Fabrication and Characterization of Thick Zinc Methacrylate/Phenanthrenequinone Codoped Poly(methyl methacrylate) Photopolymers for Volume Holographic Recording

Abstract

The acceleration of water content reduction by vibrational energy was investigated with a series of laboratory tests. Vibration was generated with a poly(vinylidene fluoride) (PVDF) film as a flexible transducer at various frequencies. Test conditions included the power and duration of sonic energy, and the soil type. Test results showed a significant increase in dewaterability when ultrasound was applied. The time required for the outflow of the same amount of water was shorter for the sonicated conditions. The degree of enhancement varied with the test conditions. Using the test results, we discuss the potential development of a new method that can reduce the dewatering period.

Holographic recording characteristics and physical mechanism of zinc methacrylate/nitroaniline‐co‐doped poly(methyl methacrylate)/9,10‐phenanthrenequinone photopolymers

“…Through this demonstration of the holographic data storage characteristics, we confirm that the properties of the PMMA/PQ photopolymer were further enhanced in the presence of DMNA [23]. On the basis of this result, and taking advantage of previous findings [16–23], we selected DMNA for codoping with the organometallic compound Zn(MA) 2 into the PMMA/PQ photopolymer.…”

“…Figure 2b presents typical optical absorption spectra of photopolymers codoped with Zn(MA) 2 . After light exposure, the signals of all of the exposed photopolymers underwent blue shifts to shorter wavelengths, again implying that the photoproducts were less conjugated than the species present in the unexposed photopolymers [8, 9, 13, 20]. The absorption bands of the exposed codoped DMNA samples were close that of the DMNA‐only doped photopolymer (Fig.…”

“…2d displays the corresponding expanded regions of the spectra. The absorption intensity in this range increased after light exposure, implying that Zn(MA) 2 reacted with PQ to form other photoproducts [17, 20]. Comparing the absorption intensities of the unexposed PMMA/PQ/DMNA/Zn(MA) 2 photopolymer and the unexposed PMMA/PQ/Zn(MA) 2 photopolymer, we find that the sample codoped with DMNA provided a stronger absorption, suggesting that some of the Zn(MA) 2 species may have interacted with DMNA molecules to form other compounds prior to light exposure [28].…”

“…Doping with organometallic compounds, such as zinc methacrylate [Zn(MA) 2 ] [16–20], can be used to improve the holographic recording characteristics of PMMA/PQ photopolymers. The addition of Zn(MA) 2 is not only to provide a catalyst to enhance the photoreaction between PQ and MMA molecules via the Zn ions in the Zn(MA) 2 molecules, but also increase the number of reactants for photoreaction [16, 20]. Both reactions are effective for improving the sensitivity and dynamic range for holographic recording characteristics.…”

“…The compounds with a higher dipole moment led to higher birefringence by the exposed samples and increased the holographic recording characteristics. Therefore, taking advantage of previous research [9, 16–23], in this study we codoped Zn(MA) 2 and nitroaniline into the PMMA/PQ photopolymer to enhance its holographic storage capacity and recording characteristics, as measured in terms of diffraction efficiency and dynamic range (M#). We also propose herein a recording mechanism, deduced from mass spectrometric and X‐ray photoelectron spectroscopic analyses.…”