33 research outputs found
Clay/Conductive Polymer Nanocomposites
This chapter describes the main strategies for designing clay nanocomposites of the most investigated inherently conductive polymers, namely, polypyrrole, polyaniline, and polythiophenes including poly(3,4-ethylenedioxythiophene) polystyrene sulfonate. It is shown that premodification of clays is an essential step to successful intercalation or exfoliation by conductive polymers. Toward this end, surfactants, reactive diazonium, and silanes permit the preparation of adhesive clay sheets for the conductive polymers once polymerization is triggered. Exfoliated nanocomposites usually exhibit superior properties compared to intercalated ones. Through selected applications (e.g., conductive fillers, catalysts, sensors, ultracapacitors), it is clear that research on clay–conductive polymer nanocomposites will continue to grow because these materials combine the best of two worlds: low-cost abundant minerals with remarkable nanostructural properties and nanostructuring abilities on the one hand and ease of synthesis, reactivity, and electrical conductivity of conjugated polymers on the other hand.Scopu
Data on the fabrication of hybrid calix [4]arene-modified natural bentonite clay for efficient selective removal of toxic metals from wastewater at room temperature
Fresh water resources on the earth are less than 0.2%; meanwhile, around 80% of the freshwater is consumed daily in agriculture, industries, and household activities [1–2]. There is an essential need to develop efficient adsorbents for wastewater treatment [1–6], in this regards, hereafter we present the rationale synthesis and characterization of hybrid natural bentonite clay modified with Calix [4] arene (denoted as B-S-Calix) as efficient adsorbents for toxic metals from wastewater. This is driven by the facile photo-radical thiol-yne addition among the thiolated clay and an alkynylated calix[4]arene. The morphology, surface modifications, and Thermal degradation of B, B-S, and B-S-Calix were investigated using TEM, FTIR, and TGA techniques. The adsorption performance of B, BS and B-S-Calix towards toxic metals including cadmium (II) ion [Cd (II)], zinc (II) ion [Zn(II)], lead(II) ion [Pb(II)], strontium(II) ion [Sr (II)], cobalt(II) ion [Co (II)], copper(II) ion [Cu(II)], and mercury (II) ion [Hg(II)] from wastewater were benchmarked 25 °C. These data are related to the article entitled “hybrid Clay/Calix[4]arene Calix[4]arene-clicked clay through thiol-yne addition for the molecular recognition and removal of Cd(II) from wastewater’’ [7]
Rational synthesis, characterization, and application of environmentally friendly (polymer–carbon dot) hybrid composite film for fast and efficient UV-assisted Cd<sup>2+</sup> removal from water
Background: Carbon dots (CDs) are of particular interest in numerous applications. However, their efficiency for heavy metal removal from wastewater was not yet reported. Herein, we rationally synthesized CDs from petroleum coke waste via hydrothermal treatment in the presence of ammonia. Results: This drove the formation of outstanding photoluminescent, water-soluble, biocompatible, and high yield of monodispersed sub-5 nm CDs. The CDs are co-doped with high 10% of N and 0.2% of S. The as-prepared CDs possess unprecedented photoluminescent properties over broad pH range making these dots unique efficient pH sensor. Conclusions: Chitosan (CH)–CDs hybrid hydrogel nanocomposite film was further prepared as a platform membrane for the removal Cd2+ metal from wastewater. The as-prepared CH–CDs membranes show relatively good mechanical properties, based on stress resistance and flexibility to facilitate handling. The equilibrium state was reached within 5 min. Intriguingly, the UV-light illuminations enhanced the Cd2+ removal efficiency of the photoluminescent CDs substantially by four times faster under. It was found that adsorption followed pseudo-second-order kinetic and Langmuir isotherm models. The maximum adsorption capacity at 25 °C was found to be 112.4 mg g−1 at pH 8. This work paves the way to new applications of CDs in water treatment.[Figure not available: see fulltext.]
Anti-corrosive and oil sensitive coatings based on epoxy/polyaniline/magnetite-clay composites through diazonium interfacial chemistry
Epoxy polymer nanocomposites filled with magnetite (Fe3O4) clay (B), named (B-DPA-PANI@Fe3O4) have been prepared at different filler loading (0.1, 0.5, 1, 3, 5 wt. %). The surface modification of clay by polyaniline (PANI) is achieved in the presence of 4-diphenylamine diazonium salt (DPA). The effects of the nanofiller loading on Tensile, mechanical and dielectric properties were systematically studied. Improved properties was highlighted for all reinforced samples. The addition of only 3 wt. % of the filler enhanced the tensile strength of the composites by 256%, and the glass transition temperature Tg by 37%. The dielectric spectra over a broad frequency showed a robust interface between the hybrid (B-DPA-PANI@Fe3O4) fillers and epoxy matrix. The results showed most significant improvement in corrosion inhibition using electrochemical impedance spectroscopy (EIS) in 3.5 wt % NaCl, as well as a significant response in oil sensing test. High charge transfer resistance of 110 × 106 Ω.cm2 using 3-wt % of filler was noted compared to 0.35 × 106 Ω.cm2 for the pure epoxy. The results obtained herein will open new routes for the preparation of efficient anticorrosion sensor coatings. © 2018, The Author(s).NPRP Award from the Qatar National Research Fund (a member of Qatar Foundation) [8-878-1-172
Rational Synthesis, Characterization, and Application of Environmentally?Friendly (Polymer?Carbon Dot) Hybrid Composite Film for Fast and Efficient UV Assisted Cd2+ Removal from Water
Carbon-dots (CDs) are of particular interest in numerous applications. However, their efficiency for heavy metal removal from wastewater was not yet reported. Herein, we rationally synthesized CDs from petroleum-coke-waste via hydrothermal treatment in the presence of ammonia.This drove the formation of outstanding photoluminescent, water-soluble, biocompatible, and high yield of monodispersed sub-5 nm CDs. The CDs are co-doped with high 10 % of N and 0.2 % of S. The as-prepared CDs possess unprecedented photoluminescent properties over broad pH range making these dots unique efficient pH sensor. chitosan (CH)-CDs hybrid hydrogel nanocomposite film were further prepared as a platform membrane for the removal Cd2+ metal from wastewater. The as prepared CH-CDs menbranes show a relatively good mechanical properties, based on stress-resistant and flexibility in order to facilitate handling. The equilibrium state was reached within 5 minutes. Intriguingly, the UV-light illuminations enhanced the Cd2+ removal efficiency of the photoluminescent CDs substantially by four times faster under. It was found that adsorption followed pseudo-second-order kinetic and Langmuir isotherm models. The maximum adsorption capacity at 25? C was found to be 112.4 mg g-1 at pH 8. This work paves the way to new applications of CDs in water treatment
Chapter 1 - Overview: Clay Preparation, Properties, Modification
This chapter reviews clay physicochemical properties and general methods of modification with a view to making a clay–polymer nanocomposite. The first part includes an overview of clays, their different structures, and their physicochemical properties. The second part concerns a literature survey of the most applied methods of organic modification of clays. New trends are also highlighted.This chapter was made possible by NPRP award [8-878-1-172] from the Qatar National Research Fund (a member of the Qatar Foundation). The statements made herein are solely the responsibility of the authors
Dimethoxytriazine-Triazole Linked Mesoporous Silica Hybrid Sorbent for Cationic Dyes Adsorption
Organic dye has always been considered one of the most serious water pollutants. Therefore, the great significance nowadays is to synthesis effective adsorbent Materials for removal of these contaminants. Herein, we prepared successfully a novel sorbent based on dimethoxy-triazine/triazole groups functionalized via a 1,3-dipolar cycloaddition click reaction on mesoporous silica SBA-15. The resulting sample denoted DMT-Tr-SBA-15 was characterized by FTIR spectra, X-ray photoelectron spectroscopy (XPS), solid-state 13C NMR spectroscopy and nitrogen adsorption/desorption isotherm. The resulting hybrid silica material was evaluated as a sorbent for adsorption of four cationic dyes in aqueous media showed high adsorption efficiency and a fast removal rate. The adsorption properties were monitored versus time; the after 40 min and using a 40 mg/L of adsorbent was reached. The maximum adsorption capacity for methylene blue at room temperature and neutral pH was 4.59 mmol g-1. These results indicate the great potential of clickable mesoporous silica to diversify the active sites for adsorption, thus demonstrating a significant interest for environmental applications
Reinforced Polymers: The Emerging Role of Diazonium Modification of Fillers
International audienceThis chapter summarizes the knowledge of filler modification with diazonium salts, with a view to designing high-performance reinforced polymer composites. Arylation of fillers serves for attaching prepolymers or for triggering polymerization processes. The level of modification is molecular or macromolecular in nature. Both arylated and macromole-modified fillers served to design reinforced polymer composites with unique mechanical and dielectric properties. One important feature is the rheology of formulations prior to cure. Interfacial chemical compositions could be investigated with surface-specific techniques such as XPS and ToF–SIMS. Handpicked cases concern the design of reinforced polymers with silica, zeolite, clays, and carbon allotropes. We demonstrate that fine control over the surface chemical composition of fillers has profound effect on mechanical, thermal, viscoelastic, and electrical properties of end polymer composites