Surface etching of methacrylic microparticles via basic hydrolysis and introduction of functional groups for click chemistry

Christian Speyerer; Kirsten Borchers; Thomas Hirth; Günter E M Tovar; Achim Weber

doi:10.1016/j.jcis.2013.02.003

Surface etching of methacrylic microparticles via basic hydrolysis and introduction of functional groups for click chemistry

J Colloid Interface Sci. 2013 May 1:397:185-91. doi: 10.1016/j.jcis.2013.02.003. Epub 2013 Feb 13.

Authors

Christian Speyerer¹, Kirsten Borchers, Thomas Hirth, Günter E M Tovar, Achim Weber

Affiliation

¹ Institute for Interfacial Engineering and Plasmatechnology IGVP, University of Stuttgart, Stuttgart, Germany. christian.speyerer@igvt.uni-stuttgart.de

PMID: 23481515
DOI: 10.1016/j.jcis.2013.02.003

Abstract

Controlled basic hydrolysis of poly(methyl methacrylate-co-ethylene glycol dimethacrylate) P(MMA-co-EGDMA) microparticles with a diameter d50=6 μm led to high densities of carboxylic groups at the particles' surface of up to 1.288 μeq g(-1) (equivalent to 1.277 μmol m(-2)). The microparticles' core has not been altered by this surface activation procedure as seen by fluorescent staining. The kinetics of the hydrolysis reaction was investigated via electrophoretic light scattering and particle charge detection employing polycation titration under shear condition. The activated microparticle's surface was subsequently exploited in carbodiimide-mediated coupling reactions using a variety of molecular reactants, that is, 11-azido-3,6,9-trioxaundecan-1-amine, cysteamine, propargylamine, and fluoresceinamine, thus enabling the introduction of chemically reactive moieties such as azides, thiols, and alkynes. Fluorescent staining of the particles' surface successfully demonstrated the versatile applications of surface functionalized microparticles via copper-catalyzed huisgen cycloaddition. Carrying on this two-step procedure in a controlled manner provides an excellent way for relatively simple but highly effective surface functionalization.