For all of the inorganic porous spin-on low-k films being developed today, a post-spin-on hydrophobic treatment is needed to reduce their moisture sensitivity. In the present work, we demonstrate that, for pure-silica-zeolite MFI spin-on low-k films, this extra hydrophobic treatment step can be potentially eliminated by using organic-functionalized pure-silica-zeolite MFI (OF PSZ MFI) nanoparticle suspension. Specifically, methyltrimethoxysilane was simply added to the synthesis solution for a PSZ MFI nanoparticle suspension that contains tetraethyl orthosilicate, tetrapropylammonium hydroxide, ethanol, and water. This approach takes advantage of the hydrophobic methyl groups in the zeolite nanocrystal framework as well as in amorphous silica in the low-k film. The improvement of the hydrophobicity of the spin-on film from this OF PSZ MFI nanoparticle suspension was demonstrated by the higher water contact angle of the film and less moisture sensitivity of the k value in an ambient atmosphere.
Carbon dots with fluorescence from blue to green have been prepared by a microwave-assisted hydrothermal reaction of a chitosan and sodium hydroxide solution. The carbon dots are conjugated graphite nuclei with developed groups on the surface. OH − acts as an activation agent to induce changes in carbon nuclei and surface properties, leading to a high percentage of CO, C− NC, and CC groups on carbon dots, which are crucial for n−π* and π−π* transitions that contribute to emission at a long wavelength. Na + is helpful in conquering quenching and favorable for the enhanced emission. When it is embedded into a matrix of PVA and boric acid, the composite exhibits obvious roomtemperature property phenomena (RTP) that can be easily recognized by the naked eye for up to 12 s with a lifetime of up to 623 ms. The N and O atoms favor the facilitation of intersystem crossing (ISC) to effectively populate triplet excitons, which contributes to the RTP with a low energy gap. The carbon dots can also act as electron donors and enable a 184% capacitance increase in graphene oxide. The prepared carbon dots exhibit potential applications in the security, sensing, and energy storage fields.
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