scholarly journals Enhancing Removal of Cr(VI), Pb2+, and Cu2+ from Aqueous Solutions Using Amino-Functionalized Cellulose Nanocrystal

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7315
Author(s):  
Qinghua Xu ◽  
Xiaodi Huang ◽  
Lukuan Guo ◽  
Yu Wang ◽  
Liqiang Jin
Keyword(s):  
Aqueous Solutions ◽  
Cellulose Nanocrystal ◽  
X Ray Diffraction ◽  
Potential Measurement ◽  
Force Microscopy ◽  
Atomic Force ◽  
Adsorption Capacities ◽  
Green Route ◽  
Pseudo Second Order ◽  
Ft Ir

In this work, the amino-functionalized cellulose nanocrystal (ACNC) was prepared using a green route and applied as a biosorbent for adsorption of Cr(VI), Pb2+, and Cu2+ from aqueous solutions. CNC was firstly oxidized by sodium periodate to yield the dialdehyde nanocellulose (DACNC). Then, DACNC reacted with diethylenetriamine (DETA) to obtain amino-functionalized nanocellulose (ACNC) through a Schiff base reaction. The properties of DACNC and ACNC were characterized by using elemental analysis, Fourier transform infrared spectroscopy (FT-IR), Kaiser test, atomic force microscopy (AFM), X-ray diffraction (XRD), and zeta potential measurement. The presence of free amino groups was evidenced by the FT-IR results and Kaiser test. ACNCs exhibited an amphoteric nature with isoelectric points between pH 8 and 9. After the chemical modification, the cellulose I polymorph of nanocellulose remained, while the crystallinity decreased. The adsorption behavior of ACNC was investigated for the removal of Cr(VI), Pb2+, and Cu2+ in aqueous solutions. The maximum adsorption capacities were obtained at pH 2 for Cr(VI) and pH 6 for Cu2+ and Pb2+, respectively. The adsorption all followed pseudo second-order kinetics and Sips adsorption isotherms. The estimated adsorption capacities for Cr(VI), Pb2+, and Cu2+ were 70.503, 54.115, and 49.600 mg/g, respectively.

scholarly journals Optical, Structural and Electrical Properties of Electrochemical Synthesis of Thin Film of Polyaniline

2018 ◽  
Vol 15 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Morphological Studies ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Structural And Electrical Properties ◽  
A Cell ◽  
Ft Ir ◽  
Ir And Raman

Polyaniline membranes of aniline were produced using an electrochemical method in a cell consisting of two poles. The effect of the vaccination was observed on the color of membranes of polyaniline, where analysis as of blue to olive green paints. The sanction of PANI was done by FT-IR and Raman techniques. The crystallinity of the models was studied by X-ray diffraction technique. The different electronic transitions of the PANI were determined by UV-VIS spectroscopy. The electrical conductivity of the manufactured samples was measured by using the four-probe technique at room temperature. Morphological studies have been determined by Atomic force microscopy (AFM). The structural studies have been measured by (SEM).

scholarly journals Preparation of Nanochitosan as an Effective Adsorbent for Removal of Pb (II) From Aqueous Solution

2019 ◽  
Author(s):  
Camellia Zareie ◽  
Saeideh Kholghi Eshkalak ◽  
Ghasem Najafpour Darzi ◽  
Mazyar Sharifzadeh baei ◽  
Habibollah Younesi ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Ph Value ◽  
Sorption Process ◽  
Sorption Data ◽  
Kinetics Of Adsorption ◽  
Force Microscopy ◽  
Freundlich Isotherms ◽  
Atomic Force ◽  
Pseudo Second Order ◽  
Sorption Parameters

In this work, nanochitosan (NC) was prepared through ionic gelation using low-molecular-weight chitosan and maleic acid (MA). The synthesized NC was charac¬terized by means of Fourier Transform Infrared Spectroscopy (FTIR), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). In the course of preparation, the particle size of the material was strongly depended on the parameters such as chitosan concentration and pH of the solution. By controlling the above parameters, NC with the size of smaller than 100 nm was prepared. The chitosan and prepared NC were used for the adsorption of Pb (II) from aqueous solutions in a batch system. Among the sorption parameters, pH showed the strongest effect on the sorption process and maximum Pb (II) removal was obtained at pH value of 6. The pseudo-first-order and pseudo-second-order were used to track the kinetics of adsorption process. Langmuir and Freundlich isotherms were subjected to sorption data to estimate the sorption capacity. NC proved to be an excellent adsorbent with remarkable capacity to remove Pb (II) ions from the aqueous solutions at various concentrations. The NC also showed incredible performance with a comparatively easier preparation process than other reported work.

Compositionally Modified Hydroxyapatite Nanocrystals for Polymer/Ceramic Scaffold Applications

2005 ◽  
Vol 897 ◽  
Author(s):  
Andrei Stanishevsky ◽  
Peserai Chinoda ◽  
Shafiul Chowdhury ◽  
Vinoy Thomas ◽  
Aaron Catledge ◽  
...  
Keyword(s):  
Polymeric Materials ◽  
Chemical Precipitation ◽  
X Ray Diffraction ◽  
Tissue Engineering Scaffolds ◽  
Force Microscopy ◽  
Ceramic Scaffold ◽  
Atomic Force ◽  
Ft Ir ◽  
Hydroxyapatite Nanocrystals ◽  
Bioresorbable Implants

AbstractThe polymer/bioceramic composite materials attract much attention for the development of bioresorbable implants and tissue engineering scaffolds. Hydroxyapatite (HA) is the most commonly used bioceramic material due to its similarity to the major mineral component of the hard tissue. We synthesized carbonated and Mg-substituted HA nanocrystals with various concentrations of CO32− and Mg2+ ions by chemical precipitation in the range of the process temperatures from 25 °C to 100 °C.The HA nanocrystals were mixed with several polymeric materials (PCL, PLA, PVA, collagen) to fabricate bulk and nanofiber polymer/HA nanoparticle composites with the HA loading up to 80 % by weight. The HA nanocrystals and polymer/HA composites were characterized by X-ray diffraction, FT-IR spectroscopy, scanning electron and atomic force microscopy. Mechanical properties of the composites were investigated using nanoindentation technique.

scholarly journals Synthesis and Self-Assembling Properties of Peracetylated β-1-Triazolyl Alkyl D-Glucosides and D-Galactosides

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 935-958
Author(s):  
Pooja Sharma ◽  
Anji Chen ◽  
Dan Wang ◽  
Guijun Wang
Keyword(s):  
Functional Materials ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Self Assembling ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Potential Applications ◽  
Ft Ir ◽  
Low Molecular Weight Gelators ◽  
Glucose Derivatives

Carbohydrate-based low-molecular-weight gelators (LMWGs) are useful classes of compounds due to their numerous applications. Among sugar-based LMWGs, certain peracetylated sugar beta-triazole derivatives were found to be effective organogelators and showed interesting self-assembling properties. To further understand the structural influence towards molecular assemblies and obtain new functional materials with interesting properties, we designed and synthesized a library of tetraacetyl beta-1-triazolyl alkyl-D-glucosides and D-galactosides, in which a two or three carbon spacer is inserted between the anomeric position and the triazole moiety. A series of 16 glucose derivatives and 14 galactose derivatives were synthesized and analyzed. The self-assembling properties of these new triazole containing glycoconjugates in different solvents were analyzed. Several glucose derivatives were found to be effective LMWGs, with compound 7a forming gels in a variety of organic solvents as well as in the presence of metal ions in aqueous solutions. The organogels formed by several compounds were characterized using optical microscopy, atomic force microscopy (AFM) and UV-vis spectroscopy, etc. The co-gels formed by compound 7a with the Fmoc derivative 7i showed interesting fluorescence enhancement upon gelation. Several gelators were also characterized using powder X-ray diffraction and FT-IR spectroscopy. The potential applications of these sugar-based gelators for drug delivery and dye removal were also studied.

scholarly journals Nanocomposites of Magnetite and Layered Double Hydroxide for Recyclable Chromate Removal

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Gyeong-Hyeon Gwak ◽  
Min-Kyu Kim ◽  
Jae-Min Oh
Keyword(s):  
Layered Double Hydroxide ◽  
Magnetite Nanoparticles ◽  
X Ray Diffraction ◽  
Potential Measurement ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
House Of Cards ◽  
Double Hydroxide ◽  
Scanning Electron

Nanocomposites containing magnetic iron oxide (magnetite) nanoparticles and layered double hydroxide (LDH) nanosheets were prepared by two different methods, exfoliation-reassembly and coprecipitation, for aqueous chromate adsorbent. According to X-ray diffraction, scanning electron microscopy, and atomic force microscopy, both nanocomposites were determined to develop different nanostructures; LDH nanosheets well covered magnetite nanoparticles with house-of-cards-like structure in exfoliation-reassembly method, while coprecipitation resulted in LDH particle formation along with magnetite nanoparticles. Zeta-potential measurement also revealed that the magnetite surface was effectively covered by LDH moiety in exfoliation-reassembly compared with coprecipitation. Time, pH, concentration dependent chromate adsorption tests, and magnetic separation experiments exhibited that both nanocomposites effectively adsorb and easily collect chromate. However, exfoliation-reassembly nanocomposite was determined to be slightly effective in chromate removal by ~10%. Chromate adsorbed nanocomposites could be regenerated by treating with bicarbonate and the regenerated nanocomposites preserved ~80% of chromate adsorption efficacy after three times of recycling.

scholarly journals Ultrasonic Preparation of PN For The Photodegradation of 17ß-Estradiol In Water And Biotoxicity Assessment Of E2 After Degradation

2021 ◽  
Author(s):  
Kun Meng ◽  
Ke-Fu Zhou ◽  
Nhat-Thien Nguyen ◽  
Bor-Yann Chen ◽  
Min Long ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solutions ◽  
Energy Dispersive Spectrometer ◽  
Degradation Efficiency ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Synergistic Interactions ◽  
Atomic Force ◽  
Weight Content ◽  
Transmission Electron

Abstract This study prepared a novel Phosphorene (PN) and load it onto TiO2 to fabricated PN-TiO2, to effectively photo degrade the hydrophobic environmental hormone 17ß-estradiol in aqueous solutions. First, the corresponding characterization of prepared materials was implemented by myriads of methods (e.g, atomic force microscopy), transmission electron microscopy, scanning electron microscopy, energy dispersive spectrometer, X-ray diffraction and Raman spectroscopy. Next, the effect of the PN on the degradation efficiency was systematically investigated. Apparently, the doping of TiO2 by PN significantly enhanced its photocatalytic and adsorption properties with the addition of PN, compared to that in the absence of TiO2. That is the addition improved the adsorption capability of the composite. The optimal PN weight content was found to be 0.5%. However, the photo degradation efficiency gradually decreased when the PN content increased further. This optimal PN content directly suggested synergistic interactions upon the photo degrading efficiency. Compare to other PN-based photocatalysts mentioned in literature, this PN-based material owned striking advantages, such as higher energy efficiency, greater remove capacity, and superior cost-effectiveness. Further, biotoxicity of the water after treatment decreased was evident by observing the development of zebrafish embryos. In conclusion, the prepared PN-based materials exhibited promising photocatalytic capabilities for removal and biotoxicity reduction of 17ß-estradiol in aqueous solutions.

scholarly journals One Step Mechanosynthesis of Graphene Oxide Directly from Graphite

2019 ◽  
Author(s):  
Victor Ibarra ◽  
Demetrio Mendoza ◽  
Alma Sanchez ◽  
Rosa Vazquez ◽  
Karina Aleman ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Thermogravimetric Analysis ◽  
Spectroscopic Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
One Step ◽  
Ft Ir ◽  
Scanning Electron

Graphene oxide was synthesized by a one-step environmentally friendly mechanochemistry process directly from graphite and characterized by Raman, FT-IR and UV/vis spectroscopies, Atomic Force Microscopy, X-ray Diffraction, Scanning Electron Microscopy, Energy-Dispersive X-ray Spectroscopy and Thermogravimetric Analysis. Spectroscopic analysis shows that the functional groups and oxygen content of the synthesized material are comparable with those of graphene oxide synthesized by other previously reported methods (Hummers). Thermogravimetric analysis reveals thermal stability up to 400 °C.

MOD oxide buffer layers on metallic substrates for YBCO coated conductors

2013 ◽  
Vol 1579 ◽  
Author(s):  
A. Augieri ◽  
M.R. Mancini ◽  
A. Vannozzi ◽  
A. A. Angrisani ◽  
F. Fabbri ◽  
...  
Keyword(s):  
Coated Conductors ◽  
Buffer Layers ◽  
Recrystallization Process ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Metallic Substrates ◽  
Force Microscopy ◽  
Atomic Force ◽  
Metal Organic ◽  
Ft Ir

ABSTRACTWe present a detailed study carried out on oxide buffer layers grown by Metal-Organic Decomposition (MOD) on metallic substrates for YBa2Cu3O7-x (YBCO) coated conductor applications. Precursor solutions have been made starting from acetates or pentanedionates and characterized by means of Differential Scanning Calorimetry (DSC) and Thermogravimetric (TG) analyses coupled with Fourier Transform Infra-Red spectroscopy (FT-IR). Thin buffer layers have been grown by spin-coating on Ni-5at.%W substrates. X-ray diffraction spectra (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) have been employed in order to optimize buffer layers in terms of film microstructure and surface quality, with the final aims of producing a suitable template for YBCO growth. It will be shown that the optimization of the recrystallization process can lead to high quality buffer layer allowing the growth of YBCO films showing good superconductive properties.

Characterization of Areva javanica fiber – A possible replacement for synthetic acrylic fiber in the disc brake pad

2018 ◽  
Vol 49 (3) ◽  
pp. 294-317 ◽  
Author(s):  
Md Javeed Ahmed ◽  
MA Sai Balaji ◽  
SS Saravanakumar ◽  
MR Sanjay ◽  
P Senthamaraikannan
Keyword(s):  
Wear Test ◽  
Disc Brake ◽  
Brake Pad ◽  
X Ray Diffraction ◽  
Acrylic Fiber ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ft Ir

Areva javanica (AJ), a natural cotton flowers fiber of Amaranthaceae family was taken up for the study of its possible utilization in a friction composite. The chemical composition of Areva javanica fiber (AJF) such as cellulose, lignin, ash, moisture, wax content, and density was evaluated. In addition to these, Fourier transform infrared (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimeter (DSC) tests were performed. The surface roughness of AJ fiber was estimated using atomic force microscopy (AFM) and the statistical analysis using Weibull distribution was carried out to identify the diameter of AJ fiber. TGA studies revealed its moderate thermal resistance upto 219℃, and a density of 1.4005 g/cc was estimated of AJF. An attempt was made to make use of the AJF as a potential reinforcement material for acrylic fibers in an organic disc brake pad formulation. Upon fibrization, AJ fibrillates and forms a dense structure, a vital property required for the production of a brake pad. The role of AJ fiber in brake pad was studied by investigating the behavior of fibers from the mixing stage to the cured brake pad. Results revealed that the developed brake pad had a density of 2.01 g/cc, hardness HRS 91, Loss on ignition 21.68%, and cold and hot shear strengths of 44 and 27 kg/cm2, respectively. These values were very close to that of an Acrylic fiber based brake pad. The wear test using Friction Assessment and Screening test (FAST) gave the wear percentage of 0.0187 in3/Hp-h which was found to be 16% higher than AJF (0.0159 in3/Hp-hr) based brake pad.

scholarly journals Microscopic and spectroscopic investigation of the calcite surface interacted with Hg(II) in aqueous solutions

2003 ◽  
Vol 67 (6) ◽  
pp. 1193-1204 ◽  
Author(s):  
A. Godelitsas ◽  
J. M. Astilleros ◽  
K. R. Hallam ◽  
J. Löns ◽  
A. Putnis
Keyword(s):  
Aqueous Solutions ◽  
Photoelectron Spectroscopy ◽  
Spectroscopic Techniques ◽  
Acetate Anion ◽  
Etch Pits ◽  
Force Microscopy ◽  
Surface Microtopography ◽  
Atomic Force ◽  
Ft Ir ◽  
Xrd Patterns

AbstractThe interaction of the {101̄4} cleavage surface of calcite with Hg(CH3COO)2 aqueous solutions with concentration of 5 mM Hg(II) (pH ≈3.5), was investigated using microscopic and spectroscopic techniques. In situ atomic force microscopy experiments showed that surface microtopography changes significantly as a result of the interaction, and that the initial rhombic etch pits induced by H2O dissolution are rapidly transformed to deeper etch pits exhibiting an unusual triangular shape. The growth of these etch pits is strongly anisotropic, moving faster along the [22̄1] direction than along the [010] direction (with step-retreat velocities of ∼12 nm s –1 and ∼4 nm s–1, respectively). The modified etch pits are due to Hg(II) sorption in the surface, rather than due to the effect of the acetate anion. The sorption (adsorption and probably absorption also) of Hg(II), in the first minutes of the interaction, is shown by X-ray photoelectron spectroscopy. After ∼2 h, the triangular etch pits are interconnected to form larger hexagonal etch pits, while Hg(II)-bearing phases (confirmed later by SEM-EDS) grow onto the surface through a heterogeneous nucleation process. The crystal growth of orthorhombic (montroydite-type) hydrated Hg(II) oxide (HgO·nH2O) on the surface of calcite was confirmed by XRD patterns and FT-IR spectra from samples exposed for longer times to Hg(CH3COO)2 solution.

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