Search results for "VDP::Technology: 500::Chemical engineering: 560"
showing 4 items of 4 documents
The Nature of Rest Silanol Groups on the Surfaces of Silica Based Solid Phase Extraction Materials
2013
Author's version of an article in the journal: Advanced Materials Research. Also available from the publisher at: http://dx.doi.org/10.4028/www.scientific.net/AMR.650.66 Chemically bonded solid phase materials are very important in separation chemistry. The chemically modified silica gel contains rest silanol groups that can affect the retention properties when they are used for separation of compounds. Some commercially available solid phase extraction (SPE) materials based on silica gel were analysed for rest silanol groups by near infrared spectroscopy. The combination frequency of the water molecules in the 5500- 5000 cm -1 region was used in identifying the nature of water molecules on…
Preliminary photochemical studies of fluorene in various aqueous media
2014
- The current study investigates the direct photochemical degradation of aqueous fluorene with the aid of a 125W polychromatic medium, pressure Hg lamp. The purpose was to test the effectiveness of the lamp in irradiation using fluorene spiked solution as substrate. A 700 ml volume of fluorene solution of 0.002 mg/l was irradiated batch-wise at 1, 3, 6, 12, 18, 24 and 48 h. The amount of fluorene removal was studied for fluorene solutions prepared from , neutral (distilled water), acidic (by adjusting pH with hydrochloric acid, HCl), basic (by adjusting pH with sodium hydroxide, NaOH) and saline (addition of sodium chloride, NaCl) solutions and there was 95.95, 92.35, 96.65 and 97.15 % remo…
Near infrared spectroscopic study on the adsorption of methanol on silica gel
2013
Author's version of an article in the journal: Advanced Materials Research. Also available from the publisher at: http://dx.doi.org/10.4028/www.scientific.net/AMR.650.150 The silanol groups on Silica gel surface are sites for adsorption of polar molecules. Alcohols and other polar molecules are easily adsorbed by forming hydrogen bondings with OH groups on silica gel surface. A study on the adsorption of methanol on silica gel was carried out by using NIR spectroscopy in combination with ssecond derivative techniques. Four of the well characterised silica gel samples were used in this study. Each of the silica gel (0.25g) samples with different surface areas and silanol number was pressed i…
Scanning Tunneling Spectroscope Use in Electrocatalysis Testing
2010
Published version of an article from the journal: Materials (1996-1944). Also available from publisher: http://dx.doi.org/10.3390/ma3063675 The relationship between the electrocatalytic properties of an electrode and its ability to transfer electrons between the electrode and a metallic tip in a scanning tunneling microscope (STM) is investigated. The alkaline oxygen evolution reaction (OER) was used as a test reaction with four different metallic glasses, Ni78Si8B14, Ni70Mo20Si5B5, Ni58Co20Si10B12, and Ni25Co50Si15B10, as electrodes. The electrocatalytic properties of the electrodes were determined. The electrode surfaces were then investigated with an STM. A clear relationship between the…