Disodium 2,2'-[(9,10-dihydro-5,8-dihydroxy-9,10-dioxo-1,4-anthrylene)diimino]bis[5-tert-butylbenzenesulphonate]

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

November 16, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Deviations:

no

GLP compliance:

no

Type of method:

OECD harmonised ring method

Key result

Surface tension:

< 60 mN/m

Temp.:

20 °C

Conc.:

999.6 mg/L

249.9 mg of the test item were put into 250 mL of de-ionized water and stirred at ambient temperature for 20 h. The test item was completely solved after the stirring period. However, according to project PS20170174-4 the test item was unstable in water. Therefore, it cannot be excluded that the test item was changed during the time of the measurement. After adapting to 20 °C the measurement of the surface tension with the test item was carried out at 20 ±0.5°C (20.3 °C), as follows: The solution to be measured was transferred to the measurement vessel, taking care to avoid foaming. The measurement vessel was placed on the table of the test apparatus. The measurement vessel was raised until the ring was immersed below the surface of the solution. The time from starting the measurement was recorded (see Table1 below ). Subsequently, the table top was lowered gradually and evenly at a rate of 0.3 cm/min to detach the ring from the surface until the maximum force was reached. The force was read on the tensiometer. The measurements were repeated until 6 measurements were within the limits of the stability criterion.

Table1: Surface tension

Measurement	1	2	3	4	5	6
Time (s)	1241	1362	1483	1604	1724	1845
s(mN/m) uncorrected	56.56	56.48	56.42	56.35	56.29	56.26
s(mN/m) corrected according to Zuidema and Waters[1]	51.30	51.21	51.16	51.10	51.03	51.01

Due to the fact that the surface tension of the aqueous solution of the test showed a time-dependence no mean value could be reported. This time dependence could have been caused by the potential instability of the test item in water. However, the surface tension was lower than 60 mN/m, the test item had surface-active properties.

[1]Zuidema, H., Waters, C.W.,Ind. Eng.Chem. Analyt.13 (1941), S. 312

Executive summary:

The surface tension of the aqueous solution at 20 °C was lower than 60 mN/m. The test item had surface-active properties. However, the test item was not stable in water according to project PS20170174-4. Therefore, it might be assumed that not the whole amount of solved test item was present in the original state during the measurement.

Description of key information

The surface tension of the aqueous solution at 20 °C was lower than 60 mN/m. The test item had surface-active properties. However, the test item was not stable in water according to project PS20170174-4. Therefore, it might be assumed that not the whole amount of solved test item was present in the original state during the measurement.