scholarly journals Structural, morphological and thermal properties of microcrystalline cellulose extracted from coconut husk fiber

Polimery ◽  
2021 ◽  
Vol 66 (3) ◽  
pp. 187-192
Author(s):  
Nur Athirah Abdullah ◽  
Muhammad Hanif Sainorudin ◽  
Mohd Saiful Asmal Rani ◽  
Masita Mohammad ◽  
Nurul Huda Abd Kadir ◽  
...  
Keyword(s):  
Cross Section ◽  
Microcrystalline Cellulose ◽  
Potassium Hydroxide ◽  
Sodium Chlorite ◽  
Solubility Test ◽  
X Ray ◽  
Chemical Treatments ◽  
Coconut Husk ◽  
Commercial Grade ◽  
Thermal Stability Of

In this work, chemically treated microcrystalline cellulose (MCC-C) was extracted from coconut husk fiber. In order to extract hemicellulose, the sieved coconut husk fiber was treated with sodium hydroxide (NaOH) for dewaxing and acidified using sodium chlorite (NaClO2) to extract the residual lignin (bleaching process). The obtained lignin-free cellulose was then treated with potassium hydroxide (KOH). The characterizations used to equate the MCC-C with commercial grade microcrystalline cellulose (MCC) are solubility test, X-ray diffractogram (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The XRD showed that the crystallinity of MCC and MCC-C increased significantly by 80.15% and 71.8% by chemical treatments. TGA found that the active removal of lignin-hemicelluloses and the thermal stability of the material were about 350–500°C and 300–500°C. The morphology of the fiber confirmed that there is an irregular cross-section, non-uniform surface, a large amount of short microfibrils and some impurities on the surface of the coconut husk fiber. The findings showed that microcrystalline cellulose has been successfully extracted from coconut husk fiber and that it can be used further.

scholarly journals Morphological, Physiochemical and Thermal Properties of Microcrystalline Cellulose (MCC) Extracted from Bamboo Fiber

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2824 ◽  
Author(s):  
Masrat Rasheed ◽  
Mohammad Jawaid ◽  
Zoheb Karim ◽  
Luqman Chuah Abdullah
Keyword(s):  
Microcrystalline Cellulose ◽  
Building Materials ◽  
Starting Material ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Bamboo Pulp ◽  
Bamboo Fibers ◽  
Thermal Stability Of

Bamboo fibers are utilized for the production of various structures, building materials, etc. and is of great significance all over the world especially in southeast Asia. In this study, the extraction of microcrystalline cellulose (MCC) was performed using bamboo fibers through acid hydrolysis and subsequently different characterizations were carried out using various advanced techniques. Fourier transform infrared (FTIR) spectroscopy analysis has indicated the removal of lignin from MCC extracted from bamboo pulp. Scanning Electron Microscopy (SEM) revealed rough surface and minor agglomeration of the MCC. Pure MCC, albeit with small quantities of impurities and residues, was obtained, as revealed by Energy Dispersive X-ray (EDX) analysis. X-ray diffraction (XRD) indicates the increase in crystallinity from 62.5% to 82.6%. Furthermore, the isolated MCC has slightly higher crystallinity compared to commercial available MCC (74%). The results of thermal gravimetric analysis (TGA) demonstrate better thermal stability of isolated MCC compared to its starting material (Bamboo fibers). Thus, the isolated MCC might be used as a reinforcing element for the production of green composites and it can also be utilized as a starting material for the production of crystalline nanocellulose in future.

scholarly journals Influence of Chemical Treatments Sequence on Morphology and Crystallinity of Sorghum Fibers

2018 ◽  
Vol 18 (2) ◽  
pp. 349 ◽  
Author(s):  
Ismojo Ismojo ◽  
Abdul Aziz Ammar ◽  
Ghiska Ramahdita ◽  
Anne Zulfia ◽  
Mochamad Chalid
Keyword(s):  
Crystallinity Index ◽  
Natural Fibre ◽  
Sodium Chlorite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Treatments ◽  
Infra Red ◽  
Promising Area ◽  
Enhanced Crystallinity ◽  
Amorphous Part

Micro-fibrillated cellulose (MFC) derived from natural fibre is continuously gaining interest to produce an environmentally-friendly material, due to economic and ecological reasons. In consequence, sorghum is one of the most-cultivated crops that usually remain the waste as by product of bioethanol production. Indeed, it will be a promising area to utilize sorghum waste to produce MFC for enhancing polymer performance, especially in terms of crystallinity. The objective of this study is to investigate the effect of a sequence of chemical modification was applied to sorghum fibres, i.e. alkalization using 4% sodium hydroxide followed by bleaching using 1.7% sodium chlorite plus acetic acid as a buffer. The treatment was purposed to unbundle the lignocellulose networks into microfibrils cellulose with less amorphous part and lower hydrophilic properties. Evaluation of the chemical treatments effect on internal microstructure, crystallinity index and chemical composition of sorghum fibre was measured via Field-Emission Scanning Electron microscope (FE-SEM), X-ray Diffraction (XRD) and Fourier Transformation Infra-Red (FTIR) Spectroscopy. The experiments show that treatments led to a removal of binding materials, such as amorphous parts hemicellulose and lignin, from the sorghum fibres, resulting MFC of sorghum fibres and enhanced crystallinity index from 41.12 % to 75.73%.

scholarly journals Preparation of Microcrystalline Cellulose from Oil Palm Empty Fruit Bunch Fibre Using Steam-Assisted Acid Hydrolysis

2021 ◽  
Vol 81 (1) ◽  
pp. 88-98
Author(s):  
Fatiha Ismail ◽  
Nur Eliyanti Ali Othman ◽  
Noorshamsiana Abdul Wahab ◽  
Fazliana Abdul Hamid ◽  
Astimar Abdul Aziz
Keyword(s):  
Thermal Stability ◽  
Acid Hydrolysis ◽  
Microcrystalline Cellulose ◽  
Crystallinity Index ◽  
Steam Treatment ◽  
Empty Fruit Bunch ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Stability Of ◽  
Scanning Electron

The isolation of microcrystalline cellulose (MCC) from empty fruit bunch fibre (EFB-fibre) using acid hydrolysis through steam treatment (autoclave) followed by ultrasonication has been successfully established. The important parameter studied was the concentration of sulphuric acid (5%, 15% and 25%) at variable fixed reaction time and temperature. The resulting MCC was characterized using FTIR, TGA, XRD and SEM. FTIR transmission at 1163 cm-1 confirmed that the structure of cellulose was retained after undergoing acid hydrolysis. Thermal stability of MCC increased after being treated with H2SO4, which was determined using TG analysis. The morphological features were identified using Scanning Electron microscope (SEM), which showed the diameters of MCC to be in the range of 10 to 200 µm. The structural property of MCC was studied using X-ray diffraction (XRD) and the results showed that the MCC produced has crystallinity index of 72%. The results revealed that the parameters used tend to influence the physicochemical properties of MCC produced. Therefore, the MCC isolated from EFB fibres will be used as precursor for future EFB derived nanocellulose as well as a promising subject in nanocomposite research.

scholarly journals Synthesis of microcrystalline cellulose from pretreated cotton obtained from Bombax ceiba L. and its characterization

2015 ◽  
Vol 50 (3) ◽  
pp. 199-204 ◽  
Author(s):  
SM Haque ◽  
AA Chowdhury ◽  
AA Rana ◽  
SM Masum ◽  
T Ferdous ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Microcrystalline Cellulose ◽  
Cellulose Content ◽  
Gravimetric Analysis ◽  
Particle Characterization ◽  
Polymeric Form ◽  
Commercial Grade ◽  
Hausner Ratio ◽  
Thermal Stability Of

Microcrystalline cellulose (MCC) is an important ingredient in pharmaceutical, food, cosmetic and other industries. Microcrystalline cellulose was synthesized from the alpha cellulose content of pretreated cotton, Bombax ceiba L. by hydrochloric acid hydrolysis. The prepared microcrystalline cellulose was characterized by determining some physicochemical properties such as pH, angle of response, Carr’s index, Hausner ratio, moisture content etc and compared with commercial-grade microcrystalline cellulose that is used in pharmaceutical industry as excipient. Scanning electron microscope (SEM) and FTIR data represented the structure and particle characterization of sample. Thermal gravimetric analysis (TGA) showed the thermal stability of the sample. The results showed that the yield of microcrystalline cellulose was about 85% and compared favorably with the commercial grade microcrystalline cellulose as well as conformed official specifications for microcrystalline cellulose in British Pharmacopeia. It was also found that the duration of acid hydrolysis affected the polymeric form of the processed alpha cellulose.Bangladesh J. Sci. Ind. Res. 50(3), 199-204, 2015

Freeze-Fracture Replication of Frozen Outer Segments of Rat Retinal Rods

1969 ◽  
Vol 27 ◽  
pp. 392-393
Author(s):  
Thomas S. Leeson ◽  
C. Roland Leeson
Keyword(s):  
Electron Microscopy ◽  
Cross Section ◽  
Outer Segment ◽  
Freeze Fracture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Outer Segments ◽  
Retinal Rods ◽  
Temperature Electron ◽  
Freeze Etching

Numerous previous studies of outer segments of retinal receptors have demonstrated a complex internal structure of a series of transversely orientated membranous lamellae, discs, or saccules. In cones, these lamellae probably are invaginations of the covering plasma membrane. In rods, however, they appear to be isolated and separate discs although some authors report interconnections and some continuities with the surface near the base of the outer segment, i.e. toward the inner segment. In some species, variations have been reported, such as longitudinally orientated lamellae and lamellar whorls. In cross section, the discs or saccules show one or more incisures. The saccules probably contain photolabile pigment, with resulting potentials after dipole formation during bleaching of pigment. Continuity between the lamina of rod saccules and extracellular space may be necessary for the detection of dipoles, although such continuity usually is not found by electron microscopy. Particles on the membranes have been found by low angle X-ray diffraction, by low temperature electron microscopy and by freeze-etching techniques.

Studies of metaphase chromosomes in the scanning transmission x-ray microscope: Image fidelity, radiation damage and specimen preparation

1992 ◽  
Vol 50 (2) ◽  
pp. 1038-1039
Author(s):  
Shawn Williams ◽  
Xiaodong Zhang ◽  
Susan Lamm ◽  
Jack Van’t Hof
Keyword(s):  
Visible Light ◽  
Radiation Damage ◽  
Cross Section ◽  
Imaging Techniques ◽  
Dose Range ◽  
Specimen Preparation ◽  
X Rays ◽  
Metaphase Chromosomes ◽  
X Ray ◽  
Scanning Transmission

The Scanning Transmission X-ray Microscope (STXM) is well suited for investigating metaphase chromosome structure. The absorption cross-section of soft x-rays having energies between the carbon and oxygen K edges (284 - 531 eV) is 6 - 9.5 times greater for organic specimens than for water, which permits one to examine unstained, wet biological specimens with resolution superior to that attainable using visible light. The attenuation length of the x-rays is suitable for imaging micron thick specimens without sectioning. This large difference in cross-section yields good specimen contrast, so that fewer soft x-rays than electrons are required to image wet biological specimens at a given resolution. But most imaging techniques delivering better resolution than visible light produce radiation damage. Soft x-rays are known to be very effective in damaging biological specimens. The STXM is constructed to minimize specimen dose, but it is important to measure the actual damage induced as a function of dose in order to determine the dose range within which radiation damage does not compromise image quality.

Searching for the causes why some of the paintings by Mihaly Munkacsy are darkening

1990 ◽  
Vol 48 (2) ◽  
pp. 204-205
Author(s):  
Imre Pozsgai ◽  
Klara Erdöhalmi-Torok
Keyword(s):  
Electron Beam ◽  
Cross Section ◽  
Polyester Resin ◽  
National Gallery ◽  
X Ray ◽  
Art Historians ◽  
Made In ◽  
Grinding And Polishing

The paintings by the great Hungarian master Mihaly Munkacsy (1844-1900) made in an 8-9 years period of his activity are deteriorating. The most conspicuous sign of the deterioration is an intensive darkening. We have made an attempt by electron beam microanalysis to clarify the causes of the darkening. The importance of a study like this is increased by the fact that a similar darkening can be observed on the paintings by Munkacsy’s contemporaries e.g Courbet and Makart. A thick brown mass the so called bitumen used by Munkacsy for grounding and also as a paint is believed by the art historians to cause the darkening.For this study, paint specimens were taken from the following paintings: “Studio”, “Farewell” and the “Portrait of the Master’s Wife”, all of them are the property of the Hungarian National Gallery. The paint samples were embedded in a polyester resin “Poly-Pol PS-230” and after grinding and polishing their cross section was used for x-ray mapping.

Fractionation of polymethylene chains: An electron crystallographic investigation

1986 ◽  
Vol 44 ◽  
pp. 794-795
Author(s):  
Douglas L. Dorset
Keyword(s):  
Cross Section ◽  
Binary Systems ◽  
Linear Chain ◽  
Pure Component ◽  
Organic Substrates ◽  
Crystallographic Investigation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Sizes ◽  
The Stability

A variety of linear chain materials exist as polydisperse systems which are difficultly purified. The stability of continuous binary solid solutions assume that the Gibbs free energy of the solution is lower than that of either crystal component, a condition which includes such factors as relative molecular sizes and shapes and perhaps the symmetry of the pure component crystal structures.Although extensive studies of n-alkane miscibility have been carried out via powder X-ray diffraction of bulk samples we have begun to examine binary systems as single crystals, taking advantage of the well-known enhanced scattering cross section of matter for electrons and also the favorable projection of a paraffin crystal structure posited by epitaxial crystallization of such samples on organic substrates such as benzoic acid.

Low-voltage EDS of magnesium ferrite Dendrites in a FEG-SEM

1996 ◽  
Vol 54 ◽  
pp. 478-479
Author(s):  
Matthew T. Johnson ◽  
Ian M. Anderson ◽  
Jim Bentley ◽  
C. Barry Carter
Keyword(s):  
Monte Carlo ◽  
Quantitative Analysis ◽  
Monte Carlo Simulations ◽  
Cross Section ◽  
Spatial Resolution ◽  
Low Voltage ◽  
Magnesium Ferrite ◽  
X Ray ◽  
Interaction Volume ◽  
Ferrite Spinel

Energy-dispersive X-ray spectrometry (EDS) performed at low (≤ 5 kV) accelerating voltages in the SEM has the potential for providing quantitative microanalytical information with a spatial resolution of ∼100 nm. In the present work, EDS analyses were performed on magnesium ferrite spinel [(MgxFe1−x)Fe2O4] dendrites embedded in a MgO matrix, as shown in Fig. 1. spatial resolution of X-ray microanalysis at conventional accelerating voltages is insufficient for the quantitative analysis of these dendrites, which have widths of the order of a few hundred nanometers, without deconvolution of contributions from the MgO matrix. However, Monte Carlo simulations indicate that the interaction volume for MgFe2O4 is ∼150 nm at 3 kV accelerating voltage and therefore sufficient to analyze the dendrites without matrix contributions.Single-crystal {001}-oriented MgO was reacted with hematite (Fe2O3) powder for 6 h at 1450°C in air and furnace cooled. The specimen was then cleaved to expose a clean cross-section suitable for microanalysis.

Analysis of crystallite size changes in a hematite and magnetite formed on steel used in the power idustry

2017 ◽  
Vol 1 (21) ◽  
pp. 65-73
Author(s):  
Monika Gwoździk
Keyword(s):  
Elevated Temperature ◽  
Oxide Layer ◽  
Cross Section ◽  
X Ray ◽  
Term Operation ◽  
Diffraction Line Profile ◽  
Crystallite Sizes ◽  
Scherrer Formula ◽  
Pipe Outlet

The paper presents results of studies on the crystallite sizes of oxide layer formed during a long-term operation on 10CrMo9-10 steel at an elevated temperature (T = 545° C, t = 200,000 h). This value was determined by a method based on analysis of the diffraction line profile, according to a Scherrer formula. The oxide layer was studied on a surface and a cross-section at the outer and inner site on the pipe outlet, at the fire and counter-fire wall of the tube. X-ray studies were carried out on the surface of a tube, then the layer’s surface was polished and the diffraction measurements repeated to reveal differences in the originated oxides layer.

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