Partial Air Wetting on Solvophobic Surfaces in Polar Liquids

Microfluidics: The No-Slip Boundary Condition

“…The conclusions have been confirmed by Molecular Dynamics simulations [135] and are consistent with studies of flow in capillaries with diameters of tens of nanometers [3,91]. In this context, the large number of recent published experiments reporting some form of (apparent) slip with λ ∼ 1 nm−1 µm in the flow of Newtonian liquids is surprising [9,16,17,18,29,30,32,33,38,39,40,67,87,88,68,108,116,125,126,150,162,163,178,192,193,194,195], and has allowed to re-discover a few early [29] Poly(carbonate)+PVP SDS solutions studies reporting some degree of slip [21,34,46,141,160]. In part, this chapter is an attempt to describe and interpret these more recent experimental results.…”

“…When probing slip in electrolyte solutions and polar liquids, the amount of slip was found to vary with electrical properties. Sedimentation experiments reported that slip was only observed for polar liquids [16]. Fluorescence-correlation measurements reported slip lengths of the same order as the screening length κ −1 , which decrease with the ionic strength of the solution [108].…”

“…The amount of slip has been observed experimentally to depend on the type and quantity of dissolved gas. It is reported in sedimentation studies [16] that slip was not observed in vacuum conditions but only when the liquid sample was in contact with air. Furthermore, the study in [63] showed that tetradecane saturated with CO 2 lead to results consistent with no-slip but significant slip when saturated with argon, whereas the opposite behavior was observed for water.…”

Microfluidics: Fluid physics at the nanoliter scale

“…The idea is that dissolved gas molecules are drawn out of solution to nucleate a gas layer at the solid-liquid interface and lower the surface energy ͑Lum et de Gennes, 2002;Attard, 2003;Gran-ick et al, 2003͒. This hypothesis is bolstered by the observation of nanobubbles using tapping-mode atomic force microscopy ͑Ishida et Attard, 2001, 2002͒, and further supported by the observation that apparent slip decreases when the fluid is degassed ͑Boehnke et al, 1999;Granick et al, 2003͒. The no-slip boundary condition never enjoyed solid theoretical backing, but rather was accepted due to its apparent experimental success ͑Goldstein, 1938͒. While no consensus has been reached on the physical origin of the measured slip, its effects will be felt as microfluidic devices are made ever smaller.…”

Sand plug washing with gassy fluids

“…Следует отметить, что в рассматри-ваемом случае влияние проскальзывания жидкости незначительно. Так согласно [16], при седиментации лиофобных частиц кварца субмикронного размера эффект проскальзывания может увеличить скорость седиментации (или скорость витания) на 20%, при-чем эффект резко снижается с увеличением размера Добавка анионного ПАВ ввиду его адсорбции на поверхности частичек улучшает смачиваемость, сни-жая объемную концентрацию зародышей и число зерен покрытых "сольватной оболочкой". Увеличение ∆h 0 при C > 0.05%, связано с мицелообразованием и сопутствующим увеличением вязкости рабочего агента.…”