ASTM C813-90(2004)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:C813–90(Reapproved 2004)
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 3.1.5.1 Discussion—See Fig. 1.
1.1 This test method covers the detection of hydrophobic
4. Summary of Test Method
contamination on glass surfaces by means of contact angle
4.1 The contact angle test is performed by depositing
measurements. When properly conducted, the test will enable
droplets of permanganate-distilled water or reagent water in
detection of fractions of monomolecular layers of hydrophobic
accordance with Specification D1193 on the surface to be
organic contaminants. Very rough or porous surfaces may
tested using a mounted hypodermic syringe, said droplets
significantly decrease the sensitivity of the test.
being deposited in such a way, as described herein, as to
1.2 This standard does not purport to address all of the
measure the advancing contact angle. The measurements shall
safety concerns, if any, associated with its use. It is the
be made by either of these two well-known methods: (1)
responsibility of the user of this standard to establish appro-
viewing the sessile drop through a comparator microscope
priate safety and health practices and determine the applica-
fitted with a goniometer scale with direct measurement of the
bility of regulatory limitations prior to use.
angle; or (2) photographing the sessile drop and measuring the
2. Referenced Documents angle with a protractor.The interpretation of the measurements
is based on the fact that organic contamination on surfaces
2.1 ASTM Standards:
results in contact angles appreciably higher than the near-zero
D1193 Specification for Reagent Water
angles measured on clean surfaces or those contaminated by
3. Terminology
hydrophilic materials.
3.1 Definitions:
5. Significance and Use
3.1.1 advancing angle—thelargestangleobservablewhena
5.1 Thecontactangletestisnondestructiveandmaybeused
liquid droplet is increased in size.
for control and evaluation of processes for the removal of
3.1.2 hydrophilic—having a strong affinity for water; wet-
hydrophobic contaminants. The test may also be used for the
table.
detection and control of hydrophobic contaminants in process-
3.1.2.1 Discussion—Hydrophilic surfaces exhibit zero con-
ing ambients. For this application, a surface free of hydropho-
tact angles.
bic films is exposed to the ambient conditions and is subse-
3.1.3 hydrophobic—having little affinity for water; nonwet-
quently tested.
table.
3.1.3.1 Discussion—Hydrophobic surfaces exhibit contact
6. Interferences
anglesappreciablygreaterthanzero:generallygreaterthan45°
6.1 Loss of sensitivity may result from either of the follow-
for the advancing angle.
ing factors:
3.1.4 receding angle—the smallest angle observable when a
6.1.1 The presence of hydrophilic substances on the surface
liquid droplet is decreased in size.
to be tested, or in the water used for the test, or
3.1.5 sessile drop—a drop of liquid sitting on the upper side
6.1.2 An unusually rough or porous surface.
of a horizontal surface.
7. Apparatus
This test method is under the jurisdiction of ASTM Committee C14 on Glass
7.1 Low-Power Comparator Microscope (53 to
and Glass Products and is the direct responsibility of Subcommittee C14.02 on
503), with goniometer scale and light source for illumination
Chemical Properties and Analysis.
of small drops.
Current edition approved Oct. 1, 2004. Published October 2004. Originally
approved in 1975. Last previous edition approved in 1999 as C813 – 90 (1999).
7.2 Camera, that can take photographs of the drop if this
DOI: 10.1520/C0813-90R04.
alternative method is used.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
7.3 Protractor, to measure the angle if the alternative
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on method is used.
the ASTM website.
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C813–90 (2004)
to force a drop having a volume of 0.02 to 0.05 mL onto the
surface to give an advancing angle (Note 1).The needle should
remain immersed in the drop and should be centered in the
drop. Care must be taken that when the syringe plunger is
releasednomotionisimpartedtotheplungersoastocauseany
retraction of the drop. Any retraction will cause the contact
angle to be less than the true advancing
...