Applying SEM-Based X-ray Microtomography to Observe Self-Healing in Solvent Encapsulated Thermoplastic Materials

• Published in: Advanced engineering materials Vol. 12; no. 3; pp. 228 - 234
• Main Authors: Mookhoek, Steven D., Mayo, Sheridan C., Hughes, Anthony E., Furman, Scott A., Fischer, Hartmut R., van der Zwaag, Sybrand
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01-03-2010; WILEY‐VCH Verlag
• Subjects: Encapsulation; Fracture mechanics; Healing; Rendering; Solvents; Thermoplastic resins; Three dimensional; X-ray microtomography
• ISSN: 1438-1656; 1527-2648
• DOI: 10.1002/adem.200900289

In this work X‐ray microtomography was used to observe fracture and healing processes in a liquid‐based self‐healing thermoplastic material. The method was able to produce data of sufficient resolution (<10 μm) to observe ∼60 μm microcapsules containing solvent within a polymeric material and in particular their behavior around a crack zone after fracture and healing. The reconstructed data showed the distribution of filled and several empty microcapsules within the matrix material. Additional color segmentation and 3D rendering of the data unambiguously demonstrated a large concentration of ruptured microcapsules near the fracture surfaces, covering ∼75 μm span on both sides of the crack. A close investigation of the crack area confirmed the presence of healed and non‐healed regions. Further analysis of the segmented data allowed a quantitative determination of the release of the encapsulated solvent.
In this work SEM‐based X‐ray microtomography is used to characterize liquid‐based self‐healing materials. 3D X‐ray microtomography coupled with image segmentation and analysis allows a quantitative analysis of the fracture and release processes in a microcapsule‐based self‐healing thermoplastic material. The method is able to produce data of sufficient resolution (<10 μm) to observe ∼60 μm microcapsules containing solvent within a polymeric material and in particular their behavior around a crack zone after fracture and healing. It is demonstrated that microtomography offers large potential for non‐destructive quantitative characterization of liquid‐based self‐healing materials in the future.