Macromolecules最新文献

{"title":"Controlling the Morphology of Conjugated Polyfluorene through Physical Stretching and Solvent Variation","authors":"Yang Xu, Zifei Chen, Lili Sun, Jamie S. Laird, Bin Liu, Salvy P. Russo, Jinyi Lin, Kenneth P. Ghiggino, Trevor A. Smith","doi":"10.1021/acs.macromol.4c03164","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c03164","url":null,"abstract":"In this paper, the intentional control of morphology and photophysical properties of a conjugated polydiarylfluorene, PODPF, in thin films is achieved through various systematic approaches including physical stretching when hosted in a highly elastic polymer, poly(vinyl butyral) (PVB) at various weight-to-weight ratios, and by varying the solvent. Microspectroscopic techniques were employed to monitor the resulting variations. Significant differences in the excitation and emission spectra are observed as functions of the concentration of PODPF mixed in the PVB film. This indicates the formation of different types of aggregates in these films through the coupling between dipoles with different relative orientations. Fluorescence anisotropy images show dramatic differences as a function of the extent of physical stretching of the film and as a function of PODPF concentration. Shifts in the emission spectra of the films as a function of the concentration in films cast from different solvents illustrate that the morphology of the films is highly dependent on the properties of the solvent from which the film is cast. The results highlight effective approaches for influencing the morphology and properties of conjugated polymers in thin films, with particular emphasis on the crucial role of solvent selection. Theoretical modeling is also employed to provide insight into the underlying principles governing these observed phenomena.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"7 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143878041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Living Anionic Polymerization of 2-Isopropenylthiophene Derivatives","authors":"Yuki Kurishiba, Daisuke Yamamoto, Chihiro Homma, Raita Goseki, Takashi Ishizone","doi":"10.1021/acs.macromol.4c02845","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02845","url":null,"abstract":"The anionic polymerization of 2-isopropenylthiophene (<b>1</b>), 2-(1-adamantyl)-5-isopropenylthiophene (<b>2</b>), 5-phenyl-2-isopropenylthiophene (<b>3</b>), and 2-cyano-5-isopropenylthiophene (<b>4</b>) was performed in tetrahydrofuran (THF) with various initiators including <i>sec</i>-BuLi, oligo(α-methylstyryl)lithium, potassium naphthalenide, and diphenylmethylpotassium at −78 °C. The anionic polymerization of <b>2</b>–<b>4</b> proceeded quantitatively to provide novel polymers with the predicted molecular weights and narrow molecular weight distributions (<i>M</i>_w/<i>M</i>_n &lt; 1.2), whereas the polymerization of <b>1</b> often suffered from side reactions, probably due to proton abstraction on the thiophene ring. After the complete polymerization at −78 °C, the propagating carbanion of the resulting polymers of <b>2</b>–<b>4</b> can be depolymerized to give the starting monomer by elevating the temperature to 0 °C. In particular, <b>3</b> showed a reversible equilibrium polymerizability similar to that of α-methylstyrene by varying the temperature of the polymerization system. From the plot of logarithm of equilibrium monomer concentration, ln[M]_e, against reciprocal temperature, the thermodynamic parameters, Δ<i>H</i> and Δ<i>S</i>, and the ceiling temperature (<i>T</i>_c) of the anionic polymerization of <b>3</b> in THF were estimated to be −8.09 ± 0.22 kcal mol^–1, −27.3 ± 0.9 cal mol^–1 K^–1, and 24 °C, respectively.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"101 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Red Sea Star-Inspired, Rapid Underwater Self-Healing Polyurethane Based on Dual Hydrophobic Units and Tandem Dynamic Bonds","authors":"Fenglong Li, Haofeng Qiu, Chao Chen, Xiaolin Wang, Minghui Cui, Shijie Qiu, Kyung Jin Lee, Jing Chen, Wu Bin Ying, Jin Zhu","doi":"10.1021/acs.macromol.4c03007","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c03007","url":null,"abstract":"Red sea stars exhibit an extraordinary underwater self-healing capability driven by fibrinolytic enzyme secretion, enabling survival in challenging marine environments. Inspired by this biological mechanism, we developed a polyurethane (DSFPU-3) capable of rapid underwater self-healing. By integrating dual hydrophobic units (alkyl side chains and fluorine groups) with tandem dynamic bonds (disulfide and imine bonds), DSFPU-3 achieved a water contact angle of 99.3° and maintained stable microphase structures and micromorphology even after 4-day water soaking. The synergistic effect of hydrophobic units and dynamic bonds enabled self-healing at a speed exceeding 33.33 μm/h, achieving 98% efficiency and allowing the material to endure significant mechanical stress post-healing. Small-molecule modeling experiments and rheological analyses validated the bond exchange mechanisms of the tandem dynamic bonds, underscoring their critical role in accelerating the self-healing process. This study presents a novel strategy for fabricating rapid underwater self-healing polyurethanes, representing a significant advancement in their application under aquatic conditions.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"74 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crystallization and Melting Behaviors of Discrete Butyolactone–Caprolactone Alternative Co-Oligomer: The Effect of End Groups","authors":"Huijun Xu, Ao Feng, Zhihao Huang, Rui Tan, Zefan Wang, Xiaohua Zhang, Zhengbiao Zhang","doi":"10.1021/acs.macromol.5c00593","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00593","url":null,"abstract":"Discrete oligomers are ideal candidates for the investigation of the crystallization behaviors of polymers since the molecular weight distribution and the precision of molecular structures play a crucial role in the crystallization behaviors of polymers. We precisely synthesize discrete alternative co-oligomers (<i>o</i>(γ-BL-<i>alt</i>-ε-CL)s) with different end groups based on ε-caprolactone (ε-CL) and γ-butyrolactone (γ-BL) as monomers using an iterative exponential growth (IEG) strategy and systematically study the crystallization and melting behaviors of the <i>o</i>(γ-BL-<i>alt</i>-ε-CL)s with precise monomer sequence. The roles that the end group plays in the crystallization and melting of co-oligomers are highlighted. The <i>o</i>(γ-BL-<i>alt</i>-ε-CL)s with different end groups (<i>tert</i>-butyldiphenylsilyl, benzoyl, acetyl) crystallize in an extended-chain conformation. Observation on the decrease of the crystallization rate of co-oligomers with the increase of the size of the end groups is associated with the slow dynamics or slow relaxation of co-oligomer chains with the large end group. The melting–recrystallization during the heating process for the <i>o</i>(γ-BL-<i>alt</i>-ε-CL)s with small end group is attributed primarily to the reduced steric hindrance effect. For the <i>o</i>(γ-BL-<i>alt</i>-ε-CL)s with large end groups, the rearrangement of co-oligomer chains is substantially hindered by steric effects, which lead to a significant suppression of the melting–recrystallization.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"35 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Network Design Parameters on the Morphology Evolution in Diels–Alder Blends via Thermodynamics and Kinetics Control","authors":"Fatemeh Sahraeeazartamar, Nirmayi Sadanand Joshi, Roos Peeters, Bram Vanderborght, Guy Van Assche, Joost Brancart","doi":"10.1021/acs.macromol.4c02936","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02936","url":null,"abstract":"Reversible polymer network blends leverage the advantageous properties of immiscible polymer backbones. Previous work showed that the phase morphology of blends of a hydrophilic poly(propylene oxide) (PPO) and hydrophobic polydimethylsiloxane (PDMS) cured by the reversible Diels–Alder reaction depends on the mass ratio of the two polymers and the maleimide-to-furan ratio used for the reversible network polymerization. This work studies the competition between the reversible Diels–Alder reaction and the phase separation kinetics and thermodynamics to control the phase formation. A furan-functionalized PPO with a molar mass of 4546 g mol^–1 was blended with furan-functionalized PDMS with different molar masses, mass ratios of the polymers, and stoichiometric ratios. At the highest molar mass of 4961 g mol^–1, the PDMS and PPO separated quickly into separate layers, creating a barrier against both water and oxygen, respectively. The thickness, morphology, and composition of the layers depend on the composition of the blend. At a lower molar mass of the PDMS, the chemistry of the furan end groups becomes more pronounced, which increases the compatibility of the two polymers, reducing the thermodynamic driving force for phase separation. In addition, the increased concentration of furan and maleimide groups increases the Diels–Alder reaction rates and leads to more cross-linked network blends. Mastering the interplay between the thermodynamics of the blends and the kinetics of the network formation and phase separation by judicious combinations of the network design parameters leads to final blend morphologies ranging from kinetically trapped uniform microstructures to almost completely phase-segregated morphologies. Finally, the solvent extraction time was used as a process parameter of the wet blending process. Slow evaporation of the solvent over the course of 1 week resulted in a near-equilibrium separation of the two immiscible polymers into separate layers with perfect interfacial bonding by the same Diels–Alder chemistry. Manipulation of these factors enables the development of Diels–Alder network blends with a wide range of properties that are suitable for a wide variety of applications. The fastest and most efficient autonomous healing is achieved at higher PPO contents and for the highest PDMS molar masses, while the best barriers against water and oxygen are obtained at the highest cross-link densities.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"7 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiscale Evolution of Chain Orientation and Crystal Structure under the Dual Action of Temperature and Stress","authors":"Chengyao Liang, Weilei Huang, Senlong Yu, Qianqian Wang, Zexu Hu, Hengxue Xiang, Meifang Zhu","doi":"10.1021/acs.macromol.5c00686","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00686","url":null,"abstract":"A comprehensive understanding of the multiscale structural evolution that governs fiber properties during polyamide formation is essential for the theoretical development of high-strength fibers. This study systematically investigates the hierarchical structural transformations in high-strength polyamide 66 fibers (H-PA66F) at key stages during high-speed spinning, with a focus on molecular chain conformations, hydrogen bonding networks, crystalline organization, orientation dynamics, and long-period structural features. By constructing a three-phase structural model, the study elucidates the progressive structural-property relationships during fiber processing. The mechanical enhancement observed throughout the formation process is attributed to synchronized structural optimizations: hot drawing enhances fiber strength through crystal perfection and increases the alignment of rigid segments, while subsequent heat setting stabilizes the structure by reducing defects. These findings establish a robust structure-performance framework, providing theoretical insights for the targeted multiscale structural engineering of high-performance polyamide fibers.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"7 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Facile Synthesis of High-Molecular-Weight Biobased Polythioethers with Outstanding Mechanical Properties and Intrinsic Antiultraviolet Performance","authors":"Qiubo Wang, Xinyu Hu, Min Yan, Xingyu Luo, Xiaojuan Liao, Meiran Xie","doi":"10.1021/acs.macromol.5c00389","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00389","url":null,"abstract":"Common methods, including adding inorganic and organic ultraviolet (UV) absorbers, for preparing anti-UV polymers inevitably have the disadvantages of poor stability, low transparency, and coloration of samples. To overcome these shortcomings, high-molecular-weight polythioethers with excellent intrinsic anti-UV performance were prepared by anion ring-opening polymerization of episulfides derived from the biobased epoxides containing a substituted phenyl group. The mechanical properties, reprocessability, and anti-UV performance of polythioethers were significantly improved through copolymerization and cross-linking modification. A cross-linked copolythioether displayed a UV protection factor value of 91.8 and a light transmittance of over 68% in the visible range and moreover exhibited outstanding mechanical properties with a tensile strength of 17.9 MPa and an elongation at break of 534%. The mechanical properties and anti-UV performance of copolythioether decreased significantly after prolonged exposure to UV light, while the cross-linked copolythioether maintained good stability. This work provided a feasible method for preparing colorless, transparent, and high-performance intrinsic anti-UV polythioethers, which can be used in the manufacture of lenses and can effectively prevent UV-light damage to the eyes.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"36 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"External Potential-Induced Enhancement of Monomer Mobility in Trapped Polymers: A Generalized Langevin Equation Study","authors":"Xiaofei Tian, Jizhong Chen, Zhi-Chao Yan, Wen-Sheng Xu, Tongfei Shi, Dapeng Wang","doi":"10.1021/acs.macromol.5c00596","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00596","url":null,"abstract":"Monomer friction in trapped polymers is a key determinant of the fundamental time scales governing a wide range of dynamic and kinetic processes in physics, chemistry, and biology. In this paper, we present a theoretical investigation of the monomer friction of individual Rouse chains trapped in a harmonic potential. Our analysis is based on the friction memory function within the framework of the generalized Langevin equation (GLE). The friction memory function comprises contributions from both solvent friction (assumed to be constant and independent of the external potential) and intra-chain friction. We demonstrate that the external potential induces an additional harmonic potential by modifying the correlations between monomers. This modification, in turn, alters the friction memory function. Our analyses of the induced potentials and relaxation time spectra reveal a characteristic chain length <i>N</i>_c, which describes the unperturbed size of the harmonically confined chain. In the long chain limit (chain length <i>N</i> ≫ <i>N</i>_c ≫ 1), the time-dependent monomer friction function exhibits universal power-law behaviors in the mediate time scale. Specifically, the exponent decreases from 1/2 to 0 as the ratio <i>k</i>′/<i>k</i> (where <i>k</i>′ is the external harmonic potential strength and <i>k</i> is the bond spring strength) increases. This behavior aligns with dynamic scaling arguments. In the long time limit, the friction function reaches a plateau, with the value varying from <i>N</i>_cγ/2 for <i>k</i>′/<i>k</i> ≪ 1 to the solvent friction γ for <i>k</i>′/<i>k</i> ≫ 1. These results indicate that the external potential enhances monomer diffusion by reducing intra-chain friction. This finding provides a fundamental understanding of the dynamics of trapped polymers and highlights the crucial role of external potentials in modifying intra-chain interactions and monomer mobility.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"259 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual Role of Ionic Liquid in High-Pressure Formation of Extended-Chain Poly(vinylidene fluoride) Crystals: Interplay between Thermodynamics and Kinetics","authors":"Haodong Huang, Ziqi Wang, Zhen Zhang, Chongyang Wang, Yanping Liu, Chuntai Liu, Chunguang Shao, Zhen Wang","doi":"10.1021/acs.macromol.5c00232","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00232","url":null,"abstract":"Exploring milder high-pressure processing conditions is essential for developing heat-resistant electroactive poly(vinylidene fluoride) (PVDF) materials based on polar extended-chain crystals (ECCs). Herein, we introduced a typical imidazole ionic liquid (IL), 1-ethyl-3-methylimidazolium tetrafluoroborate, to manipulate the melt crystallization of PVDF under high pressure. Our findings reveal a dual role of IL in ECCs formation through various structural and morphological characterizations. First, it increases the free energy of growing nuclei by raising the end surface free energy σ_e, making ECCs formation thermodynamically unfavorable. Second, it facilitates chain sliding diffusion and lowers the diffusion activation energy during nuclei growth, which promotes ECCs generation in kinetics. These two effects compete with each other, influenced by crystallization conditions and IL content. Kinetic promotion prevails at low crystallization temperatures (<i>T</i>_p) and low IL fractions, while thermodynamic inhibition dominates at high <i>T</i>_p and/or high IL fractions. This interplay is illustrated by high-pressure phase diagrams of PVDF/IL blends. A low IL fraction (e.g., 0.2%) significantly expands the ECCs growth region into lower <i>T</i>_p and pressure conditions, while a higher IL fraction has the opposite effect. This knowledge enables the rapid preparation of abundant ECCs with minimal IL addition at milder low temperatures, thereby minimizing sample degradation. Furthermore, the IL-induced ECCs primarily consist of the polar β-phase and maintain a high melting point. This study elucidates the high-pressure crystallization mechanism of PVDF/IL blends and proposes an effective strategy for enhancing the production of polar ECCs in PVDF homopolymer.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"6 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetically Separable Conjugated Microporous Triphenylphosphine Networks Enabling Dual-Gated Photoinduced Atom Transfer Radical Polymerization","authors":"Sheng Hong Jiang, Yue Zhao, Yu Rui Wang, Jianfei Chen, Xue Li, Tao Cai","doi":"10.1021/acs.macromol.5c00509","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00509","url":null,"abstract":"Magnetic stimulation demonstrates exceptional advantages in control precision, penetrability, stability, and biocompatibility, surpassing other stimulus modalities, which positions it as an ideal candidate for remote, noncontact, long-duration, and multifunctional applications. By implementing strategic molecular engineering approaches, advanced photocatalytic platforms responsive to a variety of external stimuli, beyond just light, can be developed. In this study, we report the design of a magnetism/light dual-gated photoinduced atom transfer radical polymerization (photo-ATRP) system using Fe₃O₄@PP-E core–shell nanocomposites. The nanocomposites were fabricated by incorporating triphenylphosphine as the photocatalytic component and 2,4,6-tris(4-ethynylphenyl)-1,3,5-triazine as the linker via a Sonogashira–Hagihara cross-coupling reaction on magnetite (Fe₃O₄) colloidal nanocrystal clusters. This study included the optimization of polymerization conditions to control molecular weights and achieve fast reaction kinetics while also demonstrating the recyclability of the photocatalyst through magnetic attraction. Moreover, dual-gated photo-ATRP was demonstrated by switching the light on/off and applying the magnet in/out. This system was also applied to synthesize well-defined protein–polymer conjugates under biologically relevant conditions, preserving their biological activity. This approach contributes to advancements in polymer manufacturing by enhancing catalyst removal processes and promoting sustainability.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"253 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}