Table 1. Atomic Compositions of Pristine PI and PVP/PI_hp Samplesa,b.
| sample | C/% | N/% | O/% |
|---|---|---|---|
| pristine PI | 76.5 | 5.3 | 18.2 |
| PVP/PI_hp (r.t.) | 79.7 | 4.0 | 16.3 |
| PVP/PI_hp (120 °C) | 78.7 | 3.5 | 17.8 |
| PVP/PI_hp (140 °C) | 77.4 | 3.7 | 18.9 |
| PVP/PI_hp (160 °C) | 78.5 | 2.3 | 19.2 |
| PVP/PI_hp (180 °C) | 81.6 | 2.8 | 15.7 |
| PI (theoretical value) | 75.9 | 6.9 | 17.2 |
| PVP (theoretical value) | 88.9 | 11.1 |
a
Atomic compositions were calculated using C, O, and N (C + N + O = 100%).
b
XPS spectra used for calculations were obtained using the take-off angle of 15°.