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Accurate Determination of the Equilibrium Surface Tension Values with Area Perturbation Tests
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Un método basado en regresión lineal para determinar la tensión superficial a partir de la variación de la curvatura
Carrie E Perlman1, Bret A Brandner2, Stephen B Hall2
1Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States.
Langmuir : the ACS journal of surfaces and colloids
|August 20, 2025
Resumen
Un nuevo método de regresión lineal determina con precisión la tensión superficial (γ) a partir de la curvatura interfacial, incluso con tensioactivos. Este enfoque simplifica la medición de la tensión superficial para las interfaces de fluidos, ofreciendo una herramienta valiosa para la investigación científica.
Área de la Ciencia:
- Dinámica de fluidos
- Ciencias de la superficie
- Física y química
Sus antecedentes:
- La tensión superficial (γ) es crucial para las interfaces de fluidos, equilibrada por la presión hidrostática (ΔP) a través de la relación Young-Laplace.
- Los surfactantes pueden alterar las propiedades interfaciales, lo que requiere métodos precisos para la determinación de γ.
- Los métodos existentes pueden no tener plenamente en cuenta los efectos de los tensioactivos en la tensión interfacial.
Objetivo del estudio:
- Desarrollar un nuevo método basado en la regresión lineal para determinar la tensión superficial (γ) a partir de la curvatura interfacial.
- Validar el método utilizando gotas sessiles y burbujas cautivas con monocapas de dipalmitoil fosfatidilcolina (DPPC).
- Evaluar la precisión del nuevo método con respecto a técnicas establecidas como el análisis de la forma de gota axisimétrica.
Principales métodos:
- Utilizando la relación Young-Laplace (ΔP = γ (k1 + k2)) y la variación lineal de ΔP con la elevación.
- Análisis de imágenes de gotas sessiles y burbujas cautivas para medir la curvatura interfacial (k1 + k2) a diferentes alturas.
- Aplicación de la regresión lineal al gráfico de ΔP (compensación) frente a (k1 + k2) para determinar γ.
Principales resultados:
- Se encontró que la curvatura interfacial (k1 + k2) varía linealmente con la elevación, consistente con la relación de Young-Laplace.
- El algoritmo de regresión lineal desarrollado determinó con precisión la tensión superficial (γ).
- La comparación con el análisis axisimétrico de la forma de la gota mostró una diferencia absoluta media de 0,30 ± 0,37 mN/m para las monocapas de DPPC en un rango γ de 2-70 mN/m.
Conclusiones:
- El nuevo método de regresión lineal proporciona un medio preciso y accesible para determinar la tensión superficial (γ) a partir de la curvatura interfacial.
- El método es robusto incluso en presencia de tensioactivos como el DPPC.
- La teoría subyacente es adaptable para la obtención de imágenes en 3D, extendiendo potencialmente su aplicación a geometrías interfaciales complejas.
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