Polymer Brushes via Surface-Initiated Polymerization catalysts in the final polymer brushes might have undesirable consequences for applications, such as in the biomedical or electronic industry. However, some methods, in particular A(R)GET ATRP, have been developed that allow to reduce the amount of copper to the level of a few ppm. 72 Surface-Initiated Reversible-Addition Fragmentation Chain Transfer (SI-RAFT) PolymerizationIn contrast to ATRP, where the equilibrium between the dormant and active, propagating chains is based on reversible termination, reversible-addition fragmentation chain transfer (RAFT) polymerization is based on reversible chain transfer. [114][115][116] A distinct advantage of RAFT polymerization is its relative simplicity and versatility, since conventional free radical polymerizations can be readily converted into a RAFT process by adding an appropriate RAFT agent, such as a dithioester, dithiocarbamate, or trithiocarbonate compound, while other reaction parameters, such as monomer, initiator, solvent, and temperature, can be kept constant. RAFT polymerization has also been successfully used to prepare polymer brushes via surface-initiated polymerization. SI-RAFT can be performed using two different strategies, which use either surface-immobilized conventional free radical initiators or surface-immobilized RAFT agents (Scheme 2). These two different strategies will be discussed in more detail in the following paragraphs.

Hydrophilic polymer brushes grown via surface‐initiated ATRP from silicon oxide surfaces are susceptible to detachment via hydrolytic cleavage of the anchoring siloxane bond. This paper investigates the influence of the structure of the ATRP initiator on the stability of these brushes and seeks for strategies to further enhance their stability. It is found that increasing the hydrophobicity of the organosilane modified ATRP initiator reduces the susceptibility of the brushes toward cleavage. Robust, hydrophilic polymer brushes are prepared, which are obtained by introducing a short, hydrophobic PMMA or PEHMA block between the silicon oxide substrate and the hydrophilic polymer brush.

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This manuscript reports a new strategy to guide the chemical solution deposition of thin, microstructured metal films. The proposed strategy is based on the use of poly(2-(methacryloyloxy)ethyl ammonium chloride) (PMETAC) brushes grown via surface-initiated atom transfer radical polymerization as a template. Thin gold films have been prepared by first loading the PMETAC brushes with HAuCl(4), followed by a NaBH(4) mediated reduction to produce a PMETAC-gold nanoparticle composite film and finally an oxygen plasma treatment to remove the stabilizing polymer brush matrix and generate the desired thin gold film. The thickness of the gold films was found to scale with the thickness of the PMETAC brush template. This approach can also be extended to more complex, bimetallic films by exposing the PMETAC template successively to two different precursor salts. In this way, gradient type bimetallic palladium/gold films could be prepared.

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