Machine learning(ML)has emerged as a powerful tool for predicting polymer properties,including glass transition temperature(Tg),which is a critical factor influencing polymer applications.In this study,a dataset of po...Machine learning(ML)has emerged as a powerful tool for predicting polymer properties,including glass transition temperature(Tg),which is a critical factor influencing polymer applications.In this study,a dataset of polymer structures and their Tg values were created and represented as adjacency matrices based on molecular graph theory.Four key structural descriptors,flexibility,side chain occupancy length,polarity,and hydrogen bonding capacity,were extracted and used as inputs for ML models:Extra Trees(ET),Random Forest(RF),Gaussian Process Regression(GPR),and Gradient Boosting(GB).Among these,ET and GPR achieved the highest predictive performance,with R2 values of 0.97,and mean absolute errors(MAE)of approximately 7–7.5 K.The use of these extracted features significantly improved the prediction accuracy compared to previous studies.Feature importance analysis revealed that flexibility had the strongest influence on Tg,followed by side-chain occupancy length,hydrogen bonding,and polarity.This work demonstrates the potential of data-driven approaches in polymer science,providing a fast and reliable method for Tg prediction that does not require experimental inputs.展开更多
Succinonitrile(SN)-based polymer plastic crystal electrolytes(PPCEs)are regarded as promising candidates for lithium metal batteries but suffer from serious side reactions with Li metal.Herein,we propose a multi-dimen...Succinonitrile(SN)-based polymer plastic crystal electrolytes(PPCEs)are regarded as promising candidates for lithium metal batteries but suffer from serious side reactions with Li metal.Herein,we propose a multi-dimensional optimization strategy to alleviate the side reactions between SN and Li metal,and develop a highly stable poly-vinylethylene carbonate-based PPCE(PPCE-VEC).Moreover,we identify the intrinsic factors of multi-dimensional polymer structures on the electrolyte stability by three typical classes of polyesters.The PPCE-VEC constructed by in situ polymerization exhibits much better stability than poly-vinylene carbonate-based PPCE(PPCE-VCA)and poly-trifluoroethyl acrylate-based PPCE(PPCE-TFA),which is verified by its fewer SN-decomposition species in X-ray photoelectron spectroscopy(XPS)and outstanding full cell performance.The PPCE-VEC-enabled LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)full cell achieve 73.7%capacity retention after 1400 cycles,which outperforms PPCE-VCA-and PPCE-TFA-enabled full cells(61.9%and 46.9%).Spectral analysis and theoretical calculation reveal that the high solvation ability of the carbonyl site,flexible polymer chain,and homogeneous electrolyte phase of PPCE-VEC are favorable to maximizing competition coordination with Li^(+)to weaken the Li^(+)–SN binding and shape an anion-rich solvation structure.This optimized polymer-involved Li^(+)solvation enhances SN stability and facilitates the formation of B/F enriched solid-electrolyte interphase(SEI),thus significantly improving PPCE stability.展开更多
Polypeptide brushes are attractive platforms to generate functional and responsive interfaces that are of potential interest due to their possible biodegradability, biocompatibility and tunable secondary structures. S...Polypeptide brushes are attractive platforms to generate functional and responsive interfaces that are of potential interest due to their possible biodegradability, biocompatibility and tunable secondary structures. Surface-initiated ringopening polymerization（SI-ROP） of α-amino acid N-carboxyanhydrides represents a powerful and versatile strategy to generate polypeptide brushes. This review is an attempt to capture the state-of-the-art in this field and highlights the latest developments in several selected areas. In addition to presenting an overview of the synthetic methods that have been used to generate polypeptide brushes via SI-ROP, this article will discuss the preparation of patterned polypeptide brushes, the conformational properties of surface-tethered polypeptides, ways to control chain orientation at surfaces as well as properties and applications of these thin polymer films.展开更多
The article describes ethylene polymerization reactions with transition metal catalysts based on complexes of CoCl_(2) and FeCl_(2) with an N,N,N-tridentate ligand 2,6-bis[1-(2,6-dimethylphenylimino)ethyl]pyridine. Th...The article describes ethylene polymerization reactions with transition metal catalysts based on complexes of CoCl_(2) and FeCl_(2) with an N,N,N-tridentate ligand 2,6-bis[1-(2,6-dimethylphenylimino)ethyl]pyridine. The complexes are converted into polymerization catalysts by reacting them either with polymethylalumoxane (MAO) or with a combination of Al(C2H5)2Cl and Mg(C4H9)2 at an [Al]:[Mg] ratio of ~3. Both MAO-activated complexes readily polymerize ethylene at 35 ℃ with the formation of linear, low molecular weight polymers with a narrow molecular weight distribution. The same complexes, when activated with the Al(C2H5)2Cl-Mg(C4H9)2 combination, form multi-center catalysts and generate polyethylenes with a broad molecular weight distribution.展开更多
A new carbon bridged cyclopentadienyl chromium complex of the type [（C5H4）C（CH3）2 CH2（C5H4N）]CrCl2 was prepared by treatment of CrCl3·（THF）3 in THF solution with the lithium salt of ligand containing cycl...A new carbon bridged cyclopentadienyl chromium complex of the type [（C5H4）C（CH3）2 CH2（C5H4N）]CrCl2 was prepared by treatment of CrCl3·（THF）3 in THF solution with the lithium salt of ligand containing cyclopentadienyl and pyridyl groups. The chromium complex was characterized by 1H NMR and elemental analysis（EA）, and the crystal structure was determined by X-ray diffraction analysis. Activated by Al（i-Bu）3, the chromium complex displayed a very high activity for methyl methacrylate（MMA） polymerization. After 24 hours,more than 95.5% MMA was converted to polymethyl methacrylate（PMMA） with a viscosity average molecular weight（Wη） of 416000 g·mol-1 at 60 ℃ for MMA/ Al（i-Bu）3 /chromium catalyst molar ratio of up to 2000：20：1. Effects of temperature, molar ratios of MMA/catalyst and catalyst/cocatalyst on the polymerization have been studied. The high conversion of MMA and high molecular weight of PMMA with narrow molecular weight distribution is caused by the unique stable active site formed by the new chromium complex and aluminum cocatalyst.展开更多
The title complex bis{1-{[（6-ethyl-2-pyridinyl）imino]methylenyl}-2-naphthale- nolato-N,O}-nickel（lI） （C36H32NnO2Ni） has been synthesized by the reaction of l-{[（6-ethyl-2- pyridinyl）imino]methylenyl}-2-naphtha...The title complex bis{1-{[（6-ethyl-2-pyridinyl）imino]methylenyl}-2-naphthale- nolato-N,O}-nickel（lI） （C36H32NnO2Ni） has been synthesized by the reaction of l-{[（6-ethyl-2- pyridinyl）imino]methylenyl}-2-naphthalenol with Ni（CH3COO）2·4H2O, and characterized by IR spectrum, elemental analysis and TG. The complicated space structure has been confirmed by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/c with a = 11.410（4）, b = 14.382（4）, c = 18.121（6） ,A, β = 97.147（6）% V= 2950.5（16）A3, C36H32N4O2Ni, Mr = 611.37, Z = 4, Dc = 1.376 g/cm3, μ = 0.698 mm-1 F（000） = 1280, the final R = 0.0519 and wR = 0.1493 （1 〉2σ（I））. This title compound was used as precatalysts for the polymerisation of norbornene. When activated with MAO, the complex exhibited excellent catalytic activity up to 1.98 × 107 g ofPNB （mol of Ni）-1 h-1 with high monomer conversion.展开更多
A novel phenoxyimine-based Schiff base ligand and its mononuclear complex [C（58）H（52）N2NiO2]（L = 2-benzhydryl-4-dimethoxy-3,5-dimethyl-salicylaldehyde） has been synthesized and characterized by IR spectrum, elem...A novel phenoxyimine-based Schiff base ligand and its mononuclear complex [C（58）H（52）N2NiO2]（L = 2-benzhydryl-4-dimethoxy-3,5-dimethyl-salicylaldehyde） has been synthesized and characterized by IR spectrum, elemental analysis, TG, WAXD spectra, ^1H NMR and ^（13）C NMR. In addition, the molecular structure has been measured by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/c with a = 14.510（6）, b = 18.573（7）, c = 20.961（6） A, β = 123.453（19）°, V = 4713（3）A^3, Mr = 867.73, Z = 4, Dc = 1.223 g/cm^3, μ = 0.456 mm^-1, F（000） = 1832, the final R = 0.0685 and wR = 0.1758（I 〉 2σ（I））. The complex was used as homogeneous catalysis of polymerization of norbornene, and the MAO as cocatalyst. The nickel complex exhibited good catalytic activity up to 1.913 × 10^7 g of PNB（mol of Ni）^-1h^-1,and the yields of these reactions depend on the nature of the substituent in the aromatic ring.展开更多
The syntheses, structures and catalytic activities of two yttrium complexes supported by pyrrolide ligands are reported. Treatment of Y（N（Si Me3）2）3 with one equivalent of H3bptd（H3bptd = 1,9-bis（2-pyrrolyl）-2,...The syntheses, structures and catalytic activities of two yttrium complexes supported by pyrrolide ligands are reported. Treatment of Y（N（Si Me3）2）3 with one equivalent of H3bptd（H3bptd = 1,9-bis（2-pyrrolyl）-2,5,8-triazanona-1,8-diene） in THF gave a complex of composition [Y（bptd）（THF）]2（1）. Reaction of Y（N（Si Me3）2）3 with one equivalent of H3tpa（H3tpa = tris（pyrrolyl-α-methyl）amine） in THF generated [Y（tpa）（THF）3]（2） in good yield. Complexes 1and 2 have been characterized by single-crystal X-ray diffraction, elemental analyses and NMR spectroscopy. Complex 1 is dinuclear. The two metal centers are doubly bridged by two amine nitrogen atoms to form a Y–N–Y–N four-membered rhombus ring. The geometries of Y^3＋ ions in 1and 2 are well described as pentagonal bipyramid and capped octahedron, respectively. The ring-opening polymerization reactions of ε-caprolactone initiated by 1 and 2, respectively, were investigated. They both exhibited good catalytic activity for the polymerization of ε-caprolactone. All of the obtained polymers have high molecular weights and relatively narrower PDIs. The polymers generated by 2 possessed polydispersity close to 1.1. The good catalytic activities of 1 and 2 reveal their potential applications in polymer industry.展开更多
INTRODUCTION Group transfer polymerization (GTP) is a method for controlling the structure of acrylic polymers in which reactive chain ends are covalentiy bound to a trimethylsilyl group. In the presence of a catalyst...INTRODUCTION Group transfer polymerization (GTP) is a method for controlling the structure of acrylic polymers in which reactive chain ends are covalentiy bound to a trimethylsilyl group. In the presence of a catalyst, monomer inserts into these chain ends between the silyl group and the last monomer unit. The process is illustrated by equation (1) for methyl methacrylate. GTP is a living polymerization, i. e., there is little or no chain termination and no chain transfer. A significant advantage of GTP is that it展开更多
The influence of fluorine on the structure of CaO Si（）e-Al2Oa Na2O-CaF2 continuous-casting-type slag was measured by Raman spectroscopy, and the degree of polymerization of mould flux and the structural behavior of ...The influence of fluorine on the structure of CaO Si（）e-Al2Oa Na2O-CaF2 continuous-casting-type slag was measured by Raman spectroscopy, and the degree of polymerization of mould flux and the structural behavior of F- in the melt were investigated by classifying and quantifying the structural species of F ions. The results exhibit that the main structural units of Si O tetrahedra are Q1, Q1 and Q2, and the actual measured number of non bridging oxygen ions in the [SiO4 ]-tetrahedra （denoted by NBO/T） in creases from 2. 73 to 3.44 with increasing the molar ratio of F to （F＋O） （denoted by XF/X（F-O ） from 0.06 to 0. 19. It means that the degree of polymerization o1 meh structure decreases with an increase in XE/X（F＋O）. In addition, most of F- ions were distributed in Si-O tetrahedra and Al-O tetrahedra. With increasing XF/X（F＋O）, the complex structural units Al-Otetrahedra are gradually replaced hy discrete structural units A1F4 because of the breakage of Al-O bonds in Al-Otetrahedra by F ions, and the SiO （bridging oxygen） bonds of SiO tetrahedra are broken to form [SiOnF1-n]-tetrahedra by F ions coordinating with Si4 ＋ .展开更多
Induction-Polymerization is a novel method for preparing polymers of regular structure. In the presence of a special macromolecular compound, monomer molecules are aggregeted regularly around one or more growth points...Induction-Polymerization is a novel method for preparing polymers of regular structure. In the presence of a special macromolecular compound, monomer molecules are aggregeted regularly around one or more growth points and polymerized to polymer of regular structure. Regularity of structure of the polyacrylamide prepared by this means has been verified with electron diffractograms, DSC curve and IR spectrum of the polymer.展开更多
The title complex bis{1-[[（3-methyl-pyridin-2-yl） amino] methyl-phenyl]-2-hydroxy-3,5-di-tert-butylphenol} palladium（C_（42）H_（56）O_2N_4Pd） has been synthesized by the reaction of 1-[[（3-methyl-pyridin-2-yl）a...The title complex bis{1-[[（3-methyl-pyridin-2-yl） amino] methyl-phenyl]-2-hydroxy-3,5-di-tert-butylphenol} palladium（C_（42）H_（56）O_2N_4Pd） has been synthesized by the reaction of 1-[[（3-methyl-pyridin-2-yl）amino]methyl-phenyl]-2-hydroxy-3,5-di-tert-butylphenol with Pd（OAc）_2, and was characterized by IR and elemental analyses（C, H, N）. Single-crystal X-ray diffraction analysis of the complex revealed an almost parallelogram geometry of the metal center, space group P1 with a = 12.3870（13）, b = 12.9673（12）, c = 14.3998（4） ？, α = 67.53（2）, β = 75.34（2）, γ = 86.89（3）°, V = 2065.5（3） A3, M_r = 773.32, Z = 2, D_c = 1.243 g/cm^3, μ = 0.489 mm^（-1）, F（000） = 816, the final R = 0.0649 and wR = 0.1567. The compound was investigated for the catalytic behavior towards norbornene（NB） vinyl addition polymerization. And the complex exhibits high catalytic activities up to 1.668 × 10~7 g of PNB（mol of Pd）^（-1） h^（-1） with high monomer conversion using methylaluminoxane（MAO） as the cocatalyst.展开更多
Advancing the integration of artificial intelligence and polymer science requires high-quality,open-source,and large-scale datasets.However,existing polymer databases often suffer from data sparsity,lack of polymer-pr...Advancing the integration of artificial intelligence and polymer science requires high-quality,open-source,and large-scale datasets.However,existing polymer databases often suffer from data sparsity,lack of polymer-property labels,and limited accessibility,hindering system-atic modeling across property prediction tasks.Here,we present OpenPoly,a curated experimental polymer database derived from extensive lit-erature mining and manual validation,comprising 3985 unique polymer-property data points spanning 26 key properties.We further develop a multi-task benchmarking framework that evaluates property prediction using four encoding methods and eight representative models.Our re-sults highlight that the optimized degree-of-polymerization encoding coupled with Morgan fingerprints achieves an optimal trade-off between computational cost and accuracy.In data-scarce condition,XGBoost outperforms deep learning models on key properties such as dielectric con-stant,glass transition temperature,melting point,and mechanical strength,achieving R2 scores of 0.65-0.87.To further showcase the practical utility of the database,we propose potential polymers for two energy-relevant applications:high temperature polymer dielectrics and fuel cell membranes.By offering a consistent and accessible benchmark and database,OpenPoly paves the way for more accurate polymer-property modeling and fosters data-driven advances in polymer genome engineering.展开更多
Two mixed-ligand polymeric complexes formulated as {[Zn（pda）（bpy）]·0.5H2O}n （pda = 1,4-phenylenediacetate, bpy = 2,2＇-bipyridine） 1 and {[Cd（pda）（bpy）]·1.5H2O}n 2 have been hydrothermally synthesi...Two mixed-ligand polymeric complexes formulated as {[Zn（pda）（bpy）]·0.5H2O}n （pda = 1,4-phenylenediacetate, bpy = 2,2＇-bipyridine） 1 and {[Cd（pda）（bpy）]·1.5H2O}n 2 have been hydrothermally synthesized. Single-crystal X-ray diffraction analyses reveal that the structures of complexes 1 and 2 possess similar one-dimensional zigzag chains. Crystal data for compound 1： monoclinic, space group P21/c, a = 15.965（2）, b = 8.305（1）, c= 14.856（2） °A, β= 111.048（2）°, Mr = 422.73, V = 1838.2（4）°A^3, Z = 4, Dc = 1.528 g/cm^3, μ= 1.368 mm^-1, F（000） = 868, the final R = 0.0783 and wR = 0.1469 （w =1/[σ^2（Fo^2） ＋ （0.0351P）^2＋ 8.0014P], where P = （Fo^2 ＋ 2Fc^2）/3） based on 2025 observed reflections with I〉 2σ（I）; and those for compound 2： monoclinic, space group C2/c, a = 29.921 （7）, b = 8.5400（17）, c = 15.320（3） °A,β= 99.59（3）°, Mr = 487.75, V = 3859.9（14） °A^3, Z = 8, Dc = 1.668 g/cm^3, μ= 1.169 mm^-1, F（000） = 1936, the final R = 0.0723 and wR = 0.1612 （w = 1/[σ^2（Fo^2） ＋ （0.0681P）^2 ＋ 55.9577P], where P = （Fo^2 ＋ 2Fc^2）/3） based on 2130 observed reflections with I〉 2σ（I）. Fluorescent analyses show that both complexes exhibit intense blue luminescence （λmax = 485 nm for 1 and 475 nm for 2） upon excitation at 330 nm.展开更多
In this work, we synthesized a new two-dimensional Cd（Ⅱ） coordination polymer, [Cd（1,4-NDC）（L）]（1）, by using mixed 1,4-naphthalenedicarboxylic acid（1,4-H2NDC） and typical chelating N-donor ligands 2-（2-chl...In this work, we synthesized a new two-dimensional Cd（Ⅱ） coordination polymer, [Cd（1,4-NDC）（L）]（1）, by using mixed 1,4-naphthalenedicarboxylic acid（1,4-H2NDC） and typical chelating N-donor ligands 2-（2-chloro-6-fluorophenyl）-1H-imidazo[4,5-f][1,10]phenanthroline ligand（L）. Compound 1 crystallizes in monoclinic, space group P21/n with a = 12.936（5）, b = 15.245（5）, c = 13.499（5） ？, β = 105.456（5）o, V = 2565.9（16） A^3, Z = 4, C（31）H（16）CdClFN4O4, Mr = 675.33, Dc = 1.748 g/cm^3, F（000） = 1344, μ（MoKa） = 1.011 mm^-1, R = 0.0350 and wR = 0.0926. In 1, each 1,4-NDC anion bridges three adjacent Cd（Ⅱ） atoms to give a two-dimensional layer structure. The L ligands are attached on both sides of the layer in chelating coordination modes. In addition, the N–H···O hydrogen bond between L and 1,4-NDC further stabilizes the layer structure of 1. Moreover, the solid state luminescent property of 1 was also investigated at room temperature.展开更多
4D printing has attracted great interest since the concept was introduced in 2012. The past 5 years have witnessed rapid advances in both 4D printing processes and materials. Unlike 3D printing, 4D printing allows the...4D printing has attracted great interest since the concept was introduced in 2012. The past 5 years have witnessed rapid advances in both 4D printing processes and materials. Unlike 3D printing, 4D printing allows the printed part to change its shape and function with time in response to change in external conditions such as temperature, light, electricity, and water. In this review, we first overview the history of 4D printing and discuss its definition. We then summarize recent technological advances in 4D printing with focuses on methods, materials, and their intrinsic links. Finally, we discuss potential applications and offer perspectives for this exciting new field.展开更多
A new coordination polymer, [Zn2（m-bix）（p-bdc）2] （1）, was synthesized under hydrothermal conditions by a reaction of 1,3-bis（imidazol-l-ylmethyl）benzene （m-bix）, 1,3-benzene- dicarboxylic acid （H2p-bdc） an...A new coordination polymer, [Zn2（m-bix）（p-bdc）2] （1）, was synthesized under hydrothermal conditions by a reaction of 1,3-bis（imidazol-l-ylmethyl）benzene （m-bix）, 1,3-benzene- dicarboxylic acid （H2p-bdc） and Zn（NO3）2. The colorless block crystals of complex 1 （C30H22N408Zn2） belong to the triclinic system, space group P1 with a = 10.213（2）, b = 12.052（2）, c = 12.392（3） A, a = 82.97（3）, β = 76.04（3）, y = 78.02（3）°, V= 1443.8（5） A3, Z = 2, Dc = 1.604 g/cm3, Mr = 697.26, F（000） = 708, R = 0.0403 and wR = 0.0907 for 4886 observed reflections （1 〉 2σ（I））. In 1, the tetrahedral Zn11 cations are linked by [p-bdc]2- anions into 2D sql networks, which are further connected by bix ligands forming an interesting 2-fold 4,4-connected mog-type 3D network with a point symbol of {4·6^4·8}^2{4^2·6^2·8^2}. Complex 1 was characterized by elemental, IR spectroscopy, powder X-ray diffractions and thermalgravimetric analysis. In addition, complex 1 exhibits coordination induced photoluminescent property.展开更多
An experimental measurement was performed us- ing time-resolved particle image velocimetry （TRPIV） to in- vestigate the spatial topological character of coherent struc- tures in wall-bounded turbulence of polymer ad...An experimental measurement was performed us- ing time-resolved particle image velocimetry （TRPIV） to in- vestigate the spatial topological character of coherent struc- tures in wall-bounded turbulence of polymer additive solu- tion. The fully developed near-wall turbulent flow fields with and without polymer additives at the same Reynolds number were measured by TRPIV in a water channel. The compar- isons of turbulent statistics confirm that due to viscoelastic structure of long-chain polymers, the wall-normal velocity fluctuation and Reynolds shear stress in the near-wall region are suppressed significantly. Furthermore, it is noted that such a behavior of polymers is closely related to the decease of the motion of the second and forth quadrants, i.e., the ejection and sweep events, in the near-wall region. The spa- tial topological mode of coherent structures during bursts has been extracted by the new mu-level criteria based on locally averaged velocity structure function. Although the general shapes of coherent structures are unchanged by polymer additives, the fluctuating velocity, velocity gradient, velocity strain rate and vorticity of coherent structures during burst events are suppressed in the polymer additive solution com- pared with that in water. The results show that due to the polymer additives the occurrence and intensity of coherent structures are suppressed, leading to drag reduction.展开更多
Two new Ag~Ⅰ-complexes have been synthesized based on the semi-rigid ligand 2-（（pyridin-3-ylmethyl）thio）-5-（6-quinolinyl）-1,3,4-oxadiazole（L）,obtained by the condensation reaction of 5-（6-quinolinyl）-1,3,4-...Two new Ag~Ⅰ-complexes have been synthesized based on the semi-rigid ligand 2-（（pyridin-3-ylmethyl）thio）-5-（6-quinolinyl）-1,3,4-oxadiazole（L）,obtained by the condensation reaction of 5-（6-quinolinyl）-1,3,4-oxadiazole-2-thiol and 3-chloromethyl pyridine hydrochloride. Crystallization of L with Ag OTf and Ag PF_6 in a CH_2Cl_2/MeO H mixed solvent system at room temperature affords a novel supramolecular [Ag_2L_2（CF_3SO_3）_2]（I） and a coordination polymer [Ag L（PF_6）]_n（Ⅱ）,respectively. Two complexes were characterized by TGA,X-ray powder and single-crystal diffraction.展开更多
The reaction of flexible bis（imidazole） ligand and 1,2-bis（imidazol-l＇-yl）methane （bimm） with Co（Ⅱ） salt under ionothermal method resulted in the formation of a new coordination polymer {[Co（bimm）3]·...The reaction of flexible bis（imidazole） ligand and 1,2-bis（imidazol-l＇-yl）methane （bimm） with Co（Ⅱ） salt under ionothermal method resulted in the formation of a new coordination polymer {[Co（bimm）3]·（PF6）2}n （1）. X-ray single-crystal diffraction determination reveals that 1 crystallizes in the triclinic Pi space group, with α = 8.647（6）, b = 12.092（9）, c = 14.967（1 l） A, α = 88.912（8）, β = 81.199（8）, ）, = 89.395（8）°, V= 1546 （2） A3, Z = 2, Mr = 793.39, Dc= 1.704 Mg/m3,μ = 0.768 mm-1 F（000） = 798, the final R = 0.0626 and wR = 0.1634 for 4319 observed reflections with I〉 2σ（I）. In compound 1, the Co（lI） ion is connected to another Co（ll） by two bimm ligands to form 1D double chains which are further linked by bimm ligands to form a 2D wavelike layer. Topologically, the structure of 1 represents a uninodal 2D 4-connected sq1/Shubnikov tetragonal plane net. Moreover, thermogravimetric analyses and photocatalytic property for 1 have also been investigated.展开更多
文摘Machine learning(ML)has emerged as a powerful tool for predicting polymer properties,including glass transition temperature(Tg),which is a critical factor influencing polymer applications.In this study,a dataset of polymer structures and their Tg values were created and represented as adjacency matrices based on molecular graph theory.Four key structural descriptors,flexibility,side chain occupancy length,polarity,and hydrogen bonding capacity,were extracted and used as inputs for ML models:Extra Trees(ET),Random Forest(RF),Gaussian Process Regression(GPR),and Gradient Boosting(GB).Among these,ET and GPR achieved the highest predictive performance,with R2 values of 0.97,and mean absolute errors(MAE)of approximately 7–7.5 K.The use of these extracted features significantly improved the prediction accuracy compared to previous studies.Feature importance analysis revealed that flexibility had the strongest influence on Tg,followed by side-chain occupancy length,hydrogen bonding,and polarity.This work demonstrates the potential of data-driven approaches in polymer science,providing a fast and reliable method for Tg prediction that does not require experimental inputs.
基金supported by the National Natural Science Foundation of China(22072048)the Guangdong Provincial Department of Science and Technology(2021A1515010128 and 2022A0505050013).
文摘Succinonitrile(SN)-based polymer plastic crystal electrolytes(PPCEs)are regarded as promising candidates for lithium metal batteries but suffer from serious side reactions with Li metal.Herein,we propose a multi-dimensional optimization strategy to alleviate the side reactions between SN and Li metal,and develop a highly stable poly-vinylethylene carbonate-based PPCE(PPCE-VEC).Moreover,we identify the intrinsic factors of multi-dimensional polymer structures on the electrolyte stability by three typical classes of polyesters.The PPCE-VEC constructed by in situ polymerization exhibits much better stability than poly-vinylene carbonate-based PPCE(PPCE-VCA)and poly-trifluoroethyl acrylate-based PPCE(PPCE-TFA),which is verified by its fewer SN-decomposition species in X-ray photoelectron spectroscopy(XPS)and outstanding full cell performance.The PPCE-VEC-enabled LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)full cell achieve 73.7%capacity retention after 1400 cycles,which outperforms PPCE-VCA-and PPCE-TFA-enabled full cells(61.9%and 46.9%).Spectral analysis and theoretical calculation reveal that the high solvation ability of the carbonyl site,flexible polymer chain,and homogeneous electrolyte phase of PPCE-VEC are favorable to maximizing competition coordination with Li^(+)to weaken the Li^(+)–SN binding and shape an anion-rich solvation structure.This optimized polymer-involved Li^(+)solvation enhances SN stability and facilitates the formation of B/F enriched solid-electrolyte interphase(SEI),thus significantly improving PPCE stability.
基金financially supported by the Sino-Swiss Science and Technology Cooperation(No.EG41-092011)as well as the Chinese Academy of Sciences(Visiting Professorship for Senior International Scientists to H.A.K.)
文摘Polypeptide brushes are attractive platforms to generate functional and responsive interfaces that are of potential interest due to their possible biodegradability, biocompatibility and tunable secondary structures. Surface-initiated ringopening polymerization（SI-ROP） of α-amino acid N-carboxyanhydrides represents a powerful and versatile strategy to generate polypeptide brushes. This review is an attempt to capture the state-of-the-art in this field and highlights the latest developments in several selected areas. In addition to presenting an overview of the synthetic methods that have been used to generate polypeptide brushes via SI-ROP, this article will discuss the preparation of patterned polypeptide brushes, the conformational properties of surface-tethered polypeptides, ways to control chain orientation at surfaces as well as properties and applications of these thin polymer films.
基金carried out according to the program of Fundamental Scientific Research of the Russian Federation
文摘The article describes ethylene polymerization reactions with transition metal catalysts based on complexes of CoCl_(2) and FeCl_(2) with an N,N,N-tridentate ligand 2,6-bis[1-(2,6-dimethylphenylimino)ethyl]pyridine. The complexes are converted into polymerization catalysts by reacting them either with polymethylalumoxane (MAO) or with a combination of Al(C2H5)2Cl and Mg(C4H9)2 at an [Al]:[Mg] ratio of ~3. Both MAO-activated complexes readily polymerize ethylene at 35 ℃ with the formation of linear, low molecular weight polymers with a narrow molecular weight distribution. The same complexes, when activated with the Al(C2H5)2Cl-Mg(C4H9)2 combination, form multi-center catalysts and generate polyethylenes with a broad molecular weight distribution.
基金Funded by the National Natural Science Foundation of China(No.51204125)the Natural Science Foundation of Hubei Province(Nos.2014CFB812 and 2014CFB810)the Open Fund Project Funded by the Key Laboratory of Coal Conversion and New Carbon Materials of Hubei Province in China(No.WKDM201302)
文摘A new carbon bridged cyclopentadienyl chromium complex of the type [（C5H4）C（CH3）2 CH2（C5H4N）]CrCl2 was prepared by treatment of CrCl3·（THF）3 in THF solution with the lithium salt of ligand containing cyclopentadienyl and pyridyl groups. The chromium complex was characterized by 1H NMR and elemental analysis（EA）, and the crystal structure was determined by X-ray diffraction analysis. Activated by Al（i-Bu）3, the chromium complex displayed a very high activity for methyl methacrylate（MMA） polymerization. After 24 hours,more than 95.5% MMA was converted to polymethyl methacrylate（PMMA） with a viscosity average molecular weight（Wη） of 416000 g·mol-1 at 60 ℃ for MMA/ Al（i-Bu）3 /chromium catalyst molar ratio of up to 2000：20：1. Effects of temperature, molar ratios of MMA/catalyst and catalyst/cocatalyst on the polymerization have been studied. The high conversion of MMA and high molecular weight of PMMA with narrow molecular weight distribution is caused by the unique stable active site formed by the new chromium complex and aluminum cocatalyst.
基金Supported by the Natural Science Foundation of Fujian Province(2010J01026)the Ministry of Education of China(No.208066)+1 种基金the Education Department of Fujian Province(JA07029)the State Key Laboratory of Structural Chemistry(No.20130013)
文摘The title complex bis{1-{[（6-ethyl-2-pyridinyl）imino]methylenyl}-2-naphthale- nolato-N,O}-nickel（lI） （C36H32NnO2Ni） has been synthesized by the reaction of l-{[（6-ethyl-2- pyridinyl）imino]methylenyl}-2-naphthalenol with Ni（CH3COO）2·4H2O, and characterized by IR spectrum, elemental analysis and TG. The complicated space structure has been confirmed by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/c with a = 11.410（4）, b = 14.382（4）, c = 18.121（6） ,A, β = 97.147（6）% V= 2950.5（16）A3, C36H32N4O2Ni, Mr = 611.37, Z = 4, Dc = 1.376 g/cm3, μ = 0.698 mm-1 F（000） = 1280, the final R = 0.0519 and wR = 0.1493 （1 〉2σ（I））. This title compound was used as precatalysts for the polymerisation of norbornene. When activated with MAO, the complex exhibited excellent catalytic activity up to 1.98 × 107 g ofPNB （mol of Ni）-1 h-1 with high monomer conversion.
基金Supported by the Ministry of Education of China(No.208066)the Education Department of Fujian Province(JA07029)the State Key Laboratory of Structural Chemistry(No.20130013)
文摘A novel phenoxyimine-based Schiff base ligand and its mononuclear complex [C（58）H（52）N2NiO2]（L = 2-benzhydryl-4-dimethoxy-3,5-dimethyl-salicylaldehyde） has been synthesized and characterized by IR spectrum, elemental analysis, TG, WAXD spectra, ^1H NMR and ^（13）C NMR. In addition, the molecular structure has been measured by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/c with a = 14.510（6）, b = 18.573（7）, c = 20.961（6） A, β = 123.453（19）°, V = 4713（3）A^3, Mr = 867.73, Z = 4, Dc = 1.223 g/cm^3, μ = 0.456 mm^-1, F（000） = 1832, the final R = 0.0685 and wR = 0.1758（I 〉 2σ（I））. The complex was used as homogeneous catalysis of polymerization of norbornene, and the MAO as cocatalyst. The nickel complex exhibited good catalytic activity up to 1.913 × 10^7 g of PNB（mol of Ni）^-1h^-1,and the yields of these reactions depend on the nature of the substituent in the aromatic ring.
基金Supported by NNSFC(21272167)the Priority Academic Program Development of Jiangsu Higher Education Institution,and KLSLRC(KLSLRC-KF-13-HX-1)
文摘The syntheses, structures and catalytic activities of two yttrium complexes supported by pyrrolide ligands are reported. Treatment of Y（N（Si Me3）2）3 with one equivalent of H3bptd（H3bptd = 1,9-bis（2-pyrrolyl）-2,5,8-triazanona-1,8-diene） in THF gave a complex of composition [Y（bptd）（THF）]2（1）. Reaction of Y（N（Si Me3）2）3 with one equivalent of H3tpa（H3tpa = tris（pyrrolyl-α-methyl）amine） in THF generated [Y（tpa）（THF）3]（2） in good yield. Complexes 1and 2 have been characterized by single-crystal X-ray diffraction, elemental analyses and NMR spectroscopy. Complex 1 is dinuclear. The two metal centers are doubly bridged by two amine nitrogen atoms to form a Y–N–Y–N four-membered rhombus ring. The geometries of Y^3＋ ions in 1and 2 are well described as pentagonal bipyramid and capped octahedron, respectively. The ring-opening polymerization reactions of ε-caprolactone initiated by 1 and 2, respectively, were investigated. They both exhibited good catalytic activity for the polymerization of ε-caprolactone. All of the obtained polymers have high molecular weights and relatively narrower PDIs. The polymers generated by 2 possessed polydispersity close to 1.1. The good catalytic activities of 1 and 2 reveal their potential applications in polymer industry.
文摘INTRODUCTION Group transfer polymerization (GTP) is a method for controlling the structure of acrylic polymers in which reactive chain ends are covalentiy bound to a trimethylsilyl group. In the presence of a catalyst, monomer inserts into these chain ends between the silyl group and the last monomer unit. The process is illustrated by equation (1) for methyl methacrylate. GTP is a living polymerization, i. e., there is little or no chain termination and no chain transfer. A significant advantage of GTP is that it
基金the National Natural Science Foundation of China for providing financial support(Nos.51374060 and 51374059)
文摘The influence of fluorine on the structure of CaO Si（）e-Al2Oa Na2O-CaF2 continuous-casting-type slag was measured by Raman spectroscopy, and the degree of polymerization of mould flux and the structural behavior of F- in the melt were investigated by classifying and quantifying the structural species of F ions. The results exhibit that the main structural units of Si O tetrahedra are Q1, Q1 and Q2, and the actual measured number of non bridging oxygen ions in the [SiO4 ]-tetrahedra （denoted by NBO/T） in creases from 2. 73 to 3.44 with increasing the molar ratio of F to （F＋O） （denoted by XF/X（F-O ） from 0.06 to 0. 19. It means that the degree of polymerization o1 meh structure decreases with an increase in XE/X（F＋O）. In addition, most of F- ions were distributed in Si-O tetrahedra and Al-O tetrahedra. With increasing XF/X（F＋O）, the complex structural units Al-Otetrahedra are gradually replaced hy discrete structural units A1F4 because of the breakage of Al-O bonds in Al-Otetrahedra by F ions, and the SiO （bridging oxygen） bonds of SiO tetrahedra are broken to form [SiOnF1-n]-tetrahedra by F ions coordinating with Si4 ＋ .
文摘Induction-Polymerization is a novel method for preparing polymers of regular structure. In the presence of a special macromolecular compound, monomer molecules are aggregeted regularly around one or more growth points and polymerized to polymer of regular structure. Regularity of structure of the polyacrylamide prepared by this means has been verified with electron diffractograms, DSC curve and IR spectrum of the polymer.
基金Supported by the Ministry of Education of China(No.208066)the Education Department of Fujian Province(JA07029)the State Key Laboratory of Structural Chemistry(No.20130013)
文摘The title complex bis{1-[[（3-methyl-pyridin-2-yl） amino] methyl-phenyl]-2-hydroxy-3,5-di-tert-butylphenol} palladium（C_（42）H_（56）O_2N_4Pd） has been synthesized by the reaction of 1-[[（3-methyl-pyridin-2-yl）amino]methyl-phenyl]-2-hydroxy-3,5-di-tert-butylphenol with Pd（OAc）_2, and was characterized by IR and elemental analyses（C, H, N）. Single-crystal X-ray diffraction analysis of the complex revealed an almost parallelogram geometry of the metal center, space group P1 with a = 12.3870（13）, b = 12.9673（12）, c = 14.3998（4） ？, α = 67.53（2）, β = 75.34（2）, γ = 86.89（3）°, V = 2065.5（3） A3, M_r = 773.32, Z = 2, D_c = 1.243 g/cm^3, μ = 0.489 mm^（-1）, F（000） = 816, the final R = 0.0649 and wR = 0.1567. The compound was investigated for the catalytic behavior towards norbornene（NB） vinyl addition polymerization. And the complex exhibits high catalytic activities up to 1.668 × 10~7 g of PNB（mol of Pd）^（-1） h^（-1） with high monomer conversion using methylaluminoxane（MAO） as the cocatalyst.
基金financially supported by the National Natural Science Foundation of China (Nos. 92372126,52373203)the Excellent Young Scientists Fund Program
文摘Advancing the integration of artificial intelligence and polymer science requires high-quality,open-source,and large-scale datasets.However,existing polymer databases often suffer from data sparsity,lack of polymer-property labels,and limited accessibility,hindering system-atic modeling across property prediction tasks.Here,we present OpenPoly,a curated experimental polymer database derived from extensive lit-erature mining and manual validation,comprising 3985 unique polymer-property data points spanning 26 key properties.We further develop a multi-task benchmarking framework that evaluates property prediction using four encoding methods and eight representative models.Our re-sults highlight that the optimized degree-of-polymerization encoding coupled with Morgan fingerprints achieves an optimal trade-off between computational cost and accuracy.In data-scarce condition,XGBoost outperforms deep learning models on key properties such as dielectric con-stant,glass transition temperature,melting point,and mechanical strength,achieving R2 scores of 0.65-0.87.To further showcase the practical utility of the database,we propose potential polymers for two energy-relevant applications:high temperature polymer dielectrics and fuel cell membranes.By offering a consistent and accessible benchmark and database,OpenPoly paves the way for more accurate polymer-property modeling and fosters data-driven advances in polymer genome engineering.
基金This work was supported by the National Natural Science Foundation of China (No. 20231020) and Natural Science Foundation of Fujian Province
文摘Two mixed-ligand polymeric complexes formulated as {[Zn（pda）（bpy）]·0.5H2O}n （pda = 1,4-phenylenediacetate, bpy = 2,2＇-bipyridine） 1 and {[Cd（pda）（bpy）]·1.5H2O}n 2 have been hydrothermally synthesized. Single-crystal X-ray diffraction analyses reveal that the structures of complexes 1 and 2 possess similar one-dimensional zigzag chains. Crystal data for compound 1： monoclinic, space group P21/c, a = 15.965（2）, b = 8.305（1）, c= 14.856（2） °A, β= 111.048（2）°, Mr = 422.73, V = 1838.2（4）°A^3, Z = 4, Dc = 1.528 g/cm^3, μ= 1.368 mm^-1, F（000） = 868, the final R = 0.0783 and wR = 0.1469 （w =1/[σ^2（Fo^2） ＋ （0.0351P）^2＋ 8.0014P], where P = （Fo^2 ＋ 2Fc^2）/3） based on 2025 observed reflections with I〉 2σ（I）; and those for compound 2： monoclinic, space group C2/c, a = 29.921 （7）, b = 8.5400（17）, c = 15.320（3） °A,β= 99.59（3）°, Mr = 487.75, V = 3859.9（14） °A^3, Z = 8, Dc = 1.668 g/cm^3, μ= 1.169 mm^-1, F（000） = 1936, the final R = 0.0723 and wR = 0.1612 （w = 1/[σ^2（Fo^2） ＋ （0.0681P）^2 ＋ 55.9577P], where P = （Fo^2 ＋ 2Fc^2）/3） based on 2130 observed reflections with I〉 2σ（I）. Fluorescent analyses show that both complexes exhibit intense blue luminescence （λmax = 485 nm for 1 and 475 nm for 2） upon excitation at 330 nm.
基金Supported by Science and Technology Development Projects of Jilin Province(No.20150101007JC)
文摘In this work, we synthesized a new two-dimensional Cd（Ⅱ） coordination polymer, [Cd（1,4-NDC）（L）]（1）, by using mixed 1,4-naphthalenedicarboxylic acid（1,4-H2NDC） and typical chelating N-donor ligands 2-（2-chloro-6-fluorophenyl）-1H-imidazo[4,5-f][1,10]phenanthroline ligand（L）. Compound 1 crystallizes in monoclinic, space group P21/n with a = 12.936（5）, b = 15.245（5）, c = 13.499（5） ？, β = 105.456（5）o, V = 2565.9（16） A^3, Z = 4, C（31）H（16）CdClFN4O4, Mr = 675.33, Dc = 1.748 g/cm^3, F（000） = 1344, μ（MoKa） = 1.011 mm^-1, R = 0.0350 and wR = 0.0926. In 1, each 1,4-NDC anion bridges three adjacent Cd（Ⅱ） atoms to give a two-dimensional layer structure. The L ligands are attached on both sides of the layer in chelating coordination modes. In addition, the N–H···O hydrogen bond between L and 1,4-NDC further stabilizes the layer structure of 1. Moreover, the solid state luminescent property of 1 was also investigated at room temperature.
基金financially supported by the National Natural Science Funds for Distinguished Young Scholar (No.21625402)the National Natural Science Funds for Youths (No.21604070)
文摘4D printing has attracted great interest since the concept was introduced in 2012. The past 5 years have witnessed rapid advances in both 4D printing processes and materials. Unlike 3D printing, 4D printing allows the printed part to change its shape and function with time in response to change in external conditions such as temperature, light, electricity, and water. In this review, we first overview the history of 4D printing and discuss its definition. We then summarize recent technological advances in 4D printing with focuses on methods, materials, and their intrinsic links. Finally, we discuss potential applications and offer perspectives for this exciting new field.
基金Support by the National Natural Science Foundation of China(21371052)
文摘A new coordination polymer, [Zn2（m-bix）（p-bdc）2] （1）, was synthesized under hydrothermal conditions by a reaction of 1,3-bis（imidazol-l-ylmethyl）benzene （m-bix）, 1,3-benzene- dicarboxylic acid （H2p-bdc） and Zn（NO3）2. The colorless block crystals of complex 1 （C30H22N408Zn2） belong to the triclinic system, space group P1 with a = 10.213（2）, b = 12.052（2）, c = 12.392（3） A, a = 82.97（3）, β = 76.04（3）, y = 78.02（3）°, V= 1443.8（5） A3, Z = 2, Dc = 1.604 g/cm3, Mr = 697.26, F（000） = 708, R = 0.0403 and wR = 0.0907 for 4886 observed reflections （1 〉 2σ（I））. In 1, the tetrahedral Zn11 cations are linked by [p-bdc]2- anions into 2D sql networks, which are further connected by bix ligands forming an interesting 2-fold 4,4-connected mog-type 3D network with a point symbol of {4·6^4·8}^2{4^2·6^2·8^2}. Complex 1 was characterized by elemental, IR spectroscopy, powder X-ray diffractions and thermalgravimetric analysis. In addition, complex 1 exhibits coordination induced photoluminescent property.
基金supported by the National Natural Science Foundation of China(11272233)National Key Basic Research and Development Program(2012CB720101)2012 opening subjects of The State Key Laboratory of Nonlinear Mechanics(LNM),Institute of Mechanics,Chinese Academy of Sciences
文摘An experimental measurement was performed us- ing time-resolved particle image velocimetry （TRPIV） to in- vestigate the spatial topological character of coherent struc- tures in wall-bounded turbulence of polymer additive solu- tion. The fully developed near-wall turbulent flow fields with and without polymer additives at the same Reynolds number were measured by TRPIV in a water channel. The compar- isons of turbulent statistics confirm that due to viscoelastic structure of long-chain polymers, the wall-normal velocity fluctuation and Reynolds shear stress in the near-wall region are suppressed significantly. Furthermore, it is noted that such a behavior of polymers is closely related to the decease of the motion of the second and forth quadrants, i.e., the ejection and sweep events, in the near-wall region. The spa- tial topological mode of coherent structures during bursts has been extracted by the new mu-level criteria based on locally averaged velocity structure function. Although the general shapes of coherent structures are unchanged by polymer additives, the fluctuating velocity, velocity gradient, velocity strain rate and vorticity of coherent structures during burst events are suppressed in the polymer additive solution com- pared with that in water. The results show that due to the polymer additives the occurrence and intensity of coherent structures are suppressed, leading to drag reduction.
基金financially supported by the National Natural Science Foundation of China(No.21201112)
文摘Two new Ag~Ⅰ-complexes have been synthesized based on the semi-rigid ligand 2-（（pyridin-3-ylmethyl）thio）-5-（6-quinolinyl）-1,3,4-oxadiazole（L）,obtained by the condensation reaction of 5-（6-quinolinyl）-1,3,4-oxadiazole-2-thiol and 3-chloromethyl pyridine hydrochloride. Crystallization of L with Ag OTf and Ag PF_6 in a CH_2Cl_2/MeO H mixed solvent system at room temperature affords a novel supramolecular [Ag_2L_2（CF_3SO_3）_2]（I） and a coordination polymer [Ag L（PF_6）]_n（Ⅱ）,respectively. Two complexes were characterized by TGA,X-ray powder and single-crystal diffraction.
基金supported by the Natural Science Foundation of Henan Province(132300410326)the Foundation of the Education Department of Henan Province(13A150801 and 14A150040)
文摘The reaction of flexible bis（imidazole） ligand and 1,2-bis（imidazol-l＇-yl）methane （bimm） with Co（Ⅱ） salt under ionothermal method resulted in the formation of a new coordination polymer {[Co（bimm）3]·（PF6）2}n （1）. X-ray single-crystal diffraction determination reveals that 1 crystallizes in the triclinic Pi space group, with α = 8.647（6）, b = 12.092（9）, c = 14.967（1 l） A, α = 88.912（8）, β = 81.199（8）, ）, = 89.395（8）°, V= 1546 （2） A3, Z = 2, Mr = 793.39, Dc= 1.704 Mg/m3,μ = 0.768 mm-1 F（000） = 798, the final R = 0.0626 and wR = 0.1634 for 4319 observed reflections with I〉 2σ（I）. In compound 1, the Co（lI） ion is connected to another Co（ll） by two bimm ligands to form 1D double chains which are further linked by bimm ligands to form a 2D wavelike layer. Topologically, the structure of 1 represents a uninodal 2D 4-connected sq1/Shubnikov tetragonal plane net. Moreover, thermogravimetric analyses and photocatalytic property for 1 have also been investigated.
