scholarly journals Adsorption of Paraquat by Poly(Vinyl Alcohol)-Cyclodextrin Nanosponges

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4110
Author(s):  
Ekkachai Martwong ◽  
Santi Chuetor ◽  
Jatupol Junthip
Keyword(s):  
Surface Area ◽  
Vinyl Alcohol ◽  
Exchange Capacity ◽  
Bet Surface Area ◽  
Poly Vinyl Alcohol ◽  
Maximum Adsorption Capacity ◽  
Cyclodextrin Nanosponges ◽  
Adsorption Processes ◽  
Pesticides In Water ◽  
Regeneration Times

The contamination of hydrosoluble pesticides in water could generate a serious problem for biotic and abiotic components. The removal of a hazardous agrochemical (paraquat) from water was achieved by adsorption processes using poly(vinyl alcohol)-cyclodextrin nanosponges, which were prepared with various formulations via the crosslinking between citric acid and β-cyclodextrin in the presence of poly(vinyl alcohol). The physicochemical properties of nanosponges were also characterized by different techniques, such as gravimetry, thermogravimetry, microscopy (SEM and Stereo), spectroscopy (UV-visible, NMR, ATR-FTIR, and Raman), acid-base titration, BET surface area analysis, X-ray diffraction, and ion exchange capacity. The C10D-P2 nanosponges displayed 60.2% yield, 3.14 mmol/g COOH groups, 0.335 mmol/g β-CD content, 96.4% swelling, 94.5% paraquat removal, 0.1766 m2 g−1 specific surface area, and 5.2 × 10−4 cm3 g−1 pore volume. The presence of particular peaks referring to specific functional groups on spectroscopic spectra confirmed the successful polycondensation on the reticulated nanosponges. The pseudo second-order model (with R2 = 0.9998) and Langmuir isotherm (with R2 = 0.9979) was suitable for kinetics and isotherm using 180 min of contact time and a pH of 6.5. The maximum adsorption capacity was calculated at 112.2 mg/g. Finally, the recyclability of these nanosponges was 90.3% of paraquat removal after five regeneration times.

scholarly journals Adsorption of Cationic Contaminants by Cyclodextrin Nanosponges Cross-Linked with 1,2,3,4-butanetetracarboxylic Acid and Poly(vinyl alcohol)

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 342
Author(s):  
Ekkachai Martwong ◽  
Santi Chuetor ◽  
Jatupol Junthip
Keyword(s):  
Vinyl Alcohol ◽  
Physicochemical Characteristics ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
Order Model ◽  
X Ray ◽  
Cyclodextrin Nanosponges ◽  
Pseudo Second Order ◽  
Regeneration Times ◽  
Butanetetracarboxylic Acid

Cationic organic pollutants (dyes and pesticides) are mainly hydrosoluble and easily contaminate water and create a serious problem for biotic and abiotic species. The elimination of these dangerous contaminants from water was accomplished by adsorption using cyclodextrin nanosponges. These nanosponges were elaborated by the cross-linking between 1,2,3,4-butanetetracarboxylic acid and β-cyclodextrin in the presence of poly (vinyl alcohol). Their physicochemical characteristics were characterized by gravimetry, acid-base titration, TGA, 13C NMR, ATR-FTIR, Raman, X-ray diffraction, and Stereomicroscopy. The BP5 nanosponges displayed 68.4% yield, 3.31 mmol/g COOH groups, 0.16 mmol/g β-CD content, 54.2% swelling, 97.0% PQ removal, 96.7% SO removal, and 98.3% MG removal for 25 mg/L of initial concentration. The pseudo-second-order model was suitable for kinetics using 180 min of contact time. Langmuir isotherm was suitable for isotherm with the maximum adsorption of 120.5, 92.6, and 64.9 mg/g for paraquat (PQ), safranin (SO), and malachite green (MG) adsorption, respectively. Finally, the reusability performance after five regeneration times reached 94.1%, 91.6%, and 94.6% for PQ, SO, and MG adsorption, respectively.

High-Surface-Area SBA-15 with Enhanced Mesopore Connectivity by the Addition of Poly(vinyl alcohol)

2011 ◽  
Vol 23 (8) ◽  
pp. 2062-2067 ◽  
Author(s):  
Junjiang Zhu ◽  
Kamalakannan Kailasam ◽  
Xiao Xie ◽  
Reinhard Schomaecker ◽  
Arne Thomas
Keyword(s):  
Surface Area ◽  
Vinyl Alcohol ◽  
High Surface ◽  
High Surface Area ◽  
Poly Vinyl Alcohol

Characterization of natural- and organobentonite by XRD, SEM, FT-IR and thermal analysis techniques and its adsorption behaviour in aqueous solutions

Clay Minerals ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 31-44 ◽  
Author(s):  
G. A. Ikhtiyarova ◽  
A. S. Özcan ◽  
Ö. Gök ◽  
A. Özcan
Keyword(s):  
Surface Area ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Textile Dye ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Thermal Analysis Techniques

AbstractIn this study, natural bentonite was modified with hexadecyltrimethylammonium (HDTMA) bromide to obtain organobentonite (HDTMA-bentonite). Bentonite and HDTMA-bentonite were then characterized using XRD, XRF, SEM, FT-IR, thermogravimetric (TG) analysis, elemental analysis and Brunauer-Emmett-Teller (BET) surface area techniques. The HDTMA+ cation was found to be located on the surface and enters the interlayer spaces of smectite according to the XRD and SEM results. FT-IR spectra indicated the existence of HDTMA functional groups on the bentonite surface. The BET surface area significantly decreased after the modification due to the coverage of the pores of natural bentonite. After the characterization, the adsorption of a textile dye, Reactive Blue 19 (RB19), onto bentonite and HDTMA-bentonite was investigated. The maximum adsorption capacity of HDTMA-bentonite for RB19 was 502 mg g-1 at 20°C. The adsorption process followed a pseudo-second-order kinetic model and it was exothermic and physical in nature.

scholarly journals CuAl LDH/Rice Husk Biochar Composite for Enhanced Adsorptive Removal of Cationic Dye from Aqueous Solution

2020 ◽  
Vol 15 (2) ◽  
pp. 525-537 ◽  
Author(s):  
Neza Rahayu Palapa ◽  
Tarmizi Taher ◽  
Bakri Rio Rahayu ◽  
Risfidian Mohadi ◽  
Addy Rachmat ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Malachite Green ◽  
Rice Husk ◽  
Low Cost ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Cationic Dye ◽  
X Ray ◽  
Adsorptive Removal

The preparation of CuAl LDH and biochar (BC) composite derived from rice husk and its application as a low-cost adsorbent for enhanced adsorptive removal of malachite green has been studied. The composite was prepared by a one-step coprecipitation method and characterized by X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), Brunauer-Emmett-Teller (BET), and Scanning Electron Microscopy - Energy Dispersive X-ray (SEM−EDX). The result indicated that CuAl LDH was successfully incorporated with the biochar that evidenced by the broadening of XRD peak at 2θ = 24° and the appearance of a new peak at 1095 cm−1 on the FTIR spectra. The BET surface area analysis revealed that CuAl/BC composite exhibited a larger surface area (200.9 m2/g) that the original CuAl LDH (46.2 m2/g). Surface morphological changes also confirmed by SEM image, which showed more aggregated particles. The result of the adsorption study indicated the composite material was efficient in removing malachite green with Langmuir maximum adsorption capacity of CuAl/BC reaching 470.96 mg/g, which is higher than the original CuAl LDH 59.523 mg/g. The thermodynamic analysis suggested that the adsorption of malachite green occurs spontaneously (ΔG < 0 at all tested temperature) and endothermic nature. Moreover, the CuAl/BC composite showed strong potential as a low-cost adsorbent for cationic dye removal since it showed not only a high adsorption capacity but also good reusability. Copyright © 2020 BCREC Group. All rights reserved

scholarly journals Factor Affecting Microwave Assisted Preparation of Activated Carbon from Local Raw Materials

2015 ◽  
Vol 47 ◽  
pp. 15-23 ◽  
Author(s):  
Mohamed A. Elsayed ◽  
O.A. Zalat
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Microwave Power ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Optimum Conditions ◽  
Corn Cob ◽  
Carbon Yield ◽  
Microwave Assisted ◽  
Impregnation Ratio

This study illustrates the preparation of activated carbon (AC) from Corn Cob (CC) via microwave assisted K2CO3 activation. The effect of operational parameters including chemical impregnation ratio (0.25-1.25), microwave power (90 – 800 W) and irradiation time (1 – 9 min) on the carbon yield and adsorption capability of derived Corn Cob Activated Carbon (CCAC) were investigated. The results indicated that the optimum conditions were as follows: microwave power of 600W, microwave radiation time of 5 min and the impregnation ratio of K2CO3 was 0.75 g/g. The optimum conditions resulted in CCAC with a maximum adsorption capacity of 275.32 mg/g for MB and carbon yield of 27.09%. The BET surface area, Langmuir surface area and total pore volume were determined to be 765 m2/g, 834 m2/g and 0.43 cm3/g, respectively.

scholarly journals Electrospinning Nanofibres Of Pullulan Extracted From Phylloplane Fungus, Aureobasidium Pullulans

2020 ◽  
Author(s):  
Komal Saraf ◽  
N Vigneshwaran
Keyword(s):  
Surface Area ◽  
Aureobasidium Pullulans ◽  
High Surface ◽  
Polymer Concentration ◽  
Carbon Sources ◽  
High Surface Area ◽  
Angle Measurement ◽  
Electrospinning Process ◽  
Bet Surface Area ◽  
Poly Vinyl Alcohol

Abstract Aureobasidium pullulans isolated from the phylloplane of Peltophorum tree, produced pullulan, an extracellular polysaccharide. It was grown on three different carbon sources, sucrose, wheat bran and cotton stalk dust, for maximizing the pullulan yield. A. pullulans (67.4 gL-1) had the highest yield followed by A. pullulans MTCC 1991 (63.68 gL-1). Pullulan was characterized by X-ray diffractometer (XRD), Brunauer-Emmett-Teller (BET) surface area analyzer, DSC and NMR. Electrospinning of pullulan blended with poly (vinyl alcohol) (PVA) produced bead-less nanofibres. The optimized parameters for electrospinning were 25 kV applied voltage, 0.5 mL/h flow rate, 18% polymer concentration (pullulan + PVA) and 150 mm tip-to-collector distance. The pullulan nanofibre was characterized by SEM, AFM, BET, contact angle measurement, DSC and CIE color space analyzer. A maximum surface area of 183.4 m2/g while the minimum nanofibre diameter (79 ± 19 nm by SEM) was obtained for the electrospun mat of commercial pullulan + 40% PVA. This work signifies the importance of pullulan extracted from an isolate of Peltopohorum tree for conversion to high surface area nanofibres by electrospinning process.

scholarly journals Electrospinning Nanofibres of Pullulan Extracted From Phylloplane Fungus, Aureobasidium Pullulans

2020 ◽  
Author(s):  
Komal Saraf ◽  
N Vigneshwaran
Keyword(s):  
Surface Area ◽  
Aureobasidium Pullulans ◽  
High Surface ◽  
Polymer Concentration ◽  
Carbon Sources ◽  
High Surface Area ◽  
Angle Measurement ◽  
Electrospinning Process ◽  
Bet Surface Area ◽  
Poly Vinyl Alcohol

Abstract Aureobasidium pullulans isolated from the phylloplane of Peltophorum tree, produced pullulan, 24 an extracellular polysaccharide. It was grown on three different carbon sources, sucrose, wheat 25 bran and cotton stalk dust, for maximizing the pullulan yield. A. pullulans (67.4 gL-1) had the 26 highest yield followed by A. pullulans MTCC 1991 (63.68 gL-1). Pullulan was characterized by 27 X-ray diffractometer (XRD), Brunauer-Emmett-Teller (BET) surface area analyzer, DSC and NMR. 28 Electrospinning of pullulan blended with poly (vinyl alcohol) (PVA) produced bead-less 29 nanofibres. The optimized parameters for electrospinning were 25 kV applied voltage, 0.5 mL/h 30 flow rate, 18% polymer concentration (pullulan + PVA) and 150 mm tip-to-collector distance. 31 The pullulan nanofibre was characterized by SEM, AFM, BET, contact angle measurement, DSC 32 and CIE color space analyzer. A maximum surface area of 183.4 m2/g while the minimum 33 nanofibre diameter (79 ± 19 nm by SEM) was obtained for the electrospun mat of commercial 34 pullulan + 40% PVA. This work signifies the importance of pullulan extracted from an isolate of 35 Peltopohorum tree for conversion to high surface area nanofibres by electrospinning process.

Development of poly(vinyl alcohol) / chitosan / aloe vera gel electrospun composite nanofibers as a novel sorbent for thin-film micro-extraction of pesticides in water and food samples followed by HPLC-UV analysis

2022 ◽  
Author(s):  
Saeed Hejabri kandeh ◽  
Shima Amini ◽  
Homeira Ebrahimzadeh
Keyword(s):  
Thin Film ◽  
Citric Acid ◽  
Vinyl Alcohol ◽  
Composite Nanofibers ◽  
Aloe Vera ◽  
Food Samples ◽  
Poly Vinyl Alcohol ◽  
Electrospinning Technique ◽  
Aloe Vera Gel ◽  
Pesticides In Water

Herein, a novel composite of poly(vinyl alcohol) (PVA)/citric acid (CA)/ chitosan (CS)/ aloe vera gel (AV) was fabricated via the electrospinning technique followed by a thermal treatment. The resultant composite...

Effect of Carbon Coating of TiO2/Fe3O4 Particles on Their Photocatalytic Activity

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Tarek A. Gad Allah ◽  
Shigeru Kato ◽  
Shigeo Satokawa ◽  
Toshinori Kojima
Keyword(s):  
Methyl Orange ◽  
Carbon Content ◽  
Surface Area ◽  
Carbon Coating ◽  
Degradation Rate ◽  
Sol Gel ◽  
Bet Surface Area ◽  
Poly Vinyl Alcohol ◽  
Titanium Tetraisopropoxide ◽  
X Ray

Magnetic titanium dioxide particles were prepared by depositing different amounts of TiO2 on magnetite powder using a sol-gel process. Adsorptivity of TiO2/Fe3O4 particles was increased by carbon coating which was carried out by mixing the particles with poly (vinyl alcohol) as a source of carbon. The carbon coating and calcination of particles were carried out simultaneously by heating the mixture at different temperatures. X-ray diffraction, energy dispersion fluorescence x-ray spectrometry, carbon-nitrogen analyzer and surface area analysis were used for the characterization of the prepared samples. The phase transition temperature of TiO2 from anatase to rutile was found to decrease by decreasing titanium tetraisopropoxide to magnetite (TTIP:Fe3O4) ratio while BET surface area increased by increasing this ratio. Carbon content had a significant effect on the formed phases and surface areas of the samples. The photocatalytic efficiencies of the prepared samples were investigated against degradation of methyl orange. The effect of TTIP:Fe3O4 ratio and carbon content on the degradation rate were studied. Methyl orange degradation rate increased with the increase in TTIP:Fe3O4 ratio but decreased by increasing carbon content.

scholarly journals Adsorption of tetracycline from water using glutaraldehyde-crosslinked electrospun nanofibers of chitosan/poly(vinyl alcohol)

2018 ◽  
Vol 77 (5) ◽  
pp. 1324-1335 ◽  
Author(s):  
Aliyeh Yousefi Abdolmaleki ◽  
Hamid Zilouei ◽  
Saied Nouri Khorasani ◽  
Kiomars Zargoosh
Keyword(s):  
Vinyl Alcohol ◽  
Electrospun Nanofibers ◽  
Poly Vinyl Alcohol ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Injection Flow ◽  
Before And After ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Abstract In this work, the preparation and characterization of glutaraldehyde-crosslinked electrospun nanofibers of chitosan/poly(vinyl alcohol) (GCCPN) as a new adsorbent for tetracycline (TC) is reported. Electrospun nanofibers of chitosan/poly(vinyl alcohol) (PVA) were prepared by employing a 75:25 volumetric ratio of chitosan:PVA, voltage of 30 kV, collection distance of 10 cm, and injection flow rate of 2 mL/h. Then, the nanofibers were crosslinked via applying the glutaraldehyde on them for 3 h at 40 °C. The nanofibers were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction. Uniform beadless nanofibers with minimum diameters of 3–11 and 6–18 nm were obtained before and after crosslinking, respectively. Then the applicability of the synthesized GCCPN for removal of TC from aqueous solutions was investigated. The response surface method was applied to evaluate the influence of pH (6–12), TC concentration (50–250 mg/L) and the adsorbent dose (0.05–0.25 g in 20 mL solution) on the adsorption characteristics of GCCPN. The maximum adsorption capacity was 102 mg/g. The adsorption kinetics was explained most effectively by the pseudo-second-order model. The adsorption data of TC on the GCCPN surface was explained well by the Langmuir isotherm model.

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