Preparation of inverse photonic crystals by ETPTA photopolymerization method and their optical properties

Abstract

Inverse photonic crystal films were prepared by photopolymerization of ethoxylate trimethylolpropane triacrylate (ETPTA) using opal-type templates. Their high quality was proved by investigations of structural and optical properties. The unexpectedly high refractive index, nETPTA ≈ 1.67, of polymerized ETPTA was obtained from a numerical approximation of the spectral positions of the reflectance peak of the films at different incidence angles. Fabricated samples were tested as sensors for water-ethanol mixtures, and a monotonous increase in the stop band shift with an increase in ethanol concentration was established.

Fibrous skeleton‐framed, flexible high‐energy‐density quasi‐solid‐state lithium metal batteries

“…The SUS mesh (shown in Figure S10) was introduced to the cathode paste as a conductive fibrous skeleton. The characteristic peak corresponding to acrylic C=C bond 27 of ETPTA was not observed in the FT‐IR spectrum of the fs‐cathode, confirming the successful UV curing of the ETPTA in the fs‐cathode (Figure S11). In addition, the SUS mesh in the fs‐cathode was compactly filled with the cathode components (i.e., NCM811 powders, carbon black, and gel electrolyte) (Figure 2B and Figure S12).…”

Fabrication Technique of Micropatterned Inverse Photonic Crystal Films

“…Previously, we have shown that this exposure is sufficient to complete the polymerization of ETPTA. [ 50 ] Then both glass plates were removed and SiO 2 microspheres etched in 8 vol. % HF for 1 min (Figure 1f).…”

“…The sample inherits its template preserving the quality of the structure, as it was previously reported for inverting of continuous opal films with photocurable resins. [50,54,55] SEM images of inverse micropatterned PhCs are shown in Figure 5c and d. In panel (c), the dark gray areas are ETPTA inverse striped patterns, and the light areas are structureless ETPTA spacings.…”

“…which is valid for the model of hard close-packed spheres. Here n void = 1 is the refractive index of air, n etpta = 1.67 is the refractive index of ETPTA [50] and f etpta = 0.26 is the volume fraction of ETPTA (for comparison, f SiO2 = 0.74 for SiO 2 template before inversion). It is also seen that in Figure 6b, the peak is much higher than in Figure 6a.…”

“…We have previously used this photoresist for inverting of continuous opal films and found that the inverse films retain the quality of the original template structure and exhibit even better PhC properties. [ 50 ] Thus, in this research work, we focus on the inversion of stripe patterned opal films with ETPTA photoresist, comparing the properties of the films before and after inversion, and testing the obtained samples as sensors for the alcohol content in water.…”