Applying the Langmuir-Blodgett Technique to a Well Defined Model Detergent System

Abstract

The Langmuir-Blodgett technique is used to obtain a well defined model detergent system. Spreading monolayers of arachidic acid as a model organic contaminant are transferred onto glass plates untreated and treated with two silane coupling agents, γ-aminopropyltriethoxysilane (APTES) and methyltriethoxysilane (MTES). Brewster angle microscopic images show that the LB films of arachidic acid are uniformly deposited on the substrate. Glass plates with the LB films are ultrasonically washed in various aqueous solutions, and the detergency is evaluated from the change in FTIR spectra of the substrate due to washing. The efficiency of detergency decreases as a result of the silanization of glass, especially for the APTES treated glass. The wettability and the surface charge of the substrate play important roles in the detergency, suggesting that the LB films of arachidic acid are removed directly from the substrate. Removal of LB films from the APTES-treated glass increases with increasing surfactant or ethanol concentration, and the removal rate strongly depends on temperature. As a removal technique without washing liquids, exposure of the substrates with LB films to 172 nm ultraviolet light is also attempted.

Get full access to this article

View all access options for this article.

References

1. Adam, N. K., “The Physics and Chemistry of Surfaces,” Dover, NY, 1968, pp. 43-51.

2. Beg, K. H. , Analysis of Skin Oils from Soiled Clothing, Am. Perfume Cosmet. 79, 35–42 (1964).

3. DeArmond, M. K. , Samha, H. , and Dvorak, O. , Incorporation of Metal Complex from the Subphase into a Fatty Acid Langmuir-Blodgett Film, Langmuir 1994, 343–344 (1994).

4. Gotoh, K. , Tao, J. , and Tagawa, M. , Adhesion Interaction in Water/ n-alcohol Mixtures between Silanized Silica and Polymer Particles, J. Adhes. Sci. Technol. 13, 1307–1320 (1999).

5. Gotoh, K. , Tao, J. , and Tagawa, M. , Acid-base Interaction in Adhesion of Polymer Particles to Silanized Silica in Water/n-alcohol Mixtures, in “Acid-Base Reactions: Relevance to Adhesion Science and Technology, Vol. 2,” K. L. Mittal , Ed., VSP, Utrecht, The Netherlands, 2000, pp. 539–550.

6. Gotoh, K. , Yoshimitu, S. , and Tagawa, M. , Wettability of Fibrous Quartz with Langmuir-Blodgett Films of Arachidic Acid and/or Cellulose Didecanoate, J. Adhes. Sci. Technol. 10, 1129–1140 (1996).

7. Hann, R. A. , “Langmuir-Blodgett Films,” Ed., G. Robert , Plenum Press, NY, 1990, pp. 17–92.

8. Hasegawa, T. , Umemura, J. , and Takenaka, T. , Infrared External Reflection Study of Molecular Orientation in Thin Langmuir-Blodgett Films, J. Phys. Chem. 97, 9009–9012 (1993).

9. Honig, D. , and Mobius, D. , Direct Visualization of Monolayers at the Air-water Interface by Brewster Angle Microscopy, J. Phys. Chem. 95, 4590–4592 (1991).

10.

10. Ishii, S., et al., “The Chemical Handbook I,” M. Ohki et al., Ed., Maruzen, Tokyo, 1993, p. 254.

11.

11. Manahan, S. E. , “Environmental Chemistry,” CRC Press Inc., Boca Raton, FL, 1994, pp. 783–784.

12.

12. Song, Q. , and Netravali, A. N. , Excimer Laser Surface Modification of Ultra-high-strength Polyethylene Fibers for Enhanced Adhesion with Epoxy Resins, Part 1: Effect of Laser Operation Parameters, J. Adhes. Sci. Technol. 9, 957–982 (1998).