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A series of polymers are simply synthesized by the copolymerization of vinyl functionalized polyhedral oligomeric silsesquioxanes (POSS) with vinylimidazole based linker by modulating the molar ratio of two monomers. The synthesized POSS-based polymers are capable of catalyzing the cycloaddition reaction of CO 2 with a variety of epoxides at atmospheric pressure without solvent and co-catalyst, producing cyclic carbonates with conversion up to 97.1 %. Noteworthy, the reaction kinetics studies have demonstrated that the POSS-based polymers are able to significantly reduce the activation energy of cycloaddition reactions of CO 2. In addition, as a heterogenerous catalysts, the POSS-based polymer can be recovered and recycled 5 times without reducing catalytic performance. [Display omitted] • Polymers with tunable pore size are easily prepared by controlling the ratio of crosslinker in polymerization. • The cycloaddition reaction of CO2 with epoxides mediate by POSS-based polymers under mild conditions. • The activation energy of cycloaddition reaction of epichlorohydrin with CO2 was greatly reduced by POSS-based polymers. • The synthesized POSS-based polymers are suitable for wide range of epoxy substrates and can be recycled multiple times. [ABSTRACT FROM AUTHOR]

A sustainable and green system of "heating pseudoliquid catalysis and cooling heterogeneous recovery" is constructed by cyclic polypyrazoles integrated with bromoethane, and used for efficient and stable cycloaddition of CO 2. [Display omitted] • Cyclic polypyrazoles integrated with bromoethane with low glass transition temperature. • Ionic cyclic polypyrazoles for efficient CO 2 cycloaddition with epoxides under mild conditions. • Sustainable and green system of "heating pseudoliquid catalysis and cooling heterogeneous recovery. The capture and conversion of CO 2 into value-added chemicals has become an imminent research topic in both scientific and industrial area. The cycloaddition of CO 2 with C1 resource such as epoxides to produce cyclic carbonates is an promising and efficiency pathway for CO 2 utilization. The development of catalyst for CO 2 cycloaddition with epoxides at low pressure is still a challenge. Herein, we reported the preparation of cyclic polypyrazoles integrated with bromoethane, which can serve as hydrogen bonding donor and nucleophilic groups, respectively, for activation of the epoxides and subsequent cycloaddition of CO 2. The as-obtained ionic cyclic polypyrazoles (ICPP) could exist in the form of polymetric pseudo liquid during reaction and then turns into heterogenous state after reaction due to the low glass transition temperature. By changing the reaction temperature and ratio of catalyst to epoxides, an optimized performance which show a epoxides conversion over 90 % and a selectivity of 99 % to cyclic carbonate was realized under 0.1 MPa in the absence of cocatalysts and additives. The catalyst can be facilely recovered due to its high stability, and no obvious decrease in conversion was observed after five successive runs. This work provides a sustainable and green process for CO 2 cycloaddition, and also highlights the potential of using ionic cyclic polypyrazole for conversion of CO 2 into value-added chemicals. [ABSTRACT FROM AUTHOR]

[Display omitted] • The novel block copolymer PMAA-b-PGGMA with abundant hydroxyl groups was synthesized by RAFT polymerization. • The block copolymer can effectively disperse SiO 2 particles in water with broad pH values (3–13). • The SiO 2 particles was well disoersed by spatial site-blocking effect and electrostatic repulsive effect. • Sub-micron and micron sized SiO 2 particles with high solid content (35 wt%) are effective dispersed by block copolymers in water. The dispersion of silicon dioxide (SiO 2) by a block copolymer under highly acidic or strongly alkaline conditions in water is still a challenge. In this study, block copolymers containing repeating units of methacrylic acid (MAA) and glycidyl methacrylate (GMA) were synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization. Subsequently, the epoxide groups underwent ring-opening reaction and the polymer chain end dithioester groups were removed through one-step hydrolysis, leading to the formation of a block copolymer named PMAA- b -PGGMA, which contained abundant hydroxyl groups. Hydroxyl groups act as anchoring groups and interact with the silanol groups on the surface of SiO 2 particles simultaneously, resulting in a steric site-blocking effect. Besides, the electrostatic repulsion effect of PMAA as a stable group with a negative charge on SiO 2. The block copolymer PMAA 43 - b -PGGMA 50 can effectively disperse sub-micron- and micron-sized SiO 2 even at high SiO 2 content (35 wt%) and broad pH values (3–13) in water. [ABSTRACT FROM AUTHOR]

Ring-opening Copolymerization of Epoxides and Cyclic Anhydrides catalyzed by UiO MOFs. [Display omitted] • The ROCOP of epoxides and cyclic anhydrides was succesfully carried out caltalyzed by UiO MOFs. • Polyesters with a wide range of monomer adaptability were synthesized. • The kinetic study showed that ROCOP of epoxide with cyclic anhydride catalyzed by UiO-67 was a first-order kinetic reaction. • The UiO-67 has good recoverability and without loss of catalytic activity after been reused. Ring-opening copolymerization (ROCOP) of epoxide with cyclic anhydride plays critical role in the preparation of polyesters. Herein, the UiO-type MOFs including UiO-66, UiO-66-NH 2 , UiO-66-NO 2 , UiO-66-Br and UiO-67 with octahedral morphology were synthesized by different ligands and used as heterogeneous catalysts for ROCOP of epoxide with cyclic anhydride. It was shown that the UiO-67 with ultra-high specific surface area and large pore size endows it with abundant of catalytic active sites and the highest catalytic activity, which makes UiO-67 present seven times higher turnover frequency (192.6 h−1) than that of UiO-66 (23.6 h−1) under the same conditions. Besides, the strong electron-absorbing group enhances the catalytic activity of UiO-type MOFs. The cycling test proves that the UiO-67 has good recoverability and there was no significant loss of catalytic activity after been reused for three times. The kinetic study showed that the ROCOP of epoxide with cyclic anhydride catalyzed by UiO-67 was a first-order kinetic reaction, and its apparent activation energy (E a) was about 71.75 kJ∙mol−1 calculated by the Arrhenius equation, which was 27.5% lower than that of UiO-66 (98.94 kJ∙mol−1). [ABSTRACT FROM AUTHOR]

Abstract The present paper reports a rapid and cost-effective bifunctional approach to the degradation of organic pollutants in the aqueous solution. This in situ hybrid induced photocatalytic method involves the advanced oxidation process, and photocatalytic process induced by ultraviolet radiated from the plasma discharge to improve the degradation efficiency. This powerful plasma allows the organic molecules to be cleaved either in the plasma zone or on the plasma/solution interface through hydrogen abstraction and electron transfer. Four parallel metal foil electrodes (i.e. Ta, Cu, Ti and Au coated Ti), used as cathodes in the two-electrode system, were evaluated in terms of their degradable performance to organic pollutants. It was found that the degradation rates are dependent on the electrical conduction of metal cathodes. During the discharge process, the Ti-based foil produces TiO 2 particles, which then act as catalyst in the electrolyte and perform the photocatalytic process along with the plasma discharge process to degrade organic pollutants. It is of particular interest that gold nanoparticles, generated from Au coated Ti foil film during electrode discharging, are less than 5 nm in size and further enhance the TiO 2 photocatalytic activity. In fact, this bifunctional plasma discharge process to the degradation of water pollutant provides an insight into more applications such as chemical conversion, water purification and dust pollution. Highlights • In situ hybrid induced photocatalytic method was proposed. • The degradation rates are dependent on the electrical conduction of cathodes. • Titanium-based metal foil plays bifunctional roles in the rapid degradation. • The Au film improves the electrical conductivity and also produces many Au NPs. • The degradation rate improved up to one order of magnitude. [ABSTRACT FROM AUTHOR]

The photo-induced reversible complexation-mediated radical polymerization (photo-induced RCMP) has the feature of energy-saving and environmentally friendly, which is compatible with the sustainable development advocated by the world. To promote the development of photo-induced RCMP, three two-dimensional conjugated microporous polymers (CMPs) based on different construction units were developed by aldehyde-ammonia condensation and used as catalysts, producing polymethacrylates with precise molecular weight and narrow molecular weight dispersion. Chain extension, monomer compatibility and spatiotemporal control experiments revealed the high chain end fidelity of obtain polymethacrylates and the universality of photo-RCMP process by using synthetic CMPs catalysts. The density functional theory (DFT) calculation reveals that all the highest unoccupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of three CMPs are in junction segment and connecting segment respectively, which exhibits strong electron distribution asymmetry. Moreover, the DFT and experimental results verified that the (donor-acceptor) D-A structure with push-pull electron ability and π-conjugated electron channel promote intermolecular charge transfer, which reduce the Gibbs free energy of photo-induced RCMP to increase the electron transport ability and the polymerization rate. This work indicates that by the construction of D-A structure and π-conjugated electron channel can effectively enhance the catalytic properties of CMPs-based photocatalysts, which provides a methodology to design heterogeneous photocatalysts for photo-induced RCMP. [Display omitted] • Three CMPs heterogeneous photo-catalysts were prepared by aldehyde-ammonia condensation. • D-A and higher degree of π-conjugation reduces the activation energy barrier of the initiator and raises photo-induced RCMP. • D-A structure and higher degree of π-conjugation played critical role to CMPs enhance catalytic performance. [ABSTRACT FROM AUTHOR]

Inspired by the biological tissues that can autonomously grow with respect to the surrounding mechanical environment, a dual-responsive hydrogel actuator was well developed by integrating such the characteristics as self-strengthening, strain-adaptive stiffening, and intelligent actuation into the single device. [Display omitted] • A dynamically adaptive bilayer hydrogel actuator of PVA/PNIPAm was developed. • In the bilayer hydrogel actuator, each monolayer functions differently. • This actuator can perform rapid 3D actuation upon temperature/salt stimuli. • This bio-inspired hydrogel actuator can display the self-strengthening behavior. Inspired by intelligent biomaterials which often have flexible responsiveness to multiple environmental cues and strengthen their mechanical properties by trainings, emerging soft actuators require programmable manipulation. Currently, the integration of such characteristics as rapid self-strengthening, strain-adaptive stiffening and smart actuation, into a single hydrogel actuator is urgently needed. Here, we report a self-strengthened hydrogel actuator based on the semi-interpenetrating polymer network consisting of polyvinyl alcohol (PVA) and poly(N-isopropylacrylamide) (PNIPAm), which can display diverse programmable actuations by responding to temperature/salt stimuli. In the design, the layer of freeze-thawed PNIPAm/PVA (PPGel-F) is assembled with another original PNIPAm/PVA hydrogel layer (PPGel) into one device. By taking advantage of the PVA crystalline nanofibrils in the PPGel-F matrix, the differentiated swelling degree across the bilayer structure gives rise to asymmetric deformations and the resultant shape transformation. Moreover, upon the mechanical training with less than 100 cycles, the anisotropic arrangement of PVA nanofibrils through strong hydrogen bonding interactions can swiftly immobilize the amorphous polymer chains orientation along the tensile direction. This enhances the strain-induced crystallization, thereby generating the rapid self- strengthening behavior. The proposed work provides potential solution for constructing dynamically adaptive hydrogel systems that can mimic biological tissues for more intelligent soft robotics and bionic research. [ABSTRACT FROM AUTHOR]

Porous carbon materials have been widely used as electrode materials for supercapacitors. However, low specific capacitance severely hinders the practical application. To further improve the capacitance, this work reports a facile approach to prepare N, S co-doped hierarchical porous carbon/MnO 2 composites (NSPC/MnO 2). Acidified thiourea, acting as N and S source, is used to crosslink sodium alginate (SA) to give SA-based composite gels which are pyrolyzed to produce NSPC/MnO 2. X-ray diffraction and X-ray photoelectron spectra proved that manganese exists in the porous carbon in the form of MnO 2. The obtained NSPC/MnO 2 exhibit hierarchical porous structure, remarkable mesoporous feature (the proportion of mesopores and macropores reached 32.69%), and high specific surface area of 1701 m2 g−1. Meanwhile, NSPC/MnO 2 show abundant heteroatom doping, i.e. Mn (2.05 at%), N (6.76 at%), and S (2.16 at%), which provided plenty of pseudocapacitance. The electrochemical tests show that NSPC/MnO 2 as electrode material can reach a high specific capacity of 281.1 F g−1 at 1 A g−1 (which is almost 1.85 times higher than the comparative sample), with good cycling stability (86.02% after 5000 cycles at 10 A g−1). [Display omitted] • NSPC-MnO 2 was prepared from sodium alginate by the one-step carbonization method. • The loaded MnO 2 brought rich mesoporous structure and a large amount of pseudocapacitance to the porous carbon. • NSPC-MnO2 exhibited excellent electrochemical performance (specific capacitance of 281.1 F g−1 at 1 A g−1）. [ABSTRACT FROM AUTHOR]

Facile preparation of N-doped hierarchically porous carbons (NHPCs) is an important research direction in high-performance supercapacitors (SCs). In this paper, we report a high internal phase emulsion (HIPE) template method to prepare NHPCs from melamine resins with the aid of sucrose or glucose, referred as S–NHPCs or G-NHPCs, respectively. Sucrose or glucose, formaldehyde, and melamine are dissolved in water as the continuous phase of the HIPE. Under acid catalysis, the continuous phase is cross-linked through aldimine condensation to produce porous melamine resins. Meanwhile, carbohydrate is incorporated via the interaction between the rich oxygen-containing functional groups (-OH, –C OH) of carbohydrate and the –NH 2 groups of melamine through hydrogen bonding and acetal reaction. After carbonization and activation, S–NHPCs or G-NHPCs with high specific surface areas (SSA) are obtained respectively. Besides regulating the porous morphology, biomass carbohydrate can enhance the electrochemical properties of NHPCs via increasing the SSA and hydrophilicity of NHPCs. The SSA of S – NHPC and G-NHPC increased notably from 823 to 1682 m2 g−1 and 1913 m2 g−1, respectively. Meanwhile, owing to the comprehensive N-doping and the developed porous structure, the prepared NHPC based electrodes exhibit excellent specific capacitances (up to 305 F g−1 at 1 A g−1), satisfactory cycling stability, and remarkable rate performance in a three-electrode system. [Display omitted] • N-dopped HPCs (NHPCs) with notably enhanced porosity are prepared successfully using HIPE template with the aid of biomass sucrose or glucose. • This strategy addresses the structural collapse of amino resins as carbon precursors after pyrolysis. • The S–NHPC-based symmetrical supercapacitors can successfully light up a light-emitting diode. [ABSTRACT FROM AUTHOR]

High crystallinity COF, TCPP-TPDA-COF , was constructed and employed as a heterogeneous photocatalyst using water as the reaction medium to induce oxygen-resistant reversible addition-fragmentation chain transfer polymerization under multi-wavelength LED light irradiation to produce polymers with narrow molecular weight dispersion and high chain end fidelity. [Display omitted] • Oxygen-resistant RAFT polymerization catalyzed by TCPP-TPDA-COF. • Enabling successful living radical polymerization under multi-wavelength LED. • High fidelity of the obtained polymer chain ends and narrow M w / M n values. • Excellent cycling stability along with a green reaction medium. Covalent organic frameworks (COFs) are promising heterogeneous photocatalytic platforms based on their structural designability and diversity. Here, porphyrin-based TCPP-TPDA-COF was synthesized and served as photocatalyst for the application of oxygen-tolerant photoelectron/energy transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization in the aqueous phase under visible light irradiation. The effects of catalyst loading, electron sacrificial agent dosage, solvent type, light sources and target polymerization degrees (DPs) on the polymerization behavior are discussed, and the intrinsic mechanisms of the oxygen tolerance properties are identified by the control experiments and oxygen monitoring experiments. TCPP-TPDA-COF endows the RAFT protocol with efficient light availability, high light dependence, well controllability and compatibility with different families of monomers. Programmable COFs provide a powerful avenue for further expansion of photocatalyst candidates compatible with PET-RAFT processes under oxygenated atmosphere. [ABSTRACT FROM AUTHOR]

Highlights: [•] The synthesis of cyclodextrin carbamates is facile and environmentally friendly. [•] Novel supramolecular polymer micelles are prepared by one pot method. [•] The supramolecular micelle systems have long drug release time. [ABSTRACT FROM AUTHOR]

Abstract: Supramolecular polymer micelles (SMPMs) were constructed from natural and natural-derived polymers: β-cyclodextrin (β-CD)/maleic anhydride modified β-cyclodextrin (MAh-β-CD) and methylcellulose (MC) in aqueous solution by one-pot self-assembly procedure, in which, β-CD and MAh-β-CD inclusion complexes were used as the hydrophilic shell and the free MC as the core. The shapes of the SMPMs were regular spheres with diameters of 25±5nm. The critical micelle concentrations, calculated from steady-state fluorescence emission spectra, were around 15.13 and 20.89mg/L for MC/β-CD and MC/MAh-β-CD SMPMs, respectively. The in vitro drug release behaviors of the micelles were studied using prednisone acetate as a model drug, and the results showed that the MC/MAh-β-CD micelle had a drug-enrichment core and excellent drug released behaviors with a sustaining release time of 700h. [Copyright &y& Elsevier]

High internal phase emulsion (HIPE) templating is a versatile strategy to prepare porous polymers and carbons. However, the prepared porous carbon materials usually show low specific surface area (SSA) due to the feature of macropores, which hampered their wider applications. This work developed a novel strategy, namely internal phase-external phase coefficient HIPE (IP-EP coHIPE) templating, to prepare polymer-derived hierarchically porous carbons (HPCs) with high SSA. In the strategy, sodium alginate (SA) aqueous solution was selected as the internal phase and emulsified in external oil phase containing divinylbenzene (DVB). HPCs were obtained by sequentially polymerizing the external phase, crosslinking the internal phase and carbonization. The testing results indicated that this strategy provided HPCs with notably enhanced porosity and increased SSA when compared with conventional HIPE method via the further utilization of the void space of polyHIPE-based HPCs via a facile way. The porous architectures of HPCs can be adjusted by changing the volume fraction and/or the concentration of the internal phase, respectively. The potential applications of the obtained HPCs were evaluated as the electrode material of supercapacitor. The specific capacitance of optimized HPC-based supercapacitor is 306 F/g, much higher than that based on general polyHIPE-derived HPC (145 F/g) at 1 A/g, which can be attributed to its enhanced porosity, hierarchically porous architecture and high SSA (2289 m2/g). [Display omitted] • Hierarchically porous carbons (HPCs) were prepared through an internal phase-external phase coefficient HIPE templating. • This strategy provided HPCs with notably enhanced porosity and increased specific surface area. • The HPC-based supercapacitors present satisfied energy storage performance and excellent application prospects. [ABSTRACT FROM AUTHOR]

High crystallinity of fully sp2 COF, TCPB-DMTA-COFs , was constructed and served as heterogeneous photocatalyst for inducing atom transfer radical polymerization with the assist of ppm-level of Copper as co-catalyst under LED light irradiation, producing polymers with narrow molecular weight dispersity and highly chain-end fidelity. [Display omitted] • Fully-π conjugated covalent organic framework, TCPB-DMTA-COF , was successfully designed and synthesized. • TCPB-DMTA-COF was served as photocatalyst to mediate photo-induced ATRP with the assist of ppm-level copper under LED irradiation, producing polymers with uniform molecular weight and narrow molecular weight dispersity. • The switch on/off experiments and chain extension reaction proved the high chain-end fidelity of the obtained polymers and temporal control of polymerization processes. • Comparing with TCPB-DMTA-CMP , TCPB-DMTA-COF with high crystallinity presented better catalytic properties during polymerization, providing that the crystallization of COF strongly improves its catalytic polymerization. • Mechanism study of polymerization processes by EPR experiments reveal the formation of radical. Photo-induced atom transfer radical polymerization (ATRP) becomes a significant method for preparing well-defined polymers with pre-designable molecular weight and narrow molecular weight dispersity (M w / M n). Herein, a fully-π covalent organic framework (COF) was constructed and served as heterogeneous photocatalyst for photo-induced ATRP under LED irradiation. TCPB-DMTA-COF , which was constructed by Knoevenagel polycondensation of 1,3,5-tris(4-cynomethylphenyl)benzene (TCPB) and 2, 5-Dimethoxy-terephthalaldehyde (DMTA) and exhibited remarkable performance in mediating photo-induced ATRP of methyl methacrylates with the assist of ppm-level concentration of CuII under LED irradiation, producing polymers with high chain-fidelity and low value of M w / M n (1.10–1.35). The switch "on/off" experiment exhibits excellent temporal and spatial control toward polymerization system. Compared with TCPB-DMTA-CMP, the high crystallinity and stability of TCPB-DMTA-COF endows high monomer conversion and good recyclability performance for photo-induced ATRP. These results suggest COF can be served as a promising artificial photocatalyst for photo-induced ATRP. [ABSTRACT FROM AUTHOR]

Alkyl bromide (R–Br) was employed as a starting compound (precursor) to initiate the bulk controlled radical polymerization of methyl methacrylate (MMA) under thermal condition (60 °C) in the presence of tetra-n-octylammonium iodide (Oct 4 NI) and 2,2′-azobisisoheptonitrile (V65). Alkyl iodide (R–I) and tetraoctylammonium bromide (Oct 4 NBr) were in situ generated by the reaction of R–Br with Oct 4 NI and then R–I was employed as an initiating dormant species for the polymerization. Carbon-iodine (C–I) bonds were cleaved and radicals were generated by the catalyst of Oct 4 NI and Oct 4 NBr. The chain end groups of the obtained polymers contain both I and Br, which was proved by the results of 1H nuclear magnetic resonance spectra, and elemental analysis. The reversible halogen exchange of Br with I at the polymer chain end promotes the polymerization. The introducing of V65 not only increased the polymerization speed, but also ensured high monomer conversion. Low-polydispersity (M w / M n = 1.1–1.5) polymers were obtained with high conversions (e.g., 70–90%) in the polymerizations of methyl methacrylate, styrene, acrylonitrile, and functional methacrylates. The attractive feature was that alkyl bromide was able to initiate the controlled radical polymerization of methyl methacrylate under thermal condition in the presence of organic catalyst. Besides, this new system presented desirable features of high monomer versatility and the accessibility to a wide range of polymer structural designs for use in a range of applications. Image 1 • Alkyl bromides can be used as initiator in organic catalyzed controlled radical polymerization under thermal condition. • The reversible halogen exchange of Br with I at the polymer chain end promotes the polymerization. • Ammonium bromide acts as co-catalyst to generate radical from alkyl iodides. [ABSTRACT FROM AUTHOR]