Fast proton conductors for low humidity: hydrophilic sulfonated and phosphonated polysilsesquioxanes with Al-O-P crosslinks.

Proton-conducting polysilsesquioxane oligomers with core-shell structures consisting of hydrophilic silica-rich cores surrounded by an organic layer with sulfonic and phosphonic acid groups were synthesized. They were crosslinked by mixing with phosphoric acid and aluminum ions to form a hydrophilic Al-O-P framework. The resulting polymers were clear, uniform, flexible, and exhibited a high proton conductivity above 100 °C in non-humidified low-humidity air (∼22 mS cm at 120 °C and ∼1%RH) because of their high sulfonic acid concentration and high water retention capability.

Crystal structures of the alkali aluminoboracites BAlOCl ( = Li, Na).

Single crystals of alkali aluminoboracites, BAlOCl ( = Li, Na), were grown using the self-flux method, and their isotypic cubic crystal structures were determined by single-crystal X-ray diffraction. NaBAlOCl is the first reported sodium boracite, and its lattice parameter [13.5904 (1) Å] is the largest among the boracites consisting of a cation-oxygen framework reported so far.

Kinetically Controlled Direct Synthesis of B2- and A1-Structured Cu-Pd Nanoparticles.

Atomic arrangement in Cu-Pd alloy nanoparticles (NPs) has been reported to influence the catalytic activity, but they have yet to be studied in detail. Unlike previous studies, where the B2 structure Cu-Pd NPs are obtained by heat treating the A1 structure, this study reports the one-pot direct syntheses of A1- and B2-structured Cu-Pd NPs using an alcohol reduction method. The alcohol reduction technique facilitates the kinetic control of the reduction reaction by selecting the appropriate alcohol type and complexing agent to delay the reduction of easily reducible metallic elements to realize control over the reduction kinetics for coreduction.

Temperature dependence of narrow-band UVB photoluminescence of silica-(Gd,Pr)POtransparent glass-ceramic phosphors.

The effect of temperature on photoluminescence (PL) due to theP→S(= 5/2, 7/2) transitions of Gdions was examined between 200 and 500 K for a sol-gel-derived silica-(Gd,Pr)POtransparent glass-ceramic phosphor with negligible concentration quenching under excitation into the 5d-4f transition of Prions at 220 nm. The intensity of the narrow-band ultraviolet B (UVB) PL at ∼313 nm associated with theP→Stransition slightly increased between 200 and 300 K, but was decreased to ∼86% and ∼62% of that at 300 K when temperature was raised to 400 and 500 K, respectively. The observed magnitude of the thermal quenching of the UVB PL intensity was agreed well with that recorded in a prototype narrow-band UVB lamp consisting of another silica-(Gd,Pr)POtransparent glass-ceramic window and a KrCl excimer lamp as a light source at 222 nm.

Poly(cyclohexylsilsesquioxane)-Based Hydrophilic Thermoset-Resistant Deep-Ultraviolet-Transparent Glasses with Low Melting Temperatures.

Silsesquioxane (SQ)-based glasses with low melting temperatures were prepared by the cosolvent-free (solventless) hydrolytic polycondensation of organotrimethoxysilanes with cyclopentyl (-Pe) and cyclohexyl (-Hx) groups. Copolymers consisting of phenylsilsesquioxane (Ph-SQ) units and -Pe-SQ units [poly(Ph---Pe-SQ)] or -Hx-SQ units [poly(Ph---Hx-SQ)] were melted at 140 °C and formed clear glasses. The glasses prepared by this method contained many residual SiOH groups and exhibited high adhesive strength to microscope glass plates, metals, and several polymers.

Synthesis of Electromagnetic Wave-Absorbing Co-Ni Alloys and Co-Ni Core-Shell Structured Nanoparticles.

Co-Ni alloy nanoparticles, a potential candidate for microwave absorption material, were successfully synthesized by tuning the reduction timing of Co and Ni ions by introducing oleylamine as a complexing agent and 1-heptanol as a reducing solvent. The formation mechanism elucidated using time-resolved sampling and in situ X-ray absorption spectroscopy (XAS) and ultraviolet-visible (UV-vis) spectrophotometry measurements suggested that the delay in the reduction of Co ions via complexation with oleylamine facilitated the co-reduction of Co with Ni ions and led to the formation of Co-Ni alloys. The successful synthesis of Co-Ni alloys experimentally confirmed the differences in magnetic properties between alloy and core-shell structured CoNi particles.

Strategy to Design-Synthesize Bimetallic Nanostructures Using the Alcohol Reduction Method.

Bimetallic nanomaterials have attracted much attention from various fields such as catalysis, optics, magnetism, and so forth. The functionality of such particles is influenced very much by the intermetallic interactions than their individual contribution. However, compared with the synthesis of monometallic nanoparticles, the reaction parameters that need to be controlled for tuning the size, shape, composition, and crystal structure of bimetallic nanoparticles becomes challenging.

Theoretical and Experimental Evaluation of the Reduction Potential of Straight-Chain Alcohols for the Designed Synthesis of Bimetallic Nanostructures.

Recently, the development of bimetallic nanoparticles with functional properties has been attempted extensively but with limited control over their morphological and structural properties. The reason was the inability to control the kinetics of the reduction reaction in most liquid-phase syntheses. However, the alcohol reduction technique has demonstrated the possibility of controlling the reduction reaction and facilitating the incorporation of other phenomena such as diffusion, etching, and galvanic replacement during nanostructure synthesis.

Selection Criteria for Metal Precursors and Solvents for Targeted Synthesis of Metallic Nanostructures Via Kinetic Control in the Polyol Process.

Development of a technology for the synthesis of monometallic or multimetallic nanoparticles is exceptionally vital for the preparation of novel magnetic, optical. and catalytic functional materials. In this context, the polyol process is a safe and scalable method for preparation of metal nanoparticles with controlled sizes and shapes in large scales.