Table 2.
The advancing water contact angles (qA) above and below the transition temperature (LCST) of APTES/pNIPAAm blend films cured for 3 days in vacuum at 160°C and rinsed by cold DI water. (A) various APTES/pNIPAAm ratios, (B) 50/50 APTES/pNIPAAm from solutions of different ages.
| (A)
|
(B)
|
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|---|---|---|---|---|---|
| APTES/pNIPAAm | θA (°) at 40°C > LCST | θA (°) at 25°C < LCST | solution age (days) | θA (°) at 40°C > LCST | θA (°) at 25°C < LCST |
|
|
|
||||
| 0/100* | 65.4 ± 5.7** | dissolved | 0 | 89.2 ± 1.6 | 78.4 ± 2.5 |
| 0/100 | 90.4 ± 4.7** | dissolved | |||
| 10/90 | 91.1 ± 3.6 | 53.1 ± 3.8 | 3 | 90.2 ± 0.4 | 78.6 ± 1.8 |
| 20/80 | 94.2 ± 4.1 | 82.3 ± 3.1 | 7 | 89.1 ± 1.8 | 77.5 ± 3.0 |
| 30/70 | 99.0 ± 3.4 | 79.7 ± 6.0 | |||
| 40/60 | 89.9 ± 3.2 | 78.8 ± 5.6 | 14 | 89.2 ± 1.7 | 80.8 ± 5.6 |
| 50/50 | 95.3 ± 1.7 | 75.2 ± 2.2 | |||
| 60/40 | 105.3 ± 1.3 | 77.3 ± 4.7 | 21 | 86.4 ± 2.8 | 75.2 ± 1.1 |
| 80/20 | 92.5 ± 2.8 | 74.1 ± 4.1 | 42 | 89.1 ± 1.8 | 78.6 ±2.5 |
| 100/0 | 88.1 ± 3.3 | 88.2 ± 2.5 | |||
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*
un-cured pNIPAAm film;
**
measured without rinsing the films; the average and standard derivation were the results of four to eight measurements.