Aromatic block copolymer ligand sensitized lanthanide nanostructures as ratiometric fluorescence probe for determination of residual K2CO3 in super engineering thermoplastics

Abstract

• An aromatic amphiphilic block copolymer named of D5S5 was synthesized. • D5S5 was self-assembled with Tb 3+ and Rhodamine B to obtain nanoprobe of Tb-D5S5/RB. • Tb-D5S5/RB exhibits pH dependent fluorescence emission in acid and basic solution. • Tb-D5S5/RB shows ratiometric enhanced fluorescence as the increased K 2 CO 3 content. • Tb-D5S5/RB nanoprobe is able to detect residual K 2 CO 3 in super-engineering polymer. The residual catalyst (K 2 CO 3 ) presented in the super engineering polyarylene ethers exerts side effects onto their processability and electrical properties. However, the sensitive and reliable analytical tools, that are able to detect residual K 2 CO 3 content in these high performance thermoplastics, are rarely reported. Herein, we firstly synthesized an aromatic amphiphilic block copolymer bearing pendent carboxyl and sulfonate groups (named as D5S5). Next, a lanthanide ions mediated solvent-exchange self-assembly was explored to fabricate fluorescent metallopolymeric nanospheres composed of D5S5 and Tb 3+ with strong green emission (named as Tb-D5S5). Then, the rhodamine B (RB) dyes were combined with the Tb-D5S5 to obtain the fluorescent probe of Tb-D5S5/RB, which exhibited a ratiometric fluorescence response to K 2 CO 3 . Specifically, the I 545 /I 585 (intensity ratio of two emission bands at 545 nm and 585 nm) of probe linearly increased with the increasing K + concentration of K 2 CO 3 in the range from 0.05 to 7.41 mM. Furthermore, the sensing mechanism of this probe towards K 2 CO 3 was revealed. Finally, the Tb-D5S5/RB probe was employed to determine the residual K 2 CO 3 in a super engineering polyarylene ether produced by an industrial plant, which showed 85.98 %–89.31 % recoveries of the benchmark results obtained from the inductively coupled plasma optical emission spectrometer (ICP-OES).