| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2016) | |
| Energy Harvesting & Storage | Monday Sessions |
| Session EH-MoM |
| Session: | Surfaces & Interfaces for Environmental Processes |
| Presenter: | Hyung-Jun Koo, Seoul National Univeristy of Science and Technology, Republic of Korea |
| Authors: | H.-J. Koo, Seoul National Univeristy of Science and Technology, Republic of Korea P.V. Braun, University of Illinois at Urbana-Champaign, USA K.V. Waynant, University of idaho, USA C. Zhang, University of Illinois at Urbana-Champaign, USA |
| Correspondent: | Click to Email |
Surfaces containing defined microscale chemical gradients are important for various applications including a sample library with an extremely dense variable set and a smart platform to direct 2D-molecular transport. In this regard, reliable methods to form mili- to micron-scale chemical gradients are required. We present two facile microfluidic methods to form narrow surface chemical gradients in a tertiary amine functionalized polymer brush via a selective quaternization. Two methods are on the basis of different physical mechanisms: permeation into porous media vs. diffusion at liquid/liquid laminar interface. Concentration and separation as well as directional transport driven by surface-gradient on highly hydrated polymer films will be also demonstrated. Such a new concept to control 2D transport of molecules could generally be applied for signal enhancement in chemical sensors to detect tiny amount of harmful molecules, e.g., pollutants, toxins, etc..
References:
1. H.-J. Koo, K. V. Waynant, C. Zhang, R. T. Haasch, P. V. Braun, “General Method for Forming Micrometer-Scale Lateral Chemical Gradients in Polymer Brushes”, Chemistry of Materials, 26, 2678 (2014).
2. H.-J. Koo, K. V. Waynant, C. Zhang, P. V. Braun, “Polymer Brushes Patterned with Micrometer-Scale Chemical Gradients using Laminar Co-Flow”, ACS Applied Materials & Interfaces, 6, 14320 (2014).
3. C. Zhang, A. Sitt, H.-J. Koo, K. V. Waynant, H. Hess, B. D. Pate and P. V. Braun, “Autonomic molecular transport using hydrogel films containing programmed chemical potential gradients”, Journal of the American Chemical Society, 137, 5066 (2015)