Tuning the Thermoresponsive Behavior of Surface-Attached PNIPAM Networks: Varying the Crosslinker Content in SI-ATRP
Artikel i vetenskaplig tidskrift, 2021

The synthesis and thermoresponsive properties of surface-attached poly(N-isopropylacrylamide)-co-N,N′-methylene bisacrylamide (PNIPAM-co-MBAM) networks are investigated. The networks are formed via SI-ARGET-ATRP ("grafting-from") on thiol-based initiator-functionalized gold films. This method is reliable, well controlled, fast, and applicable to patterned surfaces (e.g., nanopores) for networks with dry thicknesses >20 nm. Surface-attached PNIPAM-co-MBAM gels are swollen below their volume phase transition temperature but above collapse without complete expulsion of water (retain ∼50 vol %). The swelling/collapse transition is studied using complementary SPR and QCMD techniques. The ratio between swollen and collapsed heights characterizes the thermoresponsive behavior and is shown to not depend on network height but to vary with MBAM content. The higher the proportion of the crosslinker, the lower the magnitude of the phase transition, until all responsiveness is lost at 5 mol % MBAM. The temperature range of the transition is broadened for more crosslinked PNIPAM-co-MBAM gels but remains centered around 32 °C. Upon reswelling, less crosslinked networks display sharp transitions, while for those containing ≥3 mol % MBAM, transitions remain broad. This tunable behavior persists for gels on nanostructured gold surfaces. Investigating PNIPAM-co-MBAM networks on gold plasmonic nanowell arrays is a starting point for expanding their scope as thermo-controlled nanoactuators.

Författare

Sophia Thiele

Student vid Chalmers

John Andersson

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Andreas Dahlin Group

Andreas Dahlin

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Andreas Dahlin Group

Rebekah Hailes

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Andreas Dahlin Group

Langmuir

07437463 (ISSN) 15205827 (eISSN)

Vol. 37 11 3391-3398

Ämneskategorier

Polymerkemi

Fysikalisk kemi

Materialkemi

DOI

10.1021/acs.langmuir.0c03545

PubMed

33719454

Mer information

Senast uppdaterat

2021-04-14