Pub Date : 2025-06-20DOI: 10.1021/acsmacrolett.5c00309
Jiahui Liu, Md. Walli Ullah, Marek W. Urban
Azole-based polymeric ionic liquids (PILs) containing imidazolium (Im) p(Im-TFSI) and triazolium (Tr) p(Tr-TFSI) ring cations naturalized by bis(trifluoromethane sulfonyl)imide (TFSI) anions were synthesized to elucidate the origin of dipolar–ionic interactions and their role in conductivity and mechanical properties. Spectroscopic analysis of p(Im-TFSI) and p(Tr-TFSI) PILs revealed that the presence of polar H2O alters ionic and dipolar interactions, resulting in distinct ring-dependent hydration effects. In p(Tr-TFSI), more stable cation–anion–H2O entities result from stronger electrostatic surface potentials (∼2 kcal/mol), where distinct separation of positive and negative electrostatic potentials in Tr-TFSI cation–anion pairs facilitates the formation of localized clusters inducing dipole–dipole interactions. In the presence of H2O, ionic mobility is enhanced by solvating cation–anion pairs at the expense of weaker van der Waals interactions. The content of H2O near Tr rings is higher, but there is restricted ionic mobility due to stronger polar forces that are formed at the expense of diminished induced dipole–dipole interactions. In contrast, in Im-based polymers, H2O molecule associations with cation–anion pairs are weaker, and enhanced ionic mobility is reflected in increased conductivity values by a factor of 2. Both Im and Tr rings also facilitate distinct parallel resistor–capacitor (RC) responses with constant phase element (CPE) combinations; upon exposure to H2O, the parallel RC circuits undergo configuration by an additional in-series connected R-CPE element.
{"title":"Polar Perturbations of Dipolar Interactions in Azole-Based Poly(ionic liquids)","authors":"Jiahui Liu, Md. Walli Ullah, Marek W. Urban","doi":"10.1021/acsmacrolett.5c00309","DOIUrl":"https://doi.org/10.1021/acsmacrolett.5c00309","url":null,"abstract":"Azole-based polymeric ionic liquids (PILs) containing imidazolium (Im) p(Im-TFSI) and triazolium (Tr) p(Tr-TFSI) ring cations naturalized by bis(trifluoromethane sulfonyl)imide (TFSI) anions were synthesized to elucidate the origin of dipolar–ionic interactions and their role in conductivity and mechanical properties. Spectroscopic analysis of p(Im-TFSI) and p(Tr-TFSI) PILs revealed that the presence of polar H<sub>2</sub>O alters ionic and dipolar interactions, resulting in distinct ring-dependent hydration effects. In p(Tr-TFSI), more stable cation–anion–H<sub>2</sub>O entities result from stronger electrostatic surface potentials (∼2 kcal/mol), where distinct separation of positive and negative electrostatic potentials in Tr-TFSI cation–anion pairs facilitates the formation of localized clusters inducing dipole–dipole interactions. In the presence of H<sub>2</sub>O, ionic mobility is enhanced by solvating cation–anion pairs at the expense of weaker van der Waals interactions. The content of H<sub>2</sub>O near Tr rings is higher, but there is restricted ionic mobility due to stronger polar forces that are formed at the expense of diminished induced dipole–dipole interactions. In contrast, in Im-based polymers, H<sub>2</sub>O molecule associations with cation–anion pairs are weaker, and enhanced ionic mobility is reflected in increased conductivity values by a factor of 2. Both Im and Tr rings also facilitate distinct parallel resistor–capacitor (RC) responses with constant phase element (CPE) combinations; upon exposure to H<sub>2</sub>O, the parallel RC circuits undergo configuration by an additional in-series connected R-CPE element.","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"15 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335004","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}
Pub Date : 2025-06-20DOI: 10.1021/acsmacrolett.5c00291
Manish Kumar, Maxime Michelas, Cyrille Boyer
Advancing sustainability in the polymer industry requires efficient, ecofriendly recycling strategies. This study introduces a catalyst-free, microwave-assisted depolymerization method for RAFT-terminated polymethacrylates, utilizing methanol as a dual-functional cosolvent to enhance microwave absorption and provide a benign reaction medium. The effectiveness of this approach was demonstrated primarily with poly(methyl methacrylate) (PMMA), including variations in molecular weight (Mn ≈ 5k, 12k, 17k g/mol) and RAFT end-groups (dithiobenzoate and trithiocarbonate). Applicability was further confirmed with poly(2-hydroxyethyl methacrylate) (PHEMA) and poly(benzyl methacrylate) (PBzMA). Depolymerization efficiency showed strong temperature dependence, with significant monomer recovery observed between 110 and 140 °C, while operating effectively at high repeat unit concentrations (up to 200 mM). This rapid, catalyst-free process, operating efficiently at elevated temperatures like 120 °C, presents a green, scalable, and economically viable recycling solution, aligning with circular economy principles to mitigate polymer waste.
{"title":"Microwave-Assisted Depolymerization of Polymethacrylates","authors":"Manish Kumar, Maxime Michelas, Cyrille Boyer","doi":"10.1021/acsmacrolett.5c00291","DOIUrl":"https://doi.org/10.1021/acsmacrolett.5c00291","url":null,"abstract":"Advancing sustainability in the polymer industry requires efficient, ecofriendly recycling strategies. This study introduces a catalyst-free, microwave-assisted depolymerization method for RAFT-terminated polymethacrylates, utilizing methanol as a dual-functional cosolvent to enhance microwave absorption and provide a benign reaction medium. The effectiveness of this approach was demonstrated primarily with poly(methyl methacrylate) (PMMA), including variations in molecular weight (<i>M</i><sub>n</sub> ≈ 5k, 12k, 17k g/mol) and RAFT end-groups (dithiobenzoate and trithiocarbonate). Applicability was further confirmed with poly(2-hydroxyethyl methacrylate) (PHEMA) and poly(benzyl methacrylate) (PBzMA). Depolymerization efficiency showed strong temperature dependence, with significant monomer recovery observed between 110 and 140 °C, while operating effectively at high repeat unit concentrations (up to 200 mM). This rapid, catalyst-free process, operating efficiently at elevated temperatures like 120 °C, presents a green, scalable, and economically viable recycling solution, aligning with circular economy principles to mitigate polymer waste.","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"1 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144334973","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}
Pub Date : 2025-06-20DOI: 10.1021/acsmacrolett.5c00269
Zeyi Yan, Jingjing Xiao, Weijie Zhang, Yuxiang Zhang, Lei Liu, Bo Zhang, Anchao Feng
Although organic–inorganic lead halide perovskite nanocrystals (NCs) have emerged as new semiconductor photocatalysts with excellent photocatalytic performance, their stability remains inferior to that of all-inorganic lead halide perovskite NCs. To address this limitation, we propose a one-step in situ polymerization strategy via a CH3NH3PbBr3 NCs-initiated photoinduced electron/energy transfer-reversible addition–fragmentation chain transfer polymerization to construct CH3NH3PbBr3–PBA/PMA gel composites, demonstrating the feasibility of both oxygenated and oxygen-free preparation processes. In this system, CH3NH3PbBr3 NCs serve dual roles: catalyzing the polymerization reaction and endowing the nanocomposites with fluorescence properties. By adjusting the cross-linker content, gel composites with tunable mechanical strength were successfully fabricated. Furthermore, the composites exhibited sustained fluorescence intensity for over 15 days in air and water and enhanced ethanol resistance, with the polymer matrix significantly improving the environmental stability of CH3NH3PbBr3 NCs.
{"title":"Luminescent Perovskite–Polymer Gel Composites Prepared in Situ via PET-RAFT Polymerization","authors":"Zeyi Yan, Jingjing Xiao, Weijie Zhang, Yuxiang Zhang, Lei Liu, Bo Zhang, Anchao Feng","doi":"10.1021/acsmacrolett.5c00269","DOIUrl":"https://doi.org/10.1021/acsmacrolett.5c00269","url":null,"abstract":"Although organic–inorganic lead halide perovskite nanocrystals (NCs) have emerged as new semiconductor photocatalysts with excellent photocatalytic performance, their stability remains inferior to that of all-inorganic lead halide perovskite NCs. To address this limitation, we propose a one-step in situ polymerization strategy via a CH<sub>3</sub>NH<sub>3</sub>PbBr<sub>3</sub> NCs-initiated photoinduced electron/energy transfer-reversible addition–fragmentation chain transfer polymerization to construct CH<sub>3</sub>NH<sub>3</sub>PbBr<sub>3</sub>–PBA/PMA gel composites, demonstrating the feasibility of both oxygenated and oxygen-free preparation processes. In this system, CH<sub>3</sub>NH<sub>3</sub>PbBr<sub>3</sub> NCs serve dual roles: catalyzing the polymerization reaction and endowing the nanocomposites with fluorescence properties. By adjusting the cross-linker content, gel composites with tunable mechanical strength were successfully fabricated. Furthermore, the composites exhibited sustained fluorescence intensity for over 15 days in air and water and enhanced ethanol resistance, with the polymer matrix significantly improving the environmental stability of CH<sub>3</sub>NH<sub>3</sub>PbBr<sub>3</sub> NCs.","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":"44 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335189","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}
Pub Date : 2025-06-17DOI: 10.1021/acsmacrolett.5c00323
Jan-Michael Y Carrillo,Yangyang Wang
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.
{"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}
Pub Date : 2025-06-16DOI: 10.1021/acsmacrolett.5c00305
Pratyusha Das,Alexandra Zele,Ming-Pei Lin,J Tyler Mefford,Michael L Chabinyc,Rachel A Segalman
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.
{"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}
Pub Date : 2025-06-16DOI: 10.1021/acsmacrolett.5c00327
Yuanyuan Liu,Haiyue Zhao,Xinyu Meng,Yuxiang Fu,Yahang Dong,Jialong Li,Hongsen Liu,Chengcai Pang
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.
{"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}
Pub Date : 2025-06-13DOI: 10.1021/acsmacrolett.5c00225
Ruofei Hu, Yingru Zeng, Huanzhen Ji, Guochen Ji, Xinfang Wang, Aili Wang, Lianwen Zhou, Jing Zhao, Junping Zheng
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.
{"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<sup>–3</sup>. 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}
Pub Date : 2025-06-13DOI: 10.1021/acsmacrolett.5c00206
Hantao Zhou, Jesus Guillen Campos, Rishabh Tennankore, Wenwen Xu, Yunfeng Hu, Javier Read de Alaniz, Ryan C. Hayward
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 trans to cis 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 ortho-difluoro, dichloro-substituted azo photoswitches. These polymers exhibit near-quantitative bidirectional photoisomerization─92% conversion to cis under 617 nm irradiation and 96% conversion to trans under 405 nm irradiation, along with reversible photomelting and crystallization. Photorheological studies demonstrate a significant increase over which photomelting can be achieved, from <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.
{"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 <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}
Pub Date : 2025-06-12DOI: 10.1021/acsmacrolett.5c00208
Jun Li, Xiaoqi Cheng, Rongmin Wang, Yaping Zhang, Yufeng He, Pengfei Song
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-b-P(VMA)x, x = 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-b-P(VMA)x 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 (x = 7, 10) showed 89.0% against both E. coli and S. aureus and complete hydrolysis of the ester bonds of host–guest building blocks on the copolymer chain, while low cross-linking density (x = 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.
生物基高分子材料的发展有望减少对不可再生资源的依赖。然而，通过主客多层结构对性能进行可控调节仍然是一个巨大的挑战。为了解决这一问题，以β-环糊精衍生单体和生物质衍生香兰素单体为主体，采用可逆加成-破碎链转移（RAFT）嵌段共聚法制备了主客体嵌段共聚物(P（CD)2-b-P(VMA)x, x = 7,10,72,159）。同时，P(CD)2-b-P(VMA)x通过二维（2D）机械联锁和三维（3D）物理交联在原位自组装成蜂窝纳米孔通道材料。值得注意的是，高交联密度（x = 7, 10）对大肠杆菌和金黄色葡萄球菌均有89.0%的抑制作用，并能完全水解共聚物链上主-客构建块的酯键，而低交联密度（x = 72, 159）没有抗菌活性，且被部分水解。总的来说，这一策略展示了一种调节多层结构的方法，提供了一种具有可调节性能的环保材料。
{"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)<sub>2</sub>-<i>b</i>-P(VMA)<sub><i>x</i></sub>, <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)<sub>2</sub>-<i>b</i>-P(VMA)<sub><i>x</i></sub> 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}
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 PS+(triEG-alt-octyl) alternating polymer significantly reactivated the electron transport chain (ETC) in persister cells, achieving >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 >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.
{"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><sup><b>+</b></sup><b>(triEG-<i>alt</i>-octyl)</b> alternating polymer significantly reactivated the electron transport chain (ETC) in persister cells, achieving >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 >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}
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