scholarly journals Surface Modification of Attapulgite by Grafting Cationic Polymers for Treating Dye Wastewaters

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 792
Author(s):  
Huan Guo ◽  
Kai Xia ◽  
Mingzhao Cao ◽  
Xiaodong Zhang
Keyword(s):  
Dye Adsorption ◽  
Nitrogen Adsorption ◽  
Particle Size Analysis ◽  
Sem Analysis ◽  
Size Analysis ◽  
Reactive Black 5 ◽  
Anionic Dyes ◽  
Column Operation ◽  
Adsorption Capacities ◽  
Modified Attapulgite

In this study, the cationic polymer poly-epichlorohydrin-dimethylamine was immobilized on natural attapulgite to improve the dye adsorption capacities. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, nitrogen adsorption-desorption isotherms, scanning electron microscope (SEM) analysis, zeta potential analysis, and particle size analysis were used to determine the characteristics of modified attapulgite. Results showed that the poly-epichlorohydrin-dimethylamine had been successfully grafted onto the surface of attapulgite without altering its crystal structure. After cationic modification, the specific surface area of attapulgite obviously decreased, and its surface zeta potentials possessed positive values in the pH range from 3 to 11. The cation-modified attapulgite displayed high adsorption capacities for anionic dyes, and its maximum adsorption capacities were 237.4 mg/g for Reactive Black 5 and 228.3 mg/g for Reactive Red 239; this is corroborated by Langmuir’s isotherm studies. It was demonstrated that the two reactive dyes could be 100% removed from effluents when cation-modified attapulgite was used in column operation modes. Its treatment capacities were more than three times larger than that of activated carbon. The regeneration study verified better utilization and stability of the fabricated adsorbent in column operation. This work has conclusively confirmed the potential of the new modified attapulgite for effectively treating dye wastewaters.

scholarly journals Recycling of Waste Solution after Hydrothermal Conversion of Fly Ash on a Semi-Technical Scale for Zeolite Synthesis

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1413
Author(s):  
Rafał Panek ◽  
Jarosław Madej ◽  
Lidia Bandura ◽  
Grzegorz Słowik
Keyword(s):  
Fly Ash ◽  
Nitrogen Adsorption ◽  
Particle Size Analysis ◽  
Al2o3 Content ◽  
Size Analysis ◽  
Zeolite Synthesis ◽  
Hydrothermal Conversion ◽  
Waste Solution ◽  
X Ray ◽  
X Zeolites

Nowadays, using fly ash for zeolites production has become a well-known strategy aimed on sustainable development. During zeolite synthesis in a hydrothermal conversion large amount of post-reaction solution is generated. In this work, the solution was used as a substrate for Na-A and Na-X zeolites synthesis at laboratory and technical scale. Obtained materials were characterized using particle size analysis, X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), transmission electron microscopy (TEM), Fourier transformed infrared spectroscopy (FTIR), and nitrogen adsorption/desorption isotherm. Produced zeolites revealed high purity (>98%) and monomineral zeolitic phase composition. The SiO2 content was in the range 39–42% and 40–38%, whereas Al2O3 content was 23–22% and 25–26% for Na-X and Na-A, respectively. TEM and BET analyses revealed Na-X zeolite pores were almost identical to commercial 13X with SBET in the range 671–734 m2/g. FTIR indicated slight differences between materials obtained at laboratory and technical scale in Si-O-(Si/Al) bridges of the zeolitic skeleton. The results showed good replicability of the laboratory process in the larger scale. The proposed method allows for waste solution reusability with a view to highly pure zeolites production in line with circular economy assumptions.

scholarly journals Preparation of Chitosan/Hyperbranched Polyester/Cobalt Composite For Acid Blue 277 Dye Adsorption

2020 ◽  
Vol 11 (4) ◽  
pp. 11653-11665
Keyword(s):  
Particle Size ◽  
Dye Adsorption ◽  
Particle Size Analysis ◽  
Isotherm Models ◽  
Size Analysis ◽  
Order Kinetic ◽  
Hyperbranched Polyester ◽  
Acid Dye ◽  
Equilibrium Studies ◽  
Acid Blue

Acid dye effluents are among the popular threatening sources to the environment and human health due to their photochemical stability, complexity, and poor biodegradability. Therefore, this study aims to prepare chitosan/hyperbranched polyester (HBPE)/cobalt composite with ratio (1:1:0.5 wt %, respectively) using emulsion technique as an adsorbent to deal with the acid dye effluent. Chemical structure, morphology, particle size analysis, and thermal stability of the prepared composite were carried out using Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM),) dynamic light scattering technique (DLS) and thermogravimetric analysis (TGA). Adsorption isotherms of acid blue 277 dye (AB277), using the different isotherm models (Langmuir, Freundlich, D-R, and Temkin) under removal conditions at pH 3.0 and contact time of 1 h in 10 mL aqueous medium at 25ᴼC, were investigated. The results illustrated that the chitosan/HBPE/Co composite was successfully prepared with a particle size of around 679±494 nm relative to chitosan/HBPE (139±67.6 nm). Also, the pseudo-second-order kinetic model fitted better than the pseudo-first-order one for adsorption of AB277. Batch equilibrium studies showed that chitosan/HBPE/Co composite could be employed as an efficient adsorbent of AB277 dye with an adsorption capacity of 26.74 mg/g, relative to that of chitosan/HBPE (3.19 mg/g).

Solvothermal synthesis of zirconia and yttria-stabilized zirconia nanocrystalline particles

2007 ◽  
Vol 22 (1) ◽  
pp. 46-55 ◽  
Author(s):  
Xin M. Wang ◽  
Ping Xiao
Keyword(s):  
Electron Microscopy ◽  
Nitrogen Adsorption ◽  
Particle Size Analysis ◽  
Zirconium Hydroxide ◽  
Yttria Stabilized Zirconia ◽  
Size Analysis ◽  
Stabilized Zirconia ◽  
Particle Properties ◽  
Transmission Electron ◽  
Nanocrystalline Particles

A solvothermal method was used to prepare zirconia and yttria-stabilized zirconia (YSZ) particles using zirconium hydroxide and yttrium hydroxide particles as precursors and ethanol or isopropanol as reaction media. The particle properties were characterized with x-ray diffractometry, scanning electron microscopy, transmission electron microscopy, thermal analysis, laser particle-size analysis, nitrogen adsorption (Brunauer–Emmett–Teller method) and Zeta potential analysis. Cubic/tetragonal ZrO2 and YSZ nanocrystals with crystallite size around 5 nm were obtained. The effect of different hydroxide precursors, attrition milling of hydroxide precursors, solvothermal processing conditions, and mineralizer was investigated and discussed by referring to the crystallization process of zirconium hydroxides.

scholarly journals Magnetic Porous Controlled Fe3O4–Chitosan Nanostructure: An Ecofriendly Adsorbent for Efficient Removal of Azo Dyes

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1194 ◽  
Author(s):  
Tiago M. Freire ◽  
Lillian M. U. D. Fechine ◽  
Danilo C. Queiroz ◽  
Rafael M. Freire ◽  
Juliano C. Denardin ◽  
...  
Keyword(s):  
Azo Dyes ◽  
Average Particle Size ◽  
Molecular Size ◽  
Nitrogen Adsorption ◽  
Average Particle ◽  
Precipitation Reaction ◽  
Reactive Black 5 ◽  
Anionic Dyes ◽  
Adsorption Mechanisms ◽  
Surface Modified

In this work, chitosan/magnetite nanoparticles (ChM) were quickly synthesized according to our previous report based on co-precipitation reaction under ultrasound (US) irradiation. Besides ChM was in-depth structurally characterized, showing a crystalline phase corresponding to magnetite and presenting a spheric morphology, a “nanorod”-type morphology was also obtained after increasing reaction time for eight minutes. Successfully, both morphologies presented a nanoscale range with an average particle size of approximately 5–30 nm, providing a superparamagnetic behavior with saturation magnetization ranging from 44 to 57 emu·g−1. As ChM nanocomposites have shown great versatility considering their properties, we proposed a comparative study using three different amine-based nanoparticles, non-surface-modified and surface-modified, for removal of azo dyes from aqueous solutions. From nitrogen adsorption–desorption isotherm results, the surface-modified ChMs increased the specific surface area and pore size. Additionally, the adsorption of anionic azo dyes (reactive black 5 (RB5) and methyl orange (MO)) on nanocomposites surface was pH-dependent, where surface-modified samples presented a better response under pH 4 and non-modified one under pH 8. Indeed, adsorption capacity results also showed different adsorption mechanisms, molecular size effect and electrostatic attraction, for unmodified and modified ChMs, respectively. Herein, considering all results and nanocomposite-type structure, ChM nanoparticles seem to be a suitable potential alternative for conventional anionic dyes adsorbents, as well as both primary materials source, chitosan and magnetite, are costless and easily supplied.

Chemically Modified Castor Oil for Softening of Leather– A Novel Approach

2021 ◽  
Vol 116 (4) ◽  
Author(s):  
Bindia Sahu ◽  
M. Sathish ◽  
G. C. Jayakumar
Keyword(s):  
Castor Oil ◽  
Particle Size Analysis ◽  
Sem Analysis ◽  
Size Analysis ◽  
The Novel ◽  
Physical Strength ◽  
Novel Approach ◽  
Uniform Dispersion ◽  
The Matrix ◽  
Tanning Process

Fatliquoring is an important step of post tanning process of leathermanufacturing where incorporation of self-emulsified oil (lubricant)makes the leather soft. There are several methods which introducepolarity into oil and provide the path where reactive species ofmodified oil can interact with water which leads to form a fatliquor.The aim of this work is to introduce an extra polarity into the fattyacid moiety through chemical modification of castor oil by carbeneintermediate. The spectroscopic characterisation such as FTIR,1H-NMR and 13C-NMR of fatliquor have been carried out. Particle size analysis of fatliquor has also been done. The experimental leathers have been tested for physical strength characterisation such as tensile and tear strength verses control and found to have better properties than control. SEM analysis for morphological study of experimental leather were also carried out which clearly indicates the uniform dispersion of fiber bundles due to the fine distribution of the novel and self-emulsifying fatliquor throughout the matrix.

Oxidation of Benzyl Alcohol in Liquid Phase Catalyzed by Cobalt Oxide

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Mohammad Ilyas ◽  
Muhammad Saeed
Keyword(s):  
Liquid Phase ◽  
Benzyl Alcohol ◽  
Cobalt Oxide ◽  
Solid Phase ◽  
Nitrogen Adsorption ◽  
Particle Size Analysis ◽  
Catalyst Loading ◽  
Size Analysis ◽  
Reaction Products ◽  
Oxidation Of Benzyl Alcohol

Cobalt oxide was synthesized by mechano-chemical process in solid phase and was characterized by particle size analysis, nitrogen adsorption, XRD and DRIFT. A study was performed to evaluate the catalytic activities of cobalt oxide for oxidation of benzyl alcohol in liquid phase, using toluene as solvent. Benzaldehyde and benzoic acid were identified as the reaction products. Effects of various parameters like reaction time, temperature, catalyst loading and partial pressure of oxygen on reaction performance were studied. Activation energy was found as 46.14 kJ/mol. Langmuir-Hinshelwood type of mechanism was found to be applicable to experimental data. The catalyst was found to be heterogeneous in nature, which can be easily separated from the reaction mixture by filtration.

X-Ray Studies on PbS

2011 ◽  
Vol 699 ◽  
pp. 153-165
Author(s):  
M. Ambika ◽  
R. Saravanan
Keyword(s):  
Energy Gap ◽  
Visible Spectrum ◽  
Particle Size Analysis ◽  
Sem Analysis ◽  
Entropy Method ◽  
Size Analysis ◽  
Lead Sulphide ◽  
X Ray ◽  
Refinement Method ◽  
Uv Visible

In this work, lead sulphide has been characterized using X- ray diffraction, SEM, EDX and UV-Visible techniques. X-ray analysis is done by using the Rietveld refinement method of matching the observed and calculated profiles, and then the results obtained from the refinement process are used in finding the electron density distribution by using maximum entropy method (MEM). The local structure analysis of PbS is done by the pair distribution function (PDF). Particle size analysis is done with the use of XRD data, SEM analysis is done in finding the surface structure and EDX in finding the elemental composition of PbS sample. The energy gap of PbS is found from UV-Visible spectrum.

scholarly journals Enhancement of Solubility and Dissolution Rate of Poorly Soluble Drug Nifedipine by Solid Sedds

2020 ◽  
Vol 10 (01) ◽  
pp. 9-15
Author(s):  
Sabitri Bindhani ◽  
Utkalika Mohapatra ◽  
Snehamayee Mohapatra ◽  
Rajat K. Kar
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Dissolution Rate ◽  
Particle Size Analysis ◽  
Sem Analysis ◽  
In Vitro Dissolution ◽  
Size Analysis ◽  
Drug Content

Nifedipine is a dihydropyridine calci channel blocking agent belongs to biopharmaceutical classification system (BCS) class-II mainly applied in the treatment of hypertension and angina-pectoris. The objective of this work is to improve the solubility and dissolution rate of nifedipine by formulating into a solid-self micro emulsifying drug delivery system (solid smedds). Methods: Oil, Surfactant, and cosurfactant were selected by solubility screening study. For the determination of the best emulsion region, a pseudo ternary diagram was prepared. Based on solubility castor oil, tween 80 and polyethylene glycol (PEG) 400 was selected in which SCOSmix (a mixture of surfactant and cosurfactant) was 1:1. Thermodynamic stability study was performed for the determination of stable smedds formulation. These formulations were evaluated for self emulsification time, drug content analysis, robustness to dilution test, particle size analysis, and in vitro diffusion study. The optimized formulation was selected for formulating into solid-smedds by using aerosil 200 at a different ratio. SCF9L (0.65:1) was selected due to its good flow property. Then it was evaluated for particle size analysis, drug content study, differential scanning calorimetry (DSC), X-Ray Diffraction study (XRD), fourier transform infrared spectroscopy (FTIR) Scanning Electron Microscopy study (SEM) analysis, and in vitro dissolution study. Results: DSC and XRD result shows that the drug within the formulation was in the amorphous state. From the SEM analysis, the texture of powder showed a uniform granular structure, and there was no incompatibility between drugs. Excipients was observed from ftir study. From the in vitro dissolution study, it improved the dissolution rate of nifedipine, which was 98.68% of drug release, where pure drug release only 6.75%.

scholarly journals Synthesis and Characterization of PVP-Stabilized Palladium Nanoparticles by XRD, SAXS, SP-ICP-MS, and SEM

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Katharina Walbrück ◽  
Fabian Kuellmer ◽  
Steffen Witzleben ◽  
Klaus Guenther
Keyword(s):  
Palladium Nanoparticles ◽  
Analytical Techniques ◽  
Particle Size Analysis ◽  
Sem Analysis ◽  
Size Analysis ◽  
Palladium Chloride ◽  
Tetraethylene Glycol ◽  
X Ray ◽  
Icp Ms ◽  
Stable Particles

Due to increased emissions of palladium nanoparticles in recent years, it is important to develop analytical techniques to characterize these particles. The synthesis of defined and stable particles plays a key role in this process, as there are not many materials commercially available yet which could act as reference materials. Polyvinylpyrrolidone- (PVP-) stabilized palladium nanoparticles were synthesized through the reduction of palladium chloride by tetraethylene glycol (TEG) in the presence of KOH. Four different methods were used for particle size analysis of the palladium nanoparticles. Palladium suspensions were analyzed by scanning electron microscopy (SEM), small angle X-ray scattering (SAXS), single-particle ICP-MS (SP-ICP-MS), and X-ray diffraction (XRD). Secondary particles between 30 nm and 130 nm were detected in great compliance with SAXS and SP-ICP-MS. SEM analysis showed that the small particulates tend to form agglomerates.

Preparation and Characterization of Co-HA Powder Using Modified Electroless Method

2013 ◽  
Vol 594-595 ◽  
pp. 250-254
Author(s):  
Kasmuin Mohd Zaheruddin ◽  
Sri Asliza Md Amin ◽  
Azmi B. Rahmat ◽  
Shamsul Baharin Jamaludin ◽  
R.A. Khairel
Keyword(s):  
Particle Size ◽  
Lower Cost ◽  
Particle Size Analysis ◽  
Sem Analysis ◽  
Size Analysis ◽  
Cobalt Metal ◽  
Sintering Process ◽  
Electroless Process ◽  
Size Powder

C0-HA composite produced by simple electroless deposition method was studied. From the particle size analysis by Malvern particles analyzer its shows that 19% increment in average of the particle size powder increase after the electroless process with higher cobalt (II) chloride and reduction agent concentration. By EDX and XR-D analysis it was confirmed that cobalt metal was deposited onto HA and contribute to uniform distribution in morphologies by SEM analysis. The Vickers hardness result of up to 430HV was achieved after sintering process at 1250°C. The experimental results demonstrated that the Co-HA powder was successfully prepared by using this method and provide distinct advantages such as uniformity of deposition at lower cost and simple process.

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