scholarly journals Ecofriendly Isolation of Cellulose from Eucalyptus lenceolata: A Novel Approach

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Noor Rehman ◽  
Sultan Alam ◽  
Noor Ul Amin ◽  
Inamullah Mian ◽  
Hidayat Ullah
Keyword(s):  
Infrared Spectroscopy ◽  
Structural Changes ◽  
Analytical Techniques ◽  
Alkaline Treatment ◽  
X Ray Diffraction ◽  
Cellulose Pulp ◽  
Novel Approach ◽  
Multistep Process ◽  
Multistep Procedure ◽  
High Degree

This study reports the extraction of cellulose by means of an environment-friendly multistep procedure involving alkaline treatment and totally chlorine-free bleaching. The multistep process begins with the removal of pectin, cutin, waxes, and other extractives from Eucalyptus lenceolata straw, followed by the removal of hemicelluloses and lignin using an alkaline treatment, and lastly by further delignification of the cellulose pulp through a two-step bleaching process, first with the use of hydrogen peroxide/tetraacetylethylenediamine (TAED) and then with the use of a mixture of acetic and nitric acids. The Eucalyptus lenceolata samples were collected from the mountains of the Malakand division of Khyber Pakhtunkhwa, Pakistan and were ground into smaller particles. The pulp resulting from each step was characterized by infrared spectroscopy (ATR-FTIR) to detect structural changes. The purified cellulose was characterized through different analytical techniques such as Fourier transfer infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The isolated cellulose has a high degree of purity and crystallinity (73%) and thermal stability as verified by XRD and TGA, respectively. SEM was used to study the surface morphology of cellulose, indicating that the surface was free from lignin and hemicelluloses due to the chemical treatment. This study indicates that the multistep procedure is quite adequate for the extraction of cellulose.

What We Really Know About Biosynthesis of Cellulose from Ficus palmate: A Novel Biomass Production

2020 ◽  
Vol 234 (2) ◽  
pp. 313-321 ◽  
Author(s):  
Sultan Alam ◽  
Noor Rehman ◽  
Inamullah Mian ◽  
Hidayat Ullah
Keyword(s):  
Electron Microscopy ◽  
Alkali Treatment ◽  
X Ray Diffraction ◽  
Biomass Waste ◽  
Research Attention ◽  
X Ray ◽  
Multistep Process ◽  
Multistep Procedure ◽  
High Degree ◽  
Scanning Electron

AbstractCurrent research attention has been motivated on the successful synthesis of cellulose from biomass waste of Ficus palmate through multistep process i.e. bleaching and alkali treatment to efficiently eradicate impurities, waxy substances like pectin, cutin, waxes, extractives, hemicellulose and lignin from F. palmate. The cellulose obtained was analyzed by using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM). The isolated cellulose has high degree of purity and crystallinity (61%) and thermal stability as verified by XRD and TGA, respectively. SEM was used for surface morphology and shape. Highly visible pores with channels were detected on the surface. Moreover it also shows that the free surface from lignin and hemicelluloses due to chemical treatment. This study indicates that the multistep procedure is quite adequate for the extraction of cellulose.

scholarly journals Preparation and Properties of Nanocellulose from Miscanthus x giganteus

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Valerii A. Barbash ◽  
Olha V. Yashchenko ◽  
Olesia A. Vasylieva
Keyword(s):  
Structural Changes ◽  
Thermochemical Treatment ◽  
Crystallinity Index ◽  
Alkaline Treatment ◽  
X Ray Diffraction ◽  
Miscanthus X Giganteus ◽  
X Ray ◽  
Second Stage ◽  
20 Nm ◽  
Hydrolysis Of

Miscanthus x giganteus stalks were used to make organosolvent pulp and nanocellulose. The organosolvent miscanthus pulp (OMP) was obtained through thermal treatment in the mixture of glacial acetic acid and hydrogen peroxide at the first stage and the alkaline treatment at the second stage. Hydrolysis of the never-dried OМP was carried out by a solution of sulfuric acid with concentrations of 43% and 50% and followed by ultrasound treatment. Structural changes and the crystallinity index of OMP and nanocellulose were studied by SEM and FTIR methods. X-ray diffraction analysis confirmed an increase in the crystallinity of OMP and nanocellulose as a result of thermochemical treatment. We show that nanocellulose has a density of up to 1.6 g/cm3, transparency up to 82%, and a crystallinity index of 76.5%. The AFM method showed that the particles of nanocellulose have a diameter in the range from 10 to 20 nm. A thermogravimetric analysis confirmed that nanocellulose films have a denser structure and lower mass loss in the temperature range of 320–440°C compared to OMP. The obtained nanocellulose films have high tensile strength up to 195 MPa. The nanocellulose obtained from OMP exhibits the improved properties for the preparation of new nanocomposite materials.

Corrosion Behavior of Electrodeposited Nickel Coating Reinforced by Cr2O3 Particles

2021 ◽  
Vol 406 ◽  
pp. 203-218
Author(s):  
Saida Marmi ◽  
Shahnaz Siad ◽  
Abdelouahad Chala ◽  
Hayat Marmi
Keyword(s):  
Composite Coatings ◽  
Copper Substrate ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Electro Deposition ◽  
Corrosion Tests ◽  
Electrodeposited Nickel ◽  
Composite Deposits ◽  
High Degree ◽  
Deposited Films

The objective of this work is the characterisation of the composite deposits Ni-Cr2O3 on copper substrate; these deposits are obtained from bath of electro-deposition of Nickel watts. The different electrodeposited layers are characterized by various analytical techniques such as adhesion quality, corrosion tests, Vickers microhardness, morphology by scanning electron microscopy Followed by EDX microanalysis and X-ray diffraction. The corrosion tests are realized in a solution of 3.5 % NaCl using lost mass method, polarization and impedance spectroscopy techniques. It was found that the composite coatings Ni-Cr2O3 have an homogeneous and compact morphology, well crystallized and exhibit a high degree of codeposition of Cr2O3 particles incorporated in the nickel matrix. The co-deposited films have very good hardness, adhere perfectly to the substrate and are more resistant to corrosion.

Surface and Electrochemical Analysis of Titanium Submitted to Alkaline Treatment by SEM, XRD and EIS

2008 ◽  
Vol 396-398 ◽  
pp. 381-384 ◽  
Author(s):  
Eduardo Mioduski Szesz ◽  
Cláudia E. B. Marino ◽  
Haroldo A. Ponte ◽  
Fabiana C. Nascimento ◽  
Carlos M. Lepienski ◽  
...  
Keyword(s):  
Structural Changes ◽  
Electrochemical Impedance ◽  
Alkali Treatment ◽  
Sodium Titanate ◽  
Impedance Analysis ◽  
Alkaline Treatment ◽  
Electrochemical Analysis ◽  
Titanium Metal ◽  
X Ray Diffraction ◽  
X Ray

Although titanium metal has been used intensively in the last years as biomaterial in the medical and dental areas its surface is not bioactive. In this work, titanium metal was submitted to an alkali treatment in order to make the metal surface bioactive. The samples were submitted to alkaline treatment (AT) using NaOH 5M aqueous solution at 60°C for 24 h and after that they were heated thermically to stabilize the layer obtained with AT. The bioactivity of the samples was evaluated soaking them into the simulated body fluid (SBF) at 36,5°C for 28 days. The morphological, structural changes and the electrochemical characterization were analyzed using scanning electron microscopy, x-ray diffraction and electrochemical impedance spectroscopy (EIS), respectively. It was verified that after AT plus heat treatment (HT) a sodium titanate layer was formed on the samples surface and after the bioactivity tests an apatite layer was formed. Impedance analysis show that the resistance of film on Ti is high and this value increases when the sample is soaked in SBF. It means that the apatite (HPA) film is occurring and the value of the capacitance with the presence of the HPA film (Cp) values indicate that the film maintain a compact and uniform characteristics.

scholarly journals Facile investigation of reversible nanostructure changes in flexible crystals

2020 ◽  
Author(s):  
Shotaro Hayashi
Keyword(s):  
Structural Changes ◽  
Materials Science ◽  
Organic Crystals ◽  
Bending Stress ◽  
X Ray Diffraction ◽  
Poisson Effect ◽  
X Ray ◽  
Novel Approach ◽  
Quantitative Monitoring ◽  
Macroscopic Deformation

Abstract Detailed investigation of macroscopic deformation and nanoscopic structural changes in flexible organic crystals pose challenges for investigators. Herein, applied stress and subsequent relaxation of elastic organic crystals resulted in reversible macroscopic crystal deformation. X-ray diffraction with a curved jig revealed reversible nanoscopic structural changes in the crystal structure under the bending stress and relaxation. The crystal lattice changed quantitatively under the applied macroscopic stress-strain (%). This method enables quantitative monitoring of the dynamic nanoscopic structural changes in detail associated with crystal deformation through the use of standard laboratory X-ray diffraction analysis. Importantly, the developed method offers a way of quantitatively measuring reversible structural changes, without synchrotron X-ray analysis. Moreover, the analysis derives Poisson’s ratio, i.e., the ratio of the change in the width per unit width of materials. It is important in materials science, normally has a positive value in the range of 0.2–0.5. However, the crystals show not only the "Poisson effect" but also the unusual "negative Poisson effect". This novel approach for investigation generates unprecedented opportunities for understanding dynamic nanostructure changes in flexible organic crystals.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

On the Properties of an Ion Conductive System Incorporated in Hybrid Films

2000 ◽  
Vol 628 ◽  
Author(s):  
G. González ◽  
P. J. Retuert ◽  
S. Fuentes
Keyword(s):  
Electrochemical Impedance ◽  
Ternary Phase Diagram ◽  
Lithium Perchlorate ◽  
Molar Ratio ◽  
Ionic Conductors ◽  
X Ray Diffraction ◽  
Poly Ethylene Oxide ◽  
Ion Conducting ◽  
Poly Ethylene ◽  
High Degree

ABSTRACTBlending the biopolymer chitosan (CHI) with poly (aminopropilsiloxane) oligomers (pAPS), and poly (ethylene oxide) (PEO) in the presence of lithium perchlorate lead to ion conducting products whose conductivity depends on the composition of the mixture. A ternary phase diagram for mixtures containing 0.2 M LiClO4 shows a zone in which the physical properties of the products - transparent, flexible, mechanically robust films - indicate a high degree of molecular compatibilization of the components. Comparison of these films with binary CHI-pAPS nanocomposites as well as the microscopic aspect, thermal behavior, and X-ray diffraction pattern of the product with the composition PEO/CHI/pAPS/LiClO4 1:0.5:0.6:0.2 molar ratio indicates that these films may be described as a layered nanocomposite. In this composite, lithium species coordinated by PEO and pAPS should be inserted into chitosan layers. Electrochemical impedance spectroscopy measurements indicate the films are pure ionic conductors with a maximal bulk conductivity of 1.7*10-5 Scm-1 at 40 °C and a sample-electrode interface capacitance of about 1.2*10-9 F.

Anionic and Cationic Redox Processes in β-Li2IrO3 and Their Structural Implications on Electrochemical Cycling in Li-Ion Cell

2019 ◽  
Author(s):  
Paul Pearce ◽  
Gaurav Assat ◽  
Antonella Iadecola ◽  
François Fauth ◽  
Rémi Dedryvère ◽  
...  
Keyword(s):  
Analytical Techniques ◽  
Charge Compensation ◽  
Coupling Mechanism ◽  
Redox Processes ◽  
Positive Electrodes ◽  
X Ray ◽  
Electrochemical Cycling ◽  
Li Ion ◽  
Electrochemical Instability ◽  
High Degree

The recent discovery of anionic redox as a means to increase the energy density of transition metal oxide positive electrodes is now a well established approach in the Li-ion battery field. However, the science behind this new phenomenon pertaining to various Li-rich materials is still debated. Thus, it is of paramount importance to develop a robust set of analytical techniques to address this issue. Herein, we use a suite of synchrotron-based X-ray spectroscopies as well as diffraction techniques to thoroughly characterize the different redox processes taking place in a model Li-rich compound, the tridimentional hyperhoneycomb β-Li2IrO3. We clearly establish that the reversible removal of Li+ from this compound is associated to a previously described reductive coupling mechanism and the formation of the M-(O-O) and M-(O-O)* states. We further show that the respective contributions to these states determine the spectroscopic response for both Ir L3-edge X-ray absorption spectroscopy (XAS) and X-ray photoemissions spectroscopy (XPS). Although the high covalency and the robust tridimentional structure of this compound enable a high degree of reversibile delithiation, we found that pushing the limits of this charge compensation mechanism has significant effects on the local as well as average structure, leading to electrochemical instability over cycling and voltage decay. Overall, this work highlights the practical limits to which anionic redox can be exploited and sheds some light on the nature of the oxidized species formed in certain lithium-rich compounds.<br>

Anionic and Cationic Redox Processes in β-Li2IrO3 and Their Structural Implications on Electrochemical Cycling in Li-Ion Cell

2019 ◽  
Author(s):  
Paul Pearce ◽  
Gaurav Assat ◽  
Antonella Iadecola ◽  
François Fauth ◽  
Rémi Dedryvère ◽  
...  
Keyword(s):  
Analytical Techniques ◽  
Charge Compensation ◽  
Coupling Mechanism ◽  
Redox Processes ◽  
Positive Electrodes ◽  
X Ray ◽  
Electrochemical Cycling ◽  
Li Ion ◽  
Electrochemical Instability ◽  
High Degree

The recent discovery of anionic redox as a means to increase the energy density of transition metal oxide positive electrodes is now a well established approach in the Li-ion battery field. However, the science behind this new phenomenon pertaining to various Li-rich materials is still debated. Thus, it is of paramount importance to develop a robust set of analytical techniques to address this issue. Herein, we use a suite of synchrotron-based X-ray spectroscopies as well as diffraction techniques to thoroughly characterize the different redox processes taking place in a model Li-rich compound, the tridimentional hyperhoneycomb β-Li2IrO3. We clearly establish that the reversible removal of Li+ from this compound is associated to a previously described reductive coupling mechanism and the formation of the M-(O-O) and M-(O-O)* states. We further show that the respective contributions to these states determine the spectroscopic response for both Ir L3-edge X-ray absorption spectroscopy (XAS) and X-ray photoemissions spectroscopy (XPS). Although the high covalency and the robust tridimentional structure of this compound enable a high degree of reversibile delithiation, we found that pushing the limits of this charge compensation mechanism has significant effects on the local as well as average structure, leading to electrochemical instability over cycling and voltage decay. Overall, this work highlights the practical limits to which anionic redox can be exploited and sheds some light on the nature of the oxidized species formed in certain lithium-rich compounds.<br>

Sign in / Sign up

Export Citation Format

Share Document