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Abstract Modification of a surface with polymer brushes has emerged as an effective approach to tune the properties of a substrate. Brushes grown from an inimer‐containing cross‐linkable polymer coating provide significant advantages compared to other “grafting‐from” methods, such as improved stability, increased grafting density, and the potential to control the grafting density. So far, the inimer coating method has only been applied for surface‐initiated controlled radical polymerizations. In this work, an approach is presented for the fabrication of a stable cross‐linked ultra‐thin polymer coating containing hydroxyl groups which serve as initiating sites for surface‐initiated ring‐opening polymerization (SI‐ROP). The polymers used for the fabrication of the coatings consist of 2‐((tetrahydro‐2H‐pyran‐2‐yl)oxy)ethyl methacrylate (THPEMA), a small fraction of a cross‐linkable unit, and a diluent styrene. Three coatings with varying THPEMA and styrene content are fabricated, and poly(dimethyl siloxane) (PDMS) and poly(caprolactone) (PCL) brushes are grown by SI‐ROP of hexamethylcyclotrisiloxane (D₃), and ε‐caprolactone respectively. The brushes are characterized by atomic force microscopy (AFM), X‐ray photoelectron spectroscopy (XPS), static contact angle measurements, ellipsometry and size exclusion chromatography (SEC). The results demonstrate a well‐controlled ROP of D₃and ability to control grafting density by tuning the THPEMA content of the coatings. 

The prevalence of emerging organic contaminants (EOCs) in ground and surface water has sparked the search for more effective methods to remove EOCs from the environment. In pursuit of a solution for this environmental concern, herein we present the development of reusable films based on cellulose nanofibers (CNFs) and the block copolymer, poly(4-vinylpyridine-b-ethylene oxide) (P4VP-PEO) to adsorb sulfamethoxazole (SMX) as an EOC model compound. We hypothesize that the adsorption of SMX was achieved mainly by π-π interactions between the pyridine functionalities of the block copolymer and the electron deficient phenyl group of the SMX. Preceding preparation of the films, CNFs were modified with the alkoxysilane trimethoxy(2-phenylethyl)silane (TMPES) to increase their stability in aqueous solution. After the addition of P4VP-PEO, the process was completed by filtration followed by oven-drying. XPS and FTIR were employed to confirm the addition of TMPES and P4VP-PEO, respectively. Adsorption batch experiments were performed in aqueous solutions of SMX at a neutral pH, obtaining adsorptions of up to 0.014 mmol/g in a moderate time of 60 min. For the reusability tests, films were immersed in ethanol 95 wt.% to elude the adsorbed SMX, rinsed with deionized (DI) water, and dried at room temperature to be reused in a new adsorption cycle. We found that this new composite material could be reused several times with negligible loss of adsorption capacity. The films presented have been shown to be of substantial importance for water remediation as they find direct application in the adsorption of electron deficient aromatic compounds and are reusable.