Simple fabrication of micro/nano-porous SiOC foam from polysiloxane

Phase separation induced macroporous SiOC ceramics derived from polysiloxane

“…The bulk densities of SiOC are in the range of 1.4-1.9 g/cm 3 of 280/430 nm for SiOC-20 and SiOC-30, respectively, in agreement with the Archimedes measurement results. All porosities of our SiOCs are lower than that reported in previous works (>50% 23,24 ) owing to the low PDMS amount in our gels. The apparent density of our SiOC is 1.85-1.94 g/cm 3 slightly lower than that of dense SiOC of 2.23 g/cm 3 .…”

“…In contrast, SiOC-30 shows particulate-stacking structure with the size of ∼2 m (Fig. 8d), similar to but more compact compared to the previous porous SiOC from PSO precursor with higher PDMS concentration (>50 wt.% 23,24 ). This particulate structure arises from the decomposition of wrapped PDMS phase around spherical PSO phase after pyrolysis.…”

“…It decomposes to cyclic and linear dimethylsiloxane oligomers and completely escapes from the matrix at intermediate temperature during pyrolysis (above 400 • C) which avoids introducing other elements or impurities into the SiOC ceramics. PDMS, intrinsic or modified, has been added into sol-gel precursors, 20 PSO oils and/or resins [21][22][23][24] at high proportions (>40 wt.%) to fabricate meso-and macroporous SiOC with high surface area. However, little attention has been paid to design tailorable porous SiOC for different requirements and application utilizing the phase separation of PDMS.…”

High temperature structure evolution of macroporous SiOC ceramics prepared by a sol–gel method

“…Weinberger et al [24] prepared the SiOC monoliths through the pyrolysis of monolithic organosilica gels, which were synthesized by glycolated cyclic organosilane in the presence of the block copolymer Pluronic P123 surfactant. Wu et al [25] fabricated the micro/nano-porous SiOC foams with narrow pore size distribution by the pyrolysis of polymeric gels synthesized from the mixtures of PSO and PDMS. Parmentier et al [26] showed that the high-temperature properties of porous SiOC materials depended to a great extend on the pores and interface which influenced the diffusion of CO towards the surface of ceramics during carbothermal reduction.…”

Amperometric catechol biosensor based on laccase immobilized on nitrogen-doped ordered mesoporous carbon (N-OMC)/PVA matrix

“…The N1s spectrum in figure 2(b) can be well fitted to three components. The predominant component at 399.5 eV was assigned to N atoms trigonally bonded to three sp 2 carbon atoms from the C-N network, indicating the formation of carbon nitride [26]. The peak at 398.5 eV can be assigned to the pyridinic-type nitrogen.…”