Measurement method for contact angle of nano-film surface
1 Scope
This standard specifies the terms, principles, test equipment, environment, sample preparation, analysis steps, result calculation and test report involved in the measurement of contact angle of nano-film surface.
This standard is applicable to the nano-film coatings where the substrate is a flat surface.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 6682-2008 Water for analytical laboratory use - Specification and test methods
GB/T 8170 Rules of rounding off for numerical values & expression and judgement of limiting values
GB/T 19619 Terminology for nanomaterials
GB/T 24368-2009 Test method for hydrophobic contamination on glass by contact angle measurement
YY/T 0282 Syringe needle
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 19619 and the following apply.
3.1
contact angle
angle between the gas-liquid interface and the tangent line of the solid-liquid interface at the junction of gas, liquid and solid, symbolized as θ, in degrees (°)
3.2
sessile drop method
method of calculating the contact angle by measuring the droplet shape on the to-be-measured surface by detecting droplets
3.3
static contact angle
contact angle measured at a specified time by the sessile drop method with a constant droplet volume, symbolized as θsta, in degrees (°)
3.4
advancing contact angle
contact angle formed in the process of replacing gas-solid interface with liquid-solid interface, which does not change with the increase of droplet volume, symbolized as θadv, in degrees (°)
4 Measurement principles
As shown in Figure 1, the liquid is dropped on the solid surface, and the tangent line of the gas-liquid interface is made at the junction of solid, liquid and gas phases, and the included angle formed between this tangent line and the solid-liquid junction line is the contact angle. For a given system, the contact angle depends on the interaction between the three phase (liquid/gas, solid/gas and liquid/solid) interfaces.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Measurement principles
5 Test equipment and water for test
6 Test environment
7 Sample preparation
8 Test steps and result calculation
9 Test report
