Papers by Keyword: Dissolution Property

Abstract: In this study, E51 was appended as an additive to the PES casting solution and hybrid PES/E51 films with different E51 content were produced by phase inversion approach, applied as interleaves to improve the interlaminar fracture toughness of CF/EP composite laminates prepared by vacuum assistant resin infusion process (VARI). The time that the hybrid film dissloved into the epoxy resin depended on the content of E51 in the film, moreover, it was observed that Mode I fracture toughness of the hybrid film modified composite reduced with the addition of E51 compared with the pure PES film interleaved composite, however, the tensile properties showed the opposite tendency. The reason was the reduction in the thickness of the interlayer resin illustrated by cross-section morphologies of all types of laminates.

Abstract: Biphasic calcium phosphate (BCP) ceramics, a mixture of hydroxyapatite (HAp) and betatricalcium phosphate (β-TCP), of varying HAp/β-TCP ratios was prepared. One kinds of HAp and one kind of β-TCP powders were used to produce porous BCP bioceramics with HAp/β-TCP weight rations of 20/80, 40/60, and 80/20. A slip was obtained by adding a mixed powders of HAp and β-TCP to a solution 1.5% of deflocculant and 0.5 wt% of foaming agent. The optimum value for the minimum viscosity in these present slips with respect to its solid loading and the optimum amount of the deflocculant were investigated. The specimen obtained by casting a polyurethane foam with 1.5 wt% of deflocculant into a slip, and drying it under vacuum, was heated at 1150°C for 3 hours. The resultant porous BCP sintered body had large spherical pores of 300 /m with interconnecting rectangular voids. Many small pores in the size range of 2-3 /m or below were observed in the specimen obtained by heating at 1150°C for 3 hours. The dissolution test was done as follows. The obtained porous ceramics samples about 0.5g individually soaked into 30 mL of simulated body fluid (SBF) solution at 36.5°C. The calcium and phosphorous content of the SBF solution was analyzed by ICP. The porous body was dried, and characterized using SEM, XRD, and FT-IR.

Abstract: Biphasic calcium phosphate (BCP) ceramics, a mixture of hydroxyapatite (HAp) and beta-tricalcium phosphate (β-TCP), of varying HAp/β-TCP ratios were prepared from fine powders. Porous BCP ceramic materials with HAp/β-TCP weight rations of 20/80, 40/60, and 80/20 were prepared. In this study, the bioactivity is reduced at a larger HAp content rate, which is likely related to the high driving pore for the formation of a new phase, and the reaction rate was proportional to the β-TCP. The porous BCP ceramics having a bigger porosity rate can easily under up dissolution. The powder having a larger β-TCP content rate can easily generate a new phase. The dissolution results confirmed that the biodegradation of calcium phosphate ceramics could be controlled by simply adjusting the amount of HAp or β-TCP in the ceramics and porosity rate.

Abstract: Two kinds of tri-calcium phosphate ceramics, β-TCP, which have the same macrostructure and microstructure, but different special surface area and particle size, were used in porous ceramics. A slip was obtained by adding the powders to a solution 1.0 wt% of deflocculant, respectively. The specimen obtained by casting a polyurethane foam with 0.5wt% into a slip, and drying it under vacuum, was heated at 1150
, for 3 hours. The porous ceramics samples about 0.5g were individually soaked into 30 mL of phosphate buffer saline (PBS) at 20
for 1,3,7 and 10 days, respectively. The calcium content of the PBS solution was analyzed by (ICP). The porous bodies were filtered, dried, and characterized using SEM, XPD, and FT-IR.

Abstract: Biphasic calcium phosphate (BCP) ceramics, a mixture of hydroxyapatite (HAp) and beta-tricalcium phosphate (β-TCP), of varying HAp/β-TCP ratios were prepared from fine powders. Porous BCP ceramic materials with HAp/β-TCP weight rations of 20/80, 40/60, and 80/20 were prepared. In this study, the bioactivity is reduced at a bigger HAp content rate, which is likely related to the high driving pore for the formation of a new phase, and the reaction rate was proportional to the β-TCP. The porous BCP ceramics having a bigger porosity rate can easily under up dissolution. The powder having a bigger β-TCP content rate can easily generate a new phase. The dissolution results confirmed that the biodegradation of calcium phosphate ceramics could be controlled by simply adjusting the amount of HAp or β-TCP in the ceramics and porosity rate.