| 학회 | 한국고분자학회 |
| 학술대회 | 2004년 가을 (10/08 ~ 10/09, 경북대학교) |
| 권호 | 29권 2호, p.482 |
| 발표분야 | 고분자 구조 및 물성 |
| 제목 | Rheological behavior of fumed silica suspension in polyethylene glycol |
| 초록 | Introduction Hydrophilic fumed silica suspension in polar and non polar organic solvents has been widely investigated. The shear and strain-thickening behavior of silica suspension can be explained using a flow-induced clustering mechanism.1 It was revealed that the sol-formation in polar organic solvents4and build up gel-formation in non-polar organic solvents respectively.2,3 The main driving force for silica gelation is expected to be the formation of hydrogen bonds between silanol groups on adjacent silica units.2,3 In this study, the influence of temperature and shear force on hydrophilic fumed silica in PEG was confirmed by using rheometer, the reversibility of sol-gel formation with respect to the temperature in silica suspension was also studied. Experimental section Sample preparation Hydrophilic fumed silica in PEG were prepared by mixing the components suitably in a mechanical stirrer (RZR 2041, Heidolph Company) until homogeneity was archived. The resulting suspensions were left to itself in sealed bottles for 24 hours to remove entrained air bubbles. Rheological measurements Rheological measurements were conducted using a rheometer (UDS-200, Paar Physica Company) at ambient temperature (25℃). Two type of geometries were used: cone and-plate, paralled plate. Steady-shear rheologies were established using a cone-and-plate geometry having a diameter of 50mm and a cone angle of 2º. The flow curves were carried out using a range of shear rate from 0.1 to 1000/s. The temperature tests in rotational mode were carried out in a constant shear rate (10/s, 20/s, 30/s). Dynamic shear rheologies were also checked using a pallalled plate geometry having a diameter of 50mm.The frequency sweep was carried out using the constant amplitude and range of angular frequency at 5% of amplitude from 100 to 0.1 rad/s. References 1. Raghavan, S. R.; Khan, S. A. J. Colloid Interface Sci. 57, 185, 1997 2. Raghavan, S. R..; Walls, H. J.; Khan, S. A. Langmuir 16, 7920, 2000 3. Shirono, H.; Amano, Y.; Kawaguchi, M.;Kato, T. J. Colloid Interface Sci. 239, 555, 2001 4. Chapel, J.-P. Langmuir 10, 4237, 1994 |
| 저자 | 박종환, 김호겸, 민경은 |
| 소속 | 경북대 |
| 키워드 | reversibility; hydrophilic fumed silica; rheological behavior |
