N-isopropylmethacrylamide

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental Starting Date: 17 May 2012, Experimental Completion Date: 03 July 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study conducted to GLP and in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not effect the quality of the relevant results.

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Deviations:

yes

Remarks:

The surface tension result was not corrected using the Harkins-Jordan correction table

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Deviations:

yes

Remarks:

The surface tension result was not corrected using the Harkins-Jordan correction table

Principles of method if other than guideline:

The surface tension result was not corrected using the Harkins-Jordan correction table as the correction is not applicable to the apparatus used (a reduced ring circumference of 4 cm was used, whereas the guidelines specify 6 cm). Once calibrated, the balance and ring assembly used in this test give a direct reading for surface tension that is within the required accuracy (± 0.5 mN/m).

GLP compliance:

yes (incl. QA statement)

Type of method:

ring method

Surface tension:

68.2 mN/m

Temp.:

20 °C

Conc.:

1.1 g/L

Remarks on result:

other: The test item was considered not to be surface-active.

Results

Calibration factor

The readings, temperatures and the corresponding calibration factors for glass double-distilled water are shown in the following tables:

Table 3.10– Sample A

 

Reading (mN/m)	Temperature (ºC)	Literature Value (mN/m)	Calibration Factor
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
Mean Calibration Factor = 0.996

Table 3.11– Sample B

Reading (mN/m)	Temperature (ºC)	Literature Value (mN/m)	Calibration Factor
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
73.0	20.0	72.72	0.996
Mean Calibration Factor = 0.996

Sample solution readings

The readings, times and temperatures for the sample solution are shown in the following tables:

Table 3.12– Sample A

Time (mins)	Reading (mN/m)	Temperature (ºC)
66	67.5	20.0
79	67.5	20.0
91	67.5	20.0
108	68.0	20.0
121	68.5	20.0
134	68.5	20.0
146	68.5	20.0
159	68.5	20.0
171	68.5	20.0
Mean sample reading = 68.5 (last 5 readings)

Table 3.13– Sample B

Time (mins)	Reading (mN/m)	Temperature (ºC)
72	67.5	20.0
84	67.5	20.0
100	68.0	20.0
115	68.5	20.0
126	68.5	20.0
140	68.5	20.0
152	68.5	20.0
165	68.5	20.0
Mean sample reading = 68.5 (last 5 readings)

Surface tension:  reading x calibration factor
Sample A: 68.2 mN/m
Sample B: 68.2 mN/m
Mean : 68.2 mN/m
Temperature: 20.0 ± 0.5 ºC
pH of sample solution  :          Sample A = 5.3
                                              Sample B = 5.3

Conclusions:

The surface tension of a 1.1 g/L solution of test item in water has been determined to be 68.2 mN/m at 20.0 ± 0.5 °C. The test item was considered not to be surface-active.

Executive summary:

Surface Tension Method The determination was carried out using a White Electrical Institute Co. Ltd. torsion balance for surface and interfacial tension measurements using a procedure designed to be compatible with Method A5 Surface Tension of Commission Regulation (EC) No 440/2008 of 30 May 2008, Method 115 of the OECD Guidelines for the Testing of Chemicals, 27 July 1995.

          

Discussion

The samples were prepared at a nominal 1.1 g/L, so that when the 8.7 % water contained in the test item was accounted for, this would give a nominal sample concentration of 1.0 g/L based on the main component of the test item.

 

     

Conclusion

The surface tension of a 1.1 g/L solution of test item in water has been determined to be 68.2 mN/m at 20.0 ± 0.5 °C. The test item was considered not to be surface-active.

Description of key information

The surface tension of a 1.1 g/L solution of test item in water has been determined to be 68.2 mN/m at 20.0 ± 0.5 °C. The test item was considered not to be surface-active.

Key value for chemical safety assessment

Surface tension:

68.2

in mN/m at 20°C and concentration in mg/L:

1 100

Additional information

The determination was carried out using a White Electrical Institute Co. Ltd. torsion balance for surface and interfacial tension measurements using a procedure designed to be compatible with Method A5 Surface Tension of Commission Regulation (EC) No 440/2008 of 30 May 2008, Method 115 of the OECD Guidelines for the Testing of Chemicals, 27 July 1995.

          

The samples were prepared at a nominal 1.1 g/L, so that when the 8.7 % water contained in the test item was accounted for, this would give a nominal sample concentration of 1.0 g/L based on the main component of the test item.

The surface tension of a 1.1 g/L solution of test item in water has been determined to be 68.2 mN/m at 20.0 ± 0.5 °C. The test item was considered not to be surface-active.