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The present study reports the cymoxanil adsorption efficiency on carboxy-carbon nanotubes (CNT-COOH)/manganese(IV) oxide (MnO2)/iron(II,III) oxide(Fe3O4) nanocomposite. The optimum conditions were determined by studying the influence of pH (2-10), temperature (20-60 °C), initial cymoxanil concentration (7-20 mg L−1), adsorbent dose (0.5-5 g L−1) and contact time (2-30 min) on the adsorption process. The isotherm and kinetic models were used to analyze the experimental data. The Langmuir isotherm model was shown to provide the best fit with a 10.672 mg g−1 maximum adsorption capacity. Also, the cymoxanil adsorption follows the pseudo-second order kinetic model. According to these results, the CNT-COOH/MnO2/Fe3O4 nanocomposite may be used for cymoxanil removal from aqueous solution. [ABSTRACT FROM AUTHOR]

Different microorganisms are present in nature, some of which are assumed to be hazardous to the human body. It is crucial to control their continuing growth to improve human life. Nanomaterial surface functionalization represents a current topic in continuous evolution that supports the development of new materials with multiple applications in biology, medicine, and the environment. This study focused on the antibacterial activity of different nanocomposites based on functionalized multi-walled carbon nanotubes against four common bacterial strains. Two metal oxides (CuO and NiO) and two antibiotics (azithromycin and ciprofloxacin) were selected for the present study to obtain the following nanocomposites: MWCNT-COOH/Antibiotic, MWCNT-COOH/Fe3O4/Antibiotic, and MWCNT-COOH/Fe3O4/MO/Antibiotic. The present study included two Gram-positive bacteria (Staphylococcus aureus and Enterococcus faecalis) and two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Ciprofloxacin (Cip) functionalized materials (MWCNT-COOH/Fe3O4/Cip) were most efficient against all tested bacterial strains; therefore, we conclude that Cu and Ni reduce the effects of Cip. The obtained results indicate that the nanocomposites functionalized with Cip are more effective against selected bacteria strains compared to azithromycin (Azi) functionalized nanocomposites. The current work determined the antibacterial activities of different nanocomposites and gave fresh insights into their manufacture for future research regarding environmental depollution. [ABSTRACT FROM AUTHOR]

The aim of this paper consisted of the carbon nanotube nanocomposite testing for the removal of ampicillin from aqueous solutions. To determine the optimum experimental conditions for ampicillin adsorption on nanocomposite, several parameters were selected: the pH, initial concentration of pollutant, adsorbent dose and contact time. The highperformance liquid chromatography was used to determine the residual ampicillin concentration from aqueous solutions. The best removal of the antibiotic on the tested nanocomposite was obtained with an initial concentration of 40 mg L−1 with 1 g L−1, pH 2 in 20 min. [ABSTRACT FROM AUTHOR]

In this study the adsorption and photodegradation capabilities of modified multi-walled carbon nanotubes (MWCNTs), using tartrazine as a model pollutant, is demonstrated. MWCNT-COOH/Fe3O4 and MWCNT-COOH/Fe3O4/NiO nanocomposites were prepared by precipitation of metal oxides in the presence of MWCNTs. Their properties were examined by X-ray diffraction in powder (XRD), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, synchrotron-based Scanning PhotoElectron Microscopy (SPEM), and Brunauer-Emmett-Teller (BET) analysis. It was found that the optimal adsorption conditions were pH 4 for MWCNT-COOH/Fe3O4 and pH 3 for MWCNT-COOH/Fe3O4/NiO, temperature 25 °C, adsorbent dose 1 g L−1, initial concentration of tartrazine 5 mg L−1 for MWCNT-COOH/Fe3O4 and 10 mg L−1 for MWCNT-COOH/Fe3O4/NiO and contact time 5 min for MWCNT-COOH/Fe3O4/NiO and 15 min for MWCNT-COOH/Fe3O4. Moreover, the predominant degradation process was elucidated simultaneously, with and without simulated sunlight irradiation, using thermal lens spectrometry (TLS) and UV–Vis absorption spectrophotometry. The results indicated the prevalence of the photodegradation mechanism over adsorption from the beginning of the degradation process. [ABSTRACT FROM AUTHOR]

Nanocomposites based on half-metallic FePt (L10) magnetic nanoparticles coated with the semiconducting conjugated polymer poly(3-hexylthiophene-2,5-diyl) (P3HT) show a significant reduction in the magnetic coercivity. This study adopts a physical approach based on chemical potential equalization at the interface. The underlying charge/spin transfer mechanism unveils an imbalance: only spin-down polarized electrons are allowed to be transferred from the semiconductor to the half-metal (spin-down) conduction band, while spin-up states remain blocked at the interface. This process determines an excess of spin-up states on the P3HT side, and due to a RKKY mechanism, this effective spin system becomes ferromagnetic polarized. Due to this proximity effect, the conjugate polymer becomes exchange coupled to the hard magnetic FePt (L10) phase, thus reducing the coercivity of the half-metal. These processes make this type of composite suitable for magnetic recording applications. [ABSTRACT FROM AUTHOR]

In this paper, the applicability of carboxylic functionalized carbon nanotubes modified with metal oxides of Fe and Mn (CNT-COOH/MnO2/Fe3O4) as adsorbent for the removal of two pesticides from aqueous solution in batch method was studied. The two pesticides studied were devrinol and triadimefon. Their adsorption on nanocomposite was studied in relation to several factors such as the effect of the pH, initial concentration of pollutant, amount of adsorbent dose, temperature and contact time. The residual pesticide concentration was determined using high-performance liquid chromatography coupled with photodiode array detector (HPLC–PDA). The experimental data best fit with Langmuir isotherm model and follow the pseudo-second-order kinetic model. Depending on the temperature, the adsorption capacity of pesticides on nanocomposite varies between 14.925 and 20.492 mg g−1 for devrinol and between 12.723 and 14.706 mg g−1 for triadimefon. The thermodynamic parameters indicated that the retention of devrinol and triadimefon onto CNT-COOH/MnO2/Fe3O4 was spontaneous and endothermic. The experimental results obtained reveal that CNT-COOH/MnO2/Fe3O4 nanocomposite is a promising adsorbent for pesticides removal from the wastewater. [ABSTRACT FROM AUTHOR]

• CNT-COOH/MnO 2 /Fe 3 O 4 nanocomposite prepared is a new adsorbent. • The adsorption process depends on pH, temperature, time, adsorbent dose, drugs concentration. • High adsorption capacity of ibuprofen and paracetamol was obtained on CNT-COOH/MnO 2 /Fe 3 O 4. The nanocomposite CNT-COOH/MnO 2 /Fe 3 O 4 was synthesized and characterized by different techniques, namely X-ray diffraction, Fourier-transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetric analysis, Brunauer-Emmett-Teller analysis, magnetic measurement, point of zero charge and hydrophobicity index. Analyzes revealed the groups -COOH, MnO 2 and Fe 3 O 4 attached to the carbon nanotubes, the acidic character of the obtained nanocomposite and its stability. The surface area for the obtained nanocomposite was 114.2 m2 g−1. The prepared nanocomposite was used for adsorption of ibuprofen and paracetamol from aqueous solution. Isotherm, kinetic and thermodynamic parameters were determined for predicting the ibuprofen and paracetamol adsorption on synthetized nanocomposite. The equilibrium data obtained from adsorption were well represented by Langmuir model and kinetics data were well fitted by the pseudo-second order model. The maximum adsorption capacity obtained for ibuprofen and paracetamol was 103.093 mg g−1, 80.645 mg g−1 respectively. The thermodynamic analysis showed that the adsorption process for both pollutants was spontaneous and endothermic. The synthetized nanocomposite can be a suitable new absorbent for ibuprofen and paracetamol removal from aqueous solutions due to its high adsorbing capacity and it can be separated by an external magnetic field. [ABSTRACT FROM AUTHOR]