Effect of Carbon Spacer Length on Antifouling Performance of Polyacrylamide-based Brushes

Document Type

Conference Proceeding

Publication Date

Spring 3-16-2014


Antifouling materials with different molecular structures have shown their promising roles in avoiding interactions with biomolecules and in creating benign stealth surfaces for numerous pharmaceutical, biomedical, and industrial applications. Surface hydrations arising from hydrophilic and zwitterionic polymer surfaces appear to be important for antifouling performance. However, the exact relationship among molecular structure, surface hydration property, and antifouling performance still remains elusive. In this work, we have designed, synthesized, and characterized a series of polymer brushes of poly(N-hydroylmethyl acrylamide)(polyHMAA), poly(N-hydroxylethyl acrylamide)(polyHEAA), and poly(N-hyroxylpropyl acrylamide)(polyHPAA) using surface-initiated ATRP method. HMAA, HEAA, and HPAA monomers contain one, two, and three methylene groups between hydroxyl and amide groups, respectively, while the other groups in polymer backbones are all the same to each other. Such subtle structural differences induced by carbon spacer length and their effects on surface hydration and antifouling performance are systematically studied by combined experimental and computational methods including sum frequency generation (SFG) spectroscopy, surface plasmon resonance sensors (SPR), and molecular dynamic (MD) simulations. Film thickness is also optimized to achieve the best antifouling performance for each distinct polymer brush. Preliminary results have shown that polyHEAA brushes appear to exhibit the better antifouling performance than the other two polymer brushes. MD simulations further reveal hydration differences (i.e. hydration free energy, hydrogen bonds between polymer and water, water residence time, local diffusivity, and orientation distribution) among three polymers, confirming a strong effect from carbon spacer length (CSL) on these hydration properties of three polymers. Overall, this work highlights the importance of CSL as a structural factor to optimize the design of effective antifouling materials, and also provide a better fundamental understanding of structural-dependent interfacial interactions between polymers and proteins.

Publication Title

Abstracts of Papers of the American Chemical Society