Slip Flow through Colloidal Crystals of Varying Particle Diameter
详细信息 查看全文
- 作者：Benjamin J. Rogers ; Mary J. Wirth
- 刊名：ACS Nano
- 出版年：2013
- 出版时间：January 22, 2013
- 年：2013
- 卷：7
- 期：1
- 页码：725-731
- 全文大小：421K
- 年卷期：v.7,no.1(January 22, 2013)
- ISSN：1936-086X
文摘
Slip flow of water through silica colloidal crystals was investigated experimentally for eight different particle diameters, which have hydraulic channel radii ranging from 15 to 800 nm. The particle surfaces were silylated to be low in energy, with a water contact angle of 83掳, as determined for a silylated flat surface. Flow rates through centimeter lengths of colloidal crystal were measured using a commercial liquid chromatograph for accurate comparisons of water and toluene flow rates using pressure gradients as high as 1010 Pa/m. Toluene exhibited no-slip Hagen鈥揚oiseuille flow for all hydraulic channel radii. For water, the slip flow enhancement as a function of hydraulic channel radius was described well by the expected slip flow correction for Hagen鈥揚oiseuille flow, and the data revealed a constant slip length of 63 卤 3 nm. A flow enhancement of 20 卤 2 was observed for the smallest hydraulic channel radius of 15 nm. The amount of slip flow was found to be independent of shear rate over a range of fluid velocities from 0.7 to 5.8 mm/s. The results support the applicability of the slip flow correction for channel radii as small as 15 nm. The work demonstrates that packed beds of submicrometer particles enable slip flow to be employed for high-volume flow rates.