ASTM C813-20

• Abstract:

  SIGNIFICANCE AND USE; 5.1 The contact angle test is nondestructive and may be used for control and evaluation of processes for the removal of hydrophobic contaminants. The test may also be used for the detection and control of hydrophobic contaminants in processing ambients. For this application, a surface free of hydrophobic films is exposed to the ambient conditions and is subsequently tested.; SCOPE; 1.1 This test method covers the detection of hydrophobic contamination on glass surfaces by means of contact angle measurements. When properly conducted, this test method will enable detection of fractions of monomolecular layers of hydrophobic organic contaminants. Very rough or porous surfaces may significantly decrease the sensitivity of this test method. ; 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. ; 1.3 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. ; 1.4 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.

• Status: Published
• Publication Date: 30-Sep-2020
• ICS: 17.040.20 - Properties of surfaces
• Technical Committee: C14 - Glass and Glass Products
• Drafting Committee: C14.02 - Chemical Properties and Analysis

• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D1193-99e1 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999
• Refers: ASTM D1193-99 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999

Overview

ASTM C813-20 specifies a standard test method for detecting hydrophobic contamination on glass surfaces by utilizing contact angle measurement. This nondestructive method enables the detection of fractions of monomolecular layers of hydrophobic organic contaminants, ensuring effective quality control in glass processing and handling. The method provides a reliable means for evaluating and controlling the cleanliness of glass surfaces, which is essential in many industrial, laboratory, and processing environments.

The contact angle test defined in ASTM C813-20 is applicable to smooth, non-porous glass surfaces and involves depositing droplets of water and measuring the contact angle formed, which indicates the presence of hydrophobic substances that may compromise glass surface performance.

Key Topics

• Contact Angle Measurement: The core of ASTM C813-20 is measuring the angle at which a water droplet meets a glass surface. A significantly higher contact angle generally indicates the presence of hydrophobic contaminants.
• Detection of Monomolecular Contaminants: The method is sensitive enough to identify even fractions of a monomolecular layer of organic residues, vital for applications requiring ultra-clean glass.
• Process Evaluation and Control: This test supports cleaning process validation, helping to verify whether procedures for removing hydrophobic films are effective.
• Nondestructive Testing: The test procedure does not alter or damage the glass surface, making it suitable for ongoing quality assurance and process monitoring.
• Equipment and Techniques: Practical guidance is provided for required apparatus, such as comparator microscopes with a goniometer scale, cameras, and properly prepared water.

Applications

The ASTM C813-20 standard is widely applied across industries where glass purity and surface properties are critical. Typical applications include:

• Glass Manufacturing: Ensures the removal of hydrophobic contaminants in float glass and specialty glass products, improving product reliability.
• Laboratory Equipment: Validates the cleanliness of glassware used in sensitive analytical and biological experiments, reducing risk of contamination.
• Semiconductor and Photovoltaic Manufacturing: Supports stringent cleanliness requirements for glass surfaces in electronic device fabrication.
• Optical Components: Verifies surface preparation quality for glass used in lenses, mirrors, and other optical systems.
• Process Monitoring: Detects hydrophobic contamination in cleanroom environments or other processing ambients, enabling rapid response to contamination events.

Related Standards

ASTM C813-20 references and complements several other standards, including:

• ASTM D1193 - Specification for Reagent Water, which defines requirements for the water used in the test method.
• ASTM Glass Standards - Covers a broad range of methods and specifications relevant to glass material properties and testing.
• Other Cleanliness and Surface Analysis Standards - May be used alongside C813-20 for comprehensive contamination and surface characterization protocols.

Practical Value

Implementing ASTM C813-20 delivers practical benefits such as:

• Quality Assurance: Provides reliable verification of cleanliness, essential for high-precision applications.
• Process Optimization: Identifies failures in surface cleaning or handling, supporting continuous improvement efforts.
• Regulatory Compliance: Facilitates documentation of contamination control processes, meeting industry and customer requirements.
• Minimized Defects: Reduces risks of surface-related failures in finished glass products or assemblies.

By adhering to the procedures in ASTM C813-20, organizations can ensure the consistent removal and detection of hydrophobic contamination, safeguarding product performance and process integrity in all applications that demand pristine glass surfaces.

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.
Designation: C813 − 20
Standard Test Method for
Hydrophobic Contamination on Glass by Contact Angle
Measurement
This standard is issued under the fixed designation C813; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.2 hydrophilic, adj—having a strong affinity for water;
wettable.
1.1 This test method covers the detection of hydrophobic
3.1.2.1 Discussion—Perfectly hydrophilic surfaces exhibit
contamination on glass surfaces by means of contact angle
zero contact angles.
measurements.Whenproperlyconducted,thistestmethodwill
enable detection of fractions of monomolecular layers of
3.1.3 hydrophobic, adj—having little affinity for water;
hydrophobic organic contaminants. Very rough or porous
nonwettable.
surfaces may significantly decrease the sensitivity of this test
3.1.3.1 Discussion—Hydrophobic surfaces exhibit contact
method.
anglesappreciablygreaterthanzero(generallygreaterthan45°
1.2 The values stated in SI units are to be regarded as
for the equilibrium angle).
standard. No other units of measurement are included in this
3.1.4 receding angle, n—the smallest angle observable
standard.
when a liquid droplet is decreased in size.
1.3 This standard does not purport to address all of the
3.1.5 sessile drop, n—a drop of liquid sitting on the upper
safety concerns, if any, associated with its use. It is the
side of a horizontal surface.
responsibility of the user of this standard to establish appro-
3.1.5.1 Discussion—See Fig. 1.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4. Summary of Test Method
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard-
4.1 The contact angle test is performed by depositing
ization established in the Decision on Principles for the
droplets of permanganate-distilled water or reagent water in
Development of International Standards, Guides and Recom-
accordance with Specification D1193 on the surface to be
mendations issued by the World Trade Organization Technical
tested using a mounted hypodermic syringe, said droplets
Barriers to Trade (TBT) Committee.
being deposited in such a way, as described herein, as to
measure the equilibrium contact angle. The measurements
2. Referenced Documents
shall be made by either of these two well-known methods: (1)
2.1 ASTM Standards:
viewing the sessile drop through a comparator microscope
D1193Specification for Reagent Water
fitted with a goniometer scale with direct measurement of the
angle, or (2) photographing the sessile drop and measuring the
3. Terminology anglewithaprotractor.Theinterpretationofthemeasurements
is based on the fact that organic contamination on surfaces
3.1 Definitions:
results in contact angles appreciably higher than the near-zero
3.1.1 equilibrium contact angle, n—the angle observable
angles measured on clean surfaces or those contaminated by
immediately after a liquid droplet is increased in size.
hydrophilic materials.
5. Significance and Use
This test method is under the jurisdiction of ASTM Committee C14 on Glass
and Glass Products and is the direct responsibility of Subcommittee C14.02 on
5.1 Thecontactangletestisnondestructiveandmaybeused
Chemical Properties and Analysis.
for control and evaluation of processes for the removal of
Current edition approved Oct. 1, 2020. Published November 2020. Originally
hydrophobic contaminants. The test may also be used for the
approved in 1975. Last previous edition approved in 2014 as C813–90(2014).
DOI: 10.1520/C0813-20.
detection and control of hydrophobic contaminants in process-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ing ambients. For this application, a surface free of hydropho-
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
bic films is exposed to the ambient conditions and is subse-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. quently tested.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C813 − 20
9. Calibration and Standardization
9.1 Contactanglesofwateroncleanpolytetrafluoroethylene
shall be measured to familiarize the operator with the test and
serveasacheckontheequipmentandtechniques.Equilibrium
angles on polytetrafluoroethylene vary from 108 to 125°,
depending on the particular type of this high polymer used.
10. Procedure
10.1 Randomlyselectatleasttwositeswheremeasurements
FIG. 1 Schematic Diagram Indicating Measurement of Contact
will be made on the test surface. Bring the syringe needle into
Angle
close proximity to the test surface and, with the test surface in
a horizontal position, manipulate the hypodermic syringe so as
to force a drop having a volume of 0.02 to 0.05 mL onto the
surface to give an equilibrium contact angle (Note 1). The
6.
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C813 − 90 (Reapproved 2014) C813 − 20
Standard Test Method for
Hydrophobic Contamination on Glass by Contact Angle
Measurement
This standard is issued under the fixed designation C813; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the detection of hydrophobic contamination on glass surfaces by means of contact angle
measurements. When properly conducted, thethis test method will enable detection of fractions of monomolecular layers of
hydrophobic organic contaminants. Very rough or porous surfaces may significantly decrease the sensitivity of the test.this test
method.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 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.
2. Referenced Documents
2.1 ASTM Standards:
D1193 Specification for Reagent Water
3. Terminology
3.1 Definitions:
3.1.1 advancing angle—equilibrium contact angle, n—the largest angle observable when immediately after a liquid droplet is
increased in size.
3.1.2 hydrophilic—hydrophilic, adj—having a strong affinity for water; wettable.
3.1.2.1 Discussion—
Hydrophilic Perfectly hydrophilic surfaces exhibit zero contact angles.
3.1.3 hydrophobic—hydrophobic, adj—having little affinity for water; nonwettable.
This test method is under the jurisdiction of ASTM Committee C14 on Glass and Glass Products and is the direct responsibility of Subcommittee C14.02 on Chemical
Properties and Analysis.
Current edition approved Oct. 1, 2014Oct. 1, 2020. Published October 2014November 2020. Originally approved in 1975. Last previous edition approved in 20092014
as C813 – 90 (2009).(2014). DOI: 10.1520/C0813-90R14.10.1520/C0813-20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C813 − 20
3.1.3.1 Discussion—
Hydrophobic surfaces exhibit contact angles appreciably greater than zero: generallyzero (generally greater than 45° for the
advancing angle.equilibrium angle).
3.1.4 receding angle—angle, n—the smallest angle observable when a liquid droplet is decreased in size.
3.1.5 sessile drop—drop, n—a drop of liquid sitting on the upper side of a horizontal surface.
3.1.5.1 Discussion—
See Fig. 1.
4. Summary of Test Method
4.1 The contact angle test is performed by depositing droplets of permanganate-distilled water or reagent water in accordance with
Specification D1193 on the surface to be tested using a mounted hypodermic syringe, said droplets being deposited in such a way,
as described herein, as to measure the advancingequilibrium contact angle. The measurements shall be made by either of these two
well-known methods: (1) viewing the sessile drop through a comparator microscope fitted with a goniometer scale with direct
measurement of the angle;angle, or (2) photographing the sessile drop and measuring the angle with a protractor. The interpretation
of the measurements is based on the fact that organic contamination on surfaces results in contact angles appreciably higher than
the near-zero angles measured on clean surfaces or those contaminated by hydrophilic materials.
5. Significance and Use
5.1 The contact angle test is nondestructive and may be used for control and evaluation of processes for the removal of
hydrophobic contaminants. The test may also be used for the detection and control of hydrophobic contaminants in processing
ambients. For this application, a surface free of hydrophobic films is exposed to the ambient conditions and is subsequently tested.
6. Interferences
6.1 Loss of sensitivity may result from either of the following factors:
6.1.1 The presence of hydrophilic substances such as remnant cleaning detergent on the surface to be tested, or in the water used
for the test, or
6.1.2 An unusually rough or porous surface.
7. Apparatus
7.1 Low-PowerLow-power Comparator Microscope (5×(5 to 50×),with goniometer scale and light source for illumination of small
drops.
7.2 Camera, that can take photographs of the drop if this alternative method is used.
7.3 Protractor, to measure the angle if the alternative method is used.
FIG. 1 Schematic Diagram Indicating Measurement of Contact Angle
C813 − 20
...