scholarly journals Bio-Fibres as a Reinforcement of Gypsum Composites

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4830
Author(s):  
Alessandro P. Fantilli ◽  
Daria Jóźwiak-Niedźwiedzka ◽  
Piotr Denis
Keyword(s):  
Mechanical Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Adhesion ◽  
Hemp Fibres ◽  
Preliminary Research ◽  
Flexural Tests ◽  
Scanning Electron ◽  
Better Than ◽  
Sheep Wool

Three series of tests performed on fibre-reinforced gypsum composites are described herein. Sheep wool fibres and hemp fibres were used as reinforcement. The aim was to evaluate the capability of these biomaterials to enhance the fracture toughness of the gypsum matrix. The mechanical properties were measured by means of flexural tests on small specimens, whereas scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction were used to analyse the microstructure and composition of the fibres and of the gypsum composites. As a result, wool fibres were shown to improve the mechanical performance of the gypsum matrix, better than hemp fibres. This is due to the high adhesion at the interface of the fibre and gypsum matrix, because the latter tends to roughen the surface of the wool and, consequently to increase the bond strength. This preliminary research carried out shows that this type of biofiber—a waste material—can be considered a promising building material in sustainable and environmentally friendly engineering.

Preparation and Characterization of the Ceramsites with Microscale Pores from Iron Tailing and Fly Ash

2020 ◽  
Vol 12 ◽  
Author(s):  
Zeyang Xue ◽  
Zi Wang ◽  
Chunhu Yu ◽  
Yajing Mao ◽  
Lizhai Pei
Keyword(s):  
Fly Ash ◽  
Mechanical Performance ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sintering Time ◽  
Duration Time ◽  
Important Significance ◽  
Scanning Electron

Background: Iron tailing causes great environmental and social problems which contaminate water, air and soil. Therefore, it is of important significance to prepare iron tailing ceramsites with microscale pores which can recycle the deposited iron tailing. Objective: The aim of the research is to obtain iron tailing ceramsites with microscale pores and good mechanical performance. Methods: The iron tailing ceramsites have been characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). Influence of the content of iron tailing, temperature and duration time on the mechanical performance of the obtained ceramsites was performed and the optimal sintering parameter was determined. The bulk density, apparent density and cylinder compressive strength of the obtained ceramsites increase obviously as improving the iron tailing content, temperature and sintering time. Results: Duration time and sintering temperature play important roles in the formation and size of the pores of the ceramsites. The optimal iron tailing content and sintering parameter are 70wt.%, 1100 ℃ for 40 min. The iron tailing ceramsites mainly consist of orthorhombic CaAl2Si2O8, monoclinic CaSiO3, hexagonal Ca7Si2P2O16, triclinic MgSiO3, triclinic Al2SiO5 and triclinic Ca2Fe2O5 phases. Iron tailing ceramsites from 1100 ℃ for 40 min are composed of irregular particles with several hundreds of micrometers improving the density and strength of the ceramsites. Conclusion: Iron tailing ceramsites containing microscale pores were prepared using iron tailing and fly ash, and exhibit excellent potential for the application in the field of construction.

Enhanced photobactericidal activity of ZnO nanorods modified by meso-tetrakis(4-sulfonatophenyl)porphyrin under visible LED lamp irradiation

2015 ◽  
Vol 71 (8) ◽  
pp. 1249-1254 ◽  
Author(s):  
Rahmatollah Rahimi ◽  
Javad Shokraiyan ◽  
Mahboubeh Rabbani ◽  
Fatemeh Fayyaz
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Diffuse Reflectance ◽  
Zno Nanorods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Template Free ◽  
Inorganic Composite ◽  
Scanning Electron ◽  
Better Than

In this study, zinc oxide (ZnO) nanorods have been synthesized using a simple template-free precipitation technique and deposited on glass substrate. The meso-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) has been synthesized and then immobilized on the surface of ZnO nanorods to prepare an organic/inorganic composite. The samples were characterized by various techniques such as X-ray diffraction, diffuse reflectance spectra, Fourier transform-infrared spectroscopy and scanning electron microscopy. In addition, the photobactericidal activity of TPPS/ZnO composite, TPPS and ZnO nanorods was tested against the pathogenic bacterium of Escherichia coli under visible LED lamp irradiation. The results indicate that the photobactericidal activity of TPPS-loaded ZnO nanorods was better than TPPS or ZnO nanorods, separately.

Mangnese Dioxide Nano-Crystal as Catalyst to Remove Formaldehyde

2011 ◽  
Vol 298 ◽  
pp. 147-152 ◽  
Author(s):  
Wei Shao ◽  
Xiu Juan Chu ◽  
Kai Gao ◽  
Hua Zhang
Keyword(s):  
Hot Spot ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Formaldehyde Oxidation ◽  
Nano Crystal ◽  
Liquid Precipitation ◽  
Scanning Electron ◽  
Better Than

The purification technology and material of indoor formaldehyde is a hot spot in the field of material at present. In this paper, MnSO4, KMnO4, NaOH and H2O2 etc. are used to make manganese dioxide nanocrystal with the method of liquid precipitation. X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) were used to characterize the structure and properties. The results show that the products are nano-crystals of γ- MnO2 and δ-MnO2. The catalyze oxidation of formaldehyde using bothγ- MnO2 and δ-MnO2 as catalysts was investigated; and acetyl acetone method was used to characterize formaldehyde chroma. The catalytic ability ofγ-MnO2 nanocrystal to catalyze formaldehyde oxidation is better than that ofδ-MnO2.

scholarly journals Study of gypsum composites with fine solid aggregates at elevated temperatures

2021 ◽  
Vol 28 (1) ◽  
pp. 237-248
Author(s):  
Magdaléna Doleželová ◽  
Lenka Scheinherrová ◽  
Alena Vimmrová
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elevated Temperatures ◽  
Silica Sand ◽  
X Ray Diffraction ◽  
Volume Changes ◽  
X Ray ◽  
Final Volume ◽  
Scanning Electron ◽  
Better Than

Abstract The structure and behaviour of two gypsum composites after exposition to elevated temperatures were investigated. The silica sand and fine basalt aggregate were used as solid fillers. The changes in structure and composition at temperatures from 50 to 1,000°C were investigated by scanning electron microscopy and X-ray diffraction together with the size and strength of the samples and their pore size distribution. The structure of gypsum matrix changed significantly at 1,000°C in both composites, while the aggregate particles were not changed. It was found that even if the silica sand is considered as less suitable filler at high temperatures because of its volume changes, the gypsum with sand performed better than gypsum with basalt at the highest temperatures, because the shrinkage of the gypsum matrix was compensated by the increase in the volume of aggregate. The final volume change at 1,000°C was 3.5% in composite with silica sand and 6.8% in composite with basalt. The residual compressive strength of both composites was about 9.4%. No cracks appeared in the samples and no spalling was observed.

Preliminary Research on the Preparation of Ce-Doped TiO2 by Sol Method

2013 ◽  
Vol 785-786 ◽  
pp. 745-748
Author(s):  
Deng Liang He ◽  
Shi Xin Fang
Keyword(s):  
Electron Microscope ◽  
Methyl Orange ◽  
Scanning Electron Microscope ◽  
Room Temperature ◽  
Raw Materials ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Preliminary Research ◽  
Scanning Electron

butyl titanate, water and anhydrous ethanol were used as raw materials; Cerium-doped TiO2 was prepared by sol method at room temperature. Then it was characterized by X ray diffraction, Raman spectra, Uv-vis absorption spectra and Scanning Electron Microscope. The results show that TiO2 crystal can be got by sol method at room temperature. Cerium-doped TiO2 has the better catalytic performance for methyl orange.

Effect of screw configuration on the dispersion of nanofillers in thermoset polymers

2017 ◽  
Vol 37 (8) ◽  
pp. 815-825 ◽  
Author(s):  
Gangadhar Angadi ◽  
Hebbale NarayanaRao Narasimha Murthy ◽  
Sridhar Ramakrishna ◽  
Salim Firdosh ◽  
Raghavendra Nagappa ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
X Ray ◽  
Right Hand ◽  
Uniform Dispersion ◽  
Twin Screw ◽  
Thermoset Polymers ◽  
Scanning Electron ◽  
Better Than

Abstract This paper deals with the study of screw configuration for dispersing nanofillers in thermoset polymers using an intermesh co-rotating twin screw extruder. The influence of kneading elements on the dispersion of nanoclay in epoxy was examined using 10 different screw configurations. Nanoclay was dispersed in epoxy at a barrel temperature of 5°C and a screw speed of 100 rpm. The combination of right hand kneading block and three/four lobed kneading blocks resulted in uniform dispersion of nanofiller. Positive staggered angle with right hand kneading elements yielded uniform dispersion of the nanofiller. Mechanical properties of epoxy nanocomposites processed with these configurations were better than those of neat epoxy. Excessive shear was associated with four lobed kneading block (4KB)/4KB configuration and hence degradation of polymers leading to shorter chains, whereas inadequate shearing in neutral kneading block (NKB)/NKB configuration led to agglomerations. These observations were evidenced by scanning electron microscopy (SEM) and X-ray diffraction (XRD).

scholarly journals Carboxylic acids: effective inhibitors for calcium sulfate precipitation?

2014 ◽  
Vol 78 (6) ◽  
pp. 1465-1472 ◽  
Author(s):  
Taher Rabizadeh ◽  
Caroline L. Peacock ◽  
Liane G. Benning
Keyword(s):  
Electron Microscopy ◽  
Carboxylic Acids ◽  
Calcium Sulfate ◽  
Mineralogical Composition ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron ◽  
Better Than

Results are reported here of an investigation into the effects of three carboxylic acid additives (tartaric, maleic and citric acids) on the precipitation of calcium sulfate phases. Precipitation reactions were followed at pH 7 in the pure CaSO4 system and in experiments with 0–20 ppm carboxylic acids added using in situ UV-VIS spectrophotometry (turbidity). The solid products were characterized in terms of their mineralogical composition, using X-ray diffraction, during and at the end of each reaction, and in terms of their morphological features, by scanning electron microscopy. All additives increased the time needed for turbidity to develop (induction time, start of precipitation) and the comparison between additive and additive-free experiments showed that, at equivalent concentrations, citric acid performed far better than the other two carboxylic acids. In all cases bassanite precipitated first and with time it transformed to gypsum. The addition of citrate stabilized bassanite and changed the final gypsum habit from typical needle-like crystals in the pure CaSO4 system to plates in the citrate-additive experiments.

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.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Sem and X-Ray Analysis of Renal and Biliary Calculi

1976 ◽  
Vol 34 ◽  
pp. 306-307
Author(s):  
R. J. Narconis ◽  
G. L. Johnson
Keyword(s):  
Chemical Constituents ◽  
Natural State ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
X Ray ◽  
Additional Dimension ◽  
Biliary Calculi ◽  
Calculus Formation ◽  
Scanning Electron

Analysis of the constituents of renal and biliary calculi may be of help in the management of patients with calculous disease. Several methods of analysis are available for identifying these constituents. Most common are chemical methods, optical crystallography, x-ray diffraction, and infrared spectroscopy. The application of a SEM with x-ray analysis capabilities should be considered as an additional alternative.A scanning electron microscope equipped with an x-ray “mapping” attachment offers an additional dimension in its ability to locate elemental constituents geographically, and thus, provide a clue in determination of possible metabolic etiology in calculus formation. The ability of this method to give an undisturbed view of adjacent layers of elements in their natural state is of advantage in determining the sequence of formation of subsequent layers of chemical constituents.

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