SI-ATRP on the lab bench: A facile recipe for oxygen-tolerant PDMAEMA brushes synthesis using microliter volumes of reagents

Abstract

Facile, low-cost, and environmentally friendly procedures for the synthesis of hybrid materials are highly desirable for industrial applications and large-scale synthesis. To meet these needs, this paper presents an ultra-simple, organic solvent-free and yet effective method for the synthesis of hybrid materials consisting of an inorganic core and an organic layer of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) brushes. Bearing in mind the numerous works published in recent years on the synthesis of PDMAEMA via “normal” and low ppm ATRP using additional reductants or complicated and expensive apparatus, e.g. a photoreactor or potentiostat, this article is a step forward, reducing the costs of the process and increasing the safety of the experimenter. In order to develop the title “facile recipe” a series of reactions aimed at optimizing the synthesis conditions in which the monomer plays a dual role and participates simultaneously as a reducing agent according to the activators regenerated by electron transfer (ARGET) atom transfer radical polymerizations (ATRP) were carried out. As a result, an in-depth analysis of the synthesis conditions and the influence of the presence of oxygen allowed the development of a monomer-mediated ATRP procedure inspired by the principles of green chemistry. Finally, 30 ppm of Cu II Br 2 /TPMA (where TPMA: tris(2-pyridylmethyl)amine) and 20 μl/cm 2 of the reaction mixture were used to obtain a homogeneous polymeric brush layer with the thickness of 331 nm, which was revealed by atomic force microscopy (AFM) measurements. Additionally, the presence and composition of the obtained polymer brushes were confirmed by X-ray photoelectron spectroscopy (XPS) analyses and scanning electron microscope (SEM) with imaging of elemental composition on the decorated silicon surface. • Ultra-simple technique of ATRP was developed due to reducing properties of DMAEMA. • Oxygen-toletant SI-ATRP can be carried out directly on the lab bench. • 20 μL of reaction mixure as suffice to graft PDMAEMA brushes up to 330 nm. • Green procedure for PDMAEMA synthesis with application only 30 ppm Cu II Br 2 /TPMA.