Simple Colorimetric Method for Quantification of Surface Carboxy Groups on Polymer Particles
Andreas Hennig, Angelika Hoffmann, Heike Borcherding, Thomas Thiele, Uwe Schedler, Ute Resch-Genger
ANALYTICAL CHEMISTRY | AMER CHEMICAL SOC | Published : 2011
We present a novel, simple, and fast colorimetric method to quantify the total number of carboxy groups on polymer microparticle and nanoparticle surfaces. This method exploits that small divalent transition metal cations (M(2+) = Ni(2+), Co(2+), Cd(2+)) are efficiently bound to these surface functional groups, which allows their extraction by a single centrifugation step. Remaining M(2+) in the supernatant is subsequently quantified spectrophotometrically after addition of the metal ion indicator pyrocatechol violet, for which Ni(2+) was identified to be the most suitable transition metal cation. We demonstrate that the difference between added and detected M(2+) is nicely correlated to the..View full abstract
Awarded by Federal Ministry of Economics and Technology
Financial support from the Federal Ministry of Economics and Technology (Grant Number BMWI VI A2-17/03) is gratefully acknowledged.