Title Page
Contents
요약 9
I. Introduction 10
1. The electrospinning fiber formation and application 10
2. Coaxial electrospinning 12
3. Polydiacetylene 13
4. The research process in this study. 15
II. Experimental section 16
1. Materials and equipment 16
2. Formation of coaxial nanofiber and detection of water using the nanofiber mat 17
3. Estimation of the physical properties using UTM 20
III. Results and discussion 21
1. Formation of the nanofiber mat containing PDA 21
2. Formation of coaxial nanofiber 26
3. Color change of the nanofiber mats by one drop of H₂O 28
4. Rate of the color change of the coaxial nanofiber 32
5. The thickness change during the color change of the coaxial nanofiber 35
IV. Conclusion 37
V. References 38
Abstract 43
Table 1. Mechanical properties of the polymers used in the shell of coaxial nanofiber. 25
Fig. 1. Electrospinning equipment used in this study. 18
Fig. 2. Representative procedure to form the sensor using the coaxial nanofiber. 22
Fig. 3. The change in cross-section of coaxial nanofiber during the detection of water. 23
Fig. 4. IR spectrum (a) the coaxial nanofiber mat with PCL and PEO, (b) the coaxial nanofiber mat with PCL and PVA-99, (c) PCL, (d)... 27
Fig. 5. Color change after one drop of H₂O is added to, (a) PCL + solvent: chloroform), (b) PCL + PEO (solvent: H₂O), (c) PCL +... 29
Fig. 6. Microscopy images of the coaxial nanofibers, the core in the coaxial nanofiber (a-1) PEO (solvent: chloroform) under 200... 31
Fig. 7. Color change rate of the nanofiber mat depending on the thickness of the PCL shell material. 33
Fig. 8. Color change rate of the nanofiber mat depending on the thickness of the PEO core material. 34
Fig. 9. The microscope pictures of the coaxial nanofibers, the core: PEO (solvent: chloroform), the shell: PCL. (a) before adding H₂O, (b)... 36