The Effect of Binder Loading on the Pore Size of 3D Printed PMMA.

Binder jetting is known to produce porous objects by depositing the binder selectively layer by layer on a powder bed. In this study, the pore size of printed parts and the correlating mechanical properties are investigated on a commercially available PMMA powder binder system. Pore sizes are measured via capillary flow porometry and mechanical properties via tensile tests.

Unusually selective synthesis of chlorohydrooligosilanes.

New pathways towards molecular chlorohydrooligosilanes enable their one-pot synthesis in preparative amounts either by the selective chlorination of the corresponding perhydrosilanes with HCl/AlCl or by the partial hydrogenation of perchlorooligosilanes with substoichiometric amounts of iBuAlH. The unexpected selective formation of ClSi-substituted species in the partial hydrogenation reactions could be related to mechanistic aspects.

Synthesis and Properties of Branched Hydrogenated Nonasilanes and Decasilanes.

Branched higher silicon hydrides Si H with n > 6 were recently found to be excellent precursors for the liquid phase deposition of silicon films. Herein we report the gram-scale synthesis of the novel nona- and decasilanes (HSi)Si(SiH) Si(SiH) (2: n = 1, 5: n = 2) from (HSi)SiLi and Cl(SiPh) Cl by a combined salt elimination/dephenylation/hydrogenation approach. Structure elucidation of the target molecules was performed by NMR spectroscopy and X-ray crystallography.

Branched Hydrosilane Oligomers as Ideal Precursors for Liquid-Based Silicon-Film Deposition.

Herein a convenient synthetic method to obtain 2,2,3,3-tetrasilyltetrasilane 3 and 2,2,3,3,4,4-hexasilylpentasilane 4 on a multigram scale is presented. Proton-coupled Si NMR spectroscopy and single-crystal X-ray crystallography enabled unequivocal structural assignment. Owing to their unique properties, which are reflected in their nonpyrophoric character on contact with air and their enhanced light absorption above 250 nm, 3 and 4 are valuable precursors for liquid-phase deposition (LPD) and the processing of thin silicon films.

Selective Synthesis and Derivatization of Germasilicon Hydrides.

Mixed Si/Ge hydrides SixGeyHz are valuable precursors for the deposition of binary Si-Ge alloys. This work describes the synthesis and full characterization of the previously unknown germaisotetrasilane Ph3GeSi(SiH3)3 (2) on a multigram scale from the reaction of the lithium silanide LiSi(SiH3)3 with Ph3GeCl. The stability of the Si-Ge bond in 2 versus electrophiles and nucleophiles has been investigated with the primary aim of developing new approaches to mixed sila-H-germanes (H3Ge)xSi(SiH3)4-x.