| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2014) | |
| Biomaterial Interfaces | Tuesday Sessions |
| Session BI-TuM |
| Session: | Biomaterial & Wet Interface Characterization |
| Presenter: | Zihua Zhu, Pacific Northwest National Laboratory |
| Authors: | Z. Zhu, Pacific Northwest National Laboratory X. Yu, Pacific Northwest National Laboratory Z. Wang, Pacific Northwest National Laboratory B. Liu, Pacific Northwest National Laboratory X. Hua, Pacific Northwest National Laboratory L. Yang, Pacific Northwest National Laboratory M. Marshall, Pacific Northwest National Laboratory S. Thevuthasan, Pacific Northwest National Laboratory J. Cowin, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
In-situ analysis of liquid interfaces using ToF-SIMS is challenging because ToF-SIMS is a high-vacuum technique, but liquids often generate some considerable vapor pressure. For example, the vapor pressure of water is about 20 kPa at room temperature (20 °C), thus handling samples containing water in vacuum is not easily done. We recently developed a self-contained microfluidic device for probing aqueous surfaces and demonstrated its feasibility in ToF-SIMS and SEM.[1,2] The key feature of this device is a small round aperture with a diameter of 2-3 microns, which is opened on top of a microfluidic channel. The aperture is exposed to vacuum and serves as a detection window for ToF-SIMS measurements. Our calculations and experimental data show that vacuum compatibility and possible temperature drop due to water vaporization under vacuum can be well-controlled.Performance of the microfluidic device for in situ ToF-SIMS analysis of selected organic molecules at aqueous surfaces has been tested.[3] This new innovation has been used in in-situ study of mechanism of biofilm growth[4] and electrochemical reactions[5] that occur at liquid-solid interfaces. Such in-situ chemical information at liquid-solid interfaces is very difficult to be obtained using other techniques.
[1] L. Yang, X. Y. Yu, Z. Zhu, M. J. Iedema, J. P. Cowin, Lab Chip, 2011, 11, 2481-2484.
[2] L. Yang, X. Y. Yu, Z. Zhu, S. Thevuthasan, J. P. Cowin, J. Vac. Sci. Technol. A, 2011, 29(6), 061101.
[3] L. Yang, Z. Zhu, X. Y. Yu, S. Thevuthasan, J. P. Cowin, Anal. Methods, 2013, 5, 2515.
[4] X. Hua, X. Y. Yu, Z. Wang, L. Yang, B. Liu, Z. Zhu, A. E. Tucker, W. B. Chrisler, E. A. Hill, S. Thevuthasan, Y. Lin, S. Liu, and M. J. Marshall, Analyst, 2014, 139, 1609.
[5] B. Liu, X. Y. Yu, Z. Zhu, X. Hua, L. Yang, Z. Wang, Lab Chip, 2014, 14, 855.