Surface-initiated ATRP was performed as previously
described29 (link) with slight modifications.
Solvents were degassed by sonication (5 min) and argon bubbling for
30 min. Reactants were kept under argon atmosphere during all steps.
A mixture of 41.0 mg of 2,2-bipyridyl and 12.1 mg of a Cu(I)Cl/Cu(II)Cl2 (9/1) mixture was prepared in a glovebox under argon atmosphere,
dissolved in 5.25 mL of isopropanol/Milli-Q (1/4), and stirred for
15 min. Using argon-flushed needles, 2 mL of the resulting brown solution
(containing 0.1 mmol (1 equiv) bipyridyl and 0.045 mmol (0.45 equiv)
copper mix) was then transferred to a Schlenk flask containing 731
mg (2.5 mmol, 25 equiv) of the 3-((3-methacrylamidopropyl)dimethylammonio)propane-1-sulfonate
(SB) monomer. This mixture was stirred for 15 min or until full solubilization
of the SB monomer. Meanwhile, the required amount of initiator-functionalized
beads was bubbled with argon for 10 min in a total volume of 1 mL
of degassed isopropanol/Milli-Q (1/4). The monomer-containing solution
was then transferred (2 mL) to the beads to a final volume of 3 mL.
The polymerization reaction was carried out for 1 min at RT, while
shaking by hand to ensure proper dispersion of the beads. The reaction
was stopped by pouring the solution into an Erlenmeyer flask and adding
Milli-Q while swirling, until the solution turned blue. The blue color
indicates the oxidation, and thereby inactivation, of the copper catalyst,
which hence stops the polymerization reaction. The pSB-coated beads
were collected using a magnet and washed two times with isopropanol/Milli-Q
(1/4), twice with phosphate-buffered saline (PBS), and twice with
Milli-Q.
described29 (link) with slight modifications.
Solvents were degassed by sonication (5 min) and argon bubbling for
30 min. Reactants were kept under argon atmosphere during all steps.
A mixture of 41.0 mg of 2,2-bipyridyl and 12.1 mg of a Cu(I)Cl/Cu(II)Cl2 (9/1) mixture was prepared in a glovebox under argon atmosphere,
dissolved in 5.25 mL of isopropanol/Milli-Q (1/4), and stirred for
15 min. Using argon-flushed needles, 2 mL of the resulting brown solution
(containing 0.1 mmol (1 equiv) bipyridyl and 0.045 mmol (0.45 equiv)
copper mix) was then transferred to a Schlenk flask containing 731
mg (2.5 mmol, 25 equiv) of the 3-((3-methacrylamidopropyl)dimethylammonio)propane-1-sulfonate
(SB) monomer. This mixture was stirred for 15 min or until full solubilization
of the SB monomer. Meanwhile, the required amount of initiator-functionalized
beads was bubbled with argon for 10 min in a total volume of 1 mL
of degassed isopropanol/Milli-Q (1/4). The monomer-containing solution
was then transferred (2 mL) to the beads to a final volume of 3 mL.
The polymerization reaction was carried out for 1 min at RT, while
shaking by hand to ensure proper dispersion of the beads. The reaction
was stopped by pouring the solution into an Erlenmeyer flask and adding
Milli-Q while swirling, until the solution turned blue. The blue color
indicates the oxidation, and thereby inactivation, of the copper catalyst,
which hence stops the polymerization reaction. The pSB-coated beads
were collected using a magnet and washed two times with isopropanol/Milli-Q
(1/4), twice with phosphate-buffered saline (PBS), and twice with
Milli-Q.
