Facile synthesis of histidine functional poly(N-isopropylacrylamide): zwitterionic and temperature responsive materials

Abstract

Reductive amination facilitates the protecting group free post-polymerization functionalisation of a temperature responsive, aldehyde-containing polymer with histidine.

Spatial control of flocculation via light

“…[5][6][7] In this study, we present a highly efficient photoinitiated flocculation system formed through the trapping of a photogenerated thiobenzaldehyde with polyethylenimines (PEIs). The photocontrolled flocculation has been further demonstrated in the removal of Cu 21 .…”

“…1(a)]. 21 There are primary, secondary, and tertiary amine groups in PEI. It is well known the tertiary amine does not form imine.…”

“…22 The monosubstituted phenyl group displays a strong aromatic CAH vibration band at 752 cm 21 while the p-disubstituted phenyl group shows a strong aromatic CAH vibration band at 820 cm 21 which are characteristic to mono-and disubstituted phenyl groups. It should be noted that the reaction of PEI with thiobenzaldehyde generated from 1 does not form any floc.…”

“…To further investigate the flocculation process, the micro structures of the floc with and without Cu 21 were studied with TEM [ Fig. 4(c-e)].…”

“…There are particles observed in the polymer matrix in Figure 4(d) which have diameters of 20-40 nm. The complex of PEI and Cu 21 was also subjected to the photoinitiated flocculation process with 2. The large flocculation precipitate showed bulky aggregates which were attributed to the coordination network as well as the crosslinked imine network [ Fig.…”