Macromolecules最新文献_第4页

FRET-Integrated Polymer Brushes: What is the Most Sensitive Architecture for Probing Chain Conformation? fret集成聚合物刷：探测链构象最敏感的结构是什么？

IF 5.5 1区化学

Macromolecules Pub Date : 2025-09-25 DOI: 10.1021/acs.macromol.5c02159

Willem Van den Heuvel, Holger Merlitz, Khrystyna Rymsha, Quinn A. Besford

{"title":"FRET-Integrated Polymer Brushes: What is the Most Sensitive Architecture for Probing Chain Conformation?","authors":"Willem Van den Heuvel, Holger Merlitz, Khrystyna Rymsha, Quinn A. Besford","doi":"10.1021/acs.macromol.5c02159","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c02159","url":null,"abstract":"Polymer brush surfaces offer exciting possibilities as surface-based sensing devices, where changes in brush conformation can be used as a basis to sense stimuli. Recently, Förster resonance energy transfer (FRET) chemistry has been integrated into functional polymer brushes, which allowed for conformational changes to be spatially probed due to nanoscale proximity changes between paired fluorophores within the brushes. However, the FRET fluorophores can be arranged in a variety of different architectures within brushes (e.g., on chain ends, dispersed within, etc.), which leads to the question: what is the most sensitive arrangement of FRET fluorophores within a brush for probing conformation? Herein, we address this question from multiple directions. We devise a mathematical model of a brush which considers FRET architectures as continuous bodies of defined fluorophore density, and derive the FRET efficiency as a function of distances between bodies. For experimental based parameters (brush height, grafting density, etc.), we find that diblock random copolymer architectures are the most sensitive, followed closely by donor fluorophores dispersed within the brush, with acceptors on the chain ends. We complement this by coarse grained molecular dynamics simulations of model brush systems, and calculate the FRET efficiency as a function of brush height. The results are consistent with our model, where we find the same two brush architectures to be the most sensitive. Lastly, we compare these architectures for sensitivity from recent experimental measurements, which demonstrated reasonable agreement with both our model and simulation. Our results will inform the field on the best ways of integrating FRET chemistry into functional polymer brushes for greatest conformational sensitivity.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"21 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145141089","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}

引用次数: 0

Positional Correlation Length-Induced Morphological Transformation of Interpolyelectrolyte Complexes (IPECs) Made of Polysaccharides: The Role of Molar Charge Ratio 位置相关长度诱导的多糖多电解质间配合物（ipec）的形态转变：摩尔电荷比的作用

IF 5.5 1区化学

Macromolecules Pub Date : 2025-09-25 DOI: 10.1021/acs.macromol.5c01621

Avik Das, Sylvain Prévost, Michael Gradzielski

{"title":"Positional Correlation Length-Induced Morphological Transformation of Interpolyelectrolyte Complexes (IPECs) Made of Polysaccharides: The Role of Molar Charge Ratio","authors":"Avik Das, Sylvain Prévost, Michael Gradzielski","doi":"10.1021/acs.macromol.5c01621","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c01621","url":null,"abstract":"By combination of oppositely charged polyelectrolytes, one can form interpolyelectrolyte complexes (IPECs) that may serve, for example, as water-based delivery systems. Such macromolecular IPECs may exhibit broad size and shape distributions; thus, quantitative structural analysis is often prone to misinterpretation. By means of small-angle neutron scattering (SANS), we present a systematic analysis of the internal macromolecular structures of interpolyelectrolyte complexes (IPECs) in a quantitative fashion. As a model system, we study polyelectrolyte mixtures of anionic biosourced sodium carboxymethyl cellulose (NaCMC) and cationic synthetic poly(diallyldimethylammonium chloride) (PDADMAC). By integrating model-independent and model-dependent approaches, we reveal a morphological transformation from larger globular aggregates to smaller, multimodal lumpy structures with increasing molar charge ratio, i.e., upon approaching charge equimolarity. At the same time, the aggregates undergo significant compaction, driven by local structuring and a reduction in the characteristic correlation length of charge distribution, and they become increasingly anisometric. Additionally, the complexes retain a substantial amount of solvation water, which is gradually released as the charge ratio approaches equimolarity.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"19 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145140715","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}

引用次数: 0

Depolymerized Poly(ethylene-2,5-furanoate) as a Sustainable Feedstock for Biobased Unsaturated Polyester Resins 解聚聚乙烯-2,5-呋喃酸酯作为生物基不饱和聚酯树脂的可持续原料

IF 5.5 1区化学

Macromolecules Pub Date : 2025-09-25 DOI: 10.1021/acs.macromol.5c01600

Tomáš Foltýn, Jan Všetečka, Roman Svoboda, Štěpán Podzimek, Jaromír Vinklárek, Jan Honzíček

引用次数: 0

Development of High-Curing-Reactivity Phthalonitrile Resins Inspired by Inverse Vulcanization 以反硫化为灵感的高固化反应性邻苯二腈树脂的研制

IF 5.5 1区化学

Macromolecules Pub Date : 2025-09-25 DOI: 10.1021/acs.macromol.5c01223

Xi Zhao, Xian He, Wenjie Yang, Peng Wanqing, Li Jintao, Hang Xiao, Ke Zeng, Jianghuai Hu, Gang Yang

{"title":"Development of High-Curing-Reactivity Phthalonitrile Resins Inspired by Inverse Vulcanization","authors":"Xi Zhao, Xian He, Wenjie Yang, Peng Wanqing, Li Jintao, Hang Xiao, Ke Zeng, Jianghuai Hu, Gang Yang","doi":"10.1021/acs.macromol.5c01223","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c01223","url":null,"abstract":"Phthalonitrile (PN) resins exhibit broad application prospects in aerospace and high-temperature industries due to their excellent thermal resistance and interfacial compatibility with reinforcing fibers. However, their practical use is hindered by high curing temperatures, low curing reactivity, and high melting/softening points. This study proposes a sulfur–allyl synergistic strategy inspired by inverse vulcanization, blending elemental sulfur with a biobased eugenol-functionalized PN monomer (EPN) containing allyl groups to significantly enhance curing reactivity and reduce melting/softening points and processing temperatures. Experimental results demonstrate that the EPN system with 5 mol % sulfur achieves a softening point below room temperature after prepolymerization at 180 °C. The resin cured at 275 °C exhibits a glass transition temperature (Tg) > 360 °C and a residual carbon yield >69% at 800 °C. In situ Fourier-transform infrared spectroscopy (FTIR), 2DCS, and XPS analyses reveal that elemental sulfur ring-opening mediates nitrile cross-linking, wherein inverse vulcanization generates thiol active sites and polysulfide segments to drive stepwise curing. This work provides an effective and simple approach for the optimization of the curing process of high-performance PN resins and expands pathways for the high-value utilization of sulfur resources.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"42 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145140714","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}

引用次数: 0

Poly(vinyl ether) Star Copolymers as Bioderived Thermoplastic Elastomers 作为生物衍生热塑性弹性体的聚乙烯醚星形共聚物

IF 5.5 1区化学

Macromolecules Pub Date : 2025-09-24 DOI: 10.1021/acs.macromol.5c01668

Shelby L. Shankel, Daniel M. Krajovic, Scott W. Spring, Jocelyn Y. Zhang, Marc A. Hillmyer, Brett P. Fors

{"title":"Poly(vinyl ether) Star Copolymers as Bioderived Thermoplastic Elastomers","authors":"Shelby L. Shankel, Daniel M. Krajovic, Scott W. Spring, Jocelyn Y. Zhang, Marc A. Hillmyer, Brett P. Fors","doi":"10.1021/acs.macromol.5c01668","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c01668","url":null,"abstract":"Poly(vinyl ether) thermoplastic elastomers (TPEs) have potential as sustainable alternatives to petroleum-based TPEs, as the monomers can be bioderived, the materials are reprocessable for extended lifetime, and the polymers are degradable at the end of their life. To expand upon poly(vinyl ether) TPEs, a star architecture was utilized with poly(2,3-dihydrofuran) as the high glass transition temperature (Tg) block and poly(isobutyl vinyl ether) as the low Tg block. After purification, the physical properties were characterized to identify structure–property relationships, with specific focus on the composition and molar mass of the arms, allowing for targeted design within the physical property space. Small-angle X-ray scattering was utilized to understand the connection between the material’s morphology and the observed structure–property trends. Notably, after initial analysis, the star TPEs were reprocessed to give similar materials to the original samples and retested under cyclic stress, demonstrating the recyclability of the materials. From these experiments, we demonstrate the versatility and durability of poly(vinyl ether) star copolymers as sustainable alternatives to traditional TPEs.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"310 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145134181","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}

引用次数: 0

Enhancing the Mechanical Properties of Hydrogels Based on Photo-Polymerizable π-Conjugated Polymers 基于可光聚合π共轭聚合物的水凝胶力学性能研究

IF 5.5 1区化学

Macromolecules Pub Date : 2025-09-24 DOI: 10.1021/acs.macromol.5c01426

Yi Li, Tiezhu Piao, Yitong Bai, Jiani Wang, Xian Wu Cheng, Chunzhi Cui

引用次数: 0

Synthesis, Crystallization And Photoresponsive Behavior of Azobenzene-Containing Diblock Copolymers 含偶氮苯二嵌段共聚物的合成、结晶及光响应行为

IF 5.5 1区化学

Macromolecules Pub Date : 2025-09-24 DOI: 10.1021/acs.macromol.5c01177

Xinyi Pan, Qinguan Zhang, Yaning He

引用次数: 0

Efficient Deterministic Modeling of Reversible Copolymerizations 可逆共聚反应的高效确定性建模

IF 5.5 1区化学

Macromolecules Pub Date : 2025-09-24 DOI: 10.1021/acs.macromol.5c01421

Devon H. Callan, Christopher M. Bates

{"title":"Efficient Deterministic Modeling of Reversible Copolymerizations","authors":"Devon H. Callan, Christopher M. Bates","doi":"10.1021/acs.macromol.5c01421","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c01421","url":null,"abstract":"Mathematical modeling of copolymerizations with depropagation remains significantly more challenging than those with only irreversible propagation. Current models require solving a system of nonlinear equations to calculate chain-end dyads at every integration step, which is inefficient and prone to numerical instability. This paper formulates the core species balances as a pure system of ordinary differential equations by directly integrating these chain-end dyad balances, increasing the computational efficiency by roughly an order of magnitude and improving the numerical stability. Two model systems of controlled polymerization with a single depropagating monomer and uncontrolled polymerization where both monomers undergo depropagation were studied and validated with stochastic simulation and experimental data, respectively. A model system approximating the controlled copolymerization of ethyl lipoate and n-butyl acrylate was analyzed by systematically varying accessible experimental conditions. The developed model was used to quantify the variation in average monomer sequence length along the polymer backbone. As temperature increases or concentration decreases, the resulting copolymer transitions from a highly gradient microstructure to an even monomer distribution, revealing accessible design handles that chemists can use to manipulate sequence. For uncontrolled polymerization, the high-temperature bulk copolymerization of α-methylstyrene and methyl methacrylate was simulated and accurately reproduces experimental conversion and composition profiles. The validation of time-resolved predictions of composition and sequence length under highly reversible conditions enables applications in process monitoring and optimization. In summary, this model demonstrates sophisticated predictions of sequence statistics while retaining both efficiency and stability even under conditions with significant reversibility or compositional asymmetry.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"22 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145134179","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}

引用次数: 0

Concentration-Driven Slowdown of Chain-Exchange Kinetics in Block Copolymer Micelle Solutions 嵌段共聚物胶束溶液中链交换动力学的浓度驱动减速

IF 5.5 1区化学

Macromolecules Pub Date : 2025-09-23 DOI: 10.1021/acs.macromol.5c01714

Taehyoung Kim, Joanna M. White, Benjamin R. Magruder, Evan Danielson, Frank S. Bates, Timothy P. Lodge

{"title":"Concentration-Driven Slowdown of Chain-Exchange Kinetics in Block Copolymer Micelle Solutions","authors":"Taehyoung Kim, Joanna M. White, Benjamin R. Magruder, Evan Danielson, Frank S. Bates, Timothy P. Lodge","doi":"10.1021/acs.macromol.5c01714","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c01714","url":null,"abstract":"We investigate the dependence of chain-exchange kinetics on polymer concentration for spherical micelles prepared from a polystyrene-b-poly(ethylene-alt-propylene) (SEP) diblock copolymer (Mn = 75 kDa, Đ = 1.05, and fPS = 0.18) in the PEP-selective solvent squalane. Solutions with concentrations of 15 vol % or more adopt a body-centered-cubic (BCC) packing of micelles, or a dense liquid-like packing (LLP), as confirmed by small-angle X-ray scattering. Concurrently, the mean aggregation number of the micelles grows steadily from about 60 in dilute solution to nearly 200 by 50 vol %. Time-resolved small-angle neutron scattering (TR-SANS) analysis reveals a monotonic and substantial (i.e., more than 4 orders of magnitude) decrease in the rate of chain exchange as the polymer concentration increases from 1 to 50 vol %. The TR-SANS relaxation functions are analyzed, taking into account both changes in contrast (due to chain exchange) and evolution in the structure factor (due to refinement of micelle packing). The activation energy for chain pullout is extracted using an established model and can be expressed as a linear function of polymer concentration, indicating that, in addition to the enthalpic barrier for extracting the core block, the evolution of micelle characteristics with increasing concentration imposes further constraints on chain exchange. Consistent with a theory of Halperin, these results suggest that the dominant factor reflects steric penalties during core block pullout arising from a reduced interfacial area per chain and associated increased corona crowding, due to the increase in aggregation number. The rate of exchange is independent of whether the micelles adopt a BCC or LLP arrangement, confirming that the rate-limiting step is extraction of the core block.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"88 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145117235","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}

引用次数: 0

Benzyl Thioether: A Dynamic Covalent Motif for Covalent Adaptable Networks 苄基硫醚：共价自适应网络的动态共价基序

IF 5.5 1区化学

Macromolecules Pub Date : 2025-09-23 DOI: 10.1021/acs.macromol.5c01290

Vatsalya Gupta, Ramkrishna Sarkar

{"title":"Benzyl Thioether: A Dynamic Covalent Motif for Covalent Adaptable Networks","authors":"Vatsalya Gupta, Ramkrishna Sarkar","doi":"10.1021/acs.macromol.5c01290","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c01290","url":null,"abstract":"Covalent adaptable networks (CANs) have emerged as a promising alternative to conventional thermoset polymers, offering reprocessability and recyclability through the incorporation of dynamic covalent linkages. However, dynamic linkages often compromise the thermal and chemical stability of the polymer, which is essential for many thermosets’ applications. Designing a chemistry that imparts both robustness and efficient dynamicity to the cross-linked polymers is a major challenge. To this end, this report introduces benzyl thioether as a robust and dynamic covalent motif for designing CANs. First, using the small molecular model studies, the dynamic exchange in the thioether was demonstrated and a linear polythioether bearing benzyl thioether was prepared. The CANs were prepared by solvent-free melt polymerization of trifunctional benzyl ether with a linear dithiol. Further on, a series of CANs was prepared, and the properties of these CANs, which include swelling, glass-transition temperature (Tg), and mechanical properties, were tailored by regulating the dithiol chain lengths. The CANs demonstrated excellent thermal and chemical stability owing to the presence of robust thioether linkages. The reprocessability and efficient relaxation of the imposed stress in the CANs at elevated temperature were made possible by the dynamic exchange capability of the benzyl thioether linkage. Impressively, the dynamic behaviors of the CANs were shown to be regulated by monomer chain lengths as well as the catalyst concentration. Finally, degradation of the CANs in the presence of excess thiol was demonstrated. To the best of our knowledge, this is the first study that introduces the benzyl thioether motif for designing the robust and dynamic transthioetherification-based CAN, allowing for the fine-tuning of material properties. This approach will pave the way for the design of robust and sustainable polymeric materials.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"131 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145117233","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}

引用次数: 0