This paper reports a new approach towards the construction of a multifunctional periodic mesoporous organosilica (PMO), which integrates a range of advantages, such as mesoporous structural order, selective nucleobase-recognition properties, stimuli-responsive site-specific delivery of anticancer agents to cancer tissues, and Cu 2+ adsorption, into a single entity. First, the appropriate organic-functional-receptor precursor was synthesized by a chemical process and used to fabricate a multifunctional pyridine-containing PMO material (DMPy-PMO) by a hydrolysis and condensation route. The designed organic-inorganic hybrid mesoporous silica chemosensor showed an intrinsic selective recognition of nucleobase, specifically thymidine, through multipoint hydrogen-bonding interactions with suitably arrayed receptor sites loaded [a]

Si3N4 ceramic was densified at 1900°C for 12 hours under 1 MPa nitrogen pressure, using MgO and self‐synthesized Y2Si4N6C as sintering aids. The microstructures and thermal conductivity of as‐sintered bulk were systematically investigated, in comparison to the counterpart doped with Y2O3‐MgO additives. Y2Si4N6C addition induced a higher nitrogen/oxygen atomic ratio in the secondary phase by introducing nitrogen and promoting the elimination of SiO2, resulting in enlarged grains, reduced lattice oxygen content, increased Si3N4‐Si3N4 contiguity and more crystallized intergranular phase in the densified Si3N4 specimen. Consequently, the substitution of Y2O3 by Y2Si4N6C led to a great increase in ~30.4% in thermal conductivity from 92 to 120 W m−1 K−1 for Si3N4 ceramic.

Dense Si3N4 ceramics were fabricated by pressureless sintering at a low temperature of 1650°C with a short holding period of 1 h under a nitrogen atmosphere. The role of ternary oxide additives (Y2O3–MgO–Al2O3, Y2O3–MgO–SiO2, Y2O3–MgO–ZrO2) on the phase, microstructure, and mechanical properties of Si3N4 was examined. Only 5 wt.% of Y2O3–MgO–Al2O3 additive was sufficient to achieve >98% of theoretical density with remarkably high biaxial strength (∼1200 MPa) and prominent hardness (∼15.5 GPa). Among the three additives used, Y2O3–MgO–Al2O3 displayed the finest grain diameter (0.54 μm), whereas Y2O3–MgO–ZrO2 produced the largest average grain diameter (∼0.95 μm); the influence was seen on their mechanical properties. The low additive content Si3N4 system is expected to have superior high‐temperature properties compared to the system with high additive content. This study shows a cost‐effective fabrication of highly dense Si3N4 with excellent mechanical properties.

The process-structure-property correlationships in yttria-magnesia (YM) composite have been investigated. YM composite was synthesized using commercial powders via ball-milling route with three different grinding balls (Si 3 N 4 , Al 2 O 3 , ZrO 2 ) having two different sizes (2 and 5 mm diameter). The alteration in grinding ball material and size produces sintered ceramic having different grain sizes (420-560 nm) and degree of phase mixing homogeneity (0.40-0.70). The contamination induced by the milling ball resulted in changes in Y 2 O 3 and MgO defect chemistry, which influenced the grain growth behavior in the YM composite. The hot-pressed composite prepared using 2-mm Si 3 N 4 ball-milled powders exhibited the finest grain size (420 nm) and better phase mixing homogeneity (0.63). The subsequent impact was seen on transmittance efficiency (71%) over the 3-7-μm wavelength range, which is ∼85% of the theoretical limit. The findings show that the selection of the right size and type of grinding ball for milling commercial powder is a simple and cost-effective way for scalable production of YM composite with high transmittance efficiency for infrared windows and dome applications.