### Abstract

Interfacial energy γ_{1,2} of a liquid-liquid or solid-liquid system is of paramount importance in colloid and interface science and its applications. To assess the dependence of γ_{1,2} on the surface energies γ_{1} and γ_{2} of two materials in contact, Girifalco and Good proposed their venerable equation involving the interfacial interaction parameter ϕ. Subsequently, values of ϕ have been experimentally determined for various material pairs. Here, we show that, the data of ϕ closely follow a unique relationship ϕ = (1 − γ_{1,2}/γ_{1})^{½} for all pairs where the other material is non-polar. Theoretically, this curve describes the smallest possible ϕ. However, we also show that substituting this relationship into the Girifalco-Good equation reduces it to Antonov's rule γ_{1,2} = γ_{1}−γ_{2}. Such a simplistic approach is inaccurate, and we conclude that the plotting of ϕ vs. γ_{1,2} has contributed to overestimating the applicability of the Girifalco-Good Equation.

Original language | English |
---|---|

Pages (from-to) | 243-246 |

Number of pages | 4 |

Journal | Journal of Colloid and Interface Science |

Volume | 529 |

DOIs | |

Publication status | Published - 1 Nov 2018 |

MoE publication type | A1 Journal article-refereed |

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### Keywords

- Equation of state
- Girifalco-Good equation
- Interfacial energy
- Interfacial interaction parameter
- Interfacial tension

### Cite this

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**Another look at the interfacial interaction parameter.** / Makkonen, Lasse; Kurkela, Juha.

Research output: Contribution to journal › Article › Scientific › peer-review

TY - JOUR

T1 - Another look at the interfacial interaction parameter

AU - Makkonen, Lasse

AU - Kurkela, Juha

PY - 2018/11/1

Y1 - 2018/11/1

N2 - Interfacial energy γ1,2 of a liquid-liquid or solid-liquid system is of paramount importance in colloid and interface science and its applications. To assess the dependence of γ1,2 on the surface energies γ1 and γ2 of two materials in contact, Girifalco and Good proposed their venerable equation involving the interfacial interaction parameter ϕ. Subsequently, values of ϕ have been experimentally determined for various material pairs. Here, we show that, the data of ϕ closely follow a unique relationship ϕ = (1 − γ1,2/γ1)½ for all pairs where the other material is non-polar. Theoretically, this curve describes the smallest possible ϕ. However, we also show that substituting this relationship into the Girifalco-Good equation reduces it to Antonov's rule γ1,2 = γ1−γ2. Such a simplistic approach is inaccurate, and we conclude that the plotting of ϕ vs. γ1,2 has contributed to overestimating the applicability of the Girifalco-Good Equation.

AB - Interfacial energy γ1,2 of a liquid-liquid or solid-liquid system is of paramount importance in colloid and interface science and its applications. To assess the dependence of γ1,2 on the surface energies γ1 and γ2 of two materials in contact, Girifalco and Good proposed their venerable equation involving the interfacial interaction parameter ϕ. Subsequently, values of ϕ have been experimentally determined for various material pairs. Here, we show that, the data of ϕ closely follow a unique relationship ϕ = (1 − γ1,2/γ1)½ for all pairs where the other material is non-polar. Theoretically, this curve describes the smallest possible ϕ. However, we also show that substituting this relationship into the Girifalco-Good equation reduces it to Antonov's rule γ1,2 = γ1−γ2. Such a simplistic approach is inaccurate, and we conclude that the plotting of ϕ vs. γ1,2 has contributed to overestimating the applicability of the Girifalco-Good Equation.

KW - Equation of state

KW - Girifalco-Good equation

KW - Interfacial energy

KW - Interfacial interaction parameter

KW - Interfacial tension

UR - http://www.scopus.com/inward/record.url?scp=85048281789&partnerID=8YFLogxK

U2 - 10.1016/j.jcis.2018.06.015

DO - 10.1016/j.jcis.2018.06.015

M3 - Article

AN - SCOPUS:85048281789

VL - 529

SP - 243

EP - 246

JO - Journal of Colloid and Interface Science

JF - Journal of Colloid and Interface Science

SN - 0021-9797

ER -