Aggregation‐induced emission (AIE) technology has been demonstrated to be a facile approach for in‐situ monitoring atom transfer radical polymerization (ATRP). A series of tertraphenyl ethylene (TPE)‐containing α‐bromo compounds were synthesized and applied as ATRP initiators. The photoluminescent (PL) emission of the polymerization system is proved to be sensitive to the local viscosity owing to the AIE characteristics of TPE. Linear relationships between the resulting molecular weight Mn and PL intensity were observed in several polymerization systems with different monomers, indicating the variability of this technique. Compared to physical blending, the chemical bonding of the TPE group in the chain end has higher sensitivity and accuracy to the polymer segments and the surrounding environment. This work promoted the combination of the AIE technique and controlled living radical polymerization, and introduced such an optical research platform to the ATRP polymerization process.

Ring-opening metathesis polymerization (ROMP) in an aqueous medium provides an important environmentally friendly platform for the preparation of water-soluble polymeric materials. However, it is challenging to keep high synthetic efficacy and good control over molecular weight and distribution due to the inevitable catalyst decomposition in an aqueous medium. To meet this challenge, we propose a facile monomer emulsified aqueous ROMP (ME-ROMP) by injecting a tiny amount of a CH2Cl2 solution of the Grubbs’ third-generation catalyst (G3) into the aqueous solution of norbornene (NB) monomers without deoxygenation. Driven by the minimization of interfacial tension, the water-soluble monomers could serve as surfactants with hydrophobic NB moieties inserted into the CH2Cl2 droplets of G3, leading to the significantly suppressed catalyst decomposition and accelerated polymerization. The ME-ROMP is confirmed to be living with an ultrafast polymerization rate, near quantitative initiation and monomer conversion, for the highly efficient and ultrafast synthesis of well-defined water-soluble polynorbornenes with various compositions and architectures.

A facile fabrication strategy of transparent and upconversion photoluminescent nylon 6 (PA6) nanofiber mats was developed based on PA6 nanofiber mats, carboxylic acid-functionalized upconversion nanoparticles (UCNP-COOH), and poly(methyl methacrylate) (PMMA) solution. UCNP-COOH were prepared by a solvothermal method, followed by the ligand exchange process. The electrospinning method and the spin-coating process were employed to combine PA6 nanofiber mats with UCNP-COOH and PMMA to introduce upconversion photoluminescent properties and transparency into the nanocomposite mats, respectively. The prepared UCNP-COOH/PA6/PMMA nanofiber mats are transparent and exhibit green emission, which are similar to UCNP-COOH when they were excited under 980 nm laser. The upconversion luminescent intensity of the functional nanofiber mats can be tailored by adjusting the weight fraction of UCNP-COOH as fillers. This facile strategy can be readily used to other types of intriguing nanocomposites for diverse applications.

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