Synthetic vascular materials via a vaporization of sacrificial component (VaSC) approach

self-healing materials;poly(lactic acid) (PLA);hot pressing;vaporization of sacrificial component (VaSC);microvascular composites;fiber spinning;vascular materials

Dong, Hefei

关键词: self-healing materials;    poly(lactic acid) (PLA);    hot pressing;    vaporization of sacrificial component (VaSC);    microvascular composites;    fiber spinning;    vascular materials;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/46825/Hefei_Dong.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The introduction of microchannels into traditional composites has numerous applications ranging from self-healing to autonomous cooling materials. However, current approaches for microvascularization are hindered by scalability and lack of compatibility with the composite manufacturing proceess. Herein, we present the development of a new procedure for incorporating microchannels into composites that overcome these limitations. Namely, the vaporization of sacrificial component (VaSC). The chosen sacrificial material, poly(lactic acid) (PLA), can be easily incorporated into composites and undergoes a solid-to-gas transition at ca. 280 oC, which allows for the extraction of the gaseous product from the composite leaving hollow spaces in the matrix. The fabrication of a microvascular composite by this method necessitated the development of PLA sacrificial fibers, and three distinct production techniques for producing the desired PLA fibers were explored (chemical modification of commercial PLA fibers, homespun PLA fibers, and micro-structuring of a PLA film). The dissertation also discusses the coated sacrificial fibers (CSFs) as a building block for biomimetic vascular structures. In addition, the fabrication of a microporous battery separator via a similar VaSC approach was developed. In order to improve the safety of automobile battery systems, we sought to apply produce a thermally stable battery separator that prevents cell shortage by establishing a high-temperature fabrication route. A solution containing PLA and polyimide (PI) was cast into form a biphasic film; thermal removal of the PLA phase left a microporous PI film. Experimental evidence showed that the microporous PI film that was fabricated using the PLA sacrificial component had superior thermal properties and could potentially replace current commercial separators.