Regio -selective peroxybromination of poly(vinyl methyl ketone) as versatile tool for generation active ATRP initiation sites on solid surfaces

Surface-Initiated Controlled Radical Polymerization: State-of-the-Art, Opportunities, and Challenges in Surface and Interface Engineering with Polymer Brushes

The generation of polymer brushes by surface-initiated controlled radical polymerization (SI-CRP) techniques has become a powerful approach to tailor the chemical and physical properties of interfaces and has given rise to great advances in surface and interface engineering. Polymer brushes are defined as thin polymer films in which the individual polymer chains are tethered by one chain end to a solid interface. Significant advances have been made over the past years in the field of polymer brushes. This includes novel developments in SI-CRP, as well as the emergence of novel applications such as catalysis, electronics, nanomaterial synthesis and biosensing. Additionally, polymer brushes prepared via SI-CRP have been utilized to modify the surface of novel substrates such as natural fibers, polymer nanofibers, mesoporous materials, graphene, viruses and protein nanoparticles. The last years have also seen exciting advances in the chemical and physical characterization of polymer brushes, as well as an ever increasing set of computational and simulation tools that allow understanding and predictions of these surface-grafted polymer architectures. The aim of this contribution is to provide a comprehensive review that critically assesses recent advances in the field and highlights the opportunities and challenges for future work.

Free-Radical-Induced Grafting from Plasma Polymer Surfaces

With the advances in science and engineering in the second part of the 20th century, emerging plasma-based technologies continuously find increasing applications in the domain of polymer chemistry, among others. Plasma technologies are predominantly used in two different ways: for the treatment of polymer substrates by a reactive or inert gas aiming at a specific surface functionalization or for the synthesis of a plasma polymer with a unique set of properties from an organic or mixed organic-inorganic precursor. Plasma polymer films (PPFs), often deposited by plasma-enhanced chemical vapor deposition (PECVD), currently attract a great deal of attention. Such films are widely used in various fields for the coating of solid substrates, including membranes, semiconductors, metals, textiles, and polymers, because of a combination of interesting properties such as excellent adhesion, highly cross-linked structures, and the possibility of tuning properties by simply varying the precursor and/or the synthesis parameters. Among the many appealing features of plasma-synthesized and -treated polymers, a highly reactive surface, rich in free radicals arising from deposition/treatment specifics, offers a particular advantage. When handled carefully, these reactive free radicals open doors to the controllable surface functionalization of materials without affecting their bulk properties. The goal of this review is to illustrate the increasing application of plasma-based technologies for tuning the surface properties of polymers, principally through free-radical chemistry.

A facile method for generating Michael acceptor thin films via amine substituted poly(vinyl methyl ketone)

Alpha-morpholine substituted poly(vinyl methyl ketone) (PVMK) was determined to undergo rapid self-crosslinking by short-term vacuuming (i.e., 30–60 min) or curing at 70–100 °C. The chemical transformations involved were monitored by TGA, DSC, FT-IR, 1HNMR and solid-state 13C NMR techniques. These experiments revealed an “unzipping-like” mechanism yielding multi conjugated enone structure via consecutive deamination by β-hydrogen elimination and simultaneous Diels–Alder cyclization resulting in crosslinking. This chemistry was exploited for generating Michael acceptor thin film coatings on silica nanoparticles, in which the silica was impregnated with morpholine substituted poly(vinyl methyl ketone) and simply heated at 100 °C. The dense polyene functional films so formed were demonstrated to add amines and thiols at room temperature. The resulting silica nanoparticles were employed to form homogenous composite films using poly(butyl acrylate-stat-methylmethacrylate) as carrier matrix. Morpholine substituted poly(vinyl methyl ketone) (MSP) seems to be generally applicable for surface modification of different inorganic surfaces with organics.