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.

scholarly journals Synthesis Fe3O4/Talc nanocomposite by coprecipition-ultrasonication method and advances in hexavalent chromium removal from aqueous solution

2020 ◽  
Vol 38 (9-10) ◽  
pp. 483-501
Author(s):  
Nguyen Thi Huong ◽  
Nguyen Ngoc Son ◽  
Vo Hoang Phuong ◽  
Cong Tien Dung ◽  
Pham Thi Mai Huong ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Batch Experiments ◽  
X Ray Diffraction ◽  
Order Model ◽  
X Ray ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Langmuir And Freundlich Equations

The Fe3O4/Talc nanocomposite was synthesized by the coprecipitation-ultrasonication method. The reaction was carried out under a inert gas environment. The nanoparticles were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), fourier-transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry techniques (VSM), the surface area of the nanoparticles was determined to be 77.92 m2/g by Brunauer-Emmett-Teller method (BET). The kinetic data showed that the adsorption process fitted with the pseudo-second order model. Batch experiments were carried out to determine the adsorption kinetics and mechanisms of Cr(VI) by Fe3O4/Talc nanocomposite. The adsorption process was found to be highly pH-dependent, which made the material selectively adsorb these metals from aqueous solution. The isotherms of adsorption were also studied using Langmuir and Freundlich equations in linear forms. It is found that the Langmuir equation showed better linear correlation with the experimental data than the Freundlich. The thermodynamics of Cr(VI) adsorption onto the Fe3O4/Talc nanocomposite indicated that the adsorption was exothermic. The reusability study has proven that Fe3O4/Talc nanocomposite can be employed as a low-cost and easy to separate.

Synthesis and Properties of Poly(Vinyl Alcohol)/Calcium Aluminate Nanocomposites

1991 ◽  
Vol 245 ◽  
Author(s):  
Phillip B. Messersmith ◽  
Samuel I. Stupp
Keyword(s):  
Calcium Aluminate ◽  
Vinyl Alcohol ◽  
Organic Polymer ◽  
Poly Vinyl Alcohol ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Layer Spacing ◽  
X Ray ◽  
New Class ◽  
Cementitious Systems

ABSTRACTThis paper describes the synthesis, structure and properties of a new layered nanocomposite which may have applications in cementitious systems. This material is one example of a new class of materials which consist of inorganic crystals containing intercalated organic polymer. The nanocomposite is synthesized by precipitating Ca2Al(OH)6[X]·nH2O (X=OH−, CO3−2) in the presence of poly(vinyl alcohol) (PVA). X-ray diffraction analysis indicates that the nanocomposite consists of calcium aluminate layers separated by interlayers containing anions, water and PVA. The intercalation of PVA can only be accomplished during crystal growth and is accompanied by an expansion in layer spacing from ˜8 Å to ˜18 Å. The nanocomposite exhibited enhanced thermal stability and when compacted into a cylinder was found to have more than twice the compressive strength than the pure calcium aluminate.

Effect of syndiotacticity on the aqueous poly(vinyl alcohol) gel 4. X-ray diffraction analysis of gel

1976 ◽  
Vol 254 (11) ◽  
pp. 982-988 ◽  
Author(s):  
K. Ogasawara ◽  
T. Nakajima ◽  
K. Yamaura ◽  
S. Matsuzawa
Keyword(s):  
Diffraction Analysis ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals The plasticizing effect of properties of manganous chloride and glycerin on poly(vinyl alcohol)

2015 ◽  
Vol 17 (2) ◽  
pp. 29-33
Author(s):  
Puyou Jia ◽  
Meng Zhang ◽  
Caiying Bo ◽  
Lihong Hu ◽  
Yonghong Zhou
Keyword(s):  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Thermal And Mechanical Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
X Ray ◽  
Ft Ir ◽  
Micro Morphology ◽  
Lower Tensile Strength

Abstract Poly(vinyl alcohol) films were prepared with manganous chloride (MnCl2 · 4H2O) and glycerin as complex plasticizer. The micro morphology of pure PVA film and complex plasticizer plasticized PVA films was observed by scanning electron microscope (SEM). The interaction between complex plasticizer and PVA molecules was investigated by Fourier transform infrared spectroscopy (FT-IR). The influence of complex plasticizer on crystalline, thermal and mechanical properties of PVA films was studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TG), and tensile testing, respectively. The results showed that the complex plasticizer of MnCl2 · 4H2O/glycerin could interacted with PVA molecular and then effectively destroy the crystals of PVA. PVA films plasticized with complex plasticizer of MnCl2 · 4H2O/glycerin became soft and ductile, with lower tensile strength and higher elongation at break compared with PVA films. This is an important cause of plasticization of the complex plasticizer of MnCl2 · 4H2O/glycerin on PVA films.

scholarly journals Equilibrium and Kinetic Study of Removal Copper(II) from Aqueous Solution Using Chicken Eggshells: Low Cost Sorbent

Molekul ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 28
Author(s):  
Mohammad Jihad Madiabu ◽  
Joko Untung ◽  
Imas Solihat ◽  
Andi Muhammad Ichzan
Keyword(s):  
Aqueous Solution ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Sorption Process ◽  
X Ray Diffraction ◽  
Order Model ◽  
X Ray ◽  
Adsorption Condition ◽  
Pseudo Second Order ◽  
Effect Of Copper

The research aims to investigate feasibility eggshells as potential adsorbent to remove copper(II) ions from aqueous solution. Eggshells powder was characterized using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. Effect of copper(II) initial concentration, adsorbent dosage, and contact time have conducted. The optimum adsorption condition obtained when 0.7 g eggshells applied to 50 mg/L copper(II) solution for 50 minutes. The maximum percentage of copper(II) removal was exceeded more than 85%. Langmuir and Freundlich isotherm model were applied to describe the equilibrium adsorption. Copper(II) kinetics sorption process was fitted to pseudo-second order model with a rate constant equal to 0.516 g/mg.min. The results clearly exhibit that eggshells powder can be effectively used to remove copper(II) ions from aqueous solutions.

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 Electrically Conductive Nanocomposites Polymer of Poly(Vinyl Alcohol)/Glutaraldehyde/Multiwalled Carbon Nanotubes: Preparation and Characterization

2018 ◽  
Vol 18 (3) ◽  
pp. 383 ◽  
Author(s):  
Fitri Khoerunnisa ◽  
Hendrawan Hendrawan ◽  
Yaya Sonjaya ◽  
Rizki Deli Hasanah
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Polymer Matrix ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Electrically Conductive ◽  
X Ray ◽  
Conductive Nanocomposites

Electrically conductive nanocomposites polymer of poly(vinyl alcohol)/PVA, glutaraldehyde (GA) and multiwalled carbon nanotubes (MWCNT) has been successfully synthesized. The polymer nanocomposites were prepared by mixing PVA, GA (crosslinker), and MWCNT dispersion with an aid of ultrasonic homogenizer at 50 °C. The content of MWCNT, in particular, was varied in order to determine the effect of MWCNT on electrical conductivity of polymer composites. The polymer mixture was casted into a disc to obtain thin film. The electrical conductivity, surface morphology, and mechanical properties of the composites film were investigated by means of four probes method, FTIR spectroscopy, X-ray diffraction, SEM, AFM, and tensile strength measurement, respectively. It was found that the optimum composition of PVA (10%): GA (1%): MWCNT (1%) was 20:20:3 in volume ratio. The addition of MWCNT induced the electrically conductive network on polymer matrix where the electrical conductivity of nanocomposites film significantly increased up to 8.28 x 10-2 S/sq due to reduction of the contact resistance between conductive filler. Additionally, the mechanical strength of nanocomposites polymer were significantly increased as a result of MWCNT addition. Modification of morphological structure of composite film as indicated by FTIR spectra, X-ray diffraction patterns, SEM, and AFM images verified the effective MWCNT filler network in the polymer matrix.

scholarly journals La-Doped ZnTiO3/TiO2 Nanocomposite Supported on Ecuadorian Diatomaceous Earth as a Highly Efficient Photocatalyst Driven by Solar Light

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6232
Author(s):  
Ximena Jaramillo-Fierro ◽  
Silvia González ◽  
Francesc Medina
Keyword(s):  
Diatomaceous Earth ◽  
Diffuse Reflectance Spectroscopy ◽  
Solar Irradiation ◽  
Batch Reactors ◽  
X Ray Diffraction ◽  
Order Model ◽  
X Ray ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
La Doped

Currently, there is great interest in the use of TiO2 for photocatalytic remediation of wastewater. Doping, heterojunction, and immobilization on porous materials are effective methods to improve the photocatalytic efficiency of this semiconductor oxide. In this study, ZnTiO3/TiO2 (ZTO) and ZnTiO3/TiO2/La (ZTO/La) nanocomposites were successfully prepared and immobilized on diatomaceous earth (DE). The composition and texture of the composites prepared were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM-EDX), and specific surface area (SSA). The adsorption capacity and photocatalytic activity of the composites were determined via degradation of methylene blue (MB) in batch reactors. The materials evaluated were prepared in the shape of 0.2 cm (diameter) and 1.0 cm (length) cylindrical extrudates. The results indicate that the ZTO/La-DE composite exhibited higher efficiency for the removal of MB under solar irradiation than both ZTO-DE and DE. The pseudo-second-order model and the Langmuir isotherm model were better suited to explain the adsorption process. The highest degradation percentage of MB obtained was 96% after 150 min of irradiation. The results indicate that synthesized composite could be used for the removal of cationic dyes in wastewater.

scholarly journals Synthesis of Silver Nanoparticles from Mimusops elengi Extract of Raw Fruits and Characterization of PVA-Silver Polymer Nanocomposite Films

2021 ◽  
Vol 33 (4) ◽  
pp. 762-766
Author(s):  
BHABANI SHANKAR PANDA ◽  
MOHAMMED ANSAR AHEMAD
Keyword(s):  
Silver Nanoparticles ◽  
Vinyl Alcohol ◽  
Thermal Studies ◽  
Polymer Nanocomposite ◽  
Nanocomposite Films ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Visible ◽  
Mimusops Elengi

The present work concerns on the synthesis of silver nanoparticles at 25 ºC using raw fruits extract of Bakul (Mimusops elengi) tree via chemical reduction route development of poly(vinyl alcohol) PVA-silver polymer nanocomposite films. The nanocomposite films were subjected to characterization by UV-visible, FTIR, X-ray diffraction, field emission scanning electron microscope (FESEM) and thermal studies. The UV-visible spectrum shows a characteristic broad absorption band observed near 465 nm suggesting presence of silver nanoparticles in polymer nanocomposites (PNCs) film. The vibrational band shift of –OH group of poly(vinyl alcohol) in the presence of nanoparticle designated the chemical interaction between –OH group of poly(vinyl alcohol) and silver nanoparticles. The FESEM study confirmed that PVA is not only acted as a capping agent, but also a cross-linking agent. X-ray diffraction study shows that the existence of AgNPs in the poly nanocomposite film and nanoaparticles are crystalline in nature. Thermal studies suggest that the enhanced thermal stability is because of the good packing of the polar crystallites in β-PVA composites as compared to the non-polar α-phase of neat poly(vinyl alcohol) (PVA).

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