Liquid-Solid Adhesion Work Measurement via Capillary Force Integration
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Solution Overview
Problem
Existing methods for determining liquid-solid adhesion work are plagued by uncertainties in contact angle measurements, particularly for small contact angles, and often require direct measurement of contact angles, which can be inaccurate and deviate significantly from calculated values.
Innovation Solution
A method and apparatus that form a cylindrically symmetric capillary bridge between a circular-shaped solid surface and a tested solid surface, measuring capillary force and interfacial area changes during modifications, allowing for the integration of capillary force to determine liquid-solid adhesion work independently of contact angle measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If contact angle measurement methods are used to determine liquid-solid adhesion work, then the measurement can be performed with simple equipment, but significant measurement uncertainties occur especially for small contact angles
Solution Approach 1:
The patent replaces the optical contact angle measurement system with a mechanical force measurement system. Instead of measuring contact angles optically (which introduces uncertainties), the invention measures capillary forces mechanically using a force measurer, and integrates these forces to calculate adhesion work directly, eliminating the need for contact angle determination and its associated measurement errors.
Solution Approach 2:
The patent introduces capillary force as an intermediary quantity to bridge the gap between measurable mechanical forces and the target adhesion work parameter. By measuring capillary forces during the formation and elimination of liquid bridges, and integrating these forces, the patent obtains adhesion work directly without needing to measure contact angles, thus resolving the contradiction between measurement simplicity and precision.
2Ease of operation
If equilibrium Young contact angle is measured, then adhesion work can be calculated using Young-Dupré equation, but the equilibrium contact angle cannot be directly measured and requires calculation from advancing and receding angles
Solution Approach 1:
The patent substitutes the complex optical measurement and calculation process for determining equilibrium contact angles with a direct mechanical force measurement approach. By measuring capillary forces during liquid bridge formation and elimination, and integrating these forces, the patent calculates adhesion work directly without needing to determine advancing or receding contact angles, thereby simplifying the process while improving accuracy.
3Ease of operation
If receding contact angle is measured, then adhesion work can be determined, but the receding contact angle is not constant and decreases with the volume of the sessile drop
Solution Approach 1:
The patent replaces contact angle measurement with mechanical force measurement. By measuring capillary forces during the formation and elimination of liquid bridges and integrating these forces, the patent determines adhesion work directly. This approach eliminates the problem of contact angle non-constancy with drop volume, as the force measurement method does not depend on contact angle values but rather on the actual mechanical forces and interfacial area changes.
4Measurement precision
If force measurer is used to measure capillary force during liquid bridge formation and elimination, then adhesion work can be determined independently of contact angle, but the apparatus complexity increases
Solution Approach 1:
The patent makes the force measurer a multi-functional component that serves both as a force measurement device and as part of the liquid bridge formation and elimination system. The force measurer is integrated into the apparatus that controls and measures the liquid bridge process, allowing it to perform multiple functions: measuring capillary forces, controlling liquid bridge formation, and determining adhesion work. This reduces the need for separate specialized components, thereby managing apparatus complexity while maintaining measurement precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach provides a more accurate and efficient determination of liquid-solid adhesion work by focusing on mechanical work and interfacial area changes, reducing measurement uncertainties and enabling calculation of contact angles without direct measurement.
Implementation Method 1
a liquid cylindrically symmetric capillary bridge is formed in a fluid medium between an end portion having peripheral circular edge of a measurement element and a surface to be tested of a solid object to be tested
Implementation Method 2
the capillary force and the change of the length or the volume of the capillary bridge are measured
Data Source
AI summary
The invention is a method for determining liquid-solid adhesion work, during which, in connection with a liquid cylindrically symmetric capillary bridge in fluid medium between an end portion having peripheral circular edge of a measurement element and a solid surface-to-be-testedby performing cylindrical symmetry-keeping modification on the capillary bridgedetermining (S110a) changes of interfacial areas of the capillary bridge and fluid medium, and of the capillary bridge and surface-to-be-tested, andby determining (S100) capillary force, determining (S110b) a total mechanical work corresponding thereto,determining (S120), for the cylindrical symmetry-keeping modification, based on the interfacial area changes, total mechanical work and liquid-fluid interfacial tension a difference value of the solid-liquid and solid-fluid interfacial tensions, and by subtracting that from the liquid-fluid interfacial tension, determining (S130) the liquid-solid adhesion work.The invention is, furthermore, an apparatus for determining liquid-solid adhesion work. (FIG. 1)