English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Surface-initiated atom transfer radical polymerization (ATRP) of 2-(tert-butylamino)ethyl methacrylate (TBAEMA) produced pH-responsive secondary amine-functionalized polymer brushes with dry thicknesses ranging from 4 to 28 nm, as determined by ellipsometry. At low pH, linear PTBAEMA brushes became protonated and highly swollen; brush collapse occurred when the solution pH was increased to ca. 7.7 due to deprotonation. PTBAEMA brushes were subsequently cross-linked using tolylene-2,4-diisocyanate-terminated poly(propylene glycol) (PPG-TGI) in either THF (a good solvent for PTBAEMA) or n-hexane (a poor solvent). The intensity of the C-C-O component (286.5 eV) in the C1s X-ray photoelectron spectrum increased after reaction with PPG-TDI, suggesting that cross-linking was successful in both solvents. Ellipsometry studies indicated that the pH-responsive behavior of these cross-linked brushes is dictated by the spatial location of the PPG-TDI cross-linker. Thus, uniformly cross-linked brushes prepared in THF became appreciably less swollen at a given (low) pH than surface-cross-linked brushes prepared in n-hexane. Micro- and nanopatterned PTBAEMA brushes were prepared via UV irradiation and interference lithography, respectively, and characterized by atomic force microscopy. The change in brush height was determined as a function of pH, and these AFM observations correlated closely with the ellipsometric studies.

Spatial Control over Cross-Linking Dictates the pH-Responsive Behavior of Poly(2-(tert-butylamino)ethyl methacrylate) Brushes