Abstract
Purpose: Unidirectional freezing followed by freeze-drying is a way to produce microcellular material from a polymer solution for biomedical application. As a distinctive feature of this type of process, bundles of channels are observed with an average diameter of hundreds of microns. Variations in porous morphology, particularly in porosity, density, and degree of regularity of spatial organization of pores, have been observed when polymer concentrations and quenching temperature are changed. To examine these issues in more detail the thermally induced phase separation of a polycaprolactone/dioxane solution was studied as a function of polymer concentration and quenching temperature in connection with the ultimate morphology of the micro-cellular material.
Methods: We prepared microcellular samples of polycaprolactone by freeze/freeze-drying technique. The microstructure of the material was observed by scanning electron microscopy. Moreover, a mathematical model for the prediction of the temperature profile and morphology was developed.
Results and Conclusions: A microstructural disorder region inside the samples was sometimes observed in connection with process parameters. The developed model is able to capture the formation of such a microstructural disorder region as a direct consequence of the slowing down of the solid-liquid interface. Predictions of the model as a function of freezing rate and concentration are in excellent agreement with experimental observation.
J Appl Biomater Funct Mater 2012; 10(3): 237 - 242
Article Type: ORIGINAL RESEARCH ARTICLE
DOI:10.5301/JABFM.2012.10363
Authors
Domenico Larobina, Vincenzo Guarino, Luigi Ambrosio
Article History
- • Accepted on 10/10/2012
- • Available online on 13/12/2012
- • Published in print on 13/02/2013
This article is available as full text PDF.
Authors
- Larobina, Domenico
[PubMed]
[Google Scholar]
Institute of Composite and Biomedical Materials, National Research Council of Italy, Naples - Italy
- Guarino, Vincenzo
[PubMed]
[Google Scholar]
Institute of Composite and Biomedical Materials, National Research Council of Italy, Naples - Italy
- Ambrosio, Luigi
[PubMed]
[Google Scholar]
Institute of Composite and Biomedical Materials, National Research Council of Italy, Naples - Italy
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