This review summarizes the development, progress, applications, and future challenges of photocontrolled reversible addition–fragmentation chain transfer (RAFT) polymerization, which has attracted considerable attention in the past several years.

Since the pioneering discovery of a protein bound to poly(ethylene glycol), the utility of protein–polymer conjugates (PPCs) is rapidly expanding to currently emerging applications. Photoinduced energy/electron‐transfer reversible addition–fragmentation chain‐transfer (PET‐RAFT) polymerization is a very promising method to prepare structurally well‐defined PPCs, as it eliminates high‐cost and time‐consuming deoxygenation processes due to its oxygen tolerance. However, the oxygen‐tolerance behavior of PET‐RAFT polymerization is not well‐investigated in aqueous environments, and thereby the preparation of PPCs using PET‐RAFT polymerization needs a substantial amount of sacrificial reducing agents or inert‐gas purging processes. Herein a novel water‐soluble and biocompatible organic photocatalyst (PC) is reported, which enables visible‐light‐driven additive‐free “grafting‐from” polymerizations of a protein in ambient and aqueous environments. Interestingly, the developed PC shows unconventional “oxygen‐acceleration” behavior for a variety of acrylic and acrylamide monomers in aqueous conditions without any additives, which are apparently distinct from previously reported systems. With such a PC, “grafting‐from” polymerizations are successfully performed from protein in ambient buffer conditions under green light‐emitting diode (LED) irradiation, which result in various PPCs that have neutral, anionic, cationic, and zwitterionic polyacrylates, and polyacrylamides. It is believed that this PC will be widely employed for a variety of photocatalysis processes in aqueous environments, including the living cell system.

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Owing to current global environmental concerns, polymers must be prepared under eco-friendly reaction conditions based on sustainable chemistry. In this context, highly efficient photoinduced energy/electron transfer reversible addition− fragmentation chain-transfer (PET-RAFT) polymerization under ambient/aqueous conditions without additives and/or with the aid of sunlight is the optimal approach for producing polymers with well-defined structures. This can be accomplished with a photocatalyst (PC) that utilizes the full spectrum of sunlight for maximum efficiency and has excellent water solubility or dispersibility, oxygen tolerance, and biocompatibility. However, a PC with all of these features has not yet been developed. In this study, we confirmed that this could be achieved using Ag 2 S nanocrystals (NCs) as photocatalysts. The sufficient reducing power of Ag 2 S NCs enabled the successful aqueous PET-RAFT polymerization of numerous acrylic monomers under ambient natural sunlight illumination without any additives. Under illumination, the small band gap of Ag 2 S NCs suppressed the generation of singlet oxygen, resulting in low cytotoxicity toward three different cell lines. Finally, we demonstrated that PET-RAFT polymerization with Ag 2 S NCs can be accomplished in biologically relevant media under natural sunlight illumination, indicating adequate biocompatibility and efficacy of the system.

The purpose of this paper is to use cognitive poetics as a perspective for analyzing poems by the renowned Chinese poet Wang Wei(王維), particularly those set against an idyllic backdrop. The paper begins by outlining the cognitive poetics theory as a methodology for analyzing the poems. From the poem of Tao Yuanming, who had a significant influence on Wang Wei's poetry, ｢Returning to the Idyll(歸園田居)｣ was selected as a representative example of the knowledge structure for interpreting the poems. Based on this, the paper analyzes five poems. Through the analysis, it was confirmed that the idyllic settings that appear in Wang Wei's poems are shaped as ‘Yinyi(隱逸)’ space that restore the true self. Furthermore, during the cognitive analysis process, it was found that a literary device called “sunset,” which commonly appears in Wang Wei's poems, influenced the interpretation of the poems.