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Precise sequence‐defined polymers (SDPs) with uniform chain‐to‐chain structure including chain length, unit sequence, and end functionalities represent the pinnacle of sophistication in the realm of polymer science. For example, the absolute control over the unit sequence of SDPs allows for the bottom‐up design of polymers with hierarchical microstructures and functions. Accompanied with the development of synthetic techniques towards precision SDPs, the decoding of SDP sequences and construction of advanced functions irreplaceable by other synthetic materials is of central importance. In this Minireview, we focus on recent advances in SDP sequencing techniques including tandem mass spectrometry (MS), chemically assisted primary MS, as well as other non‐destructive sequencing methods such as nuclear magnetic resonance (NMR) spectroscopy, circular dichroism (CD), and nanopore sequencing. Additionally, we delve into the promising prospects of SDP functions in the area of cutting‐edge biological research. Topics of exploration include gene delivery systems, the development of hybrid materials combining SDPs and nucleic acids, protein recognition and regulation, as well as the interplay between chirality and biological functions. A brief outlook towards the future directions of SDPs is also presented. [ABSTRACT FROM AUTHOR]

Precise sequence‐defined polymers (SDPs) with uniform chain‐to‐chain structure including chain length, unit sequence, and end functionalities represent the pinnacle of sophistication in the realm of polymer science. For example, the absolute control over the unit sequence of SDPs allows for the bottom‐up design of polymers with hierarchical microstructures and functions. Accompanied with the development of synthetic techniques towards precision SDPs, the decoding of SDP sequences and construction of advanced functions irreplaceable by other synthetic materials is of central importance. In this Minireview, we focus on recent advances in SDP sequencing techniques including tandem mass spectrometry (MS), chemically assisted primary MS, as well as other non‐destructive sequencing methods such as nuclear magnetic resonance (NMR) spectroscopy, circular dichroism (CD), and nanopore sequencing. Additionally, we delve into the promising prospects of SDP functions in the area of cutting‐edge biological research. Topics of exploration include gene delivery systems, the development of hybrid materials combining SDPs and nucleic acids, protein recognition and regulation, as well as the interplay between chirality and biological functions. A brief outlook towards the future directions of SDPs is also presented. [ABSTRACT FROM AUTHOR]

From 2,5-furan dicarboxylic acid, a robust biomass platform molecule, furan-based porous polyamide ( FPPA-1 and -2 ) was synthesized and applied for the removal of Hg2+ from water. FPPA-1 and -2 were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The effects of pH, dosage, contact time, temperature and concentration on the adsorption of Hg2+ were systematically investigated. The pseudo-second-order kinetics and the Langmuir isotherm model are in the best agreement with the experimental data, and the maximum adsorption capacity is 462 mg g−1. Thermodynamically, the adsorption of Hg2+ is a spontaneous adsorption process. There was no significant loss of performance during five regeneration cycles. In combination with the experimental data and density functional theory (DFT) calculation, the chelation mechanism of Hg2+ was demonstrated. Our study offers new perspectives for the removal of Hg2+ from wastewater. [Display omitted] • Furan-based porous polyamides were successfully prepared and removed Hg2+ from water. • The highest adsorption capacity of furan-based porous polyamide for Hg2+ was 462 mg g-1. • Hg2+ adsorption mechanism was proposed by spectral technique and DFT calculations. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Polymer mechanochemistry on reactive species has attracted more and more attentions over the past 20 years, as the mechanochemical generation of reactive species has a great potential in developing different polymeric materials for various purposes, such as stress detection, self‐healing, self‐strengthening, controllable degradation and release of small molecules. In this review, we first discuss the recent progress on polymer mechanochemistry of the reactive species that are generated from the mechanochemical reactions of mechanophores. Five types of reactive species, including radical, zwitterion, ionic, carbene and neutral intermediates, and their applications were reviewed in detail. Since mechanochemical reactions are sensitive to the mechanophore structure and polymer framework, we then discuss how mechanophore isomerism, polymer structure, polymer attachment point, and polymer architecture influence the mechanophore activation. At last, we provide our perspectives on the polymer mechanochemistry of reactive species. Key Scientists: In the 1930s, a seminal work by Staudinger showed that the molecular weight of poly(styrene) reduced after mastication. However, polymer mechanochemistry mainly focused on the destructive effects of mechanical force, until Moore reported that the azo‐mechanophore was cleaved selectively upon sonication in 2005. Afterwards, his group also found that mechanical force changed the reaction pathway of benzocyclobutene and made spiropyran display purple color under stress. In 2009, Sijbesma revealed that metal–NHC could be used as a latent catalyst to catalyze transesterification and polymerization. Subsequently, the Craig group disclosed the special mechanical reactivity of perfluorocyclobutane in 2011 and examined the influence of polymer backbone on the reactivity of epoxides in 2012. Later, they also reported that the lever‐arm effect enhanced gDBC or gDCC mechanochemistry. Since 2015, Otsuka's group has developed a series of mechanophores that generated various carbon radicals and showed different colors under mechanical force. De Bo subsequently investigated the effect of regio‐ and stereochemistry on the reactivity of furan–maleimide adduct in 2017, and he examined the different mechanisms of the mechanical activation of tetrafluorobenzene–NHC (N‐heterocyclic carbene) adduct in 2020. During that time, the Choi group explored the influence of polymer architecture on the mechanophore activation, and Robb's group utilized a furan‐maleimide adduct to achieve the release of different small molecules. In 2020, Göstl and Herrmann employed the scission of the disulfide within polymers to release drugs and reporting molecules by ultrasound, and the Chen group also investigated the mechanochemistry of diselenides which afforded selenium radicals. In 2021, Boydston's group realized the "flex‐activation" of NHC‐carbodiimide to release NHC small molecules. Recently, the Chen group achieved multistate mechanochromism by combining two Rh structures together through a conjugated connector. In addition, Robb designed a furan‐maleimide adduct to mechanically give a donor–acceptor Stenhouse adduct that reacted with different amines to display various colors. This review has focused on the chemistry of reactive species that are generated from mechanochemical reactions. [ABSTRACT FROM AUTHOR]

In this paper, we proposed a heteroatom substitution strategy (HSS) in the δ‐valerolactone (VL) system to modulate thermodynamics toward chemically recyclable polyesters. Three VL‐based monomers containing different heteroatoms (M1 (N), M2 (S), and M3 (O)), instead of C‐5 carbon, were designed and synthesized to verify our proposed HSS. All three monomers undergo organocatalytic living/controlled ROP and controllable depolymerization. Impressively, the resulting P(M1) achieved over 99 % monomer recovery under both mild solution depolymerization and high vacuum pyrolysis conditions without any side reactions, and the recycled monomers can be polymerized again forming new polymers. The systematic study of the relationship between heteroatom substitution and recyclability shows that introducing heteroatoms does change the thermodynamics of the monomers (ΔHpo, ΔSpo and Tc values), thereby adjusting the polymerizability and depolymerizability. DFT calculations found that the introduction of heteroatoms adjusts the ring strain by changing the angular strain of the monomers, and the order of their angular strain (M2>M1>M3) is consistent with the order of the experimentally obtained enthalpy change. Notably, the one‐pot/one‐step copolymerization of two of each of the three monomers enables the synthesis of sequence‐controlled copolymers from gradient to random to block structures, by simply switching the copolymerization temperature. [ABSTRACT FROM AUTHOR]

In this paper, we proposed a heteroatom substitution strategy (HSS) in the δ‐valerolactone (VL) system to modulate thermodynamics toward chemically recyclable polyesters. Three VL‐based monomers containing different heteroatoms (M1 (N), M2 (S), and M3 (O)), instead of C‐5 carbon, were designed and synthesized to verify our proposed HSS. All three monomers undergo organocatalytic living/controlled ROP and controllable depolymerization. Impressively, the resulting P(M1) achieved over 99 % monomer recovery under both mild solution depolymerization and high vacuum pyrolysis conditions without any side reactions, and the recycled monomers can be polymerized again forming new polymers. The systematic study of the relationship between heteroatom substitution and recyclability shows that introducing heteroatoms does change the thermodynamics of the monomers (ΔHpo, ΔSpo and Tc values), thereby adjusting the polymerizability and depolymerizability. DFT calculations found that the introduction of heteroatoms adjusts the ring strain by changing the angular strain of the monomers, and the order of their angular strain (M2>M1>M3) is consistent with the order of the experimentally obtained enthalpy change. Notably, the one‐pot/one‐step copolymerization of two of each of the three monomers enables the synthesis of sequence‐controlled copolymers from gradient to random to block structures, by simply switching the copolymerization temperature. [ABSTRACT FROM AUTHOR]

Light irradiation is an external stimulus, rapidly developed in switchable atom transfer radical polymerization (ATRP) via photo‐activation methods in recent years. Herein, a photo‐deactivation strategy is introduced to regulate ATRP with the assistance of photoswitchable hexaarylbiimidozole (HABI). Under visible light irradiation and in the presence of HABI, ATRP is greatly decelerated or quenched depending on the concentration of HABI. Interestingly, with visible light off, ATRP can proceed smoothly and follow a first‐order kinetics. Moreover, photo‐switchable ATRP alternatively with light off and on is demonstrated. Besides, the mechanism of photo‐deactivation ATRP involving radical quenching is proposed in the presence of HABI. [ABSTRACT FROM AUTHOR]

Since Hermann Staudinger coined the term "macromolecule" in the 1920s, one century of development of polymers in both academia and industry has had an overwhelming impact on human society. Furthermore, polymer chemists have made tremendous efforts to regulate polymer sequences, i.e., precisely arrange monomer units along the polymer chains to mimic DNA. To build a sustainable future of polymer manufacturing, bio-based monomers and eco-friendly degradable polymers have attracted immense interest in polymer communities. [Extracted from the article]

Poly(amino ester)s (PAEs) refer to a class of synthetic polymers characterized by repeating units in the backbone having tertiary amines and ester bonds, and bringing together the inherent biodegradability of polyesters and the rich tunable functionalities provided by tertiary amines. The presence of tertiary amines allows the introduction of various pendant groups, leading to diverse PAE material and properties, such as biodegradability, biocompatibility, water-solubility, stimulus-responsiveness (pH or temperature), etc. To date, PAEs are evolving into a new class of biodegradable polymer materials independent of aliphatic polyesters and have been widely used in various biomedical fields, such as gene delivery, drug delivery, bioimaging agents, etc. In addition, a new family of PAEs, namely N -acylated PAEs, with the same pendant carbonyl groups as poly(2-oxazoline)s, is expected to develop into new biopolymer platforms similar to polypeptoids and polyoxazolines. This review comprehensively summarizes the synthesis methods of PAEs, including polycondensation (PCD), Michael addition polymerization (MAP), spontaneous zwitterionic copolymerization (SZWIP), and ring-opening polymerization (ROP). [Display omitted] [ABSTRACT FROM AUTHOR]

Fabrication of versatile hydrogels in a facile and effective manner represents a pivotal challenge in the field of biomaterials. Herein, a novel strategy is presented for preparing on‐demand degradable hydrogels with multilevel responsiveness. By employing selenol‐dichlorotetrazine nucleophilic aromatic substitution (SNAr) to synthesize hydrogels under mild conditions in a buffer solution, the necessity of additives or posttreatments can be obviated. The nucleophilic and redox reactions between selenol and tetrazine culminate in the formation of three degradable chemical bonds—diselenide, aryl selenide, and dearomatized selenide—in a single, expeditious step. The resultant hydrogel manifests exceptional adaptability to intricate environments in conjunction with self‐healing and on‐demand degradation properties. Furthermore, the resulting material demonstrated light‐triggered antibacterial activity. Animal studies further underscore the potential of integrating metformin into Se‐Tz hydrogels under green light irradiation, as it effectively stimulates angiogenesis and collagen deposition, thereby fostering efficient wound healing. In comparison to previously documented hydrogels, Se‐Tz hydrogels exhibit controlled degradation and drug release, outstanding antibacterial activity, mechanical robustness, and bioactivity, all without the need for costly and intricate preparation procedures. These findings underscore Se‐Tz hydrogels as a safe and effective therapeutic option for diabetic wound dressings. [ABSTRACT FROM AUTHOR]

Stimulus-responsive materials containing selenide under oxidizing conditions have wide application prospects, especially in biomedicine. Due to the intricate preparation process, the scarcity of studies on the structure–activity relationship of regulatory factors in the oxidative stimulus response poses challenges to material design. Herein, based on selenol-ene chemistry, a diverse library of unsymmetric selenides is synthesized, enabling systematic investigation into the regulation of selenide oxidative elimination with variable substituent groups and positions. The α/β-positions of β-carbonyl unsymmetric selenides are efficiently modified with electron-donating or electron-withdrawing groups through a one-pot, two-step reaction involving ammonolysis of γ-selenobutyrolactone (SBL), followed by nucleophilic addition with unsaturated acrylate. In situ NMR tracking shows that the oxidative elimination of selenide had a distinct substituent effect. Both the electron and steric effects of the substituent influence the induction period of the selenide oxidative and elimination reactions. With the optimal substituent and position, the selenides would exhibit a timebomb-type response upon oxidation stimulus. Finally, a novel amphiphilic polymer comprising selenide-linked polyethylene glycol (PEG) and cholesterol moieties is synthesized as a representative ROS-sensitive material and exhibits a time-dependent reduction in micelle size. [ABSTRACT FROM AUTHOR]

Photoinduced 3D printing based on the reversible addition‐fragmentation chain transfer (RAFT) process has emerged as a robust method for creating diverse functional materials. However, achieving precise control over the mechanical properties of these printed objects remains a critical challenge for practical application. Here, we demonstrated a RAFT step‐growth polymerization of a bifunctional xanthate and bifunctional vinyl acetate. Additionally, we demonstrated photoinduced 3D printing through RAFT step‐growth polymerization with a tetrafunctional xanthate and a bifunctional vinyl acetate. By adjusting the molar ratio of the components in the printing resins, we finely tuned the polymerization mechanism from step‐growth to chain‐growth. This adjustment resulted in a remarkable range of tunable Young's moduli, ranging from 7.6 MPa to 997.1 MPa. Moreover, post‐functionalization and polymer welding of the printed objects with varying mechanical properties opens up a promising way to produce tailor‐made materials with specific and tunable properties. [ABSTRACT FROM AUTHOR]

Photoinduced 3D printing based on the reversible addition‐fragmentation chain transfer (RAFT) process has emerged as a robust method for creating diverse functional materials. However, achieving precise control over the mechanical properties of these printed objects remains a critical challenge for practical application. Here, we demonstrated a RAFT step‐growth polymerization of a bifunctional xanthate and bifunctional vinyl acetate. Additionally, we demonstrated photoinduced 3D printing through RAFT step‐growth polymerization with a tetrafunctional xanthate and a bifunctional vinyl acetate. By adjusting the molar ratio of the components in the printing resins, we finely tuned the polymerization mechanism from step‐growth to chain‐growth. This adjustment resulted in a remarkable range of tunable Young's moduli, ranging from 7.6 MPa to 997.1 MPa. Moreover, post‐functionalization and polymer welding of the printed objects with varying mechanical properties opens up a promising way to produce tailor‐made materials with specific and tunable properties. [ABSTRACT FROM AUTHOR]

Stimuli responsiveness has long been a fascinating feature of smart material design. Polydopamine (PDA), a nature inspired polymeric pigment, exhibits excellent photo-responsive properties and has active surface functionality for loading various responsive motifs, making it a promising candidate for the construction of stimuli-responsive smart functional materials. PDA has long been considered as a robust coating material, but its responsive feature has rarely been emphasized in the past reviews. Herein, we present the first effort to summarize recent advances in the design strategies, responsive mechanisms, and diverse applications of stimuli-responsive PDA-based smart materials; the stimuli include light, pH, chemicals, temperature, humidity, electric fields, mechanical force, magnetic fields, and ultrasound. Moreover, the current trends, challenges, and future directions of stimuli-responsive PDA-based materials are also elaborated. [ABSTRACT FROM AUTHOR]

Recently the research on the materials for removal of heave metals is surging rapidly. Here we have studied four triazine-based sulfur-containing polymers with different linkers, namely PDT1, PDT2, EDT1, and EDT2. They have been successfully synthesized by the nucleophilic substitution reaction of cyanuric chloride with propane-1,3-dithiol (PDT1 and PDT2) and ethane-1,2-dithiol (EDT1 and EDT2) in different ratios. The physical and chemical properties of these polymers were characterized by scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, porous structure analysis and X-ray photoelectron spectroscopy. The optimized adsorption condition was established by examining dosing, co-existing substances, contact time, concentration, temperature and pH values. The adsorbing properties, which was mainly described by the pseudo-second-order kinetic and Langmuir isothermal model, indicated that the sorption of Hg2+ was the chemical adsorption. The maximum Hg2+ sorption capacities of PDT1 , PDT2 , EDT1 and EDT2 were 1440.97 mg g−1, 715.99 mg g−1, 237.87 mg g−1 and 181.48 mg g−1, respectively. Thermodynamically, the adsorption of Hg2+ by the adsorbent is a spontaneous process. Cyclic experiments demonstrated that all the adsorbents could be reused in five successive adsorption cycles without significant losses in performance. Our density functional theory calculations in combination with relevant experimental results revealed the coordination geometry of Hg and hence mercury-adsorbent chelation mechanism. These results suggested that triazine-based sulfur-containing polymers could be utilized as effective adsorbents for the removal of Hg2+ from polluted water. [Display omitted] • Four triazine-based sulfur-containing polymers with different linker were readily prepared. • The polymers shown a higher adsorption capacity for Hg2+ (up to 1441 mg g−1) and could be easily reused. • Based on experimental facts and DFT calculations, the adsorption mechanism of the polymers was proposed. [ABSTRACT FROM AUTHOR]

To date, perovskite solar cells (pero‐SCs) with doped 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐spirobifluorene (Spiro‐OMeTAD) hole transporting layers (HTLs) have shown the highest recorded power conversion efficiencies (PCEs). However, their commercialization is still impeded by poor device stability owing to the hygroscopic lithium bis(trifluoromethanesulfonyl)imide and volatile 4‐tert‐butylpyridine dopants as well as time‐consuming oxidation in air. In this study, we explored a series of single‐component iodonium initiators with strong oxidability and different electron delocalization properties to precisely manipulate the oxidation states of Spiro‐OMeTAD without air assistance, and the oxidation mechanism was clearly understood. Iodine (III) in the diphenyliodonium cation (IP+) can accept a single electron from Spiro‐OMeTAD and forms Spiro‐OMeTAD⋅+ owing to its strong oxidability. Moreover, because of the coordination of the strongly delocalized TFSI− with Spiro‐OMeTAD⋅+ in a stable radical complex, the resulting hole mobility was 30 times higher than that of pristine Spiro‐OMeTAD. In addition, the IP‐TFSI initiator facilitated the growth of a homogeneous and pinhole‐free Spiro‐OMeTAD film. The pero‐SCs based on this oxidizing HTL showed excellent efficiencies of 25.16 % (certified: 24.85 % for 0.062‐cm2) and 20.71 % for a 15.03‐cm2 module as well as remarkable overall stability. [ABSTRACT FROM AUTHOR]

Unraveling the chirality transfer mechanism of polymer assemblies and controlling their handedness is beneficial for exploring the origin of hierarchical chirality and developing smart materials with desired chiroptical activities. However, polydisperse polymers often lead to an ambiguous or statistical evaluation of the structure–property relationship, and it remains unclear how the iterative number of repeating units function in the helicity inversion of polymer assemblies. Herein, we report the macroscopic helicity and dynamic manipulation of the chiroptical activity of supramolecular assemblies from discrete azobenzene‐containing oligomers (azooligomers), together with the helicity inversion and morphological transition achieved solely by changing the iterative chain lengths. The corresponding assemblies also differ from their polydisperse counterparts in terms of thermodynamic properties, chiroptical activities, and morphological control. [ABSTRACT FROM AUTHOR]

To date, perovskite solar cells (pero‐SCs) with doped 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐spirobifluorene (Spiro‐OMeTAD) hole transporting layers (HTLs) have shown the highest recorded power conversion efficiencies (PCEs). However, their commercialization is still impeded by poor device stability owing to the hygroscopic lithium bis(trifluoromethanesulfonyl)imide and volatile 4‐tert‐butylpyridine dopants as well as time‐consuming oxidation in air. In this study, we explored a series of single‐component iodonium initiators with strong oxidability and different electron delocalization properties to precisely manipulate the oxidation states of Spiro‐OMeTAD without air assistance, and the oxidation mechanism was clearly understood. Iodine (III) in the diphenyliodonium cation (IP+) can accept a single electron from Spiro‐OMeTAD and forms Spiro‐OMeTAD⋅+ owing to its strong oxidability. Moreover, because of the coordination of the strongly delocalized TFSI− with Spiro‐OMeTAD⋅+ in a stable radical complex, the resulting hole mobility was 30 times higher than that of pristine Spiro‐OMeTAD. In addition, the IP‐TFSI initiator facilitated the growth of a homogeneous and pinhole‐free Spiro‐OMeTAD film. The pero‐SCs based on this oxidizing HTL showed excellent efficiencies of 25.16 % (certified: 24.85 % for 0.062‐cm2) and 20.71 % for a 15.03‐cm2 module as well as remarkable overall stability. [ABSTRACT FROM AUTHOR]

Unraveling the chirality transfer mechanism of polymer assemblies and controlling their handedness is beneficial for exploring the origin of hierarchical chirality and developing smart materials with desired chiroptical activities. However, polydisperse polymers often lead to an ambiguous or statistical evaluation of the structure–property relationship, and it remains unclear how the iterative number of repeating units function in the helicity inversion of polymer assemblies. Herein, we report the macroscopic helicity and dynamic manipulation of the chiroptical activity of supramolecular assemblies from discrete azobenzene‐containing oligomers (azooligomers), together with the helicity inversion and morphological transition achieved solely by changing the iterative chain lengths. The corresponding assemblies also differ from their polydisperse counterparts in terms of thermodynamic properties, chiroptical activities, and morphological control. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Mechanoredox chemistry that uses highly polarized piezoelectric materials as mechanoredox catalysts to promote redox reactions has emerged recently. It provides an alternative approach alongside the existing polymerization methods. Despite recent accomplishments, determining the quantitative relationship between the structure of ZnO and its catalytic performance for polymerization is still challenging. Herein, we prepared various ZnO crystals with different polar facets ratios to achieve efficient mechanically induced reversible addition‐fragmentation chain transfer polymerization (mechano‐RAFT). ZnO prepared from Zn(NO3)2 showed a high polar facet ratio of 1.66 and offered the highest catalytic activity among all ZnO samples. A near‐quantitative initiator efficiency of 99.5% and narrow molecular weight distribution were achieved for the polymerization of n‐butyl acrylate. Furthermore, the high chain‐end fidelity and chain extension capability were also evidenced by MALDI‐TOF MS and GPC analysis. This work highlighted the significant contribution of polar facets in ZnO to its catalytic activity and will guide the design of mechanoredox catalysis with superior catalytic performance in the future. [ABSTRACT FROM AUTHOR]

Modulating on‐demand polymerization is a challenge in synthetic macromolecules. Herein, tailoring polymerization controllability and dispersity during single‐electron transfer mediated living radical polymerization (SET‐LRP) of methyl methacrylate (MMA) is achieved. Hexaarylbiimidazole (HABI) is employed as a photoswitchable catalyst, allowing reversible control of catalytic activity between an active and inactive state. In the presence of HABI and with the light on (active state), control SET‐LRP of MMA follows first‐order kinetics, resulting in polymers with a narrow molecular weight distribution. In contrast, polymerization responds to light and reverts to their original uncontrolled state with light off (inactive state). Therefore, repeatable resetting polymerization can be easily performed. The key to photomodulating dispersity is to use an efficient molecular switch to tailor the breadths of dispersity. Besides, the mechanism of HABI‐mediated SET‐LRP with switchable ability is proposed. [ABSTRACT FROM AUTHOR]

Rational design of monomer sequence for desired properties is challenging. This study investigates the effect of monomer distribution of double hydrophilic copolymers (DHCs) with electron‐rich units on cluster triggered emission (CTE) capacity. By means of combining latent monomer strategy, reversible addition fragmentation chain transfer (RAFT) polymerization and selective hydrolysis technology, the random, pseudo di‐block and the gradient DHCs consisting of pH‐responsive polyacrylic acid (PAA) segments and thermo‐responsive poly(N‐isopropylacrylamide) (PNIPAM) segments were successfully synthesized in a controlled manner. Moreover, the gradient DHCs showed a tremendously increased luminescent intensity due to the distinct hydrogen‐bonding interaction compared to random and pseudo di‐block DHCs. To the best of our knowledge, this is the first reported the direct correlation between luminescent intensity and sequence structure of non‐conjugated polymer. Meanwhile, thermo and pH dual‐responsive clusteroluminescence could be easily performed. This work demonstrates a novel and facile method to tailor the hydrogen‐bonding for the stimuli‐responsive light‐emitting polymers. [ABSTRACT FROM AUTHOR]

Polypeptoids, structural mimics of polypeptides, have attracted considerable attention due to their biocompatibility, proteolytic stability, thermal processability, good solubility, synthetic accessibility, and structural diversity. Polypeptoids have emerged as an interesting material in both polymer science and biological field. This review primarily discusses the research progress of polypeptoids prepared by controlled ring‐opening polymerizations in the past decade, including synthetic strategies of monomers, polymerizations by different initiators, postfunctionalization, fundamental properties, crystallization‐driven self‐assembly, and potential biological applications. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Recently, piezocatalysis has attracted considerable attention as a new type of renewable mechanical energy conversion technology, which relies on the strain induced polarization of the piezoelectric material. This new technology has been extensively applied in the applications of water splitting, water remediation, gas purification and tumor therapy. Despite the rapid development in the piezocatalysis, the utilization of piezoelectric materials for synthetic purpose is still under exploration. Piezoelectric means to promote organic reactions expand the scope of piezoelectrically mediated reactions and show successes in both organic and polymer synthesis. Herein, we provide a comprehensive review on recent progress of piezoelectrically mediated reactions, catalytic mechanisms and applications in the last few years. The limitations and future directions of this area are also discussed. We believe this review will provide new insights into the underlying mechanism of piezoelectric mediated electron transfer process and guide the design of new chemistry. [ABSTRACT FROM AUTHOR]

Drug carriers and visual tracking play an important role in accurate and efficient drug delivery systems for targeted drug therapy. Polymerization‐induced self‐assembly (PISA), a powerful strategy for the fabrication of stimuli‐responsive polymeric nanoparticles has been a focus over the past decade due to its promising applications in biomedical fields such as targeted drug delivery and fluorescent nanoprobes used for tumor imaging. Herein, hypoxia‐responsive near‐infrared (NIR) fluorescent nanoprobes of amphiphilic block copolymers (PPEGMA14‐ADP‐Azo‐PBzMAx) are reported, the first example synthesized by RAFT‐mediated PISA strategy in situ to realize synchronous drug release and cell imaging. First, a series of nanoparticles with different morphologies and sizes, including spheres and vesicles, are synthesized by the PISA strategy using PPEGMA14‐ADP‐Azo‐CDPA as macro‐RAFT agents link with near‐infrared Aza‐BODIPY fluorogen and azobenzene groups. Hypoxia‐triggered dissociation of the nanoprobes and NIR fluorescence emission is then observed because of the cleavage of azo bonds. Meanwhile, the in situ DOX‐loaded nanoprobes by the PISA demonstrate synchronous drug release and NIR fluorescence enhancement against mouse colon cancer cells (CT26) under hypoxia (1% O2) compared with under normoxia (16% O2). [ABSTRACT FROM AUTHOR]

The self‐assembly of amphiphilic oligomers/polymers is a versatile and promising approach for creating nonspherical polymeric nanoparticles. Discrete amphiphilic oligomers/polymers with molecularly defined structures are ideal candidates for fabricating smart nanoparticles and for achieving a deeper understanding of structure‐controlled self‐assembly. Herein, discrete and disperse amphiphilic homopolymers of PAZOnTEG2n, with hydrophobic azobenzene are designed and synthesized as the main chains tethered with hydrophilic tetraethylene glycol monomethyl ether (TEG) units, to accurately investigate the impact of dispersity on their self‐assembly in solution. The discrete‐PAZO8TEG16 in DMF/water and in THF/water results in the formation of 2D lamellae, while the dispersed counterpart prefers to self‐assemble into spherical micelles. The significant difference is due to their distinction between interior structures of assembly. Furthermore, photoisomerization of azobenzene triggers dissociation/reassembly for discrete polymeric nanoparticles but no obvious change for the dispersed counterparts under irradiation with UV/vis light. This work reveals the influence of dispersity on the self‐assembly of amphiphilic polymers and stimuli‐responsive properties of their nanomaterials, which is desirable for universal applicability in fabricating smart 2D lamellas. [ABSTRACT FROM AUTHOR]

Digital polymers with precisely arranged binary units provide an important option for information storage. This is especially true if the digital polymers are assembled in a device, as it would be of great benefit for data writing and reading in practice. Herein, inspired by the DNA microarray technique, the programmable information storing and reading on a mass spectrometry target plate is proposed. First, an array of 4‐bit sequence‐coded dithiosuccinimide oligomers is efficiently built through sequential thiol‐maleimide Michael couplings with good sequence readability by tandem mass spectrometry (MS/MS). Then, toward engineering microarrays for information storage, a programmed robotic arm is specifically designed for precisely loading sequence‐coded oligomers onto the target plate, and a decoding software is developed for efficient readout of the data from MS/MS sequencing. Notably, short sequence‐coded oligomer chains can be used to write long strings of information, and extra error‐correction codes are not required as usual due to the inherent concomitant fragmentation signals. Not only text but also bitimages can be automatically stored and decoded with excellent accuracy. This work provides a promising platform of digital polymers for programmable information storing and reading. [ABSTRACT FROM AUTHOR]

The field of force-induced release of small cargoes within polymeric materials has experienced rapid growth over the past decade, not only including achieving diversified functional materials that report force, trigger degradation, activate drugs and release catalysts, but also involving investigations on the interesting force-coupled reactivity of mechanophores, such as ferrocenes. In this highlight article, we review the recent progress on polymer mechanochemistry that releases small cargoes, including small molecules and metal ions. Since mechanophores play a key role in force-responsive materials, we introduce the progress by discussing different types of mechanophores and their mechanochemical reactions for the release of acids, gases, fluorophores, drugs, iron ions, and so on. At the end, we provide our perspectives on the remaining challenges and future targets in this growing field. [ABSTRACT FROM AUTHOR]

Herein is presented a compilation of the main characteristics of maleimide chemistry in developing the precisely controlled polymers, including the design of sequence‐controlled polymers, topological polymers, and polymeric single‐chain nanoparticles. The synthetic methods, relied on the versatilities of the maleimide moieties as a latent monomer which leads to an efficient alternative in various innovative applications, especially in self‐healing material, self‐reporting materials for real‐time monitoring, and also in data storage and anticounterfeiting technologies. The core of the content in this review is focused on the up‐to‐data advances and publications on the major of maleimide chemistry in our research group. What is the most favorite and original chemistry developed in your research group? Maleimide chemistry in precision polymer synthesis. How do you get into this specific field? Could you please share some experiences with our readers? When I was a junior high school student, the chemistry attracted me very much. Chemistry is an extraordinary magic, which virtually generates molecules, basic units and everything on earth. I selected the polymer chemistry area when I pursuit my MSc and PhD in Soochow University. The polymer chemistry is the basic and originality of polymer science, which has created tremendous useful materials and greatly benefited humanity in the past century. Engaging in chemistry research is tedious and hard most of the time, but I like the joy and accomplishment at the moment when the experiment succeeds. It's like tea tasting, the kind of fleeting back sweetness makes me yearn and intoxicated. How do you supervise your students? I always encourage students to believe themselves, however don't always believe what others have said. The students should have their own judgments based on broad literature survey, comprehensive learning and deep thinking. The students should not take the publications but the improvements of research capability as the only target when pursuing the academic degree. What is the most important personality for scientific research? Be joyful, enthusiastic, persistent and careful. How do you keep balance between research and family? I like cooking for my family. Cooking is similar with chemical experiments. I think that cooking is a good balance between research and family. [ABSTRACT FROM AUTHOR]

Sequence control has attracted increasing attention for its ability of regulating polymer property and performance. Herein, the sequence‐controlled polymer containing acrylonitrile (AN) is achieved by using 2,5‐dimethylfuran/acrylonitrile adduct as a latent monomer. The temperature‐dependent retro Diels–Alder reaction is engaged in controlling the release of AN during RAFT polymerization, that is, regulating the instant AN concentration via a non‐invasive and in situ manner. Such control over the instant AN concentration and particularly the molar ratio of comonomer pair leads to the simultaneous change of monomer units in "living" polymeric chain, thus resulting in the sequence–controlled polymeric structures. By delicately manipulating the polymerization temperature, diverse sequence‐on‐demand structures of AN‐containing copolymers, such as poly(AN/methyl methacrylate), poly(AN/styrene), poly(AN/butyl acrylate), poly(AN/N,N‐dimethylacrylamide), and poly(AN/N‐isopropylacrylamide) are created. Meanwhile, this study presents an initial attempt in tuning the thermal responsivity of poly(AN/N‐isopropylacrylamide), which is closely correlated to the sequence of polymer structure. More importantly, the polymer with averagely distributed AN units results in the higher thermal sensitivity. Therefore, the synthetic strategy proposed in this work offers a promising platform for accessing the sequence‐controlled copolymers containing AN structures, thus expanding the investigation on the relationship between the polymer structures and correlated properties. [ABSTRACT FROM AUTHOR]

Polymer molecular weight distribution (MWD) is a key parameter of polymers. Here we present a robust method for controlling polymer MWD in controlled cationic polymerizations. A latent mediator strategy was designed and combined with temporal programming to regenerate mediators at different times during polymerization. Both the breadths and shapes of MWD curves were tuned easily by adjusting an external light source. Bimodal, trimodal, and tetramodal distributions were obtained, and the breadths could be varied from 1.06 to 2.09. Polymers with different MWDs prepared by this method had good chain end fidelity, which was demonstrated with successful chain‐extension experiments. In addition, the introduction of temporal programming with a computer‐controlled single chip for the light source opened an avenue for the use of artificial intelligence in polymer synthesis. [ABSTRACT FROM AUTHOR]

Polymer molecular weight distribution (MWD) is a key parameter of polymers. Here we present a robust method for controlling polymer MWD in controlled cationic polymerizations. A latent mediator strategy was designed and combined with temporal programming to regenerate mediators at different times during polymerization. Both the breadths and shapes of MWD curves were tuned easily by adjusting an external light source. Bimodal, trimodal, and tetramodal distributions were obtained, and the breadths could be varied from 1.06 to 2.09. Polymers with different MWDs prepared by this method had good chain end fidelity, which was demonstrated with successful chain‐extension experiments. In addition, the introduction of temporal programming with a computer‐controlled single chip for the light source opened an avenue for the use of artificial intelligence in polymer synthesis. [ABSTRACT FROM AUTHOR]

Supramolecular chirality and its complete self‐recovery ability are highly mystical in nature and biological systems, which remains a major challenge today. Herein, we demonstrate that partially cross‐linked azobenzene (Azo) units can be employed as the potential chiral trigger to fully heal the destroyed helical superstructure in achiral nematic polymer system. Combining the self‐assembly of Azo units and terminal hydroxyl groups in polymer side chains allows the vapor‐induced chiral nematic phase and covalent fixation of the superstructure via acetal reaction. The induced helical structure of Azo units can be stored by inter‐chain cross‐linking, even after removal of the chiral source. Most interestingly, the stored chiral information can trigger perfect chiral self‐recovery (CSR) behavior after being destroyed by UV light, heat, and solvents. The results pave a new way for producing novel chiroptical materials with reversible chirality from achiral sources. [ABSTRACT FROM AUTHOR]

Supramolecular chirality and its complete self‐recovery ability are highly mystical in nature and biological systems, which remains a major challenge today. Herein, we demonstrate that partially cross‐linked azobenzene (Azo) units can be employed as the potential chiral trigger to fully heal the destroyed helical superstructure in achiral nematic polymer system. Combining the self‐assembly of Azo units and terminal hydroxyl groups in polymer side chains allows the vapor‐induced chiral nematic phase and covalent fixation of the superstructure via acetal reaction. The induced helical structure of Azo units can be stored by inter‐chain cross‐linking, even after removal of the chiral source. Most interestingly, the stored chiral information can trigger perfect chiral self‐recovery (CSR) behavior after being destroyed by UV light, heat, and solvents. The results pave a new way for producing novel chiroptical materials with reversible chirality from achiral sources. [ABSTRACT FROM AUTHOR]

It is well known that macromolecular structure, including composition, topology and sequence, significantly determines the properties of conjugated polymers/oligomers. To accurately understand the structure‐induced properties, discrete oligomers/polymers with molecularly defined structures are the ideal model because they provide distinct nonstatistical results. Herein, a series of discrete conjugated fluorene‐azo oligomers with different positions of the azobenzene units along the main chain (i.e., sequence) are efficiently prepared based on CuAAC "click" chemistry via a stepwise chain‐growth strategy. Position‐dependent behavior has an evident impact on the properties of oligomers, such as thermal properties, optical properties and photoresponsive behavior in both solution and thin film states. In addition, the fluorene‐azo oligomers show less photodegradation of 9,9‐dioctyl‐fluorene in the solid‐state than oligofluorene during UV light irradiation; however, position‐dependent photodegradation is found in solution. Optimized configurations and UV–vis absorption spectra of fluorene‐azo oligomers are calculated by density functional theory. Experimental results and theoretical analysis indicate that the location of azobenzene can play a dominant role in determining the properties of fluorene‐azo oligomers resulting from sequence‐mandated conformational changes. Undoubtedly, this work can provide deeper insight into the structure–property relationships based on precisely sequence‐defined polymer structures. [ABSTRACT FROM AUTHOR]

Aqueous two-phase systems (ATPSs) based on ionic liquids (ILs) are efficient and green extraction systems. In this study, ATPSs consisted of three hydrophilic imidazolium-based ionic liquids ([C 4 mim]Br, [C 6 mim]Br, and [C 8 mim]Br) with phosphate, which were employed for Pd(II) extraction in acidic solutions. The obtained results showed that IL-ATPSs exhibited excellent Pd(II) extraction performance in acidic media, and Pd(II) was concentrated into ionic liquid rich upper phase. Palladium(II) extraction efficiencies of the three imidazolium-based ILs in acidic media were >98%, and the order of extraction efficiencies was: [C 4 mim]Br > [C 6 mim]Br > [C 8 mim]Br. Palladium(II) concentrated in IL-rich phase was recovered via direct reduction with hydrazine hydrate. Fourier transform infrared spectrometer (FT-IR) and mass spectrometry characterization indicated that Pd(II) migration into IL-rich phase followed an ion-exchange mechanism. Furthermore, transmission electron microscopy showed that "oil-in-water" micelles were formed during Pd(II) extraction. • The order of extraction efficiencies was: [C 4 mim]Br > [C 6 mim]Br > [C 8 mim]Br. • IL-based ATPSs can efficiently extract Pd(II) in acidic medium. • The Pd(II) extraction mechanism of IL-based ATPSs was studied. [ABSTRACT FROM AUTHOR]

[Display omitted] • The use of La/Ca-BDC-1 can reduce the cost of phosphorus removal by about 40%. • La/Ca-BDC-1 can efficiently remove phosphorus from natural water. • The phosphorus removal mechanism of La/Ca-BDC-1 was studied. In this study, low-cost and water-stable La/Ca bimetallic organic framework (La/Ca-BDC) are synthesized and used for the efficient removal of phosphorus in water. The study of adsorption isotherms shows that the high concentration of Ca in La/Ca-BDC-1 (prepared with Ca molar fraction in the precursor as high as 50%) has little interference to the phosphorous adsorption capacity (66.0 mg g−1) compared with that of the La-BDC (71.0 mg g−1), or only 7.0% drop, but it translates to significantly reduced cost of phosphorus removal by about 40.0%. The kinetic study of phosphorus removal process using the synthesized La/Ca-BDC-n conforms to the pseudo-second-order kinetic model. In addition, the synthesized La/Ca-BDC-1 is suitable for phosphorus removal in wide pH water (3.0–9.0). More importantly, the manufactured La/Ca-BDC-1 can efficiently remove the phosphorus in the actual water. In addition, even if there are interfering ions (Ca2+, Mg2+, CO 3 2–, HCO 3 –, SO 4 2- and Cl-) with concentration of five times of the phosphorus, the phosphorus removal efficiency of La/Ca-BDC-1is hardly affected. Interestingly, the removal efficiency of La/Ca-BDC-1 for phosphorus is still higher than 70% after five cycles. From the FT-IR and XPS analysis, it is shown that ligand exchange and complexation are the main phosphorus removal mechanisms of La/Ca-BDC-1. [ABSTRACT FROM AUTHOR]

A pendant group recyclable poly (vinyl ester) [poly vinyl 4-((tert -butyldiphenylsilyl) oxy) butanoate, PVBT] was synthesized by classic free radical polymerization of a γ -butyrolactone (γ -BL)-derived vinyl ester. With the locking by tert -butyldiphenylsilyl group on the pendant groups, the obtained PVBT is stable and available for further processing. When the locking group is removed by adding tetra - n -butylammonium fluoride, the PVBT will decompose to the widely used poly (vinyl alcohol) (PVA) with 100% recovery of γ -BL, which can be reused to synthesize the monomer. In addition, the decomposition of PVBT can be controlled by modulating the removal of the locking group, resulting in PVA with different hydroxyl substituent contents. It was found that the elongation at break of PVBT can reach 8100%, which is 30 times that of polyvinyl acetate (PVAc). Furthermore, the PVBT possesses stronger thermal stability and lower glass transition temperature than PVAc due to their longer and silicon-containing pendant groups. [Display omitted] • A new poly (vinyl ester), PVBT, that possesses pendant groups recyclability was synthesized. • The elongation at break (ε B) of PVBT can reach 8100%, which is 30 times that of poly (vinyl acetate) (PVAc). • Compared to PVAc, the PVBT exhibits stronger thermal stability and lower glass transition temperature (T g). • By removing TBDPS, the PVBT will release the PVA segments in a controlled manner with 100% recovery of γ-BL\. [ABSTRACT FROM AUTHOR]

[Display omitted] • First microflow cationic polymerization under ambient conditions. • No further purification of all reagents were required. • Well-defined poly(vinyl ether)s can be achieved within 2 min. Living cationic polymerization is a well-established method for preparing polymers with controlled molecular weights and complex architectures, but rigorous polymerization conditions limit its widespread application. Here, we report a facile strategy for simplifying the strict conditions required for traditional living cationic polymerizations of various vinyl ethers including ethyl vinyl ether (EVE), propyl vinyl ether (PVE), butyl vinyl ether (BVE) and isobutyl vinyl ether (IBVE) by utilizing continuous microflow reactors and a weak Lewis acid, zinc chloride (ZnCl 2). Well-defined polymers with controlled molecular weights and narrow molecular weight distributions (<1.20) can be obtained under ambient conditions without monomer purification, temperature control or strictly anhydrous conditions. The living nature of the polymerization was verified by kinetic experiments and successful in situ chain extension. [ABSTRACT FROM AUTHOR]

Azoreductase-based near-infrared (NIR) fluorescent probe represents a potent tool in the biological detection and drug delivery for treating hypoxic tumor and colon disease. Various azobenzene derivatives have aroused wide attention to develop these fluorescent probes based on the "profluorescence", however, most of the azobenzene derivatives have absorptions and emissions in the visible region. Herein, a novel NIR fluorescent probe ADP-Azo has been designed and synthesized, which is non-conventional azobenzene derivatives composed of a NIR fluorescent molecule Aza-BODIPY connected directly with azobenzene moiety for a convenient access to quench the fluorescence. In the presence of azoreductase, the azo bonds of ADP-Azo are cleaved and the fluorescence of the probe changes from "OFF" to "ON". In addition, the drug-loaded nanoprobe are successfully fabricated by self-assembly of the amphiphilic polymer mPEG 2k -ADP-Azo derived from the ADP-Azo in PBS buffer solution. These drug-loaded micelles indicate efficiently "ON-OFF" switch of NIR fluorescence accompanied by drug release under the action of azoreductase in a simulated colon environment. The fluorescent nanoprobes based ADP-Azo demonstrate the potential applications in fluorescence imaging and controlled drug release for treating hypoxic tumor and colon disease. [Display omitted] • Herein, a novel NIR fluorescent probe ADP-Azo has been designed and synthesized, which is non-conventional azobenzene derivatives composed of a NIR fluorescent molecule Aza-BODIPY connected directly with azobenzene moiety for a convenient access to quench the fluorescence. • In the presence of azoreductase, the azo bonds of ADP-Azo are cleaved and the fluorescence of the probe changes from "OFF" to "ON". • In addition, the drug-loaded nanoprobe are successfully fabricated by self-assembly of the amphiphilic polymer mPEG 2k -ADP-Azo derived from the ADP-Azo in PBS buffer solution. • These drug-loaded micelles indicate efficiently "ON-OFF" switch of NIR fluorescence accompanied by drug release under the action of azoreductase in a simulated colon environment. • The fluorescent nanoprobes based ADP-Azo demonstrate the potential applications in fluorescence imaging and controlled drug release for treating hypoxic tumor and colon disease. [ABSTRACT FROM AUTHOR]