NOPR Collection:

Synthesis and characterization of poly(3,4-ethylenedioxythiophene)/ Montmorillonite nanocomposites using surfactants modified clay

2022-05-17T10:46:48Z

Title: Synthesis and characterization of poly(3,4-ethylenedioxythiophene)/ Montmorillonite nanocomposites using surfactants modified clay Authors: Khiati, Zoulikha; Mrah, Lahouari Abstract: Nanocomposites of Poly (3,4-ethylenedioxythiophene) (PEDOT) and surfactant modified Maghnite clay have been successfully synthesized by in situ polymerization of EDOT monomer in the interlayer space of the organoclay. The synthesis has been assisted by ultrasonic method to improve the dispersion of PEDOT polymer between the Maghnite clay sheets. The surfactant modified clay is synthesized via cation exchange method with Hydrogenure Tetrabutylammonuim (TBAHS) and cetyltrimethylammonium (CTAB). Two types of organo-modified clays are obtained namely the Mag-TBA and Mag-CTA according to the template used. Various physico-chemical techniques are used for nanocomposites characterization such as XRD, FTIR, AFM, TGA/DTA, SEM and TEM. The results prove the formation of intercalated / exfoliated upon increasing the content of organoclay in the nanocomposites , consequently, different morphologies and structures in which the exfoliated and intercalated forms were obtained. Both nanocomposites display significant enhancement in the thermal stabilities compared to the PEDOT polymer. However, a decrease in conductivity values is observed for all samples compared to pure conducting polymer. This feature can be improved in view of desired application in electrochemical devices. Page(s): 117-127

Z-scheme heterojunction of Bi2S3/g-C3N4 and its photocatalytic effect

2022-05-17T10:43:52Z

Title: Z-scheme heterojunction of Bi2S3/g-C3N4 and its photocatalytic effect Authors: Meng, Yachu; Li, Yuzhen; Xia, Yunsheng; Chen, Wenjun Abstract: In this study, Bi2S3/g-C3N4 binary catalyst has been excellently prepared by a wet impregnation-calcination method to form Z-scheme heterojunction. The catalyst has been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS) and photoluminescence spectroscopy (PL). The physicochemical properties of the catalyst have been tested, such as crystal structure, morphology, optical properities, light absorption properties and luminescence properties. The results demonstrate that the photocatalytic activity is significantly increased when Bi2S3 with optimum weight percentage (5wt%) loaded into g-C3N4. Through photocatalytic degradation experiments, the optimal loading ratio, dosage and dye concentration of binary materials have been explored. At the same time, the effect of pH on the photocatalytic experiment under the optimal conditions is studied. Reactive blue 19 (RB19) is degraded by 97.77% in 2 h as the target pollutants. The trapping experiment further verified that ꞏO2 - is the main active species in photocatalytic degradation of RB19. Page(s): 128-138

Aluminium hydroxide impregnated sawdust adsorbent: An eco-friendly and low-cost strategy for defluoridation of water

2022-05-17T10:40:44Z

Title: Aluminium hydroxide impregnated sawdust adsorbent: An eco-friendly and low-cost strategy for defluoridation of water Authors: Mandal, Sujata; Johri, Simmi; Govind, Malarvizhi Abstract: Environment-friendly and cost-effective adsorbent is necessary for removal of excess fluoride from water to control the spread of fluorosis among people in fluoride-rich area. Plant-based cellulosic materials are the preferred choice for this purpose. In this work, aluminium hydroxide impregnated sawdust (AHSD) adsorbent has been prepared, characterized and applied for defluoridation of water through batch and fixed-bed adsorption. Fluoride adsorption capacity of AHSD in batch adsorption experiment is 4.45 mg/g for the initial fluoride concentration between 5-50 mg/L. At low fluoride concentration, the Freundlich isotherm model fit reasonably well, while at higher fluoride concentration (> 40 mg/L) the Langmuir model show better fitting with the experimental data. The adsorption kinetics follow pseudo second-order kinetic model. In fixedbed column adsorption, 4 g of the adsorbent is capable of bringing down the fluoride concentration from 5 mg/L to < 1.5 mg/L (WHO limit) for 690 mL of contaminated water. Residual aluminium in the treated water was within permissible limit of WHO. The reasonably good adsorption capacity and effectivity in both batch and fixed-bed column adsorption suggests that AHSD is an environment-friendly, cost-effective and promising adsorbent for defluoridation of water. Page(s): 139-148

Modification of montmorillonite and its effect on the thermal stability of PP/APP

2022-05-17T10:38:09Z

Title: Modification of montmorillonite and its effect on the thermal stability of PP/APP Authors: Abdelmoaty, A S; Hanna, A Abstract: The effect of montmorillonite (Mt) and the treated montmorillonite (MtT) with sulfuric acid on the efficiency of nanoparticles of ammonium polyphosphate (APP) has been studied. Five samples containing different percentage of montmorillonite are prepared and other five samples containing treated montmorillonite also prepared. The chemical analysis (XRF), the spectroscopic measurements (XRD and IR) and the morphology (SEM) studied have been performed to identify the sulfuric acid treatment for the montmorillonite on the chemical composition and on the structure of the montmorillonite layers. The results have been revealed that the acid treatment changes the layered structure of montmorillonite and no effects on the chemical composition. The thermogravimetric analysis (TGA) is used to evaluate the ammonium polyphosphate (APP)/ montmorillonite (Mt) or APP/ montmorillonite treatment (MtT) as flame retardants for Polypropylene (PP). The results show that both treated and untreated montmorillonite when mixed with APP accelerate the first step of the thermal degradation. Also, it is indicated that the time of degradation increased by adding treated or untreated montmorillonite to APP in the following sequence PP