Room temperature direct imprinting of porous glass prepared from phase-separated glass

Abstract

This work describes a room-temperature imprinting of nanoporous glass prepared by selective chemical etching of phase-separated glass. A highly porous (58%) and highly transparent (>90%) porous glass layer can be formed on a transparent phase-separated glass substrate. It is shown that the lateral resolution of the imprinting is a few tens of nanometers. As the porosity increases, the imprint depth increases and reaches up to 90% of the height of the mold pattern. The porous glass has a wider transmittance window (300-2700 nm) and a higher thermal durability (~500 °C) than other materials used for imprinting. The technique has various potential applications such as diffraction optical elements, waveguides, biosensors, and microfluidic devices.

Ultra-low permittivity porous silica-cellulose nanocomposite substrates for 6G telecommunication

“…Since silica is intrinsically a low permittivity and loss material (ε r = 3.8 and tan δ = 0.005 at 300 GHz), and a number of different procedures can be applied to develop porous materials (e.g. soft template-assisted on polymers [33][34][35], biopolymers [36], emulsions [37,38] and colloids [39]; hard templating on polymers [40], oxides [41,42] and metals [43]; selective leaching of metal alloys [44,45], inorganic [46] and polymer-inorganic composites [47]; foaming [48][49][50]; anodization [51,52]; freeze-drying [53][54][55], freeze-casting [56] and phase separation) [57], it seems to be a plausible strategy to synthesize porous silica based materials, whose properties are expected to be outstanding at high frequencies.…”

Femtosecond laser-induced stress-free ultra-densification inside porous glass

“…On the other hand, local decompaction up to the formation of hollow micro-channels in some pre-defined configurations with pre-determined channel diameters is also highly demanding. As a result of such local densification and decompaction laser-micromachining processes, PG is a novel emerging optical platform for the fabrication of integrated micro-and nano-devices for photonic, plasmonic, microfluidic and micro-pneumatic applications [14][15][16][17][18]. Similar changes of local mass density and the related refractive index in different bulk silica glasses (in part icular, fused silica), induced by ultra-short laser pulses, have attracted a lot of attention in previous years [19][20][21][22].…”