Table 2.
Static water contact angle measurements of HEMA modified SU-8 for triple repeats in air and in oxygen free environments to verify surface initiator role
| without HCPK treatment a | without UV irradiation b | with HCPK treatment and UV irradiation c | |
|---|---|---|---|
| air | 79±1° | 78±1° | 75±3° |
| Oxygen free environment | 78±3° | 77±2° | 35±1° |
Contact angle of fresh SU-8: 79±1°
All samples received the same UV dosage and HEMA amount during the polymerization step. Only the addition of surface bound photoinitiator was altered:
a
Monomer and fresh SU-8 were exposed to UV light without the initial step of adding surface bound photoinitiator
b
SU-8 material was soaked in photoinitiator solution but no UV irradiation was used for activation.
c
SU-8 was modified as described previously – photoinitiator was present and activated with UV light