ACS Macro Letters最新文献

{"title":"Shear-Induced Conformations of Salt-Free Polyelectrolytes in Semidilute Solutions.","authors":"Jan-Michael Y Carrillo,Yangyang Wang","doi":"10.1021/acsmacrolett.5c00323","DOIUrl":"https://doi.org/10.1021/acsmacrolett.5c00323","url":null,"abstract":"We present coarse-grained molecular dynamics simulations of salt-free polyelectrolyte chains in semidilute solutions under simple shear flow, with full hydrodynamic interactions and explicit dipolar solvent. At equilibrium, chain orientation statistics follow a pseudo-Voigt distribution, and the structural correlation length and chain end-to-end vector autocorrelation function exhibit scaling behavior consistent with theoretical predictions for polyelectrolytes. Under shear, chains transition from coiled to stretched states and the end-to-end vector autocorrelation function reveals oscillatory dynamics at high Weissenberg numbers. Analysis of the gyration tensor and shear strain distributions identified three distinct chain populations with directional alignment along and against the shear gradient. Compared with their neutral polymer counterparts, polyelectrolytes exhibit stronger shear thinning and enhanced chain alignment under the same Weissenberg number, which is attributed to electrostatic interactions and shear-induced counterion release. These findings provide molecular insight into the distinct flow response of charged polymers and have implications for tailoring the rheological properties of polyelectrolyte-based materials.","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"623 1","pages":"933-939"},"PeriodicalIF":5.8,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144311247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of Ionization Energy on Mixed Conduction in Polythiophene-Derived Polyelectrolyte Complexes.","authors":"Pratyusha Das,Alexandra Zele,Ming-Pei Lin,J Tyler Mefford,Michael L Chabinyc,Rachel A Segalman","doi":"10.1021/acsmacrolett.5c00305","DOIUrl":"https://doi.org/10.1021/acsmacrolett.5c00305","url":null,"abstract":"Conjugated polyelectrolyte complexes formed by the electrostatic compatibilization between a conjugated and an insulating polyelectrolyte are a versatile design platform for highly processable, high performing polymeric mixed ion-electron conductors. While electrostatic mediation in complexes allows for structure and property control, a fundamental understanding of how the properties of the constituent conjugated polyelectrolyte (CPE) translate to the resulting complex performance is necessary for future designs. To investigate the role of CPE architecture on the overall charge transport properties of the resulting complex properties, here we compare a water-soluble cationic poly(alkoxythiophene) derivative based on poly(3-alkoxy-4-methylthiophene) with an imidazolium pendant unit and bromide counterion to an analogous complex with poly(sodium 4-styrenesulfonate). Through spectroscopic, morphological, electrochemical, and charge transport characterization, we find that poly(alkoxythiophene)-based complexes exhibit high mixed conductivity, enhanced electrochemical stability, improved doping efficiency, and lower oxidation potential, relative to previously reported poly(3-alkylthiophene)-based complexes, making them more suitable candidates for electrochemical applications. Importantly, both CPE and complex films based on the poly(3-alkoxy-4-methylthiophene) chemistry display electronic conductivities on the order of 10-2-10-3 S/cm and impressive ionic conductivities up to the order of 10-4 S/cm, despite the ordered morphology of the 3-alkoxy-4-methylthiophene backbone. We make a key observation that the enhancement of the electronic conductivity of the CPE from an alkyl to alkoxythiophene backbone does not necessarily improve the electronic conduction of the resulting complex as observed in previous reports, thereby underscoring the role of complexation thermodynamics, dielectric strength of the electrostatic complex, and complex morphology on mixed conduction. This study provides fundamental insights governing future design rules of mixed-conducting polyelectrolyte complexes for next-generation energy applications.","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"228 1","pages":"925-932"},"PeriodicalIF":5.8,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144295790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Covalent Adaptable Polyester Networks Based on Citric Acid with Fast Dynamic Behaviors and Closed-Loop Recyclability.","authors":"Yuanyuan Liu,Haiyue Zhao,Xinyu Meng,Yuxiang Fu,Yahang Dong,Jialong Li,Hongsen Liu,Chengcai Pang","doi":"10.1021/acsmacrolett.5c00327","DOIUrl":"https://doi.org/10.1021/acsmacrolett.5c00327","url":null,"abstract":"Most covalent adaptable networks (CANs) based on citric acid (CA) exhibit low thermostability, low glass-transition temperatures (Tg), and poor mechanical properties. Moreover, their slow relaxation rates necessitate prolonged reprocessing time, resulting in issues such as degradation or side-reactions. Herein, a bicyclic tetracarboxylate (DMTE) derived from CA was prepared. A series of polyester CANs were prepared via catalyst-free melt-polycondensation of DMTE, CA, and 1,6-hexanediol (HDO). To our delight, the highly rigid DMTE simultaneously improved the Tg values and mechanical properties of the CANs based on CA. Furthermore, benefiting from its dissociative transesterification reaction (TER), the introduction of DMTE significantly improved their relaxation rates. This allows their reprocessing time to be significantly shortened to merely 10 s at 180 °C, compared to the long reprocessing time needed for the CAN solely based on CA (30 min). Lastly, these materials can be closed-loop recycled by catalyst-free methanolysis to recover the initial monomers in high yields.","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"11 1","pages":"917-924"},"PeriodicalIF":5.8,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144295843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid Preparation of Ultrastrong and Repairable Poly(vinyl alcohol) Gel via a Facile One-Step Strategy","authors":"Ruofei Hu, Yingru Zeng, Huanzhen Ji, Guochen Ji, Xinfang Wang, Aili Wang, Lianwen Zhou, Jing Zhao, Junping Zheng","doi":"10.1021/acsmacrolett.5c00225","DOIUrl":"https://doi.org/10.1021/acsmacrolett.5c00225","url":null,"abstract":"Gels with simultaneously high strength, large strain, great toughness, intrinsic self-healing capability, and recyclability are highly attractive for industrial development and applications. However, their preparation remains a significant challenge owing to mutually exclusive mechanisms, let alone achieving such properties within a brief period via a facile method. In this study, a one-step “frozen salting-out” strategy is proposed to rapidly prepare poly(vinyl alcohol) (PVA) gels with outstanding mechanical properties through the construction of a robust polymer network. The gel exhibits a fracture strain of 1350%, an extremely high tensile stress of 31.1 MPa, and exceptional toughness of 247.7 MJ·m^–3. The damaged gel can heal in a manner similar to that of welding and can be recycled to restore its excellent mechanical properties. Furthermore, the stress of the gel can reach 117.0 MPa through a prestretching process that optimizes the polymer network. The entire preparation process is highly convenient. Time is of the essence, and the transformation from solution to robust gel requires approximately 1 h. This study provides a facile and effective strategy for preparing superstrong and tough gels.","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"9 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144278633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semicrystalline Poly(azobenzene) with Negative Photochromism for Photochemical Melting of Thick Samples","authors":"Hantao Zhou, Jesus Guillen Campos, Rishabh Tennankore, Wenwen Xu, Yunfeng Hu, Javier Read de Alaniz, Ryan C. Hayward","doi":"10.1021/acsmacrolett.5c00206","DOIUrl":"https://doi.org/10.1021/acsmacrolett.5c00206","url":null,"abstract":"Photomechanical effects based on photochemical transformations often suffer from challenges of restricted light penetration due to strong light attenuation, limiting their operation to micrometer-scale materials with relatively inefficient bending deformation modes. While recent reports have established semicrystalline poly(azobenzene)s as a promising class of photochemically responsive materials, strong absorption of UV light required to drive <i>trans</i> to <i>cis</i> isomerization has limited switching to within several micrometers of the surface. Negative photochromism offers a possible route to circumvent this limitation, as reversible photobleaching of the ground state absorption upon switching extends the light penetration. Herein, we report the synthesis and characterization of P(Cx-dFdC-azo), a negative photochromic semicrystalline poly(azobenzene) incorporating <i>ortho</i>-difluoro, dichloro-substituted azo photoswitches. These polymers exhibit near-quantitative bidirectional photoisomerization─92% conversion to <i>cis</i> under 617 nm irradiation and 96% conversion to <i>trans</i> under 405 nm irradiation, along with reversible photomelting and crystallization. Photorheological studies demonstrate a significant increase over which photomelting can be achieved, from &lt;10 μm for conventional poly(azobenzene) to at least 300 μm for P(Cx-dFdC-azo), highlighting the potential of these materials for photochemically responsive materials with macroscopic dimensions.","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"42 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144278631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controlled Regulation of Antibacterial and Degradable Performance via Host (Cyclodextrin)–Guest (Vanillin) Multilevel Structures","authors":"Jun Li, Xiaoqi Cheng, Rongmin Wang, Yaping Zhang, Yufeng He, Pengfei Song","doi":"10.1021/acsmacrolett.5c00208","DOIUrl":"https://doi.org/10.1021/acsmacrolett.5c00208","url":null,"abstract":"The development of biobased polymeric materials is expected to reduce dependence on nonrenewable resources. However, the controlled regulation of performance via host–guest multilevel structures remains a great challenge. To tackle this challenge, host–guest block copolymers (P(CD)₂-<i>b</i>-P(VMA)_<i>x</i>, <i>x</i> = 7, 10, 72, 159) were fabricated by reversible addition–fragmentation chain transfer (RAFT) block copolymerization using β-cyclodextrin-derived monomer and biomass-derived vanillin monomer as the host–guest building blocks. In parallel, P(CD)₂-<i>b</i>-P(VMA)_<i>x</i> self-assembled in situ into honeycomb nanoporous channel materials via two-dimensional (2D) mechanical interlocking and three-dimensional (3D) physical cross-linking. Notably, high cross-linking density (<i>x</i> = 7, 10) showed 89.0% against both <i>E. coli</i> and <i>S. aureus</i> and complete hydrolysis of the ester bonds of host–guest building blocks on the copolymer chain, while low cross-linking density (<i>x</i> = 72, 159) had no antibacterial activity and was partially hydrolyzed. Overall, this strategy showcases an approach for regulating the multilevel structures, providing an eco-friendly material with adjustable properties.","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"27 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144269216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrophilic–Hydrophobic Sequence Regulation in Alternating Polysulfoniums Enables “Wake-and-Kill” Eradication of Antibiotic-Tolerant Persisters and Their Biofilms","authors":"Yisheng Huang, Shilong Cai, Liuqi Shi, Zhiyuan Zhu, Jingyi Rao, Xiao Yu, Yang Xun","doi":"10.1021/acsmacrolett.5c00253","DOIUrl":"https://doi.org/10.1021/acsmacrolett.5c00253","url":null,"abstract":"Phenotypically tolerant persister bacteria can survive antibiotic treatment by entering a metabolically dormant state and are widely recognized as major contributors to infection relapse. To address this challenge, we systematically investigated how the alternating hydrophilic–hydrophobic sequence pattern of polysulfoniums modulate the membrane potential and respiratory activity in dormant bacterial cells. While rifampicin and ampicillin at 25–100 × MIC (mininum inhibitory concentration) were ineffective against persister populations, the <b>PS</b>^<b>+</b><b>(triEG-<i>alt</i>-octyl)</b> alternating polymer significantly reactivated the electron transport chain (ETC) in persister cells, achieving &gt;9-log reductions in viability at 8–16 μg/mL (2–4 × MIC) via precise sequence regulation of hydrophilic and hydrophobic segments. Integration of nanoparticle-assisted delivery with NIR-triggered release enabled efficient penetration of persister-dominated biofilms, resulting in ∼90% biomass clearance and &gt;99.9% elimination of embedded persister cells. These findings highlight the sequence modulation of cationic polymers that offers a highly effective “wake-and-kill” strategy for the eradication of persisters and their associated biofilms.","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"65 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144269225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thiazole Groups without Hydrogen-Bond Donors Endow PIM Membrane with High CO2 Separation Performance","authors":"Yi Feng, Haodong Wang, Feng Zhang, Chenxiang Ai, Juntao Tang, Shuai Gu, Chuang Chen, Guipeng Yu","doi":"10.1021/acsmacrolett.5c00266","DOIUrl":"https://doi.org/10.1021/acsmacrolett.5c00266","url":null,"abstract":"Polymers of intrinsic microporosity (PIMs) are promising membrane materials for CO₂ separation, but suffer from the trade-off effect between permeability and selectivity. And it is a challenge to design suitable groups in PIMs to improve the CO₂ separation performance. Herein, this work reports that thiazole groups without hydrogen-bond donors could endow the PIM membrane with high CO₂ permeability and separation selectivity. The abundant N atoms of the thiazole groups could provide Lewis acid–base interactions with CO₂ and significantly enhance the solubility selectivity. The lack of hydrogen-bond donors and the rigid structure of thiazole unit could inhibit the pore collapse and enhance the permeability and stability of PIM membranes. The resultant PIM membranes exhibit CO₂/N₂ and CO₂/CH₄ selectivities of 36.6 and 22, respectively, with corresponding CO₂ permeabilities of 9196 and 3801 Barrer. This work provides new insights into the rational design of functional groups for PIMs with high gas separation performance.","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"90 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144269226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Particle Dispersion Controls the Gas-Separation Properties of Polymer-Grafted Nanoparticle Membranes","authors":"Huina Lin, Maninderjeet Singh, Kaylie K. Musard, Sanat K. Kumar, Brian C. Benicewicz","doi":"10.1021/acsmacrolett.5c00160","DOIUrl":"https://doi.org/10.1021/acsmacrolett.5c00160","url":null,"abstract":"Membranes based on polymer-grafted nanoparticles (PGNPs) have emerged as strong candidates for key gas separations due to their tunable permeability, selectivity, mechanical properties, and aging resistance. Here, we show the importance of keeping nanoparticles spatially well-dispersed through the whole process of grafting chains onto their surfaces─this is illustrated by measuring the gas-separation properties of PGNP membranes. Specifically, while we start with well-dispersed bare NPs in solution, this dispersion state is affected when we functionalize their surface with the polymer initiating agent, which then causes local NP agglomeration (i.e., effectively leading to a larger NP core, to which chains are grafted) and poor gas-separation performance relative to our previous results on PGNP membranes. Instead, when we cap the NPs with a protective layer that prevents NP agglomeration during surface functionalization, followed by grafted polymer synthesis, we obtain significantly higher gas permeabilities. While these results can be rationalized by the fact that the gas-permeation properties of smaller NPs grafted with polymer chains are better than those of larger NPs at the same effective grafting density and graft chain length, these results emphasize the important role of particle dispersion during all steps of the formation of PGNPs.","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"10 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144260505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"What is the Role of Relative Humidity on Conductivity in Polymer Electrolytes?","authors":"Nico Marioni,&nbsp;Akhila Rajesh,&nbsp;Rahul Sujanani,&nbsp;Zidan Zhang,&nbsp;Leo W. Gordon,&nbsp;Raphaële J. Clément,&nbsp;Rachel A. Segalman,&nbsp;Benny D. Freeman and Venkat Ganesan*,&nbsp;","doi":"10.1021/acsmacrolett.5c0021610.1021/acsmacrolett.5c00216","DOIUrl":"https://doi.org/10.1021/acsmacrolett.5c00216https://doi.org/10.1021/acsmacrolett.5c00216","url":null,"abstract":"<p >Ion transport properties in polymer electrolytes have been widely studied under rigorously dry and highly water-swollen conditions. However, the transition between these extremes, i.e., the low hydration regime, is still poorly understood at the molecular level and relevant to applications ranging from battery electrolytes to electrophoretic separations. In this study, we apply atomistic molecular dynamics simulations to probe the role of hydration on ion mobilities and conductivities in LiTFSI-doped polyethers at low water content (less than 10% water by volume), which corresponds to 0–80% relative humidity conditions. With increasing water content, Li⁺ ions exhibit two distinct regimes in their mobilities. At low water content, the majority of the Li⁺ ions are weakly hydrated (two or fewer water molecules per Li⁺ ion), maintaining strong interactions with their polymer solvation cage, and therefore exhibit only a weak increase in mobility relative to dry conditions. As water content increases, Li⁺ ions form complete hydration shells, residing within water-rich domains that promote faster mobilities. Further, Li⁺ mobilities increase more significantly in polymer electrolytes composed of more hydrophilic polymers and higher salt concentrations due to the formation of larger water-rich domains. In contrast, TFSI^– has comparatively weak interactions with both the polymer and water, exhibiting a monotonic increase in mobility as a function of water content. Overall, these results help clarify the molecular mechanisms underlying ionic mobilities and conductivities in polymer electrolytes at low water content.</p>","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"14 6","pages":"865–871 865–871"},"PeriodicalIF":5.1,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144296667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}