Alcohols, C12-15, ethoxylated

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

not available

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

no guideline followed

Principles of method if other than guideline:

Measuring surface tension using a handheld tensiometer (SITA on-line t60). This tensiometer measures the dynamic surface tension up to the semi-static range. The device works by measuring bubble pressure. This is accomplished by pumping air through a capillary with a radius r, into the liquid to be analysed. According to Young-Laplace, the difference in pressure ¿p, which is needed to form a bubble, is proportional to the surface tension s. The device measures the difference in pressure ¿p and transforms it into a reading of surface tension. The formula for this is (s = ¿p*r/2). Simultaneously, the tenisometer records the bubble frequency, the lifetime of the bubbles and the temperature of the liquid. The surface tension value obtained at the longest bubble rate is recorded as the surface tension for that sample at a temperature of 20 +/- 0.5 °C.Although not actually the equilibrium value, the surface tension at a slow bubble rate would be only slightly higher than the true equilibrium value and would provide assurance that the equilibrium value was under the surface tension limit for classification according the Shell guidelines.

GLP compliance:

no

Type of method:

other: henadheld tensionmeter, measuring bubble pressure

Surface tension:

21.9 - 28.8 other: dynes/cm

Temp.:

20 °C

Conc.:

0.5 vol%

The substance is surface active.

Conclusions:

Surface active

Description of key information

21.9 - 28.8 dynes/cm at 20 °C, concentration = 0.5% vol.

Additional information

Surface active