia (0.2 % of O2) was observed. No toxicity of zeolite FAU-X nanoparticles was detected after 24 h and 72 h. The results clearly showed that the nanosized zeolites crystals were rapidly internalized via energy-requiring mechanism by cancer cells and even more in the hypoxic conditions. Once the zeolite nanoparticles were internalized into cells, they appeared to be safe and stable and therefore, they are envisioned to be used as carrier of various compounds to target cancer cells.

MoS2 nanosheets/silver nanoparticles anchored onto textile fabric as "dip catalyst" for synergistic p-nitrophenol hydrogenation.

Attaining a synergistic merge between the performance of homogenous catalysts and the recyclability of heterogeneous catalysts remains until now a concerning issue. The main challenge is to design efficient, low-cost catalyst with outstanding reusability, facile recovery, and ease of retrieval and monitoring between the reuses. Despite the vast efforts in the development of silver nanoparticle-based catalyst for the reaction of hydrogenation of 4-nitrophenol, the aforementioned criteria are infrequently found in a chosen system. Herein, we report a MoS2 nanosheet/silver nanoparticle-anchored PES-based textile as an efficient and recyclable "dip catalyst" for the 4-NP hydrogenation in the presence of sodium bohydride as model reaction. The textile fabric-based catalyst was processed via a simple sono-coating approach using MoS2 nanosheets as first coating layer followed by an in situ deposition of silver nanoparticles. The "dip catalyst" fabric is rapidly and easily removed from the reaction and then reinserted in the batch system to attain over 10 reaction cycles. Additionally, the produced textile materials were characterized via spectroscopic and microscopic tools such as FTIR, XRD, SEM, and EDX. Moreover, the sources of the high catalytic activity are also discussed and a plausible reaction mechanism is suggested. The present study demonstrates the potential of metal nanoparticle-textile material combination for future applications in chemical sustainable catalysis for environmental remediation purposes.

Engineering of amine-based binding chemistry on functionalized graphene oxide/alginate hybrids for simultaneous and efficient removal of trace heavy metals: Towards drinking water.

Engineering of versatile binding chemistry on graphene oxide surface using nucleophilic substitution/amidation reactions for highly efficient adsorption of Cd (II), Cu (II) and Pb (II) is herein proposed. Graphene oxide (GO) was used as a precursor for covalent bonding of hexamethylenediamine (HMDA) molecules via the nucleophilic substitution/amidation reactions on epoxy (COC) and carboxyl (COOH) groups to yield hexamethylenediamine functionalized graphene oxide (GO-HMDA) with multiple binding chemistries such as oxygen and nitrogen. Afterwards, GO-HMDA was encapsulated in alginate hydrogel beads with different loadings 5, 10, 15 and 20 wt% to produce Alg/GO-HMDA hybrid adsorbents for the removal of trace heavy metal ions from aqueous solution. Batch adsorption studies showed remarkable adsorption rates reaching 100% for Pb (II), 98.18% for Cu (II) and 95.19 for Cd (II) (~1 mg L-1) with only 15 wt% of GO-HMDA incorporated into the alginate beads. Moreover, Alg/GO-HMDA showed high removal efficiencies of heavy metals from tap water with a removal order of (Pb > Cu > Cd) similar to that observed in single aqueous solution. In Addition, the Alg/GO-HMDA adsorbents displayed excellent regeneration ability for six consecutive adsorption-desorption cycles confirming the high performance and potential of these adsorbents, for real heavy metals remediation in environment and in drinking waters in both single and multiple systems. Finally, the adsorption mechanism of traces heavy metals resulted from several phenomena including the electrostatic interactions occurring between the COOH groups of Alginate and the GO-HMDA surface groups as well as, through chelation interactions occurring between the metal cations and amino-functionalized groups of Alg/GO-HMDA 15 hybrid adsorbent.

Emerging Chemical Functionalization of g-C3N4: Covalent/Noncovalent Modifications and Applications.

Atomically 2D thin-layered structures, such as graphene nanosheets, graphitic carbon nitride nanosheets (g-C3N4), hexagonal boron nitride, and transition metal dichalcogenides are emerging as fascinating materials for a good array of domains owing to their rare physicochemical characteristics. In particular, graphitic carbon nitride has turned into a hot subject in the scientific community due to numerous qualities such as simple preparation, electrochemical properties, high adsorption capacity, good photochemical properties, thermal stability, and acid-alkali chemical resistance, etc. Basically, g-C3N4 is considered as a polymeric material consisting of N and C atoms forming a tri-s-triazine network connected by planar amino groups. In comparison with most C-based materials, g-C3N4 possesses electron-rich characteristics, basic moieties, and hydrogen-bonding groups owing to the presence of hydrogen and nitrogen atoms; therefore, it is taken into account as an interesting nominee to further complement carbon in applications of functional materials. Nevertheless, g-C3N4 has some intrinsic limitations and drawbacks mainly related to a relatively poor specific surface area, rapid charge recombination, a limited light absorption range, and a poor dispersibility in both aqueous and organic mediums. To overcome these shortcomings, numerous chemical modification approaches have been conducted with the aim of expanding the range of application of g-C3N4 and enhancing its properties. In the current review, the comprehensive survey is conducted on g-C3N4 chemical functionalization strategies including covalent and noncovalent approaches. Covalent approaches consist of establishing covalent linkage between the g-C3N4 structure and the chemical modifier such as oxidation/carboxylation, amidation, polymer grafting, etc., whereas the noncovalent approaches mainly consist of physical bonding and intermolecular interaction such as van der Waals interactions, electrostatic interactions, π-π interactions, and so on. Furthermore, the preparation, characterization, and diverse applications of functionalized g-C3N4 in various domains are described and recapped. We believe that this work will inspire scientists and readers to conduct research with the aim of exploring other functionalization strategies for this material in numerous applications.

New amino group functionalized porous carbon for strong chelation ability towards toxic heavy metals.

Herein, ethylenediamine functionalized porous carbon (PC-ED/1.5) was synthesized, then characterized by various methods and finally used as a functional material for Cu(ii) and Pb(ii) ion removal from water. XPS revealed the presence of numerous functionalities within the surface of PC including -NH and C-N-C groups. Furthermore, S BET, RS, XRD and FTIR analyses confirmed the changes implemented on the PC surface. Thereafter, a systematic study was implemented to analyze the interactions of the PC-ED/1.5 surface with Cu(ii) and Pb(ii) heavy metal ions. Hence, adsorption experiments showed that the PC-ED/1.5 exhibits maximum adsorption capacities of 123.45 mg g-1 and 140.84 mg g-1 for Cu(ii) and Pb(ii), respectively. Moreover, in situ electrostatic interactions occurring between the divalent cation and the PC-ED/1.5 functional groups was investigated. The mechanism involves chelation processes, electrostatic interactions and mechanical trapping of the metal ions in the adsorbent pores. Interestingly, a synergistic effect of the pores and surface active sites was observed. Finally, by using alginate bio-polymer we prepared membrane films of PC-ED/1.5 which showed long-term stability, regeneration capabilities and high mass recovery.

High extent mass recovery of alginate hydrogel beads network based on immobilized bio-sourced porous carbon@Fe3O4-NPs for organic pollutants uptake.

This work goes inside the understanding of organic pollutants adsorption mechanism over network alginate hydrogel beads based on immobilized bio-sourced PC@Fe3O4-NPs (PC@Fe3O4-NPs@Alginate) and highlights its high extent mass recovery in aqueous media. The samples were successfully synthesized, we previously developed porous carbon (PC), which, was used to elaborate PC@Fe3O4-NPs via simple in situ coprecipitation (PC@ Fe3O4-NPs), which was encapsulated by alginate-Ca2+ via the blend crosslinking method. The structural, textural, chemical and morphological proprieties of as prepared materials were studied by XRD, FTIR, Raman spectroscopy, nitrogen adsorption-desorption, XPS, SEM and TEM. The adsorption kinetic and isotherm data were well fitted to the pseudo-second-order and Langmuir models. Magnetic particles exhibited an excellent ability to adsorb methylene blue (MB) from aqueous solutions with maximum MB adsorption capacity of 180.42 mg g-1 (PC@Fe3O4 NPs powder) and 49.66 mg g-1 (beads based PC@Fe3O4-NPs@Alginate). Response surface methodology was used to optimize the removal efficiency of MB from aqueous solution and optimum parameters were determined. Magnetic beads based PC showed good magnetic propriety, long-term stability, regeneration capabilities and high extent mass recovery.

Combined Methane Energy Recovery and Toxic Dye Removal by Porous Carbon Derived from Anaerobically Modified Digestate.

Valorization of agri-food organic waste in order to reach zero waste using cleaner methods is still a challenge. Therefore, both anaerobic co-digestion (ACD) (biological process) and adsorption (physicochemical process) were used in combination for this objective. ACD allows the activation of biodegradable organic matter by microbial action and produces a digestate (co-product). This coproduct was used as a raw material to produce porous carbon having a high specific surface area after chemical treatment using sulfuric acid and thermal activations at temperature T = 350 °C. The resulted material was used for the preparation of core-shell particles with a core made of porous carbon and a shell consisting mainly of alginate and a calcium ion layer. The final core-shell particles were then used for dye treating wastewater and solving the solid-liquid separation problem in the adsorption process. We show here that in the ACD process, significant bio-methane potential (BMP) was produced. Furthermore, the data indicate that 153 L CH4 kg·SV-1 of BMP was produced under optimum conditions of pH = 8 and inoculum/load ratio = 1.2. The overall results concerning the methylene blue (MB) adsorption from water onto the core-shell particles show the occurrence of a maximum adsorbed amount equal to 26.178 mg g-1, and good agreement was found between the experimental adsorption data with pseudo-second-order and Langmuir theoretical models. The response surface methodology coupled with the central composite design has allowed the identification of optimal conditions for MB removal and has led to the elucidation of adsorption mechanism and the regeneration of the adsorbent without the occurrence of the solid/liquid separation problem.

Aqueous-phase catalytic hydroxylation of phenol with H2O2 by using a copper incorporated apatite nanocatalyst.

Copper incorporated apatite (Cu-apatite) nanomaterial was prepared by a co-precipitation method. The obtained material was characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) and Raman spectroscopy, scanning electron microscopy (SEM, STEM) and nitrogen adsorption-desorption. The as-prepared Cu-apatite was used to catalyze phenol hydroxylation with hydrogen peroxide as an oxidant. The influencing parameters including reaction time, temperature, H2O2/phenol ratio and catalyst mass have been investigated. Under the optimized conditions, the Cu-apatite catalyst gave a phenol conversion of 64% with 95% selectivity to dihydroxybenzenes. More importantly, the results of catalyst recycling indicated that the same catalytic performance has been obtained after four cycles with a slight loss of activity and selectivity.

Iron oxide encapsulated by copper-apatite: an efficient magnetic nanocatalyst for N-arylation of imidazole with boronic acid.

N-Arylation of imidazole was carried out with various arylboronic acids on iron oxide encapsulated by copper-apatite (Fe3O4@Cu-apatite), producing excellent yields. Firstly, the iron nanoparticles were prepared using a solvothermal method, and then they were encapsulated by copper-apatite to obtain magnetic Fe3O4@Cu-apatite nanocatalysts. Several physico-chemical analysis techniques were used to characterize the prepared nanostructured Fe3O4@Cu-apatite catalyst. The prepared Fe3O4@Cu-apatite was used as a nanocatalyst for N-arylation of imidazole with a series of arylboronic acids with different substituents to reaffirm the effectiveness of this magnetic nanocatalyst. The Fe3O4@Cu-apatite nanocatalyst can also be easily separated from the reaction mixture using an external magnet. More importantly, the as-prepared Fe3O4@Cu-apatite exhibited good reusability and stability properties in successive cycles. However, there was a notable loss of its catalytic activity after multiple cycles.