Synthesis and Characterization of Single-Phase α-Cordierite Glass-Ceramics for LTCC Substrates from Tuff

Single-phase α-cordierite glass-ceramics for a low-temperature co-fired ceramic (LTCC) substrate were fabricated from tuff as the main raw material, using the non-stoichiometric formula of α-cordierite with excess MgO without adding any sintering additives. The sintering/crystallization behavior and the various performances of dielectric properties, thermal expansion, and flexural strength of the glass-ceramics were detected. The results indicated that only single-phase α-cordierite crystal was precipitated from the basic glass sintered at the range 875–950 °C, and μ-cordierite crystal was not observed during the whole sintering-crystallization process. The properties of glass-ceramics were first improved and then deteriorated with the increase in tuff content and sintering temperature. Fortunately, the glass-ceramics sintered at 900 °C with 45 wt.% tuff content possessed excellent properties: high densify (2.62 g∙cm−3), applicable flexural strength (136 MPa), low dielectric loss (0.010, at 10 MHz), low dielectric constant (5.12, at 10 MHz, close to α-cordierite), and suitable coefficients of thermal expansion (CTE, 3.89 × 10−6 K−1)

Strong Blue Emissive Supramolecular Self-Assembly System Based on Naphthalimide Derivatives and Its Ability of Detection and Removal of 2,4,6-Trinitrophenol

Two simple and novel gelators (<b>G-P</b> with pyridine and <b>G-B</b> with benzene) with different C-4 substitution groups on naphthalimide derivatives have been designed and characterized. Two gelators could form organogels in some solvents or mixed solvents. The self-assembly processes of <b>G-P</b> in a mixed solvent of acetonitrile/H₂O (1/1, v/v) and <b>G-B</b> in acetonitrile were studied by means of electron microscopy and spectroscopy. The organogel of <b>G-P</b> in the mixed solvent of acetonitrile/H₂O (1/1, v/v) formed an intertwined fiber network, and its emission spectrum had an obvious blue shift compared with that of solution. By contrast, the organogel of <b>G-B</b> in acetonitrile formed a straight fiber, and its emission had an obvious red shift compared with that of solution. <b>G-P</b> and <b>G-B</b> were employed in detecting nitroaromatic compounds because of their electron-rich property. <b>G-P</b> is more sensitive and selective toward 2,4,6-trinitrophenol (<b>TNP</b>) compared with <b>G-B</b>. The sensing mechanisms were investigated by ¹H NMR spectroscopic experiments and theoretical calculations. From these experimental results, it is proposed that electron transfer occurs from the electron-rich <b>G-P</b> molecule to the electron-deficient <b>TNP</b> because of the possibility of complex formation between <b>G-P</b> and <b>TNP</b>. The <b>G-P</b> molecule could detect <b>TNP</b> in water, organic solvent media, as well as using test strips. It is worth mentioning that the organogel <b>G-P</b> can not only detect <b>TNP</b> but also remove <b>TNP</b> from the solution into the organogel system