TY - JOUR
T1 - Two-photon absorption cross-sections of common photoinitiators
AU - Schafer, Katherine J.
AU - Hales, Joel M.
AU - Balu, Mihaela
AU - Belfield, Kevin D.
AU - Van Stryland, Eric W.
AU - Hagan, David J.
N1 - Funding Information:
The authors wish to thank CIBA Specialty Chemicals Corporation for the generous contribution of their photoinitiators, and gratefully acknowledge the support of the National Science Foundation (ECS 0217932), the donors of The Petroleum Research Fund of the American Chemical Society, and the Research Corporation Cottrell College Science Award.
PY - 2004/3/15
Y1 - 2004/3/15
N2 - Recent interests in and applications of two-photon absorption (2PA) induced photopolymerization have afforded advanced opportunities to perform three-dimensionally resolved polymerization, resulting in intricate microfabrication and imaging. Many of the reported 2PA-induced polymerizations make use of commercially available photoinitiators, and a key parameter to consider is the two-photon absorption cross-section (δ) of the initiator. To date, there has been no comprehensive investigation of two-photon absorptivity of commercial photoinitiators, though a few studies presenting novel photoinitiators for two-photon polymerization have appeared. Herein, we report the 2PA properties of common, commercially available photoinitiators typically utilized in conventional radiation curing science and technologies, and often used in 2PA-based polymerizations. Z-scan and white-light continuum (WLC) pump-probe techniques were utilized to obtain two-photon absorption cross-sections (δ). The results for most compounds were found to yield good agreement between the two methods. Most of the photoinitiators studied possess low δ, except Irgacure OXE01, indicating a need for the development of new photoinitiators with improved properties optimized for 2PA applications. A compound prepared in our laboratories exhibits high 2PA and was useful as a two-photon free-radical photoinitiator.
AB - Recent interests in and applications of two-photon absorption (2PA) induced photopolymerization have afforded advanced opportunities to perform three-dimensionally resolved polymerization, resulting in intricate microfabrication and imaging. Many of the reported 2PA-induced polymerizations make use of commercially available photoinitiators, and a key parameter to consider is the two-photon absorption cross-section (δ) of the initiator. To date, there has been no comprehensive investigation of two-photon absorptivity of commercial photoinitiators, though a few studies presenting novel photoinitiators for two-photon polymerization have appeared. Herein, we report the 2PA properties of common, commercially available photoinitiators typically utilized in conventional radiation curing science and technologies, and often used in 2PA-based polymerizations. Z-scan and white-light continuum (WLC) pump-probe techniques were utilized to obtain two-photon absorption cross-sections (δ). The results for most compounds were found to yield good agreement between the two methods. Most of the photoinitiators studied possess low δ, except Irgacure OXE01, indicating a need for the development of new photoinitiators with improved properties optimized for 2PA applications. A compound prepared in our laboratories exhibits high 2PA and was useful as a two-photon free-radical photoinitiator.
KW - Darocure
KW - Irgacure
KW - Photoinitiators
KW - Photopolymerization
KW - Two-photon absorption
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U2 - 10.1016/S1010-6030(03)00394-0
DO - 10.1016/S1010-6030(03)00394-0
M3 - Article
AN - SCOPUS:1342307566
SN - 1010-6030
VL - 162
SP - 497
EP - 502
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
IS - 2-3
ER -