1.1 该测试方法涵盖了当使用便携式（即手持式）测角装置沉积液体并获得测量结果时施加到表面上的液滴的接触角的测量。 1.2 该测试方法旨在补充制造商对用于进行测量的器械的说明，但不旨在取代它们。 1.3 测试液体的选择取决于所执行的分析类型。可以使用许多液体，例如溶剂、表面活性剂和分散剂溶液，只要它们与特定仪器的构造相容。常见的测试液体包括水、二碘甲烷、乙二醇、甲酰胺等。 1.4 该测试方法基于测角法，其包括观察固体基底上的无柄测试液滴。1.5 虽然接触角由固体和液体的表面自由能决定，但这种测试方法不能用于直接测量表面张力。接触角可用于估算固体表面的表面自由能（试验方法 D7490 ). 1.6 单位- 以SI单位表示的值应被视为标准。括号中给出的值仅供参考。 1.7 本标准并不旨在解决与其使用相关的所有安全性问题（如果有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践并确定法规限制的适用性。 1.8 本国际标准是根据世界贸易组织发布的关于制定国际标准、指南和建议的原则的决定中确立的国际公认的标准化原则制定的贸易(TBT)委员会。 ======意义和用途====== 5.1 该测试方法可用于表征表面的润湿性。易于润湿的表面是其上的涂层更可能提供良好的粘附性和外观，并且不太可能遭受与表面张力相关的缺陷，例如凹坑、针孔、橘皮和鱼眼。接触角可用于测量表面的即时润湿性以及由于老化或磨损效应引起的变化，例如防水涂层或膜在暴露于环境或磨损测试时的变化。 5.2 表面的润湿性也是影响材料表面特性的过程的有用控制参数，例如模制、成形、机加工、清洁、表面处理、储存、包装和处理。5.3 接触角由测试液体的表面张力和固体的表面能决定。计算固体的表面能需要一种以上流体的接触角。一旦确定了固体的表面能，就可以将单一流体的接触角与固体表面能相关联。 5.4 液体的接触角由液体与固体表面最上面的几个分子层的相互作用决定。因此，接触角对样品组成、历史和少量污染物的存在的微小变化非常敏感。 5.5 水可用作确定表面是否亲水性的测试液体（

1.1 This test method covers the measurement of the angle of contact of a drop of liquid applied to a surface when using a portable (that is, handheld) goniometric device to deposit the liquid and obtain the measurement. 1.2 This test method is intended to supplement the manufacturer’s instructions for the device being used to make the measurements but is not intended to replace them. 1.3 The choice of test liquid depends on the type of analysis being performed. Many liquids such as solvents, surfactant, and dispersant solutions can be used providing they are compatible with the construction of the particular instrumentation. Common test liquids include water, diiodomethane, ethylene glycol, formamide, and so forth. 1.4 This test method is based on goniometry, which involves the observation of a sessile drop of test liquid on a solid substrate. 1.5 Although contact angles are governed by surface free energy of the solid and the liquid, this test method cannot be used to measure surface tension directly. Contact angles can be used to estimate surface free energy of solid surfaces (Test Method D7490 ). 1.6 Units— The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 This test method is useful for characterizing the wettability of surfaces. A surface that is easy to wet is one over which a coating is more likely to give good adhesion and appearance and less likely to suffer surface-tension-related defects such as cratering, pin holing, orange peel, and fish eyes. Contact angles can be used to measure immediate wettability of surfaces as well as changes due to aging or effects of wear, for example changes in a water repellent coating or film with exposure to environmental or wear testing. 5.2 The wettability of a surface is also a useful control parameter for processes that affect the surface properties of materials, such as molding, forming, machining, cleaning, surface treating, storage, packaging, and handling. 5.3 The contact angle is governed by the surface tensions of the test liquids and the surface energy of the solids. Contact angles of more than one fluid are necessary to calculate the surface energy of a solid. Once the surface energy of the solid has been determined, the contact angle of a single fluid can be correlated to the solid surface energy. 5.4 The contact angle of a liquid is determined by the interaction of the liquid with the uppermost few molecular layers of the solid surface. As such, contact angles are very sensitive to slight variations in sample composition, history, and the presence of small amounts of contaminants. 5.5 Water can be used as a test liquid to establish whether a surface is hydrophilic (<~45°) or hydrophobic. Water contact angles have been used to estimate surface cleanliness before and after cleaning operations, ease of wettability of surfaces by waterborne coatings, or level and uniformity of treatment level by, for example, corona, flame, plasma, or laser ablation. Water contact angles are particularly sensitive to the presence of polar functional groups. 5.6 Factors that may affect contact angles may include surface chemical composition, surface topography (such as those that create air pockets under the droplet, that is, the lotus effect or high-energy roughness that creates microcapillaries, that is, a grit-blasted aluminum surface), and substrate absorbency of the liquid. 5.7 An organic liquid can also be used to characterize a substrate. The contact angle established by non-polar organic liquids will be particularly sensitive to the non-polar nature of the substrate surface. 5.8 If contact angles are determined using two or more liquids having different polar and non-polar characteristics (for example, water and diiodomethane), the total surface energy of the solid may be calculated as the sum of polar and non-polar components, as per Test Method D7490 . 5.9 Contact angles can be used to map a surface in terms of hydrophilicity and hydrophobicity, presence of contaminants, and uniformity of treatment. Other analytical techniques such as infrared spectroscopy would be required to determine the origin of any non-uniformity.