Title Page
Abstract
Contents
Chapter 1. Introduction 11
1.1. Study Background 11
1.2. Purpose of Research 13
Chapter 2. Fabrication 16
2.1. Overview 16
2.2. Fabrication Parameters 17
2.3. General Characterization 22
2.4. Method 28
Chapter 3. Mass transporation in AACNF 32
3.1. Overview 32
3.2. Viscous Flow 33
3.3. Microparticle 37
3.4. Method 41
Chapter 4. Applications 45
4.1. Hydrogel Integration 45
4.2. Microbial Fuel Cell 51
4.3. Method 59
Chapter 5. Conclusion and Perspectives 62
Bibliography 64
국문 초록 67
Figure 1. Examples of template electrodes with various size scale. (a) Carbon paper. (b) Carbon cloth. (c) Graphene-oxide foam. (d) Ni foam. (e)... 12
Figure 2. Visualization of Ag and Au distribution in AACNF using SEM and EDS elemental mapping. 13
Figure 3. The schematic illustration of the AACNF as template electrode for nanometer to micrometer scale substances. 14
Figure 4. Hierarchical structures of AACNF with the PAAm hydrogel (a), PEDOT:PSS hydrogel (b), the fibroblast cell (c), and the Geobacter Anodireducens (d). 15
Figure 5. The schematic illustration of the fabrication principle for AACNF. 16
Figure 6. The schematic illustration of the different states of PVP on the AgNW surface with respect to the existence of ethanol. 16
Figure 7. Photographic images comparing the morphology of AACNF fabricated without (a) or with (b) ethanol. 17
Figure 8. (a) The morphology of the fabricated AACNF with respect to the ethanol volume fraction. (b) The plot of fabricated AACNF volumes against the... 19
Figure 9. (a) The morphology of the fabricated AACNF with respect to the weight ratio of the Au against the Ag. (b) ICP-MS analysis of the released Ag ions from... 20
Figure 10. The morphology of the fabricated AACNF (a) and the plot of electrical conductivity (left axis) and density (right axis) of the AACNF (b) with respect to... 21
Figure 11. Comparing AACNF and previously reported studies on the relationship between electrical conductivity and density. 22
Figure 12. (a) Fabrication process of the sample for measuring the electrical conductivity of the AACNF over time. (b) Photographic images measuring the... 24
Figure 13. Normalized electrical conductivity of the AACNF with varying densities against the synthesis time. 24
Figure 14. (a) Photographic images of printed letter, "Ag Au" (i), and the printed letters seen through the 1 mm thick AACNF with 0.2 wt% of NWs (ii) and 0.5 wt%... 25
Figure 15. Transmittance spectra of the 1 mm thick AACNF with varying densities by UV-Vis spectroscopy. 26
Figure 16. (a) a photographic image of the UTM setup for compressive stress-strain curve measurements. The diameter of the UTM compression platen was 50... 27
Figure 17. (a) Examples of substances on the nanometer to micrometer scale that is permeable into AACNF. (b) The super-porous structure demonstrated by AACNF... 32
Figure 18. (a) AACNF samples to test the effect of the NW density. (b) The compression-mold for AACNF with NW densities from 1.0 to 4.0 wt%. 34
Figure 19. (a) Diagram of the experimental setup diagram to measure viscous permeability of porous materials via pressure difference and mass flux across the... 34
Figure 20. (a) Viscous permeability against volumetric flux across the AACNF with different weight percent of NWs from 0.25 to 2.0. The error bars are the s.d.... 35
Figure 21. (a) Diagram of the two-chamber diffusion cell to measure the mass diffusivity across the porous material. (b) Photograph of the mass diffusivity test.... 35
Figure 22. (a) The glucose concentration over time measured from the receptor chamber according to varying densities of AACNFs. The error bars are the s.d. for... 36
Figure 23. The schematic illustration of cell-embedding, incubation and observation process, with the L929 cells requiring 24-36 hours of settlement time.... 38
Figure 24. The microscopic image (bright-field/live/dead) of L929 cells settled on the 3D nanowire matrix of AACNF (0.25 wt% NWs) at 36 h the cell viability... 38
Figure 25. Seven days of viability test conducted on L929 cells showing the biocompatibility of AACNF. 39
Figure 26. Microscopic images (DAPI) of L929-embedded AACNFs of varying NW densities, showing cell distribution by depths from the top surface. The L929... 40
Figure 27. The cell population ratio by depth from the top of the AACNF with varying densities. The error bars are the s.d. for N=4 samples. 40
Figure 28. The schematic comparison of the PAAm hydrogel-embedded AACNF fabrication process (a) and the PAAm hydrogel with AgNWs (b). 45
Figure 29. The fabrication process for PAAm hydrogel-embedded AACNF. 46
Figure 30. Electrical conductivity of the AACNF, PAAm hydrogel-embedded AACNF, and the PAAm hydrogel with AgNWs against the weight percent of the... 46
Figure 31. Photographic images of PAAm hydrogel-embedded AACNF with different NW content before and after stretching. 47
Figure 32. Cross-sectional SEM images of the stretched PAAm hydrogel-embedded AACNF with different densities. AACNF with 0.4wt% of NW under 0%... 48
Figure 33. (a) A photographic image of the PEDOT:PSS hydrogel-embedded AACNF before the cut. (b) A photographic image of the PEDOT:PSS hydrogel-... 48
Figure 34. (a) Fabrication process of the sample for measuring the electrical conductivity of the PAAm hydrogel-embedded AACNF before and after stretching.... 50
Figure 35. (a) Relative resistance with respect to the strain applied to the PAAm hydrogel-embedded AACNF with varying NW content. (b) Cyclic loading and... 50
Figure 36. (a) The schematic illustration of the operating mechanism of a single-chamber MFC using AACNF as an anode electrode. (b) Photographic image of the... 52
Figure 37. SEM images of the geobacter anodireducens culture inside the AACNF (a-c) and on the dense 2D network of NWs(d). 52
Figure 38. Polarization curve (a) and power density curve (b) of the MFC using AACNF as an anode with respect to the microbial culture time. 53
Figure 39. The analytic method of analyzing the polarization curve of a microbial fuel cell (MFC). 55
Figure 40. (a) Polarization curves of the MFC with varying densities of the AACNF. The error bars are the standard deviation (s.d.) for N=5 samples. (b)... 57
Figure 41. MFC maximum power against time for 25 days of long-term operation. The red arrow indicates the basal broth supply to the Geobacter anodireducens... 58