Synthesis of Silylborazines and Their Utilization as Precursors to Silicon-Containing Boron Nitride⋆

Synthesis and structures of lithium alkoxytris(dimethylphenylsilyl)borates

The X-ray crystallography showed that the structures of the silyl-substituted borates are affected by the alkoxy groups.

Polymer-Derived Silicoboron Carbonitride Foams for CO2 Capture: From Design to Application as Scaffolds for the in Situ Growth of Metal-Organic Frameworks

A template-assisted polymer-derived ceramic route is investigated for preparing a series of silicoboron carbonitride (Si/B/C/N) foams with a hierarchical pore size distribution and tailorable interconnected porosity. A boron-modified polycarbosilazane was selected to impregnate monolithic silica and carbonaceous templates and form after pyrolysis and template removal Si/B/C/N foams. By changing the hard template nature and controlling the quantity of polymer to be impregnated, controlled micropore/macropore distributions with mesoscopic cell windows are generated. Specific surface areas from 29 to 239 m(2)  g(-1) and porosities from 51 to 77 % are achieved. These foams combine a low density with a thermal insulation and a relatively good thermostructural stability. Their particular structure allowed the in situ growth of metal-organic frameworks (MOFs) directly within the open-cell structure. MOFs offered a microporosity feature to the resulting Si/B/C/N@MOF composite foams that allowed increasing the specific surface area to provide CO2 uptake of 2.2 %.

Feasibility of novel (H3C)nX(SiH3)3−ncompounds (X = B, Al, Ga, In): structure, stability, reactivity, and Raman characterization from ab initio calculations

Stability of the (H₃C)_nX(SiH₃)_3−ncompounds.

Ordered mesoporous polymer-derived ceramics and their processing into hierarchically porous boron nitride and silicoboron carbonitride monoliths

This review describes the elaboration of ordered mesoporous non-oxide materials such as BN and SiBCN and the subsequent fabrication of derived monoliths by spark plasma sintering using the as-prepared powders.

The Route to the Structure Determination of Amorphous Solids: A Case Study of the Ceramic Si3B3N7

Si(3)B(3)N(7) is the parent compound of a new class of amorphous ceramics containing silicon, boron, nitrogen, and carbon that display a unique spectrum of properties. It consists of a random network in which the constituent elements are linked by predominantly covalent bonds. Similarly to quartz glass, the composition of amorphous Si(3)B(3)N(7) is virtually stoichiometric. As all three of its constituent elements can serve as the objects of various structural probes, Si(3)B(3)N(7) was selected as the basis of a systematic structural investigation, in which methods for the structure determination of solids without translational symmetry could be validated and improved. However, as the complete amorphous structure cannot be deduced from experimental data, these results must be complemented by computer simulations. Thus, five classes of structure models were generated and compared to experimental results. Only the models generated by following the actual synthesis route as closely as possible agreed well with the experimental data.

Nonequilibrium Dynamics in Amorphous Si3B3N7

We present extensive numerical investigations of the structural relaxation dynamics of a realistic model of the amorphous high-temperature ceramic a-Si3B3N7, probing the mean-square displacement of the atoms, the bond survival probability, the average energy, the specific heat, and the two-point energy average. Combining the information from these different sources, we identify a transition temperature Tc approximately 2000 K below which the system is no longer ergodic and physical quantities observed over a time t(obs) show a systematic parametric dependence on the waiting time t(w), or age, elapsed after the quench. The aging dynamics "stiffens" as the system becomes older, which is similar to the behavior of highly idealized models such as Ising spin glasses and Lennard-Jones glasses.