Synthesis and Characterization of Polymer Brushes from PDMS Surfaces
Heqing Huang, Adam J. Nolte, Jun Y. Chung, Christopher Stafford
In recent years, poly(dimethylsiloxane) (PDMS) has found increased application in the areas of microfluidic devices, chromatographic packing materials and membranes, as well as in medical and drug delivery devices. However, the hydrophobic surface of PDMS is normally modified prior to each use especially in aqueous or biological systems to allow wetting of the surface as well as to decrease bio-fouling. In this work, a novel and facile modification scheme based on hydrochloric acid treatment was found to introduce hydroxyl groups to the surface of PDMS, which serve to covalently attach initiator groups for subsequent atom transfer free radical polymerization. These initiator-functionalized PDMS surfaces can then be used to form a wide variety of biocompatible and bioactive polymer brushes In contrast to popular approaches such as ultraviolet/ozone or plasma treatment, the interface between the newly formed polymer brushes and the PDMS substrate is well defined so that wrinkling metrology, attenuated total reflectance infrared (ATR-IR) spectroscopy, and spectroscopic ellipsometry can be used to characterize their mechanical properties and chemical composition. Moreover, we showed that our wrinkling metrology and ATR-IR offer new routes to overcome difficulties associated with thickness measurement of polymer brushes on transparent and flexible substrates. The covalent attachment of the polymer chains to the substrate also enables the wrinkled pattern to be completely reversible (wrinkled/flat) by alternating thermal and solvent treatments. The ability to switch between wrinkled and flat states suggests applications in fields such as biosensors and microfluidics, where surface morphology plays a key role in governing device performance.
American Chemical Society Division of Polymeric Materials: Science and Engineering| |Proceedings of the ACS Division of Polymeric Materials: Science & Engineering |ACS
, Nolte, A.
, Chung, J.
and Stafford, C.
Synthesis and Characterization of Polymer Brushes from PDMS Surfaces, American Chemical Society Division of Polymeric Materials: Science and Engineering| |Proceedings of the ACS Division of Polymeric Materials: Science & Engineering |ACS, New Orleans, LA, US, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=854492
(Accessed June 1, 2023)