One pot preparation of CeO2@Alginate composite beads for the catalytic reduction of MB dye: Effect of cerium percentage

This study focuses on the preparation of composite beads CeO2@Alginate using a one-pot method. Ce(III) was used as a crosslinking agent and then was modified with a base to transform it into CeO2 encapsulated in the alginate matrix. To study the catalytic behavior of this material the reduction of MB dye in the presence of NaBH4 was selected as a model reaction. Several parameters affecting the reduction of the MB dye were studied such as the effect of cerium content in the composite beads, the concentration of NaBH4 and the concentration of the MB dye. The results showed that the dispersion of alginate in a solution containing Ce(III) leads to the formation of hydrogel beads. The treatment of the beads with a basic solution leads to the in-situ formation of CeO2 inside the beads with a porous structure. The catalytic activity of composite beads has shown interesting results via the reduction of MB dye. The reduction of MB dye catalyzed by CeO2@ALG(2%) was total in 2 min and the associated rate constant was 2.3 min–1. The reuse tests were studied during five successive cycles, in which it was shown that the CeO2@ALG(2%) catalyst was stable without losing its effectiveness

Green nanocomposites from rosin-limonene copolymer and algerian clay

Green nanocomposites from rosin-limonene (Ros-Lim) copolymers based on Algerian organophilic-clay named Maghnite-CTA+ (Mag-CTA+) were prepared by in-situ polymerization using di erent amounts (1, 5 and 10% by weight) of Mag-CTA+ and azobisisobutyronitrile as a catalyst. The Mag-CTA+ is an organophilic montmorillonite silicate clay prepared through a direct exchange process; the clay was modified by ultrasonic-assisted method using cetyltrimethylammonuim bromide in which it used as green nano-filler.The preparation method of nanocomposites was studied in order to determine and improve structural, morphological, mechanical and thermal properties ofsin.The structure and morphology of the obtained nanocomposites(Ros-Lim/Mag-CTA+) were determined using Fourier transform infrared spectroscopy, X-ray di raction, scanning electronic microscopy and transmission electronic microscopy. The analyses confirmed the chemical modification of clay layers and the intercalation of rosin-limonene copolymer within the organophilic-clay sheets. An exfoliated structure was obtained for the lower amount of clay (1% wt of Mag-CTA+), while intercalated structures were detected for high amounts of clay (5 and 10% wt of Mag-CTA+). The thermal properties of the nanocomposites were studied by thermogravimetric analysis (TGA) and show a significant improvement inthe thermal stability of the obtained nanocomposites compared to the purerosin-limonene copolymer (a degradation temperature up to 280ºC).info:eu-repo/semantics/publishedVersio

Ultrasound Assisted Synthesis of Polylimonene and Organomodified-clay Nanocomposites: A Structural, Morphological and Thermal Properties

Polylimonene-clay nanocomposites (PLM-Mag 2, 3, 6 and 10% by weight of clay) were prepared by mixing Maghnite-CTA+ (Mag-CTA+) and polylimonene (PLM) in solution using ultrasonic irradiation. The catalyst preparation method were studied in order to determine and evaluate their structural, morphological and thermal properties. The Mag-CTA+ is an organophylic montmorillonite silicate clay prepared through a direct exchange process, using green natural clay of Maghnia (west of Algeria) called Maghnite. The Algerian clay was modified by ultrasonic-assisted method using cetyltrimethylammonuim bromide (CTAB) in which they used as green nano-reinforcing filler. Polylimonene was obtained by the polymerization of limonene, using Mag-H+ as a catalyst. The morphology of the obtained nanocomposites was studied by X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electronic microscopy (TEM) and infrared spectroscopy (FT-IR). Thermogravimetric analysis (TGA) shows that the nanocomposites have a high degradation temperature (200−250 °C) compared with the pure polylimonene (140 °C). The analyses confirmed the chemical modification of montmorillonite layers and their uniformly dispersion in the polylimonene matrix. Exfoliated structures were obtained for low amounts of clay (2 and 3% by weight), while intercalated structures and immiscible regions were detected for high amounts of clay (6 and 10% by weight). Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Polymer-Clay Nanocomposites: Exfoliation and Intercalation of Organophilic Montmorillonite Nanofillers in Styrene–Limonene Copolymer

Nanocomposites from Styrene-Limonene copolymers and Algerian organophilic-clay named Maghnite-CTA+ (Mag-CTA+), were prepared by in-situ polymerization using different amounts (2, 5, and 10% by weight) of clay and Azobisisobutyronitrile (AIBN) as a catalyst. The Mag-CTA+ is an organophilic silicate clay prepared through a direct exchange process, using Cetyltrimethylammonuim bromide (CTAB) in which it used as green nano-filler. The preparation method of nanocomposites was studied in order to determine and improve structural, morphological and thermal properties of Sty-Lim copolymer. The struc ture and morphology of the obtained nanocomposites (Sty-Lim/Mag) were determined using Fourier trans form infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM). The analyses confirmed the chemical modification of clay layers and the intercalation of Sty-Lim copolymer within the organophilic clay sheets. Exfoliated structure was obtained for the lower amount of clay (2 wt %), while intercalated structures were detected for higher amounts of clay (5 and 10 wt %). The thermal properties of the obtained nanocomposites were studied by thermogravimetric analysis (TGA) and show a significant improvement in the thermal stability compared with the pure copolymer. The obtained nanocomposites show an optimal degradation temperature of 320°C.info:eu-repo/semantics/publishedVersio

Assessment of AgNPs@Cu@Alginate Composite for Efficient Water Treatment: Effect of the Content of Cu(II) Crosslinking Agent

This work concerns the preparation of multifunctional composite beads based on Cu-Alginate and AgNPs. First, the Cu-Alginate hydrogel was obtained by adding alginate at different concentrations of the crosslinking agent Cu2+ (2%, 4%, and 8%). The obtained hydrogels were modified by Ag+ species then by a chemical treatment (using NaBH4) followed by freeze-drying. The obtained aerogel beads were characterized by different methods and then were used as catalysts for the reduction of organic pollutants in a simple and binary system, and also as antibacterial and antifungal agents on different strains. The results showed the formation of a porous structure containing well-dispersed silver nanoparticles in the alginate matrix. The concentration of the Cu2+ crosslinking agent significantly influences the content of encapsulated AgNPs, the catalytic activity, and thus the antibacterial and antifungal properties of the resulting material. In the catalysis part, the Cu(2%)-ALG(AgNPs) material was selected as the most efficient catalyst due to the presence of high content of AgNPs and their good dispersion in the alginate biopolymer. High conversions of MO, 4-NP, MB, and CR were obtained in a reaction time of 2.5, 26, 23, and 29 min, respectively. Thus for binary systems, the Cu(2%)-ALG(AgNPs) catalyst was more selective with the MB dye. For antibacterial and antifungal activities all materials were effective through six strains, but it was shown that materials with unreduced Ag+ species were more effective

Design, synthesis and thermo‑chemical properties of rosin vinyl imidazolium based compounds as potential advanced biocompatible materials

Rosin is a natural material extracted from the pine tree that is vastly used as an adhesive in the construction industry. It chemically consists of cyclic carboxylic structure that is known as rosin acids or abietic acid and other isomers. The abietic acid or/and its isomers can structurally be altered to design for different applications. Herein we envisage the potentials of altering the rosin structure to investigate its thermal and physicochemical properties for advanced material applications. In this regard we have utilised the potassium rosinate (rosin soap) also known as the saponified rosin. Saponified rosin is reacted through an anion exchange metathesis process promoted by ultrasound, with either an ionic liquid or a poly(ionic liquid), namely the 3-octyl-1-vinylimidazolium bromide and the poly (3-octyl-1-vinylimidazolium bromide) as a scope to improve thermal and mechanical applications. The structures of these new compounds were determined using fourier transform infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance spectroscopy (NMR). The rosin/ionic liquid based compound found to be a better fitting candidate for advanced material applications, due to significant improvement in the thermal stability compared to the crude rosin (up to 70 °C raise in the thermal degradation) and promising mechanical characters such as elasticity and malleability.info:eu-repo/semantics/publishedVersio

Green Nanocomposites from Rosin-Limonene Copolymer and Algerian Clay

Green nanocomposites from rosin-limonene (Ros-Lim) copolymers based on Algerian organophilic-clay named Maghnite-CTA+ (Mag-CTA+) were prepared by in-situ polymerization using different amounts (1, 5 and 10% by weight) of Mag-CTA+ and azobisisobutyronitrile as a catalyst. The Mag-CTA+ is an organophilic montmorillonite silicate clay prepared through a direct exchange process; the clay was modified by ultrasonic-assisted method using cetyltrimethylammonuim bromide in which it used as green nano-filler.The preparation method of nanocomposites was studied in order to determine and improve structural, morphological, mechanical and thermal properties ofsin.The structure and morphology of the obtained nanocomposites(Ros-Lim/Mag-CTA+) were determined using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electronic microscopy and transmission electronic microscopy. The analyses confirmed the chemical modification of clay layers and the intercalation of rosin-limonene copolymer within the organophilic-clay sheets. An exfoliated structure was obtained for the lower amount of clay (1% wt of Mag-CTA+), while intercalated structures were detected for high amounts of clay (5 and 10% wt of Mag-CTA+). The thermal properties of the nanocomposites were studied by thermogravimetric analysis (TGA) and show a significant improvement inthe thermal stability of the obtained nanocomposites compared to the purerosin-limonene copolymer (a degradation temperature up to 280 °C)

Synthesis and Characterization of Copolymers and Nanocomposites from Limonene, Styrene and Organomodified-Clay Using Ultrasonic Assisted Method

In the present work, we report a simple synthesis method for preparation of copolymers and nanocomposites from limonene and styrene using clay as a catalyst. The copolymerization reaction is carried out by using a proton exchanged clay as a catalyst called Mag-H+. The effect of temperature, reaction time and amount of catalyst were studied, and the obtained copolymer structure (lim-co-sty) is characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (1H-NMR) and differential scanning calorimetry (DSC). The molecular weight of the obtained copolymer is determined by gel permeation chromatography (GPC) and is about 4500 g·mol−1. The (lim-co-sty/Mag 1%, 3%, 7% and 10% by weight of clay) nanocomposites were prepared through polymer/clay mixture in solution method using ultrasonic irradiation, in the presence of Mag-CTA+ as green nano-reinforcing filler. The Mag-CTA+ is organophilic silicate clay prepared through a direct exchange process, using cetyltrimethylammonuim bromide (CTAB). The prepared lim-co-sty/Mag nanocomposites have been extensively characterized by FT-IR spectroscopy, X-ray diffraction (XRD), scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM). TEM analysis confirms the results obtained by XRD and clearly show that the obtained nanocomposites are partially exfoliated for the lower amount of clay (1% and 3% wt) and intercalated for higher amounts of clay (7% and 10% wt). Moreover, thermogravimetric analysis (TGA) indicated an enhancement of thermal stability of nanocomposites compared with the pure copolymer

Green Copolymers and Nanocomposites from Myrcene and Limonene Using Algerian Nano-Clay as Nano-Reinforcing Filler

In this work, we report a new facile method for the preparation of myrcene-limonene copolymers and nanocomposites using a Lewis acid as a catalyst (AlCl3) and organo-modified clay as a nano-reinforcing filler. The copolymer (myr-co-lim) was prepared by cationic copolymerization using AlCl3 as a catalyst. The structure of the obtained copolymer is studied and confirmed by Fourier Transform Infrared spectroscopy, Nuclear Magnetic Resonance spectroscopy, and Differential Scanning Calorimetry. By improving the dispersion of the matrix polymer in sheets of the organoclay, Maghnite-CTA+ (Mag-CTA+), an Algerian natural organophilic clay, was used to preparenanocomposites of linear copolymer (myr-co-lim). In order to identify and assess their structural, morphological, and thermal properties, the effect of the organoclay, used in varyingamounts (1, 4, 7, and 10% by weight), and the preparation process were investigated. The Mag-CTA+ is an organophylic montmorillonite silicate clay prepared through a direct exchange process in which they were used as green nano-reinforcing filler. The X-ray diffraction of the resulting nanocomposites revealed a considerable alteration in the interlayer spacing of Mag-CTA+. As a result, interlayer expansion and myr-co-lim exfoliation between layers of Mag-CTA+ were observed. Thermogravimetric analysis provided information on the synthesized nanocomposites’ thermal properties. Fourier transform infrared spectroscopy and scanning electronic microscopy, respectively, were used to determine the structure and morphology of the produced nanocomposites (myr-co-lim/Mag). The intercalation of myr-co-lim in the Mag-CTA+ sheets has been supported by the results, and the optimum amount of organoclay needed to create a nanocomposite with high thermal stability is 10% by weight. Finally, a new method for the preparation of copolymer and nanocomposites from myrcene and limonene in a short reaction time was developed