Heterogenization of Ketone Catalyst for Epoxidation by Low Pressure Plasma Fluorination of Silica Gel Supports

Abstract

Low pressure plasma was used for preparing heterogeneous organocatalysts 2-(A)-(C) suitable for dioxirane-mediated epoxidations. Heterogenization was accomplished by adsorption of the methyl perfluoroheptyl ketone (2) on fluorinated supports (A)-(C) deriving from the treatment of commercial C8-silica gel in low pressure plasma fed with fluorocarbons. Catalyst 2-(C) proved to be the most efficient one, promoting epoxidation of an array of alkenes, including unsaturated fatty esters like methyl oleate (10) and the triglyceride soybean oil (11), with the cheap potassium peroxymonosulfate KHSO5 (caroate) as a green oxidant. Notably, the perfluorinated matrix gives rise to the activation of caroate, generating singlet oxygen. Materials were characterized by infrared Attenuated Total Reflectance spectroscopy (ATR-FTIR), X-ray Photoelectron Spectroscopy (XPS ) and Emission Scanning Electron Microscope (FESEM).

Low pressure plasma functionalized cellulose fiber for the remediation of petroleum hydrocarbons polluted water

“…Here we show that the affinity of cellulose extracted from SB fibers for TPHs can be improved, by a non-equilibrium plasma treatment of their surface, with tetrafluoromethane (CF 4 ) [37][38][39][40][41]. The non-equilibrium plasma approach is an eco-friendly versatile tool allowing the modification of the uppermost layers of flat substrates, fibers or granules [42][43], both at low or atmospheric pressure [39,40,44].…”

Photocatalytic inactivation of Escherichia coli bacteria in water using low pressure plasma deposited TiO2 cellulose fabric

“…22,23 Here, we have explored the possibility to use a low pressure plasma sputtering technique for the deposition of TiO2 on Spanish Broom cellulose surface. Generally, non-equilibrium plasma processes, both at low or atmospheric pressure, are ecofriendly, versatile and, thanks to their low temperature (near to room), allow the modification of the uppermost layers of flat substrates, 24 fibers or granules, [25][26][27][28][29] without changing their bulk properties.…”