Studies in surface chemistry of carbon blacks. Part I. High temperature evacuations

✍ Scribed by Balwant Rai Puri; R.C Bansal

• Publisher: Elsevier Science
• Year: 1964
• Tongue: English
• Weight: 398 KB
• Volume: 1
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(64)90006-5

✦ Synopsis

Surface complexes on 15 samples of carbon blacks of different varieties were studied by evacuating at 1200". The total oxygen evolved as CO,, CO and H,O was fairly close to the value obtained by ultimate analysis. The total hydrogen evolved as water vapour and free hydrogen was significantly less, by 30-40 per cent, than the hydrogen content obtained by ultimate analysis, showing that hydrogen was held much more firmly. The evolution of CO, commenced at around 200-300" and finished at about 500-700" while that of CO commenced at approximately 500-700" and finished in the 1000-1200' temperature range. The liberation of free hydrogen commenced in the 500-700 range and continued even at 1200". There was no correlation between total oxygen (or any part thereof) and total hydrogen (or any part thereof). The oxygen content was less than 1.5 per cent in furnace blacks, varied between 3 and 4 per cent in channel blacks and between 4 and 8 per cent in colour blacks. Broadly speaking, the furnace, channel and colour blacks contained 9, 25 and 30 mg oxygen/100 m3 of the surface. The channel blacks ranked with furnace blacks in having a lower value of oxygen disposed ofl as CO$-complex but with colour blacks in having a higher value of oxygen disposed as COz-complex but with colour blacks in having a higher value of oxygen disposed as CO-complex per unit surface. Suitable explanations based on the history of formation of the carbon blacks have been offered.