TY - JOUR
T1 - Photoinitiation and inhibition under monochromatic green light for storage of colored 3D Images in Holographic Polymer-Dispersed Liquid Crystals
AU - Chen, Guannan
AU - Ni, Mingli
AU - Peng, Haiyan
AU - Huang, Feihong
AU - Liao, Yonggui
AU - Wang, Mingkui
AU - Zhu, Jintao
AU - Roy, V. A.L.
AU - Xie, Xiaolin
N1 - Publisher Copyright:
© 2016 American Chemical Society
PY - 2017/1/18
Y1 - 2017/1/18
N2 - Holographic photopolymer composites have garnered a great deal of interest in recent decades, not only because of their advantageous light sensitivity but also due to their attractive capabilities of realizing high capacity three-dimensional (3D) data storage that is long-term stable within two-dimensional (2D) thin films. For achieving high performance holographic photopolymer composites, it is of critical importance to implement precisely spatiotemporal control over the photopolymerization kinetics and gelation during holographic recording. Though a monochromatic blue light photoinitibitor has been demonstrated to be useful for improving the holographic performance, it is impractical to be employed for constructing holograms under green light due to the severe restriction of the First Law of Photochemistry, while holography under green light is highly desirable considering the relatively low cost of laser source and high tolerance to ambient vibration for image reconstruction. Herein, we disclose the concurrent photoinitiation and inhibition functions of the rose bengal (RB)/N-phenylglycine (NPG) system upon green light illumination, which result in significant enhancement of the diffraction efficiency of holographic polymer-dispersed liquid crystal (HPDLC) gratings from zero up to 87.6 ± 1.3%, with an augmentation of the RB concentration from 0.06 × 10−3 to 9.41 × 10−3 mol L−1. Interestingly, no detectable variation of the ϕ1/2kp/kt1/2, which reflects the initiation efficiency and kinetic constants, is given when increasing the RB concentration. The radical inhibition by RBH• is believed to account for the greatly improved phase separation and enhanced diffraction efficiency, through shortening the weight-average polymer chain length and subsequently delaying the photopolymerization gelation. The reconstructed colored 3D images that are easily identifiable to the naked eye under white light demonstrate great potential to be applied for advanced anticounterfeiting.
AB - Holographic photopolymer composites have garnered a great deal of interest in recent decades, not only because of their advantageous light sensitivity but also due to their attractive capabilities of realizing high capacity three-dimensional (3D) data storage that is long-term stable within two-dimensional (2D) thin films. For achieving high performance holographic photopolymer composites, it is of critical importance to implement precisely spatiotemporal control over the photopolymerization kinetics and gelation during holographic recording. Though a monochromatic blue light photoinitibitor has been demonstrated to be useful for improving the holographic performance, it is impractical to be employed for constructing holograms under green light due to the severe restriction of the First Law of Photochemistry, while holography under green light is highly desirable considering the relatively low cost of laser source and high tolerance to ambient vibration for image reconstruction. Herein, we disclose the concurrent photoinitiation and inhibition functions of the rose bengal (RB)/N-phenylglycine (NPG) system upon green light illumination, which result in significant enhancement of the diffraction efficiency of holographic polymer-dispersed liquid crystal (HPDLC) gratings from zero up to 87.6 ± 1.3%, with an augmentation of the RB concentration from 0.06 × 10−3 to 9.41 × 10−3 mol L−1. Interestingly, no detectable variation of the ϕ1/2kp/kt1/2, which reflects the initiation efficiency and kinetic constants, is given when increasing the RB concentration. The radical inhibition by RBH• is believed to account for the greatly improved phase separation and enhanced diffraction efficiency, through shortening the weight-average polymer chain length and subsequently delaying the photopolymerization gelation. The reconstructed colored 3D images that are easily identifiable to the naked eye under white light demonstrate great potential to be applied for advanced anticounterfeiting.
KW - Anticounterfeiting
KW - Green light
KW - Holography
KW - Inhibition
KW - Photopolymerization
KW - Rose bengal
UR - http://www.scopus.com/inward/record.url?scp=85030692982&partnerID=8YFLogxK
U2 - 10.1021/acsami.6b13129
DO - 10.1021/acsami.6b13129
M3 - Article
C2 - 28001037
AN - SCOPUS:85030692982
SN - 1944-8244
VL - 9
SP - 1810
EP - 1819
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 2
ER -