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PA1212 exhibits blue fluorescence and persistent room-temperature green phosphorescence. Hydrogen-bond-constructed amide clusters play an important role in the emission. The order and extension of the hydrogen bonds regulate the luminescence process.

Targeting sustainable and eco-friendly polymer synthesis, we demonstrate here a synergistically catalyzed atom transfer radical polymerization (ATRP) induced and controlled by interplay between ball milling (BM) and piezoelectric nanoparticles (piezoNPs). BM-induced electron transfer can be achieved through piezoNPs deformation under impact force, serving as an external stimulus to mediate polymerization. The ppm level of copper loading is sufficient in fabrication of a polymer with well-defined molecular weight and low polydispersity. High-molecular-weight polymers ranging from 33 to 74 kDa were prepared successfully through DMSO-assisted grinding. Besides, its good performance on availability of water as liquid-assisted grinding additive, the recyclability of piezoNPs, and the formation of cross-linker-free composite resin make our ATRP approach a green and practical option alongside the existent heat-, electro-, and photo-induced methods.

Owing to the benefits of using natural or artificial light sources as a stimulus, photoinduced reversible-deactivation radical polymerization (photoRDRP) techniques have been recognized to be a powerful "green" platform for the preparation of well-defined polymers. However, the development of highly efficient visible light-induced photoRDRP processes in aqueous dispersed media remains a challenge due to light scattering and refraction by monomer droplets or colloidal particles. In this work, an efficient green photocatalyst, carbon quantum dots (CQDs), was introduced to visible light-mediated miniemulsion atom transfer radical polymerization (ATRP), leading to highly efficient polymerizations with reaction rates (80% monomer conversion within 1 h) much higher than in previous studies. This heterogeneous photocatalytic system is presumed to involve three catalytic cycles in (i) the aqueous phase, (ii) the oil-water interface, and (iii) the monomer droplets. The effect of different polymerization parameters on the polymerization reaction was investigated, including the amounts of surfactant and CQDs, CuBr

Anisotropic thermally conductive composites are very critical for precise thermal management of electronic devices. In this work, in order to prepare a composite with significant anisotropic thermal conductivity, polyamide 12/styrene–acrylic copolymer–boron nitride (PA12/SA–BN) composites with macro and micro double anisotropic structures were fabricated successfully using 3D printing and micro-shear methods. The morphologies and thermally conductive properties of composites were systematically characterized via SEM, XRD, and the laser flash method. Experimental results indicate that the through-plane thermal conductivity of the composite is 4.2 W/(m·K) with only 21.4 wt% BN, which is five times higher than that of the composite with randomly oriented BN. Simulation results show that the macro-anisotropic structure of the composite (caused by the selective distribution of BN) as well as the micro-anisotropic structure (caused by the orientation structure of BN) both play critical roles in spreading heat along the specified direction. Therefore, as-obtained composites with double anisotropic structures possess great potential for the application inefficient and controllable thermal management in various fields.

Broadband photoinduced electron/energy transfer RAFT (PET-RAFT) polymerization was achieved by Au/g-C3N4 complex photocatalysts.

SiQD-catalyzed visible light induced ATRP provides not only good control of polymerization, but also has the potential for application in controlled surface modification through surface grafting photoATRP (SG-ATRP) with the assistance of MPS.

Silver nanocrystal arrays had attracted much attention due to the unique plasmonic effect of their ordered nanostructure and the synergy among adjacent nanocrystals. Conventional preparation methods had several limitations, such as high cost, harsh preparation conditions, and complicated influencing factors, which could not be employed to fabricate the nanocrystal arrays in highly controlled fashion. To solve these issues, we reported ordered arrays of different Ag nanocrystals with precise control prepared by utilizing amphiphilic star-like poly(4-vinylpyridine)

Realizing precise control over the size and functionality of nanomaterials is a prerequisite to their diverse applications in the areas of biology, environment, energy, and other emerging nanotechnologies. Herein, we demonstrate a general template strategy capable of fabricating functional noble metallic nanorods and nanopeapods. The templates are hollow silica nanotubes (HSNTs) produced from unimolecular micelles of bottlebrush copolymers. The variation of chain length and chemical composition of bottlebrush copolymers achieved through the reversible-deactivation radical polymerization dictates the length (L), inner diameter (D), and thickness (h) of HSNTs. Using such HSNTs as nanoreactors enables the fabrication of noble metals such as Au, Ag, and Pt nanorods or nanopeapods with silica shells in a space-confined manner. While the thickness and the interior space of HSNTs regulate the diffusion and intake of metal ion precursors, the formation of nanorods or nanopeapods with different lengths and diameters is well controlled. Upon etching out the silica shell, the resulting metallic nanorods are readily functionalized with polymeric ligands for excellent dispersity in aqueous and/or organic media. This feasible and versatile strategy represents a great leap forward in the controlled synthesis of one-dimensional metallic nanomaterials and hopefully promotes understanding their structure-determined physiochemical properties and board applications in medicine and catalysis.

Photoinduced atom transfer radical polymerization (ATRP) has been proved to be a versatile technique for polymer network formation. However, the slow polymerization rates of typical ATRP limited its application in the field of additive manufacturing (3D printing). In this work, we introduced carbon quantum dots (CQDs) for the first time to the ATRP in aqueous media and developed an ultrafast visible-light-induced polymerization system. After optimization, the polymerization could achieve a high monomer conversion (90%) within 1 min, and the polydispersity index (PDI) of the polymer was lower than 1.25. This system was then applied as the first example of ATRP for the 3D printing of hydrogel through digital light processing (DLP), and the printed object exhibited good dimensional accuracy. Additionally, the excellent and stable optical properties of CQDs also provided interesting photoluminescence capabilities to the printed objects. We deduce this ATRP mediated 3D printing process would provide a new platform for the preparation of functional and stimuli-responsive hydrogel materials.

Various piezoelectric nanomaterials were utilized in ultrasound-mediated atom transfer radical polymerization (ATRP), owing to their outstanding piezoelectric effect. However, the relationship between the morphology of those piezocatalysts and polymerization has not been clearly established. Herein, we employed different piezoelectric zinc oxide (ZnO) nanomaterials to achieve novel mechano-induced ATRP (mechano-ATRP). Based on the synergistic effect of piezoelectric properties and specific surface area, the catalytic activity of 1D ZnO nanorods (1D-ZnO NRs) with increased aspect ratio outperformed that of 0D ZnO nanoparticles (0D-ZnO NPs). Compared to the conventional ATRP system, this system exhibited extraordinary activity toward the less activated monomer acrylonitrile (67% conversion after 6 h), with a narrow molecular weight distribution (polydispersity index ∼ 1.19). Furthermore, implications of ZnO loading, copper salt amount, degree of polymerization, monomer, and solvent were also studied for the highly efficient mechano-ATRP.

The utilizing light with broadband range has attracted lots of research interest for the photo induced reversible-deactivation radical polymerization (RDRP). However, it is still a challenge for a single catalyst to simultaneously respond to various lights with highly varied wavelengths. Here, we proposed a simple strategy for the preparation of a heterogeneous photocatalyst suitable for photo induced atom transfer radical polymerization (photoATRP) under full spectrum (from UV/vis light to NIR), by combining pyridine nitrogen doped carbon dots (N-CDs) and upconversion nanoparticles (UCNPs). In the presence of these robust UCNP@SiO

The past few years witnessed the rapid development of bottom-up synthesis strategies for preparing various nanostructures (i.e., nanoparticles, nanorods, nanowires, etc.) with distinct morphology-dependent properties. In this study, we reported a facile and efficient synthesis method for preparing anatase titanium dioxide (TiO2) nanorings based on multiarm, starlike amphiphilic polystyrene-b-poly(acrylic acid) (PS-b-PAA) diblock copolymers as nanoreactors which were prepared via a sequential atom-transfer radical polymerization (ATRP) technique followed by the conversion of polystyrene-b-poly(tert-butyl acrylate) (PS-b-PtBA) to PS-b-PAA. The outer PAA block of nanoreactors possessed carboxylic acid groups which could coordinate with a titanium precursor followed by high-temperature calcination to form crystalline TiO2 nanorings. The living nature of ATRP enabled the precise preparation of starlike diblock copolymer nanoreactors with a controlled length of each block (i.e., PtBA and PS), thereby tailoring the inner diameter and wall thickness of the resulting TiO2 nanorings, which were inaccessible to conventional routes.

The ambient stability and processability of organic solar cells (OSCs) are important factors for their commercialization. Herein, we selected four benzo[1,2-b:4,5-b']difuran (BDF) polymers and two electron acceptors to examine the role of photovoltaic materials in the ambient stability. The investigations revealed that the MoOx layer is the detrimental factor for the ambient stabilities. The penetration of MoOx into the active layer and their interactions will strengthen the interface and form a favorable contact, hence leading to the increased photovoltaic performance, in which the efficiency loss induced by air was balanced out. As such, these BDF polymer-based non-fullerene (NF) OSCs possessed very promising ambient stabilities even after ∼1000 h with the almost maintained power conversion efficiencies (PCEs). These results drive us to further investigate the ambient processability of these NF-OSCs. The PCEs from the devices processed under ambient condition only possessed 0.3-2% loss compared to those devices under inert conditions, which suggest the significant potentials of BDF polymers to develop highly efficient and stable NF-OSCs for the practical applications.

Approaches to achieve stable perovskite nanocrystals (PNCs) of interest, in particular those with large structural anisotropy, through protective coating of the inorganic shell at a single-nanocrystal (NC) level are comparatively few and limited in scope. Reported here is a robust amphiphilic-diblock-copolymer-enabled strategy for crafting highly-stable anisotropic CsPbBr3 nanosheets (NSs) by in situ formation of a uniform inorganic shell (1st shielding) that is intimately ligated with hydrophobic polymers (2nd shielding). The dual-protected NSs display an array of remarkable stabilities (i.e., thermal, photostability, moisture, polar solvent, aliphatic amine, etc.) and find application in white-light-emitting diodes. In principle, by anchoring other multidentate amphiphilic polymer ligands on the surface of PNCs, followed by templated-growth of shell materials of interest, a rich variety of dual-shelled, multifunctional PNCs with markedly improved stabilities can be created for use in optics, optoelectronics, and sensory devices.

Multiple and two-way reversible shape memory polymers (M/2W-SMPs) are highly promising for many fields due to large deformation, lightweight, strong recovery stress, and fast response rates. Herein, a semi-crystalline block poly(urethane-urea-amide) elastomers (PUUAs) are prepared by the copolymerization of isocyanate-terminated polyurethane (OPU) and amino-terminated oligomeric polyamide-1212 (OPA). PUUAs, composed of OPA as stationary phase and PTMEG as reversible phase, exhibit excellent rigidity, flexibility, and resilience, and cPUUA-C

Nitroxide-mediated polymerization (NMP) is a typical reversible deactivation radical polymerization (RDRP) with simple components and pure product. Here we presented the first example of NMP with oxygen tolerance, using alkoxyamine 3-(((2-cyanopropan-2-yl)oxy)(cyclohexyl)amino)-2,2-dimethyl-3-phenylpropanenitrile (Dispolreg 007) as the initiator. Without traditional degassing operation, the resultant polymerization exhibited similar living and control behavior as the one performed under degassing. This oxygen tolerant NMP system was suitable for the homopolymerization of both 1,1-disubstituted monomers as well as the monosubstituted. And the chain extension based on macroalkoxyamines derived from Dispolreg 007 could also be performed without degassing. The characteristics of this oxygen tolerant and simple system may provide exciting new opportunities for increased versatility of NMP polymerization in the industrial fields.

We report the first example of in situ polymer brush growth on the surface of upconversion nanoparticles (UCNPs) in a one-pot near-infrared (NIR) light mediated reversible addition–fragmentation chain transfer (RAFT) polymerization. In the process of polymerization, the surface growth of polymer brushes was realized through an efficient in situ ligand exchange between a photo-activated chain transfer agent (CTA) and the ligand groups on the surface of UCNPs. BF4− was found to be the most efficient ligand in comparison with oleic acid and pyridine. The 980 nm NIR-mediated RAFT polymerization exhibits good temporal control with a low dispersity (Mw/Mn < 1.30), and the thickness of the polymer brushes can be easily adjusted by changing the polymer molecular weight and light exposure time. Moreover, the growth of polymer brushes can proceed even if there is a barrier (e.g. chicken skin) outside the reactor due to the excellent penetration ability of the NIR light.

Gold (Au) nanocrystals were recognized to be a remarkable photocatalyst because of their strong localized surface plasmon resonance (LSPR). Here Au nanocrystals were exploited as plasmonic photocatalysts for photo-regulated reversible addition–fragmentation chain-transfer (RAFT) polymerization. In addition to the well-controlled RAFT polymerization process under a broadband of light (from visible to the near-infrared region), the dimension (0-D nanospheres and 1-D nanorods) and aspect ratio (length/width) of the nanocrystals exhibited a remarkable effect on the polymerization rate under different light sources. The reduction of plasmon damping leads to a relatively long-lived region of high electron density on the surface of the Au nanorods, which can accelerate charge transfer and induce a higher polymerization rate. Moreover, the aspect ratio related to the longitudinal absorption band of the Au nanorods may provide more flexible choices for advanced macromolecular photosynthesis for potential in biomedical and industrial applications.

Tetraphenylethylene (TPE)-containing 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl (NH2-TEMPO) and 3-(((2-cyanopropan-2-yl)oxy)(cyclohexyl)amino)-2,2-dimethyl-3-phenylpropanenitrile (Dispolreg 007) were synthesized and utilized to mediate/initiate NMP in both homogeneous and heterogeneous polymerization systems. The introduction of TPE groups decreased the C–O bond dissociation energy (BDE) of NH2-TEMPO-St and led to more efficient NMP with a higher reaction rate, even at lower temperatures. Moreover, for both solution polymerization and miniemulsion polymerization, quantitative information of the polymerization process could be easily acquired with the naked eye without destroying the reaction system, by building the relationship between the increased photoluminescence (PL) intensity of the system and monomer conversion as well as the molecular weight (Mn).

Recently, carbon dots (CDs) have been utilized as efficient and environmentally friendly catalysts for photo-induced atom transfer radical polymerization (ATRP) and reversible addition–fragmentation chain-transfer (RAFT) polymerization. Here, we have explored the effect of N types in CDs on photo-induced ATRP, as N is a typical dopant for CDs and may result in an upward shift of the Fermi level and a change in the optical properties. N-Doping significantly enhanced the UV-vis absorption of CDs, resulting in the CDs catalyzing broadband-light induced ATRP. Pyridinic N proved to be key for improving the activity of CDs as catalysts for photo-induced ATRP, compared with pyrrolic N and graphitic N. Even in N-doped CDs with mixed types of N atoms, the ratio of pyridinic N also seriously affected the polymerization rate. This work is of great importance for the application of CDs as photocatalysts for the RDRP system, and to promote the progress of green catalytic polymerization.

Size and surface functionality are critically important for organic–inorganic hybrid semiconductive nanocomposites in terms of stable photoelectrochemical properties and superior device performance. The ability of reversible deactivation radical polymerization to control the chain length and dispersity of polymers is herein extended to the tailor-made synthesis of nanocomposites with tunable size, distribution, and surface coating. This is exemplified by the fabrication of cadmium selenide (CdSe) quantum dots (QDs) with uniform sizes from 2 to 10 nm that are intimately coated with poly(3-hexylthiophene) (i.e., CdSe@P3HT).

Non-radiative recombination loss (ΔEnon-rad) has become the main limiting factor for the power conversion efficiency (PCE) of organic solar cells (OSCs). Herein, two benzo[1,2-b:4,5-b′]difuran (BDF) polymers (P-FT and P-FP) in combination with two electron acceptors (m-ITIC and Y6) in OSCs were employed to systemically investigate the impact of molecular orientation and interaction on energy loss in OSCs. The use of the Y6 acceptor instead of ITIC provided a reduced energy loss in OSC, regardless of the donor used, and the energy loss was lower in OSC based on P-FP, as compared to that based on P-FT. ΔEnon-rad as small as 0.23 eV was obtained in the P-FP:Y6 device, due to the small energetic disorder. In addition, the P-FP:Y6 device also possessed a promising EQEmax of 86.7%. These results provide a deep understanding of the role molecular interactions between the polymer donor and acceptor play in reducing energy loss and promoting device performance through synergic selection and optimization of donor and acceptor in OSCs.