Controlling dispersion, stability and polymer content on PDEGMA-functionalized core-brush silica colloids

CINTIA BELÉN CONTRERAS; MARIA JAZMÍN PENELAS; JUAN GIUSSI; ALEJANDRO WOLOSIUK; OMAR AZZARONI; GALO SOLER ILLIA

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2019

0927-7757

Core-brush hybrid nanoparticles containing PEG surface functions are highly interesting as biologically inert and smart stimuli-responsive materials for applications in biosensors, drug delivery, tissue engineering and optical systems. In this context, surface modification methodologies are critical to exert a thorough control of morphological and functional aspects such as grafting density, polymer conformation or colloidal dispersability. In this work, we present a study on the synthesis routes of hybrid SiO2 colloids functionalized with an oligo(ethyleneglycol)-based polymer. Di(ethylene glycol) methyl ether methacrylate (DEGMA) was successfully grafted using the grafting-from approach. In particular, we compared DEGMA grafting on SiO2 particlesusing three pathways. Route 1 and 2 correspond to surface-initiated atom radical polymerization (SI-ATRP), while pathway 3 consists in a photo-grafting polymerization. The polymer density grafted on the SiO2 surface, as well as the dispersion and stability of the core-brush particles were investigated. We demonstrate that although all the methodologies were successful in immobilizing the PDEGMA on the surface, selection of the synthetic route is key to control crucial characteristics of core-brush NPs: grafted polymer density, dispersion and colloidal stability. The accurate control of these critical features through the synthesis pathway is of great importance for the performance of these novel materials.