Research on the Efficient Application of Silica Fume in High-Tech Cement-Based Materials

2011 ◽  
Vol 374-377 ◽  
pp. 1537-1540
Author(s):  
Dong Lin ◽  
Zi Yun Wen

The comparison experiments are carried out at different silica fume dosage between the silica fume with pre-treatment and the silica fume without pre-treatment. The results show that the pre-treatment of silica fume improved the strength greatly and the silica fume dosage corresponding to the strength peak somewhat moved forward from 0.20 for the cement-based materials with pre-treatment of silica fume to 0.21 for the cement-based materials without pre-treatment of silica fume. The particles distribution experiment results indicate that after the pre-treatment of silica fume, the average particle diameter of silica fume reduced from 2.865μmto 0.151μm. Based on Aim-Goff model, it is concluded that the increase in the compressive strength and flextural strength of cement-based materials with pre-treatment of silica fume, are attributed to the dispersion of silica fume agglomeration and the increase in the packing density of the cement-based materials.

2014 ◽  
Vol 1030-1032 ◽  
pp. 142-146
Author(s):  
Yong Jiang ◽  
Wen Fu Zeng ◽  
Yan Huai Ding ◽  
Jiu Ren Yin

The EP/ZnO nanocomposites were prepared by using epoxy resin as matrix, nanoZnO as the modifier, polyamide as curing agent. The surface morphology of nanoZnO was observed,the average particle diameter of nanoZnO is 20nm. Their mechanics properties were studied and the experiment results were analyzed. The results indicated that the compressive stress-strain curves of the nanocomposites had obvious three phases characters, i.e., linear elastic phase, plastic yield flat phase and compact phase. Along with the nanograins content of the nanocomposites increasing, the compressive elastic modulus and compressive strength of the nanocomposites augmented. When the nanograins content is 5% and the transfiguration speed is 10mm/min, the compressive elastic modulus and compressive strength of the nanocomposites respectively improved 36.4% and 48.9% comparing with their of the pure epoxy resin. At the same nanograins content, with the transfiguration speed increasing, their compressive strength added.


2014 ◽  
Vol 936 ◽  
pp. 429-433
Author(s):  
Wen Fu Zeng ◽  
Yong Jiang ◽  
Shao Fen Bu ◽  
Yan Huai Ding ◽  
Jiu Ren Yin

The EP/SiO2 nanocomposites were prepared by using epoxy resin as matrix, nanoSiO2 as the modifier, polyamide as curing agent. The surface morphology of nanoSiO2 was observed,the average particle diameter of nanoSiO2 is 20nm. Their mechanics properties were studied and the experiment results were analyzed. The results indicated that the compressive stress-strain curves of the nanocomposites had obvious three phases characters, i.e., linear elastic phase, plastic yield flat phase and compact phase. Along with the nanograins content of the nanocomposites increasing, the compressive elastic modulus and compressive strength of the nanocomposites augmented. When the nanograins content is 5% and the transfiguration speed is 10mm/min, the compressive elastic modulus and compressive strength of the nanocomposites respectively improved 22.7% and 35.2% comparing with their of the pure epoxy resin. At the same nanograins content, with the transfiguration speed increasing, their compressive strength added.


2014 ◽  
Vol 941-944 ◽  
pp. 436-440
Author(s):  
Shao Fen Bu ◽  
Yong Jiang ◽  
Wen Fu Zeng

The EP/TiO2 nanocomposites were prepared by using epoxy resin as matrix, nanoTiO2 as the modifier, polyamide as curing agent. The surface morphology of nanoTiO2 was observed,the average particle diameter of nanoTiO2 is 20nm. Their mechanics properties were studied and the experiment results were analyzed. The results indicated that the compressive stress-strain curves of the nanocomposites had obvious three phases characters, i.e., linear elastic phase, plastic yield flat phase and compact phase. Along with the nanograins content of the nanocomposites increasing, the compressive elastic modulus and compressive strength of the nanocomposites augmented. When the nanograins content is 5% and the transfiguration speed is 10mm/min, the compressive elastic modulus and compressive strength of the nanocomposites respectively improved 49.2% and 45.2% comparing with their of the pure epoxy resin. At the same nanograins content, with the transfiguration speed increasing, their compressive strength added.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2232
Author(s):  
Huiwen Wan ◽  
Zhangyin Hu ◽  
Gang Liu ◽  
Jiadong Xiao

Electrical properties are one of the essential parameters of cement-based materials used in suspension porcelain insulators. This paper studied the electrical properties of aluminate cement adhesives (ACA) containing silica fume (SF), as well as their compressive strength and porosity. The results indicated that the addition of silica fume improved the resistivity of ACA under a saturated state (relative humidity is 50%). This was mainly attributed to the decrease of the ACA’s pore connectivity due to the SF’s filling effect. However, the early compressive strength of ACA was slightly reduced by the addition of SF. Under an unsaturated state, the ACA’s resistivity without the SF gradually exceeded that with the SF at the extension of drying time. The nuclear magnetic resonance (NMR) results indicated that the addition of SF content increased the ACA’s porosity; for the tiny pores especially, (the size less than 25 nm), this increased by 3.4%. Meanwhile, the addition of SF increased the tortuosity of the ACA’s conductive channels, which could improve its resistivity. Therefore, SF is recommended to be used in cement-based adhesives on insulators to lower the cost and improve the resistivity.


Author(s):  
Haigang Wu ◽  
Jinni Liu ◽  
Gugangke Xu ◽  
Zhaowei Ye ◽  
Jicheng Liu and Benchi Yi

We evaluated the pharmacokinetics of cefquinome sulfate (CEF) liposomes in eight healthy goats following intramuscular administration at 4 mg/kg. The average particle diameter of CEF liposomes prepared by the ethanol injection method was 335nm with a CEF entrapment efficiency of 69.56%. The elimination half-life (t1/2b) of CEF liposomes was 33.04h compared with 16.21 h for CEF injected without carrier (p less than 0.05). The area under the concentration curve (AUC) for CEF liposomes was approximately three-times greater than for CEF alone (P less than 0.05). The time-point of maximum plasma concentration of the drug (Tp) and the maximum plasma concentration (Cmax) were 4.38 h and 1.99 ìg/mL for CEF liposomes, compared with 1.86 h and 3.55 ìg/mL for CEF without carrier, respectively. 


Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4358
Author(s):  
Nicole Janoszka ◽  
Suna Azhdari ◽  
Christian Hils ◽  
Deniz Coban ◽  
Holger Schmalz ◽  
...  

The confinement assembly of block copolymers shows great potential regarding the formation of functional microparticles with compartmentalized structure. Although a large variety of block chemistries have already been used, less is known about microdomain degradation, which could lead to mesoporous microparticles with particularly complex morphologies for ABC triblock terpolymers. Here, we report on the formation of triblock terpolymer-based, multicompartment microparticles (MMs) and the selective degradation of domains into mesoporous microparticles. A series of polystyrene-block-polybutadiene-block-poly(L-lactide) (PS-b-PB-b-PLLA, SBL) triblock terpolymers was synthesized by a combination of anionic vinyl and ring-opening polymerization, which were transformed into microparticles through evaporation-induced confinement assembly. Despite different block compositions and the presence of a crystallizable PLLA block, we mainly identified hexagonally packed cylinders with a PLLA core and PB shell embedded in a PS matrix. Emulsions were prepared with Shirasu Porous Glass (SPG) membranes leading to a narrow size distribution of the microparticles and control of the average particle diameter, d ≈ 0.4 µm–1.8 µm. The core–shell cylinders lie parallel to the surface for particle diameters d < 0.5 µm and progressively more perpendicular for larger particles d > 0.8 µm as verified with scanning and transmission electron microscopy and particle cross-sections. Finally, the selective degradation of the PLLA cylinders under basic conditions resulted in mesoporous microparticles with a pronounced surface roughness.


2014 ◽  
Vol 1004-1005 ◽  
pp. 311-314
Author(s):  
Yang Zhao ◽  
Jian Wei Ren

The starch based polymer microspheres were synthesized in the system of the inverse emulsion polymerization. These polymer microspheres were characterized by Scanning Electron Microscope and Grain Size Analyzer. Adsorption behavior of starch based polymer microspheres for Pb2+ was investigated by atomic absorption spectrophotometry. The results showed that the average particle diameter of starch based polymer microspheres was about 43.9 μm, and surface of starch microsphere was rough and porous which could be beneficial to form adsorption layer. And the starch based polymer microsphere exhibited good adsorption of lead ions.


1982 ◽  
Vol 10 (4) ◽  
pp. 162 ◽  
Author(s):  
R Horstman ◽  
KA Peters ◽  
RL Meltzer ◽  
MB Vieth ◽  
SW Ping

2015 ◽  
Vol 820 ◽  
pp. 155-160 ◽  
Author(s):  
Mirele Costa da Silva ◽  
N.C.O. Costa ◽  
D.S. Lira ◽  
Joelda Dantas ◽  
A.C.F.M. Costa ◽  
...  

Among the vast applications in which the α-alumina can apply, the literature has reported researches which aim to achieve better features of these materials varying the obtainment methodology and some post-obtainment techniques. Thus, this paper aims to evaluate how different milling time lengths of 15, 30, 45 and 60 minutes alter the structure and morphology of α-alumina powders synthesized by combustion reaction. The time and temperature of the combustion reaction were evaluated during the synthesis of the alumina. The samples of non-milled and milled alumina were characterized by XRD and particle size analysis. The results showed that the maximum achieved temperature of reaction was 598°C. The milling time length variation did not alter the stable α-Al2O3majority crystal phase present in all samples. The average particle diameter was reduced from 23.3 to 10.5 μm comparing the non-milled and the sample milled for 60s.


1992 ◽  
Vol 272 ◽  
Author(s):  
Robin R. Chandler ◽  
Jeffery L. Coffer ◽  
C. David Gutsche ◽  
Iftikhar Alam ◽  
Hong Yang ◽  
...  

ABSTRACTWe describe here the use of calixarenes, methylene (-CH2-) linked phenolic macrocyclic molecules, to stabilize the formation of quantum-confined (Q-) CdS clusters. Specifically, we focus on the use of an amino-derivatized calixarene, para-[(dimethylamino)- methyl]calix[6]arene, to stabilize Q-CdS clusters which have been characterized by High Resolution TEM (HREM), as well as absorption and emission spectroscopies. Under typical preparative conditions, an average particle diameter of 36 Å is obtained. HREM, in combination with Selected Area Diffraction (SAD), confirms the structure of the clusters as zinc blende CdS. Spectroscopic studies using absorption and emission methods indicate that both particle size and cluster photophysics are sensitive to the ratio of CdS to calixarene.


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