Topic
Direct process
About: Direct process is a research topic. Over the lifetime, 92 publications have been published within this topic receiving 1307 citations.
Papers published on a yearly basis
Papers
TL;DR: In this article, the authors describe a direct process in which SiO2 is reacted with ethylene glycol and an alkali base to produce highly reactive, pentacoordinate silicates which provide access to a wide variety of new silicon compounds.
Abstract: THE potential role of inorganic and organometallic silicon compounds in the development of new chemical reagents, polymers, glasses and ceramics1 is limited at present by the paucity of simple silicon-containing starting materials. Whereas industrial carbon-based chemistry can draw on the diversity of compounds produced from crude oil, coal or other natural sources, silicon chemistry2 relies almost exclusively on the carbothermal reduction of SiO2 to silicon. This is then transformed into feedstock chemicals by reaction with HCl, or by routes such as the 'direct process' for making methylchlorosilanes2, in which silicon is reacted with methyl chloride at 200–350°C over a copper/tin catalyst. Organosilicon compounds are in demand in fields ranging from organic synthesis to ceramics to the electronics industry. New synthetic routes to these materials are therefore highly desirable, especially if they rely on low-cost SiO2 and on rocessing methods that avoid the energy-intensive and equipment-intensive carbothermal reduction step which currently precedes almost all silicon chemistry. Here we describe a direct process in which SiO2 is reacted with ethylene glycol and an alkali base to produce highly reactive, pentacoordinate silicates which provide access to a wide variety of new silicon compounds.
144 citations
TL;DR: In this paper, the authors describe a direct process in which SiO2 is reacted with ethylene glycol and an alkali base to produce highly reactive, pentacoordinate silicates which provide access to a wide variety of new silicon compounds.
Abstract: THE potential role of inorganic and organometallic silicon compounds in the development of new chemical reagents, polymers, glasses and ceramics1 is limited at present by the paucity of simple silicon-containing starting materials. Whereas industrial carbon-based chemistry can draw on the diversity of compounds produced from crude oil, coal or other natural sources, silicon chemistry2 relies almost exclusively on the carbothermal reduction of SiO2 to silicon. This is then transformed into feedstock chemicals by reaction with HCl, or by routes such as the 'direct process' for making methylchlorosilanes2, in which silicon is reacted with methyl chloride at 200–350°C over a copper/tin catalyst. Organosilicon compounds are in demand in fields ranging from organic synthesis to ceramics to the electronics industry. New synthetic routes to these materials are therefore highly desirable, especially if they rely on low-cost SiO2 and on rocessing methods that avoid the energy-intensive and equipment-intensive carbothermal reduction step which currently precedes almost all silicon chemistry. Here we describe a direct process in which SiO2 is reacted with ethylene glycol and an alkali base to produce highly reactive, pentacoordinate silicates which provide access to a wide variety of new silicon compounds.
76 citations
TL;DR: The direct process for methylchlorosilane production in a laboratory-scale fluidized bed reactor was studied in this paper, where the silicon was found to have discrete sites at which silanes were produced, and the density of sites was controlled by the nature of the native oxide layer over the silicon.
65 citations
TL;DR: In this article, a catalyst system consisting of copper, zinc, and tin was discovered which yielded 90% dimethyldichlorosilane with nearly complete silicon utilization, which is a major improvement over the best previously reported performance.
65 citations
TL;DR: In this article, the three most important nonrotational mechanisms, the Van Vleck direct process, the van Vleck-Raman process, and the Orbach process have been studied.
Abstract: The intermolecular potentials in liquids are modulated by the motion of the molecules, and the electron spin in an s=½ molecule senses this variation in electric field through spin—orbit coupling. The three most important nonrotational mechanisms, the Van Vleck direct process, the Van Vleck—Raman process, and the Orbach process have been studied. The Raman process is negligible compared to the direct process unless ω02τc2≪1, where ω0 is the Zeeman frequency and τc is a mean correlation time for intermolecular fluctuations; under these conditions the direct process is proportional to the applied field squared and the Raman process is independent of field, but both processes appear to be of minor importance. If ω02τc2≫1, the Raman effect is negligible; the direct process is independent of applied field and probably not important. Even at ω02τc2≈1, the direct process is probably insignificant compared to other mechanisms such as spin—rotational relaxation. The Orbach process is significant if (δ0nℏ/kT) is no...
61 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2020 | 2 |
| 2019 | 2 |
| 2017 | 1 |
| 2015 | 1 |
| 2014 | 1 |