Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

Characterization of Porous β-type Tricalcium Phosphate Ceramics Formed by Physical Foaming with Freeze-Drying

Version 1 : Received: 3 April 2024 / Approved: 3 April 2024 / Online: 3 April 2024 (08:36:44 CEST)

How to cite: Hashimoto, K.; Oikawa, H.; Shibata, H. Characterization of Porous β-type Tricalcium Phosphate Ceramics Formed by Physical Foaming with Freeze-Drying. Preprints 2024, 2024040267. https://doi.org/10.20944/preprints202404.0267.v1 Hashimoto, K.; Oikawa, H.; Shibata, H. Characterization of Porous β-type Tricalcium Phosphate Ceramics Formed by Physical Foaming with Freeze-Drying. Preprints 2024, 2024040267. https://doi.org/10.20944/preprints202404.0267.v1

Abstract

Porous β-tricalcium phosphate (Ca3(PO4)2; β-TCP) was prepared by freeze-drying and the effects of this process on pore shapes and sizes were investigated. Various samples were prepared by freezing β-TCP slurries above a liquid nitrogen surface at −180 °C with subsequent immersion in liquid nitrogen at −196 °C. These materials were then dried under reduced pressure in a freeze-dryer after which they were sintered by heating. Compared with conventional heat-based drying, the resulting pores were more spherical, which increased both the mechanical strength and porosity of the β-TCP. These materials had a wide range of pore sizes from 50 to 200 µm, with the mean and median values both approximately 100 µm regardless of the freeze-drying conditions. Mercury porosimetry data showed that the samples contained small, interconnected pores with sizes of up to 1.24 µm and macroscopic, interconnected pores up to 25.8 µm in size. The effects of non-ionic surfactants having different hydrophilic/lipophilic balance (HLB) values on foaming and pore size were also investigated. Materials made with surfactants having lower HLB values exhibited smaller pores and lower porosity whereas higher HLB surfactants gave higher porosity and slightly larger macropores. Even so, the pore diameter could not be readily controlled solely by adjusting the HLB value. The findings of this work indicated that high porosity (75%) and good compressive strength (>2 MPa) can both be obtained in the same porous material and that foaming agents with HLB values between 12.0 and 13.5 were optimal.

Keywords

porous β-tricalcium phosphate; physical foaming method; freeze drying; cellulose nanofiber; non-ionic surfactants; hydrophilic/lipophilic balance (HLB)

Subject

Chemistry and Materials Science, Biomaterials

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our Diversity statement.

Leave a public comment
Send a private comment to the author(s)
* All users must log in before leaving a comment
Views 0
Downloads 0
Comments 0
Metrics 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.