Page 123 - Handbook of Surface Improvement and Modification

118 Surface Tension and Wetting

ink composition and the surface tension remained low during drying of the ink composi-
41
tion.
A sublimation transfer ink to be discharged by an ink jet process contains water, a
42
sublimation dye, and a trehalose. The presence of water allows the viscosity and surface
tension of the sublimation transfer ink to be suitably adjusted to fall within their respective
42
preferred ranges and makes the ink very easy to discharge by an ink jet process. The sur-
face tension modifiers such as anionic, amphoteric, cationic, and nonionic surfactants can
42
also be added. The surface tension (at 25°C) of the sublimation transfer ink should pref-
42
erably be in the range of 20 to 40 mN/m.
The wetting agent comprises a biodegradable surfactant which is present in a solu-
43
tion in water and allows foam to be formed during the electroplating application. The
stability of the foam formed allows the retarded release of the hydrogen that is formed
43
during the galvanic application. This wetting agent is stable to degradation and has no
43
effect on the electroplating application but exhibits good biodegradability. The nonionic
43
43
surfactant is a sugar surfactant. It contains isothiazolinone as a biocide.
Liquids with a surface tension below the critical surface tension of a substrate can
44
wet the substrate surface. Oleic acid was used as a test liquid to verify the anti-finger-
print property of the modified glass surfaces because the surface tension of pure oleic acid
is 31.8 mN/m, which is in a range of the surface tension of human fingerprints (20-50 mN/
m) and comparable to the surface tension of organosilane-modified glass surfaces (20.9-
44
42.5 mN/m). The glass substrates finished with an organooxysilane compound such as a
hybrid of trimethoxymethylsilane and octadecyltrimethoxysilane exhibited significantly
44
high contact angles to prevent fingerprint.
A dry-erase article has a good writing receptivity to dry erase ink and easy removal
45
of dry-erase ink even after a long time between writing and erasing. The writing surface
2 45
has a surface wetting tension of from 30 to 38 mJ/m . An ink has surface tension that is
45
less than the surface energy of the writing surface. The dry erase marker ink contains a
surfactant to reduce the surface tension of ink to less than the surface energy of writing
45
surface. Fluorochemical oligomers suitable for use in dry erase articles of the invention
45
include the commercially available chemicals Fluorad™ FC-4430 and FC-4432.
REFERENCES
1 Abbate dos Santos, F; Bruno Tavares, MI, Polym. Testing, 47, 92-100, 2015.
2 Pesek, SL; Lin, Y-H; Mah, HZ; Kasper, W; Chen, B; Rohde, BJ; Robertson, ML; Stein, GE; Verduzco, R,
Polymer, 98, 495-504, 2016.
3 Taloub, N; Liu., L; Du, Y; Rahoui, N; Huang, Y, Surf. Coat. Technol., 334, 312-8, 2018.
4 Saihi, D; El-Achari, A; Ghenaim, A; Caze, C, Polym. Testing, 21, 615-8, 2002.
5 Hakkou, M; Petrissans, M; Zoulalian, A; Geardin, P, Polym. Deg. Stab., 89, 1-5, 2005.
6 Seo, J; Lee, S; Han, H; Chung, Y; Lee, J; Kim, S-D; Kim, Y-W; Lim, S; Lee, T, Thin Solid Films,
527, 179-85, 2013.
7 Di Nicola, G; Coccia, G; Pierantozzi, M, Fluid Phase Equilibria, 418, 88-93, 2016.
8 Li, M; Xie, J; Dai, Q; Huang, W; Wang, X, J. Mech. Beh. Biomed Mater., 76, 266-72, 2018.
9 Khorasani, MT; Mirzadeh, H; Kermani, Z, Appl. Surf. Sci., 242, 339-45, 2005.
10 Alghunaim, A; Kirdponpattara, S; Newby, B-mZ, Powder Technol., 287, 21-5, 2016.
11 Hou, W; Zhang, L; Long, Y, J. Colloid Interface Sci., 362, 629-32, 2011.
12 Fan, X; Zheng, L; Cheng, J; Xu, S; Wen, X; Cai, Z; Pi, P; Yang, Z, Surf. Coat. Technol., 213, 90-7, 2012.
13 Nakamura, M; Hori, N; Ando, H; Namba, S; Toyama, T; Nishimiya, N; Yamashita, K, Mater. Sci., Eng. C,
62, 283-92, 2016.
14 Spriano, S; Sarath Chandra, VS; Cochis, A; Uberti, F; Rimondini, L; Bertone, E; Vitale, A; Scolaro, C;
Ferrari, M; Cirisano, F; di Confiengo, GG; Ferraris, S, Mater. Sci. Eng. C, 74, 542-55, 2017.