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Geometrical Description of Contact Line Fluctuations in Heterogeneous Systems with Controlled Wettability
Journal of Colloid and Interface Science
|August 16, 2000
Summary
This study investigates fluid displacement in heterogeneous systems by analyzing contact line fluctuations. Results reveal how surface defects influence displacement front dynamics and saturation behavior, crucial for industrial applications.
Area of Science:
- Physics
- Materials Science
- Chemical Engineering
Background:
- Understanding contact line fluctuations in heterogeneous systems is vital for industrial processes but remains poorly understood.
- Controlled wettability and surface defects significantly impact fluid displacement dynamics.
Purpose of the Study:
- To experimentally study fluid displacement on modified Hele-Shaw cells with controlled surface heterogeneities.
- To determine the morphology and deformation energy of the displacement front across different surface coverage regimes.
- To characterize the width of the displacement front using roughness and growth exponents.
Main Methods:
- Utilized modified Hele-Shaw cells with controlled surface defect coverage to create heterogeneous systems.
- Investigated fluid displacement and analyzed the morphology and deformation energy of the displacement front.
- Quantified the front width using roughness exponent (alpha) and growth exponent (beta).
Main Results:
- Displacement front width increases logarithmically with time, followed by a crossover to saturation.
- Crossover time is dependent on surface defect coverage.
- For low coverage, beta values ranged from 0.51-0.59 and alpha from 0.65-0.67; medium/high coverage showed similarities to directed percolation.
- Deformation energy analysis identified the pinning role of individual surface defects.
Conclusions:
- Surface heterogeneities, controlled by defect coverage, dictate fluid displacement front dynamics.
- The observed crossover behavior and exponent values provide insights into pinning effects and universality classes.
- Findings contribute to a better understanding of fluid behavior in complex, industrially relevant systems.
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