Volume holographic recording in multicomponent photopolymers with hyperbranched polymers as organic nanoparticles

Abstract

We describe the diffraction properties of organic nanoparticle-dispersed photopolymers in which hyperbranched polymers (HBPs) act as transporting organic nanoparticles that increase the refractive-index contrast of a hologram. We prepared HBPs by the living radical vinyl polymerization of inimers under ultraviolet-light illumination. Such synthesized HBPs are easy to disperse into monomers without any aggregation, so that samples with good optical quality are available. We investigate the role of HBPs in the recording process for two different types of photopolymers capable of radical polymerization and cationic ring-opening polymerization. We also evaluate the effect of HBP dispersion on recording sensitivities and polymerization shrinkage.

Photopolymerizable nanocomposite photonic materials and their holographic applications in light and neutron optics

“…However, it can also be seen that the fixed grating is formed in the NPC sample without HPS organic nanoparticles. It was found that such grating fixing was caused by the parasitic concentration modulation of remaining titanocene (the refractive index of 1.71 due to the incorporation of Ti atoms) and/or its decomposed species containing Ti atoms, which was confirmed by the EPMA measurement [ 170 ]. It was also found that could be reduced to 1.0% by the dispersion of 32 vol.% HPS organic nanoparticles.…”

“…Tomita et al [ 65 , 170 ] demonstrated volume holographic recording in NPCs incorporating HBPs acting as organic nanoparticles. They prepared the following two types of HBPs of approximately 10 nm size (estimated by an AFM): hyperbranched poly(ethyl methacrylate) (HPEMA) and hyperbranched polystyrene (HPS), as illustrated in Figure 14 ( a ) and ( b ), respectively.…”

“…Since HBP organic nanoparticles are generally easy to disperse in many types of monomers, there is an opportunity to achieve low shrinkage with CROP monomer-based NPCs incorporating HBP organic nanoparticles. Indeed, Tomita et al [ 170 ] investigated the holographic recording properties of CROP monomer-based NPCs incorporating HPS organic nanoparticles. They used a CROP monomer system of oxetane monomer, 1,4-bis[(3-ethyl-3-oxetanyl)methoxy]methylbenzene, and epoxy monomer, 7-oxabicyclo[ 1 , 4 ]heptan-3-yl-methyl7-oxabicyclo[ 1 , 4 ]heptane-3-carboxylate.…”

Phenanthraquinone-Doped Polymethyl Methacrylate Photopolymer for Holographic Recording

“…In the same year, Tomita et al also studied the diffraction characteristics of hyperbranched polymers (HBPs) as transporting organic nanoparticles dispersed in photopolymers and experimentally prepared a transmitted hologram on 51 μm sample films with a diffraction efficiency of nearly 100% [ 112 ]. Subsequently, they found that doping with inorganic nanoparticles [ 113 ] or organic nanoparticles (hyperbranched polymers) can improve the holographic properties of photopolymers, but the size and aggregation of inorganic nanoparticles will be accompanied by different degrees of holographic scattering, and the use of smaller-diameter nanoparticles will greatly reduce the holographic scattering.…”

Characterization of volume holographic recording in photopolymerizable nanoparticle-(thiol-ene) polymer composites at 404 nm

“…Indeed, we adopted these polymerization mechanisms for NPCs and demonstrated substantive shrinkage mitigation. [25][26][27][28] In particular, we showed excellent performance of volume holographic recording in NPCs using thiol-ene monomers 29,30 that possess the step-growth polymerization mechanism with which gelation occurs late in conversion since the molecular weight increases throughout the course of the reaction. Shrinkage occurring before and during gelation can be readily accommodated by the liquid mixture of oligomers since high-molecular-weight polymer is not obtained until the end of the polymerization.…”