Developing Low Fouling on PET Film via Surface‐initiated ARGET ATRP of Carboxybetaine under Air Condition

Abstract

Poly(ethylene terephthalate) (PET) is one of the most popular thermoplastics for daily use and finds application in packaging products for food and beverage storage, as well as textile materials for clothing. 1 The important features of PET, such as shatterproof nature, high strength to weight ratio, low cost, and recyclability make it feasible for use at the industrial scale for the aforementioned products. 2,3 In addition, PET shows flexible processability as well as moderate mechanical durance and physicochemical stability when in direct contact with body fluids; hence, it is a promising biomaterial for the development of medical products, including implantable devices, vascular grafts, and biosensors. 4,5 However, PET has poor biocompatibility, which results from non-specific binding to proteins because of its inherent hydrophobicity. 6 For example, non-specific protein adsorption onto a sensing platform would decrease the signal-to-noise ratio and reduce the sensitivity for target detection. 7 In the case of medical implants, adsorption of fibrinogen and platelet adhesion can cause immune responses, limiting their applications. 8 The most effective and general approach to reduce non-specific binding of proteins in the coating method is to form a hydrophilic polymer brush onto the surface of interest via a two-step process: functionalization of the initiator onto the target surface, and then, polymer brush formation by surface-initiated atom transfer radical polymerization (SI-ATRP) under airtight conditions. 9 However, there are several concerns regarding the use of the conventional protocol on PET substrates in biomedical applications. First, chemical inertness of PET is relatively difficult to be functionalized by initiators compared to other well-known surface chemistry, such as thiols on golds and silanes on oxides. 10 Second, the substrates for PET-based biomedical devices are not limited to small planar ones, but vary in size, shape, and curvature. This makes deoxygenation in the conventional SI-ATRP process difficult, where the presence of air can lead to early radical termination. Therefore, an alternative strategy is required to realize PET substrates with non-fouling properties for biomedical applications.In this work, we report aryl azide-based photochemical methods to immobilize the initiator, followed by activators regenerated by electron transfer (ARGET) for ATRP that Communication

Synthesis of Polymer Brushes Via SI‐PET‐RAFT for Photodynamic Inactivation of Bacteria

“…For the PTFEA brushes, X‐ray photoelectron spectroscopy (XPS) revealed the emergence of the characteristic fluorine F1s peak at BE F1s = 689.0 eV, further confirming the successful preparation of the brush coating (Figure S3C, Supporting Information). [ 21 ]…”

Surface-Initiated ARGET ATRP of Antifouling Zwitterionic Brushes Using Versatile and Uniform Initiator Film

“…However, its reaction conditions should be carefully applied under low temperatures, limiting their practical usage for the surface coating. In this sense, we introduced an aryl azide-based initiator (ABI) that can be feasibly immobilized on a TA-Fe III film when irradiated with UV light. − The synthesized ABI can be classified into three components, namely, the head, spacer, and terminal initiator groups. Perfluorophenylazide (PFPA) was selected as a head group because the photolysis of PFPA can generate a reactive nitrene group that can functionalize the sp 2 -rich hydrocarbon network of TA.…”

“…Second, it has been reported that fluorine groups of the aromatic ring suppress the intramolecular ring expansion of nitrene, increasing the insertion/addition adducts with hydrocarbons, in this case, TA . On the basis of our previous report, the photochemical PFPA group was utilized to immobilize the biotin or ATRP initiator group in carbon-based materials, such as graphene, a cyclic olefin copolymer (COC), or polyethylene terephthalate (PET) . The head and terminal initiator groups were linked with short ethylene glycol to increase their overall solubility and flexibility.…”

“…43 On the basis of our previous report, the photochemical PFPA group was utilized to immobilize the biotin or ATRP initiator group in carbonbased materials, such as graphene, 40 a cyclic olefin copolymer (COC), 41 or polyethylene terephthalate (PET). 42 The head and terminal initiator groups were linked with short ethylene glycol to increase their overall solubility and flexibility.…”

Formation of Various Polymeric Films via Surface‐Initiated ARGET ATRP on Silicon Substrates

“…19 Because of this regenerative catalytic cycle, ARGET ATRP needs no deoxygenating steps for the reaction solutions and it can be proceeded with a very low concentration of a Cu catalyst (at the level of several ppm) under ambient conditions. Along the same line with grafting-from approach, surface-initiated ARGET ATRP (SI-ARGET ATRP) has been successfully applied to a variety of applications including the preparation of low fouling surfaces, 20,21 development of the universal polymer grafting method to fabricate blood compatible surfaces, 22 and the preparation of biocompatible graphene nanosheets. 23 While SI-ARGET ATRP has been widely utilized to prepare functional coatings by grafting polymers from surfaces, there has been little study to investigate systematically the polymer grafting of various monomers over time using the same platform.…”