Showing papers on "Sessile drop technique published in 1979"
01 Jan 1979
TL;DR: In this paper, the authors investigated how the structure of a solid surface affects the contact angle that a liquid forms on the solid, and the level of structure considered there included features that are not macroscopically observed, such as microheterogeneities, or minute peaks, pits, hills, and grooves.
Abstract: The previous chapter was largely theoretical, in that it dealt with the interpretation of contact angle results in terms of solid surface energies. It also delved into the question of how the structure of a solid surface affects the contact angle that a liquid forms on the solid. The level of structure considered there included features that are not macroscopically observed, such as microheterogeneities, or minute peaks, pits, hills, and grooves in various geometries. Their existence may be inferred from certain observations, such as contact angle hysteresis, and sometimes they can be observed directly, e.g., with the optical or electron microscope.
314 citations
TL;DR: In this article, the surface tension of Al-Pb, Al-Bi and Zn-Bi alloys were measured using two different methods (maximum bubble pressure and sessile drop) and the experimental results were compared with those given in the literature.
59 citations
TL;DR: In this article, the Zisman concept of critical surface tension and Fowkers' hypothesis of additivity in the contribution of polar and dispersion forces to surface tension are criticized and a new approach to the problem is proposed.
26 citations
TL;DR: The sessile drop method was used for the determination of the density in liquid state in this paper, and the results for stainless steel 1.4970 using uranium dioxide as substrate material in the temperature range 1690 K (liquidus temperature T 1 ) are ρ = 6.82 × 10 3 − 10.5 kg/m 3, and α = 1.50 × 10 − 4 K −1.
22 citations
TL;DR: Advancing contact angles measured on compacts of several drugs by the sessile drop method and by penetration through a column of drug granules were used to find the critical surface tension of the drugs, providing that the surfaces of the compacts were smooth and highly reflective.
15 citations
3 citations
Patent•
01 Oct 1979TL;DR: In this paper, a method of measuring the dynamic wetting angle between a liquid and a solid surface moving into the liquid as a function of the speed of the solid surface relative to the liquid is proposed.
Abstract: A method of measuring the dynamic wetting angle between a liquid and a solid surface moving into the liquid as a function of the speed of the solid surface relative to the liquid comprising the steps of moving the solid surface into the liquid at a constant speed, adjusting the angle of the surface entering the liquid until the wetting angle is equal to the angle between the solid surface and the quiescent surface of the surrounding liquid, and measuring said adjusted angle. In another embodiment, the speed of the solid surface entering at a selected angle is adjusted until the meniscus adjacent the surface becomes level, and the speed is measured.
2 citations
TL;DR: In this paper, the effects of addition of ethanol and surface active agent to the suspension on the agglomeration behavior of sulfisomidine dispersed in chloroform were investigated, and the contact angles of bridging liquid on solid particles were measured as a function of surfactant concentration and the methodology, i.e., sessile drop, hanging drop and Wilhelmy method.
Abstract: The wet spherical agglomeration technique with a small amount of bridging liquid which preferentially wets solid particles, is one of the accepted method to agglomerate the particles dispersed in liquid. In the present study, the effects of addition of ethanol and surface active agent to the suspension on the agglomeration behavior of sulfisomidine dispersed in chloroform were investigated. Addition of a suitable amount of ethanol, say 100ml, slightly increased the agglomerate size compared with the case without addition. When the ethanol was added more than this amount, the agglomerate size decreased significantly. While, the agglomeration did not occur absolutely when ionic surfactant was added.The contact angles of bridging liquid on solid particles in the same system as the agglomeration process were measured as a function of surfactant concentration and the methodology, i. e. sessile drop, hanging drop and Wilhelmy method. The contact angles obtained by the sessile drop method were reasonably correlated with the agglomerate size, which decreased with increasing the contact angle. The correlation of agglomerate size with both parameters of the interfacial tension between the bridging liquid and the dispersing medium and the contact angle were described linearly by equation (11) as seen in Fig. 6.
2 citations
2 citations
TL;DR: In this article, the statistical mechanical deduction of Fowler for surface tension from the assumption of a discontinuous step function profile of the surface density is used in conjunction with Evan's pseudo-atom theory to calculate surface properties such as surface entropy and tension for hard-sphere and square-well types of interactions in liquid metals.
1 citations