## 3 Results and Discussion  
### Characterization of Electrospun PET, WPET, PET-SiAMPy, and WPET-SiAMPy Nanofibres  
The SiAMPy-modified PET and WPET nanofibres were characterized with HRSEM to visualize the morphology of the composite nanofibres as shown in Figure 1.  
The HRSEM image of SiAMPy as supplied is shown in Figure 1a while the ground SiAMPy in Figure 1b demonstrated the agglomerated structure of the powder with a size range from 85 to 103 nm. The supplied SiAMPy initially possessed large, agglomerated units that needed to be ground to powder. This was performed to increase the surface area of the SiAMPy, thus increasing the adsorption capacity by limiting diffusional constraints of large units and making the powder SiAMPy easier to incorporate into the polymer solutions, respectively. The powder SiAMPy was completely dissolved in the electrospinning solvent. Figure 1c,d show the HRSEM images with the nanofibre morphology of PET and WPET, both of which consisted of smooth, uniform, homogeneous, and well-structured nanofibres with varying diameters in the range of 90-130 nm, respectively. The polymer solution flow rate and collecting distance of WPET was varied for possible spinnability conditions, with the PET electrospinning conditions as the reference. The WPET polymer solution was spinnable at 0.05 mL/h flow rate and at a collecting distance of 14 cm. The homogeneous structured PET and WPET nanofibres in Figure 1c,d prove the success of the electrospinning procedure and the optimum conditions under which PET and WPET nanofibre formation occurred (see Table 1). In the HRSEM images of PET-SiAMPy (e) and WPET-SiAMPy (f) composite nanofibres showed bead formation on the PET-SiAMPy nanofibres that were spun using a flow rate of 0.8 mL/h. The formation of beading visible in Figure 1e could be due to the repulsive forces between PET polymer and S-AMPy nanoparticles' ionic groups that arise due to the application of the high electric field during electrospinningning. Figure 1f showed consistent, smooth, and homogeneous nanofibres for WPET-SiAMPy nanofibres that were spun at a flow rate of 0.05 mL/h. The electrospinningning flow rate was set according to the polymer solution viscosity. The WPET-SiAMPy polymer solution was more viscous compared to the PET-SiAMPy polymer solution, thus the WPET-SiAMPy polymer solution electrospinning flow rate was observed to be lower than PET-SiAMPy polymer solution. The HRSEM image (f) shows good blending between the SiAMPy and the WPET polymer under the applied electrospinning conditions which were 0.05 mL/h flow rate, 20 kV applied electric field voltage and 14 cm collecting distance. The interconnected nanofibres in the HRSEM image (e) were due to the polymer concentration and the concentration of the solvent TFA. [PERSON] et al. (2017) previously reported that TFA formed interconnected nanofibres with branches and twigs, due to the high TFA concentration that lowered the evaporation rate and caused bonding between nanofibres. The WPET-SiAMPy nanofibres thus had better nanofibre morphology compared to the PET-SiAMPy nanofibres, showing the benefit of reusing WPET for preparing functional nanofibres. The FTIR spectra for PET and WPET nanofibres shown in Figure 2a demonstrate similar FTIR patterns which means that the PET commercial nanofibres and the recycled WPET nanofibres possess the same functional groups. Figure 2: ATR-FTIR patterns of (**a**): PET (0.8 mL/h, 17 kV, 17 cm) and WPET (0.05 mL/h, 17 kV, 14 cm) nanofibres; (**b**): PET-SiAMPy (0.8 mL/h, 20 kV, 14 cm) and WPET-SiAMPy (0.05 mL/h, 20 kV, 14 cm) and (**c**): SiAMPy.