The Effect of Strong Alkali Treatment on the Cell-Wall Structure of Ramie Fiber

1977 ◽  
Vol 47 (6) ◽  
pp. 437-440 ◽  
Author(s):  
P. K. Ray ◽  
B. K. Das
Keyword(s):  
Cell Wall ◽  
Sodium Hydroxide ◽  
Room Temperature ◽  
Sodium Hydroxide Solution ◽  
Alkali Treatment ◽  
Wall Structure ◽  
Ramie Fiber ◽  
Cellulose Ii ◽  
X Ray ◽  
Sodium Hydroxide Treatment

Transverse sections of degummed ramie fiber, after treatment with 24% w/w sodium hydroxide solution at room temperature and the boiling condition, have been examined by light microscopy. The peripheral S1 layer of the secondary wall is not distinctly visible in most of the transverse sections of the fibers after sodium hydroxide treatment at boil. X-ray diagrams of the fibers showed that the conversion to cellulose II was complete in both the conditions of treatment. The microfibrillar orientation and mechanical properties of the fibers were in harmony with the change in the structure of the cell wall.

A Novel Alkali-Metal Hydrido-tris(pyrazolyl)borate (Tp*) Complex. Isolation and Crystal Structure of [(Me2CO)3(NaTp*)2]

2014 ◽  
Vol 69 (7) ◽  
pp. 793-798
Author(s):  
Laurent Plasseraud ◽  
Hélène Cattey
Keyword(s):  
Crystal Structure ◽  
Alkali Metal ◽  
Sodium Hydroxide ◽  
Title Compound ◽  
Room Temperature ◽  
Crystallographic Analysis ◽  
Monoclinic Space Group ◽  
Large Excess ◽  
X Ray ◽  
Acetone Water

The title compound was isolated from the treatment of Tp*Sn(Cl)2Bu (1) with a large excess of sodium hydroxide in a mixture of acetone-water at room temperature. [(Me2CO)3(NaTp*)2] (2) crystallizes at 4 °C as prismatic colorless crystals, in the monoclinic space group P21/c with Z = 4, a = 12.2837(6), b = 24.3197(12), c = 16.9547(8) Å, β = 110.017(1)°, and V = 4759.0(4) Å3. The X-ray crystallographic analysis revealed a dinuclear unit in which two Tp*Na moieties are held together by three bridging acetone molecules acting as oxygen-based donors.

Fine structure in the red algae - II. The structure of the cell wall of Rhodymenia Palmata

1959 ◽  
Vol 150 (941) ◽  
pp. 447-455 ◽  
Keyword(s):  
Cell Wall ◽  
Chemical Treatment ◽  
Amorphous Matrix ◽  
Dry Weight ◽  
Wall Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Floridean Starch ◽  
Thin Sectioning ◽  
Paper Chromatographic Separation

The cell-wall structure of the red alga Rhodymenia palmata has been examined by the methods of X -ray diffraction analysis and electron microscopy, including ultra-thin sectioning. The cell wall is shown to consist of numerous lamellae each of which is made up of unoriented, crystalline microfibrils embedded in an amorphous matrix of other cell-wall constituents. The material can be stretched reversibly up to 100% when wet, and the stretching induces orientation of the microfibrils. The ‘∝ cellulose' fraction, which accounts for only 2 to 7 % of the original dry weight, was isolated chemically and was analyzed by means of hydrolysis and paper chromatographic separation of the resulting sugars, and it was found to be composed of approximately equal quantities of glucose and xylose residues. Chemical treatment of the cell wall was found to cause considerable variations in the X -ray diagrams, which are discussed. It is concluded that the microfibrils contain both glucose and xylose residues in approximately equal proportions and that chemical treatment in this case causes changes in crystallinity of the structural component of the wall. The importance of these findings for the meaning of the term cellulose is discussed. The X -ray diagram of older fronds was found to be complicated by the occurrence of extra rings due to the presence of floridean starch, and the highly elastic properties of the thallus enabled the diagrams of the starch and the cell wall to be separated.

Optimization of alkali treatment condition on jute fabric for the development of rigid biocomposite

2016 ◽  
Vol 47 (5) ◽  
pp. 640-655 ◽  
Author(s):  
Ammayappan Lakshmanan ◽  
Rakesh Kumar Ghosh ◽  
Swati Dasgupta ◽  
Sujay Chakraborty ◽  
Prasanta Kumar Ganguly
Keyword(s):  
Mechanical Properties ◽  
Sodium Hydroxide ◽  
Treatment Condition ◽  
Alkali Treatment ◽  
Compression Moulding ◽  
Fabric Reinforcement ◽  
Jute Fabric ◽  
Liquor Ratio ◽  
Jute Fabrics ◽  
Sodium Hydroxide Treatment

Jute fiber has poor compatibility with hydrophobic thermosetting polymeric resin for the development of a biocomposite. In this present study, plain weave jute fabric was treated with 1% sodium hydroxide (owf) in three different time (30, 60 and 90 minutes), temperature (30, 40 and 50℃) and material-to-liquor ratio (1:5, 1:10 and 1:15) as per orthogonal array and the treated jute fabrics were used for the preparation of the biocomposite sheet by hand laying-cum-compression moulding method. Developed biocomposite sheets were evaluated for their mechanical properties as per ASTM standards and results were analyzed by Taguchi model to optimize the sodium hydroxide treatment condition. Results inferred that jute fabric reinforcement treated with 1% sodium hydroxide at 50℃ for 60 minutes in 1:10 material-to-liquor ratio could be the optimum condition to develop the biocomposite sheet with higher mechanical properties than other conditions.

scholarly journals The Cell Wall Structure of Xylem Parenchyma

1952 ◽  
Vol 5 (2) ◽  
pp. 223 ◽  
Author(s):  
AB Wardrop ◽  
HE Dadswell
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Secondary Cell Wall ◽  
Primary Cell Wall ◽  
Wall Structure ◽  
Xylem Parenchyma ◽  
Cell Axis ◽  
X Ray ◽  
Ray Methods ◽  
Longitudinal Cell

The fine structure of the cell wall of both ray and vertical parenchyma has been investigated. In all species examined secondary thickening had occurred. In the primary cell wall the micellar orientation was approximately trans"erse to the longitudiJ)aI cell axis. Using optical and X-ray methods the secondary cell wall was shown to possess a helical micellar organization, the micelles being inclined between 30� and 60� to the longitudinal cell axis.

scholarly journals Fabrication of New Geopolymer Binder from Demolition Waste and Ignimbrite Slits for Application in the Construction Industry

2019 ◽  
Vol 303 ◽  
pp. 01005
Author(s):  
D.L. Mayta-Ponce ◽  
P. Soto-Cruz ◽  
F.A. Huamán-Mamani
Keyword(s):  
Sodium Hydroxide ◽  
Room Temperature ◽  
Sodium Hydroxide Solution ◽  
Fine Sand ◽  
Mechanical Resistance ◽  
Binder Phase ◽  
Compression Tests ◽  
Demolition Waste ◽  
Hydroxide Solution ◽  
Geopolymer Binder

Geopolymeric mortars with volumetric fractions of 0.6:1:0.3 for a binder powder, fine sand and sodium hydroxide solution (12M), respectively; have been fabricated by mixing the solid materials and the subsequent addition of sodium hydroxide solution 12M to form a workable paste, to later be cured for 28 days at room temperature. The microstructures of the fabricated materials reveal the existence of two phases with notable difference, one continuous to the geopolymer binder phase and another discontinuous of fine sand particles agglutinated by the binder phase. Mechanical compression tests are performed at a constant compression rate of 0.05 mm/min and at temperatures ranged from room temperature to 500°C. The mechanical results are ranged from 19 and 69 MPa for all the materials studied. On the other hand, there was an increase in mechanical resistance up to test temperatures of 200°C and the progressive reduction of resistance at temperatures above 200°C, with a fragile-ductile transition zone between 400 and 500°C and completely ductile behavior from test temperatures of 500°C.

scholarly journals Modifications in the methods to extract pectin from cv. “Pedro Sato” guavas during ripening

2018 ◽  
Vol 21 (0) ◽  
Author(s):  
Samira Haddad Spiller ◽  
Tamara Rezende Marques ◽  
Anderson Assaid Simão ◽  
Mariana Aparecida Braga ◽  
Lucimara Nazaré Silva Botelho ◽  
...  
Keyword(s):  
Cell Wall ◽  
Shelf Life ◽  
Room Temperature ◽  
Hydrolytic Enzymes ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Fruit Firmness ◽  
Edta Extraction

Abstract Guava is a highly perishable fruit due to its intense metabolism during ripening, with a shelf life of up to five days at room temperature. The loss of firmness during ripening is caused by the activity of hydrolytic enzymes that promote dissolution of the pectin constituents of the cell wall. Although guava is considered to be rich in pectin, the amounts reported in the literature do not exceed 2.4%, a content indicating it is not responsible for the firmness of guava. The aim of this study was to extract pectin from the guava pulp during 7 days of ripening by two methods (ethanol and EDTA extraction) and suggest modifications in the methods by adding to the extraction residue, cellulase and pectinase to degrade the cell wall structure of the fruit and obtain larger amounts of pectin, which would imply the participation of pectin in the maintenance of fruit firmness. It was possible to infer there were no differences in the pectin levels extracted by the two methods, due to sugar contamination. As from the new stage in the execution by the two methods, the extraction was more efficient: 9.10% of pectin with EDTA and 7.63% with ethanol. The pectin contents found were higher than those mentioned in the literature, better explaining their responsibility in fruit firmness.

scholarly journals Alkali Activated Paste and Concrete Based on of Biomass Bottom Ash with Phosphogypsum

2020 ◽  
Vol 10 (15) ◽  
pp. 5190
Author(s):  
Danutė Vaičiukynienė ◽  
Dalia Nizevičienė ◽  
Aras Kantautas ◽  
Vytautas Bocullo ◽  
Andrius Kielė
Keyword(s):  
Compressive Strength ◽  
Sodium Hydroxide ◽  
Sodium Hydroxide Solution ◽  
Bottom Ash ◽  
Control Sample ◽  
Test Methods ◽  
X Ray ◽  
Hydroxide Solution ◽  
Fine Grained ◽  
Alkali Activated

There is a growing interest in the development of new cementitious binders for building construction activities. In this study, biomass bottom ash (BBA) was used as aluminosilicate precursor and phosphogypsum (PG) was used as a calcium source. The mixtures of BBA and PG were activated with the sodium hydroxide solution or the mixture of sodium hydroxide solution and sodium silicate hydrate solution. Alkali activated binders were investigated using X-ray powder diffraction (XRD), X-ray fluorescence (XRF) and scanning electron microscopy (SEM) test methods. The compressive strength of hardened paste and fine-grained concrete was also evaluated. After 28 days, the highest compressive strength reached 30.0 MPa—when the BBA was substituted with 15% PG and activated with NaOH solution—which is 14 MPa more than control sample. In addition, BBA fine-grained concrete samples based on BBA with 15% PG substitute activated with NaOH/Na2SiO3 solution showed higher compressive strength compered to when NaOH activator was used −15.4 MPa and 12.9 MPa respectfully. The NaOH/Na2SiO3 activator solution resulted reduced open porosity, so potentially the fine-grained concrete resistance to freeze and thaw increased.

Thermomechanical evaluation of new geopolymer binder from demolition waste and ignimbrite slits for application in the construction industry

MRS Advances ◽  
2019 ◽  
Vol 4 (54) ◽  
pp. 2951-2958
Author(s):  
D.L. Mayta-Ponce ◽  
P. Soto-Cruz ◽  
F.A. Huamán-Mamani
Keyword(s):  
Sodium Hydroxide ◽  
Room Temperature ◽  
Sodium Hydroxide Solution ◽  
Fine Sand ◽  
Mechanical Resistance ◽  
Binder Phase ◽  
Compression Tests ◽  
Demolition Waste ◽  
Hydroxide Solution ◽  
Geopolymer Binder

ABSTRACTGeopolymeric mortars with volumetric fractions of 0.6:1:0.3 for a binder powder, fine sand and sodium hydroxide solution (12M), respectively; have been fabricated by mixing the solid materials and the subsequent addition of sodium hydroxide solution 12M to form a workable paste, to later be cured for 28 days at room temperature. The microstructures of the fabricated materials reveal the existence of two phases with notable difference, one continuous to the geopolymer binder phase and another discontinuous of fine sand particles agglutinated by the binder phase. Mechanical compression tests are performed at a constant compression rate of 0.05 mm/min and at temperatures ranged from room temperature to 500°C. The mechanical results are ranged from 19 and 69 MPa for all the materials studied. On the other hand, there was an increase in mechanical resistance up to test temperatures of 200°C and the progressive reduction of resistance at temperatures above 200°C, with a fragile-ductile transition zone between 400 and 500°C and completely ductile behavior from test temperatures of 500°C.

Fine structure in the red algae III. A general survey of cell-wall structure in the red algae

1959 ◽  
Vol 150 (941) ◽  
pp. 456-459 ◽  
Keyword(s):  
Cell Wall ◽  
Red Algae ◽  
Amorphous Matrix ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
X Ray Diffraction ◽  
Cellulose I ◽  
General Survey ◽  
X Ray ◽  
Floridean Starch

A general survey of cell-wall structure in the red algae has been carried out using the methods of X -ray diffraction analysis and electron microscopy. The fifteen species all show a similar wall structure consisting of numerous lamellae each of which is made up of random micro-fibrils embedded in an amorphous matrix. The X -ray diagrams obtained from several species are complicated by the existence of crystalline floridean starch, but nevertheless reveal the absence of cellulose I.

Effect of Concentrated Alkali Treatment on the Properties of Naturally Colored Brown Cotton

2011 ◽  
Vol 332-334 ◽  
pp. 173-178
Author(s):  
Li Chen ◽  
Yu Sen Liu ◽  
Wei Guo Sun ◽  
Xiao Yan Zhou
Keyword(s):  
Sodium Hydroxide ◽  
Cotton Fiber ◽  
Breaking Strength ◽  
Sodium Hydroxide Solution ◽  
Fiber Strength ◽  
Alkali Treatment ◽  
Treatment Temperature ◽  
Color Differences ◽  
Colored Cotton ◽  
Naturally Colored Cotton

The naturally colored cotton fiber was treated by sodium hydroxide solution with different concentrations and temperatures.The surface morphology,crystalline structure, mechanical properties and color feature value of fiber after treatment were tested by SEM,XRD,electronic single fiber strength tester and Computer Color Matching meter.The results show that the longitudinal convolutions of the naturally colored cotton fiber treated by concentrated sodium hydroxide decreased or disappeared,and the fiber became nearly cylindrical or cylindrical.The crystallinity of fiber after treatment decreased,part of the celluloseⅠ changed into celluloseⅡ．The breaking strength and breaking elongation of fiber after treatment increased.The total color differences（ΔE） and value a*of fiber after treatment increased，to the contrary，value L* and value b* decreased，which leaded to that the color of fiber treated by alkali became darker．In addition,the treatment temperature had larger influence on the properties of fiber.

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