Preparation of SiOC Foam Ceramics Using Polysiloxane

2008 ◽  
Vol 368-372 ◽  
pp. 920-922
Author(s):  
Hong Li Liu ◽  
Wen Wu Zhong ◽  
Yang Wu Mao
Keyword(s):  
Porous Structure ◽  
Compression Strength ◽  
Pyrolysis Temperature ◽  
Raw Materials ◽  
High Porosity ◽  
Microstructural Study ◽  
Maximum Compression ◽  
Nano Powder ◽  
Polyurethane Sponge

The SiOC foam ceramics were prepared using polyurethane sponge and polysiloxane as raw materials. The effects of the pyrolysis temperature, the concentration of polysiloxane solutions, and the content of SiC nano-powder on compression strength of the SiOC foam ceramics have been investigated respectively. The optimum compression strength of SiOC foam ceramics is obtained at the pyrolysis temperature of 1250°C and the concentration of solution PSO of 0.8 g/ml. Adding SiC nano-powder into PSO can effectively increase compression strength of samples, and the maximum compression strength, 20.8 MPa, is obtained when the content of SiC nano-powder is 5 wt%. Microstructural study reveals that the foam ceramics have an open, uniform and interconnected porous structure with high porosity of 80%.

Fabrication of Calcite Foam by Inverse Ceramic Foam Method

2012 ◽  
Vol 529-530 ◽  
pp. 153-156 ◽  
Author(s):  
Tram Nguyen Xuan Thanh ◽  
Michito Maruta ◽  
Kanji Tsuru ◽  
Alireza Valanezhad ◽  
Shigeki Matsuya ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Porous Structure ◽  
Polyurethane Foam ◽  
Ceramic Powder ◽  
Three Dimensional ◽  
Ceramic Foam ◽  
Carbonate Apatite ◽  
High Porosity ◽  
Synthetic Resin ◽  
Polyurethane Sponge

We have previously reported that calcite foam that had interconnected porous structure could be prepared by ceramic foam method and it transformed to carbonate apatite (CO3Ap). In the ceramic foam method, polyurethane sponge was used as a template. The polyurethane sponge was immersed in the ceramics slurry, and the strut of the polyurethane foam was covered by ceramic powder. After that it was dried and sintered at high temperature. Calcite foams produced by this approach were comprised of a three-dimensional (3D) interconnected porous structure that facilitated cell penetration. However, all foams have a common limitation: the inherent lack of mechanical strength associated with high porosity. Therefore, in this study, an inverse ceramic foam method was studied; multi polyurethane coating method using polyurethane foam as a template. In this study, the compressive strength was improved by an inverse replication allowed for decreasing porosity while at the same time maintaining the interconnectivity. The burnable synthetic resin coating layer was introduced onto struts of polyurethane foam to make the triangular struts become more round and thick, consequently producing large round capillary within the foam structure fulfilling the requirement for osteoblast colonization. In particular, polyurethane foam was dipped orderly into two monomers, followed by centrifugation to remove excess liquids inside foam. After resin curing, a layer of synthetic resin was coated strut of foam. Calcium hydroxide Ca (OH)2 slurry was then infiltrated into resin coated-polyurethane foam. By firing at 600°C in O2-CO2 stream, polyurethane template was burnt off and Ca (OH)2 was converted into calcite. Negative replicated calcite foam was fabricated and characterized micro-structurally with interconnectivity and improved mechanical strength. The results obtained in this study suggested that this method dramatically improved the mechanical strength of the calcite foam without sacrificing the interconnected structure, and this means that the calcite foam obtained in this method could be precursors for the 3D interconnected porous CO3Ap foam.

Research on Properties of Low Grade Cement-Based Composite Materials Modified by Silica Fume

2012 ◽  
Vol 174-177 ◽  
pp. 751-756
Author(s):  
Zi Fang Xu ◽  
Ming Xu Zhang ◽  
Jin Hua Li
Keyword(s):  
Silica Fume ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Cement Matrix ◽  
Hardened Cement ◽  
Low Grade ◽  
X Ray ◽  
Matrix Microstructure ◽  
Nano Powder ◽  
Strength And Durability

In order to notably improve the mechanical properties and durability of low-grade cement-based material, superfine silica fume was used to modify the cement-based composite based on special perfomance and effects of nano powder. The mechanical performance and durability were investigated.Then the phase compositions,microstructure and morphologies of as-received cement-based composite were studied by X-ray Diffractometer、TGA-DTA and SEM. The results show that： the best formula of raw materials is 1:1:0.025:0.015, and hydration can be accelerated and increasing of hydration products is observed after modification. In the hardened cement matrix, microstructure is very compacted and C-S-H gel forms densed structure, so the structure defect is notably reduced. This means that both strength and durability of cement-based composite are notably improved by the addition of superfine silica fume.

scholarly journals MFC/NFC-Based Foam/Aerogel for Production of Porous Materials: Preparation, Properties and Applications

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5568
Author(s):  
Chenni Qin ◽  
Mingzhu Yao ◽  
Yang Liu ◽  
Yujie Yang ◽  
Yifeng Zong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Porous Materials ◽  
Raw Materials ◽  
Sewage Treatment ◽  
Nanofibrillated Cellulose ◽  
High Specific Surface Area ◽  
High Porosity ◽  
Retention Performance ◽  
Plant Fibers ◽  
Technical Problems

Nanofibrillated cellulose and microfibrillated cellulose are potential raw materials separated from plant fibers with a high aspect ratio and excellent mechanical properties, which can be applied in various fields (packaging, medicine, etc.). They have unique advantages in the preparation of aerogels and foams, and have attracted widespread attention in recent years. Cellulose-based porous materials have good biodegradability and biocompatibility, while high porosity and high specific surface area endow them with strong mechanical properties and liquid retention performance, which can be used in wall construction, sewage treatment and other fields. At present, the preparation method of this material has been widely reported, however, due to various process problems, the actual production has not been realized. In this paper, we summarize the existing technical problems and main solutions; in the meantime, two stable systems and several drying processes are described, and the application potential of cellulose-based porous materials in the future is described, which provides a reference for subsequent research.

Fabrication of Porous Structure of BCP Sintered Bodies Using Microwave Assisted Synthesized HAp Nano Powder

2007 ◽  
Vol 534-536 ◽  
pp. 49-52 ◽  
Author(s):  
Min Ho Youn ◽  
Rajat Kanti Paul ◽  
Ho Yeon Song ◽  
Byong Taek Lee
Keyword(s):  
Calcium Phosphate ◽  
Porous Structure ◽  
Relative Density ◽  
Polymethyl Methacrylate ◽  
Biphasic Calcium Phosphate ◽  
Sintering Temperature ◽  
Microwave Assisted ◽  
Nano Powder ◽  
Maximum Value ◽  
Porous Biphasic Calcium Phosphate

Using microwave synthesized HAp nano powder and polymethyl methacrylate (PMMA) as a pore-forming agent, the porous biphasic calcium phosphate (BCP) ceramics were fabricated depending on the sintering temperature. The synthesized HAp powders was about 70-90 nm in diameter. In the porous sintered bodies, the pores having 150-180 μm were homogeneously dispersed in the BCP matrix. Some amounts of pores interconnected due the necking of PMMA powders which will increase the osteoconductivity and ingrowth of bone-tissues while using as a bone substrate. As the sintering temperature increased, the relative density increased and showed the maximum value of 79.6%. From the SBF experiment, the maximum resorption of Ca2+ ion was observed in the sample sintered at 1000°C.

Use of Industrial Waste and Raw Materials in Iron Sorption

2016 ◽  
Vol 721 ◽  
pp. 154-158
Author(s):  
Edmunds Lodins ◽  
Inga Pudze ◽  
Ineta Rozenstrauha ◽  
Linda Krage
Keyword(s):  
Industrial Waste ◽  
Iron Reduction ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Chemical Properties ◽  
High Porosity ◽  
Processing Waste ◽  
Iron Compounds ◽  
Physical Chemical ◽  
Made In

This work focuses on pellets made by Latvian industrial waste (waste cullet glass, sewage sludge, metallurgical slag and alumina scrap metal processing waste and raw mineral materials (limeless clay) to gain high porosity and water sorptiom. Iron sorption using ceramic pellets is explored more detailed. Physical-chemical properties and microstructure were researched to obtain a deeper understanding of how these qualities affect water purification from iron compounds. Three pellets with different properties were made in this paper : B5, A5 and E1. Composition B5 indicates highest iron sorption rate at sintering temperature 1100 °C and shows considerable iron reduction in a solution after one week.

Preparation and Properties of CaF2 Nano-Powder

2016 ◽  
Vol 680 ◽  
pp. 257-260
Author(s):  
Meng Yun Dong ◽  
Cheng Zhang ◽  
Jin Feng Xia ◽  
Hong Qiang Nian ◽  
Dan Yu Jiang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Sintering Temperature ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Direct Precipitation ◽  
Scanning Electron

CaF2 nano-power was prepared by direct precipitation methods with Ca(NO3)2 and KF as raw materials. The influences of presintering temperature and sintering temperature on the particle size and distribution of CaF2 nano-power were studied by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). This study provided an experimental method for preparation of CaF2 nano-power. The results show that the best presintering temperature of CaF2 nano-power is 500°C and the best sintering temperature of CaF2 ceramic is 900°C.

Manufacture of Ceramic High-Porosity Cellular Materials Based on Raw Materials and Production Wastes in Uzbekistan

2015 ◽  
Vol 72 (1-2) ◽  
pp. 35-37
Author(s):  
M. Kh. Rumi ◽  
G. V. Voronov ◽  
M. A. Zufarov ◽  
N. A. Kulagina ◽  
É. P. Mansurova ◽  
...  
Keyword(s):  
Raw Materials ◽  
Cellular Materials ◽  
High Porosity ◽  
Production Wastes

Rapid Forming of Hydroxyapatite-Silica Ceramics

2010 ◽  
Vol 450 ◽  
pp. 137-140
Author(s):  
Fwu Hsing Liu ◽  
Tsui Yen Ni ◽  
Yung Kang Shen ◽  
Jeou Long Lee
Keyword(s):  
Porous Structure ◽  
Cross Section ◽  
3D Model ◽  
Treatment Process ◽  
Crystallization Process ◽  
Laser Energy ◽  
Raw Materials ◽  
Three Dimensional ◽  
Silica Matrix ◽  
Atomic Force

This paper proposes a solid freefrom fabrication (SFF) technology for fabricating hydroxyapatite(HA)-silica ceramics, which can generate porous three-dimensional physical objects. The HA powder and the silica are mixed with water into slurries form as raw materials. The slurries are paved by a scraper to from a thin layer which is selective scanned by a laser beam according to the cross-section of a 3D model. The HA particles are embeded in the sintered silica matrix to form green parts via a suitable range of process parameters. The benefits of this process are: bio-ceramic parts can be built by lower laser energy and faster fabricating speed. Following a subsequence heat treatment process has been developed to optimize the crystallization process and to increase the strength of the sintered parts. The parts were analyzed by an Atomic Force Microscope (AFM) to determine the surface roughness. The results obtained indicate that the proposed process was possible to generate multilayer, overhanging, and porous structure with brittle property but sufficient integrity for handling prior to post-processing. It was possible to produce the porous structure from the proposed hydroxyapatite-silica ceramics, which had a greater potential for possible bone scaffolds fabrication.

scholarly journals Characteristics Of The Porous Body Sintered By Nano-Sized Fe-Cr-Al Alloy Powder

2015 ◽  
Vol 60 (2) ◽  
pp. 1275-1279
Author(s):  
Su-In Lee ◽  
Si-Hyeong Lee ◽  
Bon-Uk Gu ◽  
Dong-Won Lee ◽  
Byoung-Kee Kim
Keyword(s):  
Oxidation Resistance ◽  
Porous Body ◽  
Alloy Powder ◽  
Sintering Temperature ◽  
Porous Metal ◽  
Honeycomb Structure ◽  
Al Alloy ◽  
Liquid Droplets ◽  
Nano Powder ◽  
Polyurethane Sponge

Abstract Porous metal with uniform honeycomb structure was successfully produced by sintering using Fe-Cr-Al nano powder, which was prepared by the pulsed wire evaporation (PWE) in ethanol. Its process consisted of the several steps; 1) coating on the surface of polyurethane sponge with the liquid droplets generated from the ethanol-based slurry where the Fe-Cr-Al nano powders were uniformly dispersed, 2) heat treatment of debinding to remove the polyurethane sponge and 3) sintering of the porous green body formed by Fe-Cr-Al nano powders. The strut thickness of porous Fe-Cr-Al was increased by the increase of spraying times in ESP step. Also, The shrinkages and the oxidation resistance of the sintered porous body was increased with increase of sintering temperature. The optimal sintering temperature was shown to 1450°C in views to maximize the oxidation resistance and sinterability.

scholarly journals Tailoring the strength and porosity of rapid-hardening magnesia phosphate paste via the pre-foaming method

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Li-Jie Liu ◽  
Jin-Hong Li ◽  
Xiang Wang ◽  
Ting-Ting Qian ◽  
Xiao-Hui Li
Keyword(s):  
Compressive Strength ◽  
Porous Structure ◽  
Bulk Density ◽  
Sodium Silicate ◽  
Average Pore Size ◽  
Hydration Product ◽  
Polypropylene Fibers ◽  
High Porosity ◽  
Average Pore ◽  
Maximum Compressive Strength

Abstract High-porosity magnesia phosphate paste (HPMPP) was prepared via the pre-foaming method. In the pre-foaming method, sintering treatment was not required. The bulk density and maximum compressive strength of the HPMPP prepared according to the ratio of water to solids (W/So) of 0.32 reached 464.00 ± 5.00 Kg/m3 and 0.30 ± 0.05 MPa, respectively. The compressive strength increased with the increases in the addition amounts of sodium silicate and polypropylene fibers. The bulk density of HPMPP increased with the increase in the addition of sodium silicate and decreased with the increase in the addition of polypropylene fibers. Besides, the porosity of the magnesia phosphate paste increased from 79.85% to 81.27% and from 80.31% to 83.75% after the addition of sodium silicate and polypropylene fibers respectively. The highest porosity (83.75%) of the prepared HPMPP was realized under the addition proportion (sodium silicate: polypropylene fibers: solids = 0.06:0.0025:1). The average pore size of the prepared HPMPP is about 180 μm and the pore distribution range is relatively narrow. The hydration product (struvite) is combined with MgO particle one by one and then coated on the surface of bubbles. With the decrease of the water content, after breaking bubbles, the porous structure can be achieved.

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