Fabrication of hollow core carbon spheres with hierarchical nanoarchitecture for ultrahigh electrical charge storage
摘要:
A simple and reproducible sol-gel synthesis strategy was developed to fabricate hollow core carbon spheres (HCCSs) with hierarchical nanoarchitecture through the hydrolysis, self-assembly and co-condensation of bis-[3-(triethoxysilyl) propyl] disulfide (TESPDS) and octadecyltrimethoxysilane (C18TMS). This synthesis route allows one to fabricate thioether-bridged organosilica (TBOS) with tailored spherical structure and particle size which can be further converted to HCCS upon calcination under N-2 flow. It is assumed that hydrophobic octadecyl chains of hydrolyzed C18TMS first form a micelle-like self-assembly structure with hydrophilic trihydroxysilyl groups as heads, and a reactive core is then expanded by the base-catalyzed co-condensation of TESPDS and/or C18TMS over the C18TMS self-assembly structure. The organic moieties of TESPDS and C18TMS not only serve as a porogen during the formation of TBOS but also as a carbon precursor for transformation of TBOS into HCCS during the carbonization. Due to its unique hierarchical nanostructure composed of hollow macroporous core and meso/microporous shell, which facilitates fast mass transport, along with large surface area for electrical charge storage, the HCCS for the first time exhibits ultrahigh specific capacitance and energy, good cycling performance and rate capability.
An Easily Accessed Nickel Nanoparticle Catalyst for Alkene Hydrosilylation with Tertiary Silanes
作者:Ivan Buslov、Fang Song、Xile Hu
DOI:10.1002/anie.201606832
日期:2016.9.26
non‐precious nanoparticlecatalyst for alkenehydrosilylation with commercially relevant tertiarysilanes has been developed. The nickelnanoparticlecatalyst was prepared in situ from a simple nickel alkoxide precatalyst Ni(OtBu)2⋅x KCl. The catalyst exhibits high activity for anti‐Markovnikov hydrosilylation of unactivated terminal alkenes and isomerizing hydrosilylation of internal alkenes. The catalyst
Dispersity, mesoporous structure and particle size modulation of hollow mesoporous silica nanoparticles with excellent adsorption performance
作者:Guiju Tao、Wenjun He、Yu Wang、Fengping Yu、Junwei Ge、Weimin Yang
DOI:10.1039/c8dt01940a
日期:——
Hollow mesoporous silica nanoparticles (HMSNs) with different dispersities, mesoporous structures and particlesizes have been systematically synthesized by simply changing the octadecyltrimethoxysilane (C18TMS, mesopore-forming agent) percentage of the total silica sources over a wide range. The effects of the C18TMS percentage on the dispersity, mesoporous structure and particlesize of HMSNs have
This disclosure provides low viscosity, low volatility alkylated siloxane compounds and alkylated alkoxy silane compounds. This disclosure also provides processes for producing the alkylated siloxane compounds and alkylated alkoxy silane compounds, and lubricating oil basestocks and lubricating oils containing one or more of the alkylated siloxane compounds or one or more of the alkylated alkoxy silane compounds. This disclosure further provides a method for improving one or more of solubility and dispersancy of polar additives and/or sludge in a lubricating oil by using as the lubricating oil a formulated oil containing one or more of the alkylated siloxane compounds or one or more of the alkylated alkoxy silane compounds.