Surface energy values usually have the units of mJ/m 2. Some sources quote the critical surface tension in units of mN/m, which is equivalent to surface energy. The surface energy values of some typical materials are shown in the two tables. The first table shows values for low and high surface energy solid materials, whilst the second table shows values for the liquids used in contact angle measurements that are used to determine surface energies.
There are various methods for obtaining surface energy values and there can be some variation in the values determined, dependent on the method used. This variation reflects the genuine difficulties that exist in performing these types of measurement, and this topic is still an area of active research as greater levels of understanding are sought.
Table of surface energy values of solid materials
| Material type | Surface energy (mJ/m 2), γS (Experimental, estimate * or theoretical † .) |
|---|
| Low energy surfaces - plastics, rubber and composites |
Polyhexafluoropropylene
Polytetrafluoroetylene - PTFE
Poly(vinylidene fluoride) - PVF
Poly(chlorotrifluoroethylene)
Polyethylene - PE
Polypropylene - PP
Poly(methylmethacrylate) - PMMA
Polystyrene - PS
Polyamide - PA, Nylon-6,6
Poly(vinylchloride) - PVC
Poly(vinylidene chloride)
Poly(ethylene terephthalate)
Epoxy - typical rubber toughened
Epoxy - typical amine-cured
Phenol-resorcinol resin
Urea-formaldehyde resin
Styrene-butadiene rubber
Acrylonitrile-butadiene rubber
Carbon fibre reinforced plastic (CFRP) abraded |
12.4
19.1
30.3
33.5
32.4
33 (*)
40.2
40.6
41.4
41.5
45.0
45.1
45.5
46.2
52 (*)
61 (*)
29.1
36.0
58.0 |
| High energy surfaces - metals, oxides and ceramics |
Aluminium oxide (Al 2O 3) - anodised
Aluminium oxide (Al 2O 3) - sapphire
Berylium oxide (BeO)
Copper
Graphite
Iron oxide (Fe 2O 3)
Lead
Mercury
Mica
Nickel
Platinum
Silicon dioxide - silica
Silver |
169
638
1107 ( † )
1360 ( † )
1250 ( † )
1357 ( † )
442 ( † )
319 ( † )
120
1770 ( † )
2672
287
890 ( † ) |
Source of information: 'Adhesion & Adhesives - Science & Technology', A J Kinloch, Chapman & Hall, London, 1987.
Table of surface energy values of liquids used for surface energy measurements
| Liquid | Surface energy (mJ/m 2) γLV |
|---|
Hexane
Octane
Decane
Dedecane
Tetradecane
Hexadecane
2-Ethoxyethanol
Polyglycol 15-200
Polyglycol E-200
Dimethylformamide
Pyridine
Tricresylphosphate
Dimethylsulphoxie
1-Bromonaphthalene
Ethan-1,2-diol
Di-iodomethane
Formamide
Glycerol
Water |
18.4
21.8
23.9
25.4
26.7
27.6
28.6
36.6
43.5
37.3
38.0
40.7
43.6
44.6
48.3
50.8
58.3
64.0
72.2 |
Source of information: 'Adhesion & Adhesives - Science & Technology', A J Kinloch, Chapman & Hall, London, 1987
Further information
For assistance with this technology please contact us.