TY - JOUR
T1 - One- and two-photon induced polymerization of methylmethacrylate using colloidal CdS semiconductor quantum dots
AU - Strandwitz, Nicholas C.
AU - Khan, Anzar
AU - Boettcher, Shannon W.
AU - Mikhailovsky, Alexander A.
AU - Hawker, Craig J.
AU - Nguyen, Thuc Quyen
AU - Stucky, Galen D.
PY - 2008/7/2
Y1 - 2008/7/2
N2 - The development of one- and two-photon induced polymerization using CdS semiconductor quantum dots (QDs) and amine co-initiators to promote radical generation and subsequent polymerization is presented. Two-photon absorption (TPA) cross-section measurements, linear absorption, and transmission electron microscopy are used to characterize the QDs. The effectiveness of the co-initiators in increasing the efficiency of photopolymerization (polymer chains formed per excitation) is examined. Triethylamine was observed to be most effective, yielding quantum efficiencies of initiation of >5%. The interactions between the co-initiators and QDs are investigated with steady-state photoluminescence and infrared spectroscopies. Possible initiation mechanisms are discussed and supported by electrochemical data. Making use of the surface chemistry developed here and the large QD TPA cross-sections, two-photon induced polymerization is demonstrated. The large TPA cross-sections coupled with modest quantum efficiencies for initiation reveal the unique potential of molecularly passivated QDs as efficient two-photon photosensitizers for polymerization.
AB - The development of one- and two-photon induced polymerization using CdS semiconductor quantum dots (QDs) and amine co-initiators to promote radical generation and subsequent polymerization is presented. Two-photon absorption (TPA) cross-section measurements, linear absorption, and transmission electron microscopy are used to characterize the QDs. The effectiveness of the co-initiators in increasing the efficiency of photopolymerization (polymer chains formed per excitation) is examined. Triethylamine was observed to be most effective, yielding quantum efficiencies of initiation of >5%. The interactions between the co-initiators and QDs are investigated with steady-state photoluminescence and infrared spectroscopies. Possible initiation mechanisms are discussed and supported by electrochemical data. Making use of the surface chemistry developed here and the large QD TPA cross-sections, two-photon induced polymerization is demonstrated. The large TPA cross-sections coupled with modest quantum efficiencies for initiation reveal the unique potential of molecularly passivated QDs as efficient two-photon photosensitizers for polymerization.
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U2 - 10.1021/ja711295k
DO - 10.1021/ja711295k
M3 - Article
C2 - 18529003
AN - SCOPUS:46049107357
SN - 0002-7863
VL - 130
SP - 8280
EP - 8288
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 26
ER -