Perhydropolysilazane derived silica for flexible transparent barrier foils using a reel-to-reel wet coating technique: Single- and multilayer structures

Structural Study of Silica Coating Thin Layers Prepared from Perhydropolysilazane: Substrate Dependence and Water Penetration Structure

“…Because the hydration number of 8.0-9.0 is higher for the hydrophobic SiO 2 molecule, the water penetration into the PDS layers was not due to hydration for SiO 2 molecules, but to the formation of water-pool structures in the PDS layers (this image is shown in Figure 6). In fact, the SiO 2 density of the PDS layer was estimated to be 1.33 g/cm 3 in the PDS/Si sample, indicating that the density of the PDS layer is low compared to that of the natural SiO 2 (2.2 g/cm 3 ). Therefore, it is reasonable to suppose that the PDS layer has nano-air holes randomly distributed within the layer, and that the holes are transformed into water pool structures by water penetration into the PDS layer.…”

“…Pulsed neutron beams were generated using a mercury target at 25 Hz, and the NR data were measured using the time-of-flight (TOF) technique. The neutron-source to sample distance was 15.5 m, and the sample to 3 He gas point detector distance was 2.5 m. The wavelength (λ) range of the incident neutron beam was tuned to be approximately λ = 2.2-8.8 Å using disk choppers. The covered Q z range was Q z = 0.008-0.09 Å -1 , where Q z = (4π/λ)sinθ (here, θ represents the incident angle).…”

“…Because the hydration number of 8.0-9.0 is higher for the hydrophobic SiO2 molecule, the water penetration into the PDS layers was not due to hydration for SiO2 molecules, but to the formation of water-pool structures in the PDS layers (this image is shown in Figure 6). In fact, the SiO2 density of the PDS layer was estimated to be 1.33 g/cm 3 in the PDS/Si sample, indicating that the density of the PDS layer Thickness: t (Å), scattering length density (SLD): ρ (×10 −6 Å −2 ), surface or interface roughness: σ (Å).…”

“…Inorganic precursors, sush as perhydropolysilazane (PHPS, Figure 1), are one of the more promising materials for protection of these materials because inorganic precursors can be easily used to synthesize high-quality thin SiO 2 layers by hydrolysis or oxidation [1,2]. In fact, PHPS was applied in transparent gas barrier materials [3], thin-film light addressable potentiometric sensors [4], and waterproofing layer of metal magnetic material [5]. The major concern with using silicon-based materials is that the formation behavior of SiO 2 layers may change depending on the nature of the surface or condition of the PHPS-protected material.…”

Formation and Gas Barrier Characteristics of Polysilazane-Derived Silica Coatings Formed by Excimer Light Irradiation on PET Films with Vacuum Evaporated Silica Coatings

“…However, coatings formed in this way still have insufficient gas barrier characteristics, and are costly to produce because they require the use of complex high vacuum facility. A simpler method involves coating with an inorganic precursor solution, but since this precursor solution has to be heated to several hundred degrees centigrade (˚C) to form a compact inorganic coating, this method is unsuitable for organic films with low heat tolerance [13] Another method that has been studied recently involves applying polysilazane coatings to PET films, which are then exposed to excimer light irradiation or ultraviolet ray irradiation [18]- [26]. This method is able to form compact inorganic coatings at low temperature, and has been used to develop organic films with reasonably good gas barrier characteristics.…”