Macromolecules最新文献

{"title":"Cross-Sectional Effects on Nanorod Diffusion in Polymer Melts","authors":"Jia Zhang, Lijun Yang, Hai-Xing Wang, Jiuling Wang, Ruo-Yu Dong","doi":"10.1021/acs.macromol.5c00629","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00629","url":null,"abstract":"The diffusion of anisotropic nanoparticles, such as nanorods, in complex polymer environments is relevant to several scientific and industrial topics, including nanocomposites, and drug delivery. Despite recent advancements in understanding the dynamics of thin nanorods in polymer melts through scaling analyses and simulations, systematic investigations into the cross-sectional effects of nanorods on diffusion processes remain limited. In this study, coarse-grained molecular dynamics (CGMD) simulations were performed to explore the translational and rotational dynamics of a single nanorod in unentangled and entangled linear polymer melts. To introduce cross-sectional effects, we increased the nanorod diameter <i>d</i>, and analyzed the rotational diffusion for spinning <i>D</i>_RS, which is distinct from the rotational diffusion for end-overend tumbling <i>D</i>_RT. We conducted quantitative analyses to examine the scaling behavior of various diffusion coefficients with respect to the nanorod diameter, categorizing nanorods as either ‘thin’ (with diameters smaller than the tube diameter) or ‘thick’ (with diameters larger than the tube diameter). Our findings reveal a significant crossover in the scaling of the translational diffusion coefficient as <i>d</i> increases, while the scaling of the rotational diffusion coefficient remains almost constant. Hopping mechanisms contribute to nanorod dynamics in entangled melts, exhibiting different variations of translational and rotational dynamics with <i>d</i>. We finally unveiled that, the coupling between nanorod diffusion and polymer chain fluctuations enhances translational-rotational correlation at short time intervals but diminishes in the Fickian regime.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"114 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143893712","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":"Manipulating the Mechanical Properties of Thermoplastic Polyurethane via Regulating Hard Segment Aggregation","authors":"Zehao Wang, Chending Wang, Xiaoli Zhao, Xiaoniu Yang","doi":"10.1021/acs.macromol.5c00142","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00142","url":null,"abstract":"Performance optimization of thermoplastic polyurethane (TPU) is hindered by the mysterious structure–property relationship due to intricate hard segment (HS) aggregation structures. Here, a typical MDI-BDO-based TPU was employed as a model to investigate the HS aggregation structures from multiscale morphology, and different annealing conditions were applied to transform them to effectively manipulate TPU’s mechanical properties. The pristine TPU has three HS aggregation structures. Structure I is hard domains with irregularly stacked hard blocks and disordered HS packing, while structures II and III are crystalline hard domains with loosely and compactly stacked hard blocks, respectively. Therefore, the reduced moduli (E_r) of structures II and III are 19 and 57% higher than that of structure I, respectively. Annealing at 170 °C enlarged structure I but decreased its number density, slightly lowering TPU’s modulus to 108.0 from 110.8 MPa. Annealing at 200 and 220 °C reorganized less ordered HSs into crystalline structures II and III, respectively, which significantly enhanced TPU’s modulus to 141.8 and 187.1 MPa, respectively. For viscoelasticity, TPU’s stress relaxation resistance decreased with annealing temperature because 170, 200, and 220 °C very slightly, partly, and completely broke the hard domain’s long-range connectivity, respectively. This work elucidated the evolution of HS aggregation structures during annealing, which provides guidelines for TPU’s performance optimization and design.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"43 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143893709","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":"Epitaxial Crystallization-Driven Self-Assembly of Block Copolymers with Asymmetric Stereoblock Polylactides into 3-D Triangular Prisms","authors":"Jae Hak Lee, Mo Beom Koo, Yongbeom Kwon, Kyoung Taek Kim","doi":"10.1021/acs.macromol.5c00758","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00758","url":null,"abstract":"The crystallization-driven self-assembly (CDSA) of block copolymers (BCPs) with crystallizable core-forming blocks typically produces low-dimensional nanostructures such as one-dimensional nanowires and two-dimensional platelets. This occurs because the solvent-soluble polymer blocks passivate a significant portion of the surface of the crystalline core. In this study, we report the formation of three-dimensional triangular prisms through the epitaxial CDSA of BCPs with asymmetric stereoblock polylactide, specifically [(<span>d</span>-lactide)₃₂-(<span>l</span>-lactide)₁₆]-<i>b</i>-PEG₄₅. The iterative exponential growth (IEG) of enantiopure lactides into stereochemically sequence-defined polylactides results in the formation of [DLA₃₂-LLA₁₆]. The programmed chain folding of the stereochemically sequence-defined [DLA₃₂-LLA₁₆] block via intramolecular stereocomplexation between size-matched enantiomeric oligo(lactide) domains allows the excess [DLA₁₆] domain to coexist with the stabilizing poly(ethylene glycol) (PEG) blocks on the top and bottom surfaces of the triangular core (approximately 9 nm in thickness) formed by the CDSA of this BCP. These surface-exposed homochiral [DLA₁₆] domains serve as nucleation sites for the epitaxial growth of the triangular cores into triangular prisms with thickness exceeding 600 nm. We determined that the concentration-dependent kinetics of chain folding and crystallization of the asymmetric stereoblock polylactide, steric passivation by surface-located PEG chains, and the enantiopurity of the protruding oligolactide domains are critical factors that enable epitaxial CDSA.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"47 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143893711","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":"Nanoscale Morphology in Disodium Salt-Anchored Polyethylene Ionomers","authors":"Mengen Zhang, Ruijia Wang, Tinghao Jia, Congjing Ren, Jingdai Wang, Yongrong Yang, Yao Yang","doi":"10.1021/acs.macromol.5c00167","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00167","url":null,"abstract":"A molecular-level understanding of the ion cluster morphology is crucial to designing the structure and enhancing the properties of random polyethylene ionomer. Here, we report that the strategic addition of aliphatic disodium salt has a pronounced effect on the mechanical properties and nanoscale morphology. With the addition of various aliphatic disodium salts, both the tensile strength and Young’s modulus are significantly increased. By comparing the results of atomistic molecular dynamics simulations with experimental characterization data, the ionic cluster nanoscale morphology varies with different chain-length disodium salts, while maintaining the crystallization of the polyethylene matrix. The alkyl disodium salts with relatively short alkyl chains (&lt;C8) tend to anchor to the same cluster, forming encapsulation or loop structure. The alkyl disodium salts with relatively long alkyl chains (&gt;C12) bridge between clusters by anchoring to two different clusters, helping to redistribute the clusters within the polymer matrix and providing additional cross-link strength. The cluster morphological evolution during stretching was simulated, and its relation to mechanical properties is comprehensively discussed. This, in turn, unlocks the potential for structural regulation at the nanoscale by additive manufacturing to enhance the performance.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"114 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143893873","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":"Expanding the Toolbox of DNA Supramolecular Polymerization for Hyperbranched Nanopolymers","authors":"Qianlin Cai, Tianyun Cai, Jiaping Lin, Liangshun Zhang","doi":"10.1021/acs.macromol.5c00606","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00606","url":null,"abstract":"With the unique combination of polymer-like functionality and biologically inspired dynamics, supramolecular DNA nanopolymers have become a highly promising platform for engineering next-generation smart soft materials. Realizing their full functional potential requires expanding the architectural diversity of DNA nanopolymers in a manner akin to that of classical polymers. In this contribution, we present a remarkable advancement in the introduction of trivalent DNA nanostars with carefully designed sequences of sticky ends. Through the coarse-grained molecular dynamics simulations, it is revealed that the trivalent DNA nanostars have the capability to yield the hyperbranched nanopolymers with a tunable branching degree under one-pot programmable self-assembly. Importantly, extending the classical model of polymerization kinetics enables the quantitative prediction of the growth kinetics and branching degree of hyperbranched DNA nanopolymers, which can be tailored through the designed elements of trivalent DNA nanostars. Furthermore, the terminations of hyperbranched DNA nanopolymers are used as active sites to ligate the DNA-functionalized nanoparticles and yield the hierarchical coassemblies of branched nanoarchitectures, a previously unreported topology. We envision that the polymerization-like self-assembly of DNA nanostars will serve as a versatile platform for diversifying the topological architectures of supramolecular nanostructures, thereby advancing the broad applicability of DNA-based functional materials.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"18 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884953","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":"Terahertz Birefringence and Anisotropic Absorption Characteristic of Ordered Polymer Structures for Simultaneous Orientation Measurement in Crystalline and Amorphous Regions","authors":"Haokun Xiao, Jianjian Huang, Xiaowen Bian, Mengmeng Wang, Xianrong Liang, Maoyuan Li, Gang Jin","doi":"10.1021/acs.macromol.5c00078","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00078","url":null,"abstract":"Strain-induced crystallization (SIC) is one of the most significant phenomena in semicrystalline polymers. During the stretching process, ordered structures occur in the crystalline and amorphous regions, accompanied by a complex evolution process. The ordered structure of the crystalline region is usually a perfect crystal, while that of the amorphous region mainly consists of locally ordered chain segments. The simultaneous characterization of ordered structures in both crystalline and amorphous regions faces significant challenges due to differences in the scale of the ordered structure. This research proposed a method for simultaneously measuring ordered structures of poly(ethylene terephthalate) (PET) in both crystalline and amorphous regions based on terahertz time-domain spectroscopy (THz-TDS) with extreme sensitivity to the long-range ordered structure. The models between orientation and birefringence and absorption anisotropy in the THz band were established. The evolution of the refractive index and absorption coefficient of samples at different draw ratios was investigated. The results showed that birefringence was proportional to the orientation of <i>trans</i> conformations, and the orientation–birefringence model was validated in the THz band. Then, two characteristic absorption bands, ranging within 1.3–2.3 and 2.3–3.0 THz, in the absorption spectra of stretched PET are closely related to the content and orientation of <i>trans</i> conformation in the amorphous and crystalline regions of PET. Finally, the mechanism of strain-induced anisotropy of the refractive index and absorption coefficient was elucidated, which originates from the orientation of the molecular chain during necking and undergoes rapid changes once necking occurs. These insights deepen the understanding of the refractive index and absorption in the THz frequency range and provide an effective method for simultaneously characterizing the ordered structures in the amorphous and crystalline regions.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"69 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143889857","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":"Characterizing the Mechanical Response of a Polycarbonate Coarse-Grained Model Developed with Energy Renormalization","authors":"Heather L. White, Müge Fermen-Coker, Wei Chen, Sinan Keten","doi":"10.1021/acs.macromol.5c00302","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00302","url":null,"abstract":"Polycarbonate (PC) possesses uniquely high toughness among polymers, making it well-suited for use as an impact-resistant barrier material. This propensity toward energy dissipation has been associated with characteristics such as backbone flexibility, high entanglement density, and homogeneity. While recent works have enhanced our understanding of how these nanoscale mechanisms contribute to toughness in PC, it remains unclear how they are affected by the deformation mode, rate, and molecular weight of the chains. To study these effects over spatiotemporal scales that extend beyond the reach of atomistic models, we utilized a coarse-grained molecular dynamics (CGMD) model of PC developed with the energy renormalization method. We establish that yield stress rate dependence follows the Cowper–Symonds model for flow stress, the fit for which asymptotically converges to values consistent with low-rate experimental data. As a demonstration of the model’s utility, we additionally explore the effects of PC chain length on fracture behavior and show that toughness is improved through the augmentation of extensive entanglement networks that enable increased stress levels in the material. For chains 50 monomers and longer, chain length has a minimal effect on yield stress and elastic modulus, suggesting that small-strain mechanical response is dominated by nonbonded interactions. This work enables an enhanced understanding of molecular contributions to the macroscopic mechanical behavior of PC and reflects the importance of the polycarbonate chain network in modulating energy dissipation. It additionally highlights the importance of bond breaking in MD models subjected to large strain. More broadly, it represents a critical step toward the CGMD modeling of PC-based nanocomposites.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"8 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884952","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":"Deuteration Effects on the Physical and Optoelectronic Properties of Donor–Acceptor Conjugated Polymers","authors":"Kundu Thapa, Madison Mooney, Guorong Ma, Zhiqiang Cao, Gage T. Mason, Naresh Eduguorala, Surabhi Jha, Derek L. Patton, Jason D. Azoulay, Simon Rondeau-Gagné, Xiaodan Gu","doi":"10.1021/acs.macromol.4c02778","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02778","url":null,"abstract":"The significant differences in scattering cross sections between deuterium and protium are unique to neutron scattering techniques and have been a long-standing area of interest within the neutron scattering community. Researchers have explored selective deuteration to manipulate scattering contrast in soft matter systems, leading to the widespread use of deuterium labeling in materials development. As deuteration changes the atomic mass, it alters physical properties such as molecular volume, polarizability, and polarity, which in turn may affect noncovalent interactions and crystal ordering. Despite previous studies, there remains a limited understanding of how deuteration impacts donor–acceptor (DA) conjugated polymers. To address this, we synthesized deuterated DPP polymers and systematically investigated the effects of side-chain deuteration on their thermal stability, crystal packing, morphology, and optoelectronic properties. We found that deuteration increased the melting and crystallization temperatures of DPP polymers, although it did not significantly alter their morphology, molecular packing, or charge mobility. These properties were assessed by using atomic force microscopy (AFM), X-ray scattering, and thin-film transistor device measurements, respectively, for DPP polymers. Our work shows that deuterium labeling could be a powerful method for controlling scattering length density, enabling neutrons to study the structure and dynamics of conjugated polymers without impacting their electronic performance.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"40 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884950","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":"Elastin-Based Janus Hydrogel Tape with Adhesive, Stretchable, and Conductive Properties for Soft Bioelectronic Applications","authors":"Zhongwei Guo, Yilin Guo, Shiqiang Zhang, Wenlong Yu, Qiulei Gao, Jiyu Chen, Yahui Xiong, Lei Chen, Jingjiang Qiu, Ronghan Wei","doi":"10.1021/acs.macromol.5c00150","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00150","url":null,"abstract":"Achieving robust adhesion and optimal conductivity simultaneously is highly important and challenging for soft bioelectronics. Although numerous adhesive hydrogels have been investigated, they are designed for double-sided adhesion and lack optimal sensing performance. Therefore, we developed a two-step casting strategy to fabricate Janus hydrogel tape (J-Tape) for soft bioelectronics. The J-Tape was composed of an adhesive poly(acrylic acid)-<i>N</i>-hydroxysuccinimide/elastin-methacrylate (PAAc-NHS/ElaMA) bottom layer and a nonadhesive poly(acrylic acid)/gelatin-methacrylate (PAAc/GelMA) top layer and exhibited multiple functions, such as sufficient bioadhesion, high stretchability, optimal sensitivity, and good biocompatibility. Benefiting from the NHS ester group, the bottom layer can rapidly and robustly adhere to biological tissues. In addition, the top layer was supplemented with PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)) to enhance its conductive performance. The application of this J-Tape for tissue adhesion and wound sealing <i>in vitro</i> was successfully demonstrated. When exploited as a strain sensor to monitor diverse physiological signals, the hydrogel showed excellent sensitivity and reliability. Furthermore, J-Tape was integrated with a machine learning algorithm and developed into a wireless wearable electronic sensing system that can recognize diverse gestures with up to 98.87% accuracy. Overall, this work may provide new insights for the design and fabrication of functional bioelectronics.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"9 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143889858","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":"Time-Dependent Information Encryption Using a Supramolecular Polymer Gel Based on a Pillararene","authors":"Yujie Cheng, Bicong Liang, Xuehong Wei, Sidian Li, Pi Wang, Danyu Xia","doi":"10.1021/acs.macromol.5c00290","DOIUrl":"https://doi.org/10.1021/acs.macromol.5c00290","url":null,"abstract":"With the rapid development of information technology, information security has become a hot topic of global concern. Many efforts have been devoted to developing intelligent materials for safeguarding information. Time-dependent information encryption based on supramolecular polymer gel (SPG) materials has many advantages including intrinsic stimuli responsiveness, good processability, excellent self-healing property, and so on. Herein, we report a time-dependent information encryption material constructed by a SPG with tunable fluorescence emission based on a pillararene. A bipyridine derivative-containing fluorescent polymer <b>P1</b> and a pillararene-containing polymer <b>P2</b> were prepared. <b>P1</b> underwent a fluorescence emission decrease with a red shift from blue to blue-green after adding the acid due to the protonation of its bipyridine group. The protonated form of <b>P1</b> was denoted as <b>P1H</b>. When <b>P1H</b> was mixed with <b>P2</b>, a SPG formed, accompanied by quenching of the blue-green fluorescence due to the host–guest interactions between a pillararene and the protonated bipyridine derivative guest. Intriguingly, adjusting the concentration of the acid added to the SPG can control the rate of fluorescence color change, enabling dynamic information encryption that can vary over different time scales. Due to the reversible property of this supramolecular system under external stimuli, the decrypted information could be encrypted again by treating with base or waiting for a period of time without any treatment, avoiding the leakage of the stored information and upgrading the information security.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"18 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143885452","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}