Papers by Keyword: Hydrothermal Hot Pressing

Abstract: Apatite forming and bonding ability of Ti based bulk metallic glass ((Ti0.40Zr0.10Cu0.36Pd0.14)99Ca1: BMG) were investigated as a new type of biomaterials. Powder mixture of CaHPO4･2H2O and Ca(OH)2 and the BMG disks were treated with autoclave for hydrothermal hot-pressing simultaneously (150°C, 40MPa). And then the BMG disks were soaked in simulated body fluid (SBF, Kokubo solution). Apatite were deposited and covered on the surface of the BMG. It was firstly demonstrated that surface of Ti based bulk metallic glass could be revealed apatite forming ability.

Abstract: In this study, the synthesis of the bulky and dense mesoporous silica such as FSM was attempted by a hydrothermal hot-pressing (HHP) with a surfactant as a template and a subsequent calcination. According to TEM observation, the dense bulks obtained by HHP had a hexagonal mesopore structure. Also, these dense FSM bulks possessed high specific surface areas. Furthermore, Ag-supported dense FSM bulks were successfully synthesized by HHP with Ag salt and a subsequent calcination in H2. Thus, this HHP method is useful for synthesizing dense bulks and simultaneous supporting novel metals such as Ag on bulky FSM.

Abstract: Synthesis of bulky Y-zeolite was attempted by a hydrothermal hot-pressing (HHP) method. These bulky products synthesized under hydrothermal conditions were identified as Y-zeolite single phase. Especially, bulky Y-zeolite having translucency, high density and large surface area was obtained by HHP treatment at 423K for 2h with 17wt% of 5M-NaOH solution. This solidified zeolite like single-crystal was considered to be made by dissolution and precipitation mechanism. High-density bulky zeolites can be expected as novel molecular sieves and catalysts with high activity.

Abstract: Porous hydroxyapatite/tricalcium phosphate composite block has been prepared using a hydrothermal hot pressing (HHP) technique to achieve having a high mechanical strength and controlled biodegradability. The SEM result of the sample shows that the pore sizes are ranged from 100µm to 300µm. The observed X-ray powder diffraction pattern of the sample after sintered 1200oC is composed of hydroxyapatite and tricalciumphosphste.

Abstract: Porous hydroxyapatite has been prepared using a hydrothermal hot pressing method from calcium carbonate as a starting material. SEM result shows porous hydroxyapatite block is formed of three dimensionally inter-connected pores of 100-400µm in size, similar to human cancellous bone. At the ~ 70% porosity, the compressive strength was about 4MPa, which is similar to that of the commercially available porous hydroxyapatite derived from natural coral.

Abstract: The hydrothermal hot-pressing (HHP) technique was used to prepare hydroxyapatite (HAp) ceramics from a HAp powder with low crystallinity, and the effects of processing factors such as temperature, loading pressure and reaction time on densification were investigated. The crystallinity of HAp was increased by the HHP treatments. With the increase in reaction temperature, loading pressure and reaction time, the density and Vickers hardness of the compacts increased. The HAp compact with high relative density of 83% and high Vickers hardness of 2.9 GPa was successfully prepared by the HHP treatment at 200°C for 3 h under loading pressure of 60 MPa.

Abstract: The hydrothermal hot pressing (HHP) technique is a method by which hard solid bodies of powders can be produced in a short time and at a relatively low temperature under saturated vapor pressure. In this study, the hydrothermal hot pressing (HHP) technique is used for preparing porous hydroxyapatite/TCP block having a high mechanical strength. The SEM result of the sample shows that all the pores are interconnected from 200µm to 300µm in sizes. The observed X-ray powder diffraction pattern of the sample after sintering at 1200oC is composed of hydroxyapatite and tricalciumphosphste.