The effects of surface roughness on low haze ultrathin nanocomposite films

Towards natural-fibre-based thermoplastic films produced by conventional papermaking

“…Upon hot pressing, the uneven structure of the modified paper is more or less completely transformed to a smooth film surface without distinct features (at higher magnification, however, nanofibrils can be seen; results not shown), which largely explains the significant decrease in haze upon pressing since haze is in many materials largely due to surface roughness. [27][28][29] Quite remarkably, if the non-pressed or pressed, modified papers are soaked in water and strained until failure, fibres become clearly visible as they protrude from the failure surface ( Fig. 6g and h), showing that the modification and hot pressing do not significantly affect the macroscopic fibre structure but makes possible a very close contact between individual fibres, still leaving the fibres as discrete entities.…”

Ultra-Short Pulse HiPIMS: A Strategy to Suppress Arcing during Reactive Deposition of SiO2 Thin Films with Enhanced Mechanical and Optical Properties

“…The transmittance spectra (not shown here) revealed the absence of interference fringes (due to the same refractive index of thin film and substrate, n ≈ 1.5 at 550 nm) and an average transmittance value of 98.5% in the 190-1100nm wavelength range. The average transmittance decreased through the haze (scattering) effect [25] caused by the increased surface roughness (from 2.0 to 60.3 nm). The rough surface structure scattered the incident light at wide angles, resulting in low transmittance in the direction of the While the film deposited with a pulse duration of 3 µs showed a smooth and an almost droplet-free surface, increasing the pulse duration up to 10 µs led to the deposition of films with surfaces covered by unwanted droplets and defects, whose topography and texture significantly changed from smooth and fine to rough and coarse.…”

“…The transmittance spectra (not shown here) revealed the absence of interference fringes (due to the same refractive index of thin film and substrate, n ≈ 1.5 at 550 nm) and an average transmittance value of 98.5% in the 190-1100-nm wavelength range. The average transmittance decreased through the haze (scattering) effect [25] caused by the increased surface roughness (from 2.0 to 60.3 nm). The rough surface structure scattered the incident light at wide angles, resulting in low transmittance in the direction of the detector.…”

Transparent, Flexible, Conformal Capacitive Pressure Sensors with Nanoparticles

“…Scattering of light by particles similar to, or larger than, the wavelength of light is explained by the Mie scattering theory . According to the Mie scattering theory, this haze—represented by 1 − exp[ − (4 πσ rms C | n 1 − n 2 |/λ) β ] where λ is the wavelength of the light; n 1 and n 2 are the refractive indices of the incident and transmission media, respectively; C and β are fitting parameters; σ rms is the root‐mean‐square surface roughness—can be minimized by reducing σ rms ; i.e., high optical transparency can be achieved when the surface roughness is less than 100 nm, but this results in low sensitivity ( Figure a). In order to support this point, exclusive tendency has been observed between transparency and pressure sensitivity in the transparent capacitive pressure sensors recently reported in the literature (Figure S1, Supporting Information) .…”

“…[6,8,10,12,14,17,[24][25][26][29][30][31][32][33][34][35][36][37][38] For example, when the surface is rough, the surface structures scatter the incident light, thus resulting in high haze, defined by the percentage of transmitted light deviated from the incidence by more than 2.5°. [39] Scattering of light by particles similar to, or larger than, the wavelength of light is explained by the Mie scattering theory. [40] According to the Mie scattering theory, [41] this haze-represented by 1 − exp[ − (4πσ rms C|n 1 −n 2 |/λ) β ] where λ is the wavelength of the light; n 1 and n 2 are the refractive indices of the incident and transmission media, respectively; C and β are fitting parameters; σ rms is the root-mean-square surface roughnesscan be minimized by reducing σ rms ; i.e., high optical transparency can be achieved when the surface roughness is less than 100 nm, [39] but this results in low sensitivity (Figure 1a).…”