The surface tension of liquids can be easily measured. Whether we can calculate the interfacial tension between two liquids from the surface tension of them I am unsure and require some advice.
Dear Ting Si,
if your first liquid L1 partially wets your second liquid L2 and if your system is at equilibrium (i.e. surface of L2 is perfectly plane and smooth, there is no chemical reaction between L1 and L2 and L2 is chemically homogeneous), then you can use Young's equation :
γL2 = γL1L2 + γL1 cos θ,
γL1 is the surface tension of liquid L1, γL2 is the surface tension of liquid L2, γL1L2 is the interfacial tension between L1 and L2, θ is the contact angle between L1 and L2.
Hope that it answers to your question.
In the case your question is addressed to differentiate the surface tension and interfacial energy between 2 inmiscible liqiids, NO DIFFERENCE EXIST. This is one and the same in different words.
I would advise you to check the sites below:
http://www.thermopedia.com/content/30/#SURFACE_AND_INTERFACIAL_TENSION_FIG1
http://www.thermopedia.com/content/27/
http://www.thermopedia.com/content/33/
You can also find some interesting information from page 11 to page 14 in my book: " Condensation Dans Un Microcanal En Silicium: Etude Du Transfert Thermique Local Et Identification Des Structures D'écoulement ".
Surface tension in contact with air is mainly due to nonpolar components of the liquid. Interfacial tension between 2 liquids , ie water and liquid is mainly related to the polar components of the liquid.
So knowing the surface tension, you can absolutly not deduce the interfacial tension with water ( or water solution).
Hi
I've worked on something similar
See the work of Good & Girifalco (1957) or Fowkes (1962)
Actually for the second one you need to be able to know the Debye part of the interfacial Free Energy (so the remark before is not wrong) and for the first one you need (to measure?) a fitting parameter
They are cited in this paper I will attach (for a short time):
On thermodynamic closures for two-phase flow with interfacial area concentration transport equation Olivier Sero-Guillaume, Nicolas Rimbert International Journal of Multiphase Flow 31 (2005) 897–920
Also, the book cited before is a good one...
Hope this helps,
Sincerely
Hi
Yes of course there is a relationship between the inter facial tension and the surface tension of liquids. Indeed, you can used the Young law:
cos θ= γ(L1,V)-γ(L2,V) / γ(L1,L2)
γL1,V is the surface tension of liquid L1, γL2,V is the surface tension of liquid L2, γL1,L2 is the interfacial tension between L1 and L2, θ is the contact angle between L1 and L2.
May be there are some relationship between them. but it is hard to calculate the IFT from SFT. We can also measure the interracial tension for example by pendant bubble set up.
The basic relationship between surface tension and interfacial tension is the Young Equation that most friend has pointed it: γL2 = γL1L2 + γL1 cos θ. But, it is the theoritical equation that you can't use it easily in practical use. Moreover,The most works of Good & Girifalco (1957) or Fowkes (1962) are about measuring the surface tension of solids. To determine interfacial tension of two liquids there are some methods including Pendant drop method. You'd better to search for this method.
IFT from surface tensions of liquids can be calculated by
1. Good and Girifalco eq
γl1.l2 = γl+γ2-2φ(γl*γ2)^0.5 where normally φ =1 (interaction parameter)
2, OWRK Method
γl1.l2 = γl+γ2-2*[(γl1d*γl2d)^0.5+(γl1p*γl2p)^0.5]
γl1d and γl2d are 1st and 2nd liquid dispersive components
γl1p and γl2p are 1st and 2nd liquid polar components
+ 2nd method is also used in Goniometer to calculate surface energy of solid substrate by two liquid approach (2L SE in ram e hart instruments)
Agree with the previous recommendations regarding determination of the polar and disperse components of the surface tension of both liquids and then use OWRK or other models such as Fowkes, Wu, etc. to determine IST.
However, IST can be estimated using the so-called equation of state proposed by NeumannArticle Equation of state for interfacial tensions of solid-liquid systems
. It was developed for solid-liquid systems, but also works for liquid-liquid interfaces for IST >10- Badges
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