Preparation and Mechanical Properties of Modified Magnesium Oxysulfate Cement Incorporating Alkali Conditioner

2020 ◽  
Vol 12 (10) ◽  
pp. 1558-1567
Author(s):  
Shengbin Li ◽  
Haoqian Ren ◽  
Qin Wu ◽  
Yiyang Ye
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Calcium Carbonate ◽  
Mechanical Test ◽  
Mechanical Tests ◽  
Molar Ratio ◽  
Buffer Solution ◽  
Magnesium Oxysulfate ◽  
Scanning Electron

Magnesium oxysulfate cement is an ecological gas-hardening cementitious material. The cement has a complex system, insufficient hydration, and unstable hydration products, so that the cement mechanical property is poor. In this study, calcium chloride/carbon dioxide/weak buffer solution is used to generate alkaline additive, namely vaterite calcium carbonate. The additive material is characterized by scanning electron microscopy and X-ray diffraction, and then the optimal MgO/MgSO4/H2O molar ratio after calcium carbonate is added to magnesium oxysulfate cement, the optimal laying method and reasonable amount of vaterite calcium carbonate are analyzed by mechanical tests. In the experiment, the basic additive is characterized firstly. It is found that the XRD of the additive mainly includes the peaks of calcite and vaterite. It can be seen by scanning electron microscopy that many calcites and vaterites are not formed, the calcites are accumulated more, and there is a large number of particles, which are not appeared before. In the mechanical test of magnesium sulfide cement, the mechanical properties of magnesium oxysulfate cement will increase firstly and then decrease with the increase of MgO/MgSO4 molar ratio in the way of long-cut calcium carbonate for reinforcement. Compared with the layout of long-cut calcium carbonate-magnesium oxysulfate cement, the layout of short-cut calcium carbonate-magnesium oxysulfate cement can enhance the toughness of the modified cement, increase the amount of calcium carbonate, and improve the flexural strength and toughness index of the modified magnesium oxysulfate cement. The blending ratio is better to be 6%. Based on above researches and demonstrations, blending the calcium carbonate-based alkaline additive can effectively improve the mechanical properties of the magnesium oxysulfate cement.

Synthesis of Precipitate Calcium Carbonate with Variation Morphology from Limestone by Using Solution Mixing Method

2019 ◽  
Vol 966 ◽  
pp. 200-203
Author(s):  
Zaenal Arifin ◽  
Triwikantoro ◽  
Bintoro Anang Subagyo ◽  
Mochamad Zainuri ◽  
Darminto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Carbonate ◽  
Molar Ratio ◽  
Mixing Process ◽  
X Ray Diffraction ◽  
Precipitate Calcium Carbonate ◽  
X Ray ◽  
Mixing Method ◽  
Scanning Electron

Abstract. In this study, the CaCO3 powder has been successfully synthesized by mixing CaCl2 from natural limestone and Na2CO3 in the same molar ratio. The mixing process of solutions was carried out by employing the molar contents of 0.125, 0.25, 0.375 and 0.5M at varying temperatures of 30, 40, 60 and 80ᴼC. The produced CaCO3 microparticles were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The highest content of aragonite phase with morphology rod-like of the samples is around 29 wt%, resulting from the process using solution of 0.125 M at 80 ᴼC. While at 30 ᴼC and 40 ᴼC produced 100 wt% calcite phase.

Crystallization, Morphology and Mechanical Properties of PLA/PBAT/CaCO3 Composites

2012 ◽  
Vol 602-604 ◽  
pp. 768-771 ◽  
Author(s):  
Nan Shi ◽  
Jun Cai ◽  
Qiang Dou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Crystallization Behavior ◽  
Mechanical Test ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Crystallization Morphology ◽  
Morphology And Mechanical Properties ◽  
Scanning Electron

The melting, crystallization behavior, morphology and mechanical properties of poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT)/calcium carbonate (CaCO3) composites were investigated by means of differential scanning calorimetry (DSC), scanning electron microscopy(SEM), and mechanical test. It is shown that PBAT decreases the crystallinity, while CaCO3 increases the crystallinity of the composites. A synergistic toughening effect is obtained by the combination of CaCO3 and PBAT. The optimum mechanical properties can be achieved in case of the composite (PLA: PBAT: CaCO3=60: 20: 20).

Wool felt: Characterization, comparison with other materials, and investigation of its use in hospital accessories

2020 ◽  
pp. 004051752091583
Author(s):  
Heloisa Nazaré dos Santos ◽  
Sebastiana Luiza Bragança Lana Lara ◽  
José Henrique Martins Neto
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Mechanical Tests ◽  
Hospital Environment ◽  
Dry Process ◽  
Washing Process ◽  
Mechanical Scanning ◽  
Scanning Electron

This article presents groundbreaking research on wool felt for use in hospital accessories. The results of mechanical, scanning electron microscopy (SEM), chemical, flammability, and microbiological tests are presented, as well as research on the acceptability of three wool felt hospital accessories (i.e. sheet cover, pillowcase cover, and insole). An innovative approach was utilized to compare the mechanical properties of unwashed and washed wool felt samples by three different washing machines, with textiles commonly used in hospital (i.e. nonwoven of polyester felt, woven of 100% cotton, and woven of a blend of 67% cotton and 33% polyester). The mechanical tests showed that the wool felt had tensile resistance similar to that of polyester felt, superior elongation to the 100% cotton and the blend, inferior tearing stress, lower resistance to slippage, and good pilling resistance. After washing, the wool felt washed with the extractor washer and dry washer increased their tensile strength 33% and 19%; the tear strength did not change; the slippage decreased; and the samples washed with the dry washer showed 14% less pilling than those not washed. The SEM tests showed differences in appearance of the fibers after the washing processes. Chemical tests revealed that 0.11% of lanolin was retained in the wool felt after washing the samples with the dry process. The flammability tests showed the dependence of carbonization length with the wool felt washing process. The volunteers showed a good acceptance of the wool felt accessories emphasizing the feeling of freshness, release of pain, and reduction in sweating and unpleasant odors. Microbiological tests showed growth in the insoles of the bacterium Staphylococcus aureus and the fungus Candida albicans, commonly found in the hospital environment.

Electron Microscopic Observation of the Longitudinal Organization of Poly (p-Phenylene Terephthalamide) Fibers

1982 ◽  
Vol 40 ◽  
pp. 680-681
Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Microscopic Observation ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Aromatic Polyamides ◽  
Radial Arrangement ◽  
Scanning Electron ◽  
Better Than

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.

scholarly journals Analysis of PLA Composite Filaments Reinforced with Lignin and Polymerised-Lignin-Treated NFC

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2174
Author(s):  
Diana Gregor-Svetec ◽  
Mirjam Leskovšek ◽  
Blaž Leskovar ◽  
Urška Stanković Elesini ◽  
Urška Vrabič-Brodnjak
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Glassy State ◽  
Nanofibrillated Cellulose ◽  
Dynamic Mechanical Properties ◽  
Initial Modulus ◽  
Surface Modified ◽  
Scanning Electron

Polylactic acid (PLA) is one of the most suitable materials for 3D printing. Blending with nanoparticles improves some of its properties, broadening its application possibilities. The article presents a study of composite PLA matrix filaments with added unmodified and lignin/polymerised lignin surface-modified nanofibrillated cellulose (NFC). The influence of untreated and surface-modified NFC on morphological, mechanical, technological, infrared spectroscopic, and dynamic mechanical properties was evaluated for different groups of samples. As determined by the stereo and scanning electron microscopy, the unmodified and surface-modified NFCs with lignin and polymerised lignin were present in the form of plate-shaped agglomerates. The addition of NFC slightly reduced the filaments’ tensile strength, stretchability, and ability to absorb energy, while in contrast, the initial modulus slightly improved. By adding NFC to the PLA matrix, the bending storage modulus (E’) decreased slightly at lower temperatures, especially in the PLA samples with 3 wt% and 5 wt% NFC. When NFC was modified with lignin and polymerised lignin, an increase in E’ was noticed, especially in the glassy state.

scholarly journals Corrosion Behavior and Mechanical Properties of a Nanocomposite Superhydrophobic Coating

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 652
Author(s):  
Divine Sebastian ◽  
Chun-Wei Yao ◽  
Lutfun Nipa ◽  
Ian Lian ◽  
Gary Twu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Nanocomposite Coating ◽  
Superhydrophobic Coating ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Images ◽  
Scanning Electron

In this work, a mechanically durable anticorrosion superhydrophobic coating is developed using a nanocomposite coating solution composed of silica nanoparticles and epoxy resin. The nanocomposite coating developed was tested for its superhydrophobic behavior using goniometry; surface morphology using scanning electron microscopy and atomic force microscopy; elemental composition using energy dispersive X-ray spectroscopy; corrosion resistance using atomic force microscopy; and potentiodynamic polarization measurements. The nanocomposite coating possesses hierarchical micro/nanostructures, according to the scanning electron microscopy images, and the presence of such structures was further confirmed by the atomic force microscopy images. The developed nanocomposite coating was found to be highly superhydrophobic as well as corrosion resistant, according to the results from static contact angle measurement and potentiodynamic polarization measurement, respectively. The abrasion resistance and mechanical durability of the nanocomposite coating were studied by abrasion tests, and the mechanical properties such as reduced modulus and Berkovich hardness were evaluated with the aid of nanoindentation tests.

Research on compatibility and surface of high impact bio-based polyamide

2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Crystallization Behavior ◽  
High Impact ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.

scholarly journals Effect of Annealing Process on the Mechanical Properties of X70 Pipeline Steel

2018 ◽  
Vol 186 ◽  
pp. 02001
Author(s):  
Teng-wei Zhu ◽  
Cheng-liang Miao ◽  
Zheng Cheng ◽  
Zhipeng Wang ◽  
Yang Cui ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Annealing Temperature ◽  
Pipeline Steel ◽  
Annealing Process ◽  
X70 Pipeline Steel ◽  
Grain Sizes ◽  
Scanning Electron

The influence of the mechanical properties of X70 pipeline steel under different annealing temperature was studied. The corresponding microstructure was investigated by the Field Emission Scanning Electron Microscopy. The results showed that the yield strength and the tensile strength both experienced from rise to decline with the increase of annealing temperature. The grain sizes were coarse and a large amount of cementite precipitated due to preserving temperature above 550 °, which induced matrix fragmentation and deteriorate the -10 ° DWTT Toughness. There were little changes on the microstructure and mechanical properties when the annealing temperature was under 500 °.

Study on the Element Composition of Southern Celadon Porcelain and Coloring Mechanism

2014 ◽  
Vol 484-485 ◽  
pp. 96-99
Author(s):  
Xue Wen Gao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Field Emission ◽  
Element Composition ◽  
Molar Ratio ◽  
Experimental Sample ◽  
Fe Content ◽  
Firing System ◽  
Pink Coloration ◽  
Scanning Electron

This paper mainly discusses the Si/Al molar ratio, RO/R2O molar ratio, Fe content, glazing and firing system on the thickness of Longquan Celadon pink coloring effects, and using a colorimeter, field emission scanning electron microscopy were used to analyze better experimental sample microstructure and color and so on. We explored the Longquan Celadon of pink coloration mechanism.

Hierarchical Design and Nanomechanics of the Calcified Byssus of Anomia simplex

2009 ◽  
Vol 1187 ◽  
Author(s):  
Jakob R Eltzholtz ◽  
Marie Krogsgaard ◽  
Henrik Birkedal
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Mechanical Performance ◽  
Blue Mussel ◽  
Hierarchical Design ◽  
Reduced Modulus ◽  
Different Types ◽  
Microscopy Images ◽  
Scanning Electron

AbstractBiology has evolved several strategies for attachment of sedentary animals. In the bivalves, byssi abound and the best known example being the protein-based byssus of the blue mussel and other Mytilidae. In contrast the bivalve Anomia sp. has a single calcified thread. The byssus is hierarchical in design and contains several different types of structures as revealed by scanning electron microscopy images. The mechanical properties of the byssus are probed by nanoindentation. It is found that the mineralized part of the byssus is very stiff with a reduced modulus of about 67 GPa and a hardness of ˜3.7 GPa. This corresponds to a modulus roughly 20% smaller than that of pure calcite and a hardness that is about 20% larger than pure calcite. The results reveal the importance of microstructure on mechanical performance.

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