Pub Date : 2025-02-23DOI: 10.1021/acs.macromol.4c02021
Shota Ando, Kohzo Ito
Polymeric materials, often represented as thread-like molecules, are frequently utilized as network structures through the chemical or physical cross-linking of polymer chains. Recently, materials incorporating rotaxanes or polyrotaxanes─quintessential topological supramolecular structures─into this cross-linked architecture (termed Slide-Ring Materials, SRMs) that exhibit distinct physical properties compared to materials directly cross-linked by conventional polymer chains have emerged. The mobility of the cross-linking points allows for the redistribution of tensile and compressive stresses exerted on the polymer chains, thereby enhancing the toughness and durability of the material. In addition to the conformational entropy of the polymers, which underpins rubber elasticity, the entropy of the rings also contributes to the elasticity, resulting in various physical properties that diverge from traditional materials with fixed cross-links. Initially introduced as gels, materials with movable cross-links have subsequently expanded to rubbers, elastomers, resins, and composites. Research has also intensified on materials that not only consist solely of rotaxanes or polyrotaxanes but also those that incorporate small quantities of rotaxanes or polyrotaxanes into conventional polymer materials. Particularly, the latter has become significant especially in terms of application for various fields, as it retains the myriad advantages of traditional polymer materials while achieving enhanced toughness, making the application of SRMs highly advantageous. In this perspective, we review recent advancements in the synthesis, structure, properties, and functions of SRMs, and briefly touch upon the future prospects of SRMs.
{"title":"Recent Progress and Future Perspective in Slide-Ring Based Polymeric Materials","authors":"Shota Ando, Kohzo Ito","doi":"10.1021/acs.macromol.4c02021","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02021","url":null,"abstract":"Polymeric materials, often represented as thread-like molecules, are frequently utilized as network structures through the chemical or physical cross-linking of polymer chains. Recently, materials incorporating rotaxanes or polyrotaxanes─quintessential topological supramolecular structures─into this cross-linked architecture (termed Slide-Ring Materials, SRMs) that exhibit distinct physical properties compared to materials directly cross-linked by conventional polymer chains have emerged. The mobility of the cross-linking points allows for the redistribution of tensile and compressive stresses exerted on the polymer chains, thereby enhancing the toughness and durability of the material. In addition to the conformational entropy of the polymers, which underpins rubber elasticity, the entropy of the rings also contributes to the elasticity, resulting in various physical properties that diverge from traditional materials with fixed cross-links. Initially introduced as gels, materials with movable cross-links have subsequently expanded to rubbers, elastomers, resins, and composites. Research has also intensified on materials that not only consist solely of rotaxanes or polyrotaxanes but also those that incorporate small quantities of rotaxanes or polyrotaxanes into conventional polymer materials. Particularly, the latter has become significant especially in terms of application for various fields, as it retains the myriad advantages of traditional polymer materials while achieving enhanced toughness, making the application of SRMs highly advantageous. In this perspective, we review recent advancements in the synthesis, structure, properties, and functions of SRMs, and briefly touch upon the future prospects of SRMs.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"110 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143473535","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}
Pub Date : 2025-02-22DOI: 10.1021/acs.macromol.4c02287
Wei Wei, Song Li, Xingping Zhou, Haiyan Peng, Xiaolin Xie
Holographic polymer nanocomposites comprising liquid crystals (LCs), which are basically formulated by periodic photopolymerization-induced phase separation under coherent lasers, exhibit significant application value in a myriad of high-tech fields such as augmented reality (AR)/virtual reality (VR), 3D displays, advanced anticounterfeiting, and holographic sensing. Herein, by coupling the dissipative particle dynamics (DPD) simulation in the mesoscale and finite-difference time-domain (FDTD) simulation in the macroscale, we disclose that the thiol–ene click polymerization can lead to greater LC ordering in holographic polymer nanocomposites. Besides, compared to the thiol–acrylate polymerization system, step-growth polymerization dominates in the thiol–ene click polymerization system, giving rise to more regular phase separation structures with higher polymer density and lower interfacial roughness. Due to the high LC ordering at the DPD temperature of T* = 0.40 kBT, a maximum LC ordering parameter is achieved, i.e., Su = 0.51 ± 0.01. Consequently, significant polarization-dependent diffraction is observed, with a maximum diffraction efficiency of 92.5 ± 0.3% and 69.3 ± 5.4%, respectively, when probed by s- and p-polarized light. The cross-scale coupled DPD-FDTD simulation not only provides valuable insights into the fundamental structure–property relation of holographic polymer nanocomposites but also offers a viable tool to study structure-ordered materials.
{"title":"Thiol–Ene Photopolymerization Enhances Liquid Crystal Ordering and Structural Regularity in Holographic Polymer Nanocomposites: A Coupled DPD-FDTD Simulation","authors":"Wei Wei, Song Li, Xingping Zhou, Haiyan Peng, Xiaolin Xie","doi":"10.1021/acs.macromol.4c02287","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02287","url":null,"abstract":"Holographic polymer nanocomposites comprising liquid crystals (LCs), which are basically formulated by periodic photopolymerization-induced phase separation under coherent lasers, exhibit significant application value in a myriad of high-tech fields such as augmented reality (AR)/virtual reality (VR), 3D displays, advanced anticounterfeiting, and holographic sensing. Herein, by coupling the dissipative particle dynamics (DPD) simulation in the mesoscale and finite-difference time-domain (FDTD) simulation in the macroscale, we disclose that the thiol–ene click polymerization can lead to greater LC ordering in holographic polymer nanocomposites. Besides, compared to the thiol–acrylate polymerization system, step-growth polymerization dominates in the thiol–ene click polymerization system, giving rise to more regular phase separation structures with higher polymer density and lower interfacial roughness. Due to the high LC ordering at the DPD temperature of <i>T</i>* = 0.40 <i>k</i><sub>B</sub><i>T</i>, a maximum LC ordering parameter is achieved, i.e., <i>S</i><sub>u</sub> = 0.51 ± 0.01. Consequently, significant polarization-dependent diffraction is observed, with a maximum diffraction efficiency of 92.5 ± 0.3% and 69.3 ± 5.4%, respectively, when probed by <i>s</i>- and <i>p</i>-polarized light. The cross-scale coupled DPD-FDTD simulation not only provides valuable insights into the fundamental structure–property relation of holographic polymer nanocomposites but also offers a viable tool to study structure-ordered materials.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"23 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470462","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}
Pub Date : 2025-02-21DOI: 10.1021/acs.macromol.4c03089
Rounak Jana, Lily A. Gido, David M. Halat, Carol Sempira, Jeffrey Fedenko, A. P. van Bavel, Nitash P. Balsara
We report the design and synthesis of a triblock copolymer-based membrane for enabling selective transport of lactic acid from aqueous solutions. This is relevant to the production of polylactic acid, one of the few biodegradable and biobased polymers with sufficient mechanical strength for practical applications. The end blocks are positively charged with negatively charged lactate counterions. The middle block is polybutadiene (PBD). Due to microphase separation, the charged blocks form channels for transporting lactic acid. The mechanical integrity of the membrane is controlled by cross-linking the PBD block. Transport of lactic acid and water across the membrane was studied by placing the membrane between two chambers, a feed chamber containing aqueous lactic acid solutions, and a receiving chamber containing pure water. The lactic acid concentration in the receiving chamber was monitored as a function of time using conductivity, HPLC, and NMR. The corresponding flux of water from the receiving chamber to the feed chamber was measured using an NMR-based approach. The lactic acid and water permeabilities through our membrane were (1.12 ± 0.05) × 10–8 and (8.58 ± 0.75) × 10–9 cm2 s–1. To our knowledge, there are no reports of lactic acid permeabilities through any membrane in the literature. The separation factor of our membrane, αLA/water, 1.305 ± 0.123, is comparable to that of membranes used for selective transport of ethanol, despite the fact that lactic acid is a much larger molecule than ethanol. Selective transport of lactic acid in our membrane is governed mainly by differences in solubility; lactic acid is 18 times more soluble in the membrane than water.
{"title":"Designing a Block Copolymer Membrane for Selective Transport of Lactic Acid from Aqueous Mixtures","authors":"Rounak Jana, Lily A. Gido, David M. Halat, Carol Sempira, Jeffrey Fedenko, A. P. van Bavel, Nitash P. Balsara","doi":"10.1021/acs.macromol.4c03089","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c03089","url":null,"abstract":"We report the design and synthesis of a triblock copolymer-based membrane for enabling selective transport of lactic acid from aqueous solutions. This is relevant to the production of polylactic acid, one of the few biodegradable and biobased polymers with sufficient mechanical strength for practical applications. The end blocks are positively charged with negatively charged lactate counterions. The middle block is polybutadiene (PBD). Due to microphase separation, the charged blocks form channels for transporting lactic acid. The mechanical integrity of the membrane is controlled by cross-linking the PBD block. Transport of lactic acid and water across the membrane was studied by placing the membrane between two chambers, a feed chamber containing aqueous lactic acid solutions, and a receiving chamber containing pure water. The lactic acid concentration in the receiving chamber was monitored as a function of time using conductivity, HPLC, and NMR. The corresponding flux of water from the receiving chamber to the feed chamber was measured using an NMR-based approach. The lactic acid and water permeabilities through our membrane were (1.12 ± 0.05) × 10<sup>–8</sup> and (8.58 ± 0.75) × 10<sup>–9</sup> cm<sup>2</sup> s<sup>–1</sup>. To our knowledge, there are no reports of lactic acid permeabilities through any membrane in the literature. The separation factor of our membrane, α<sub>LA/water</sub>, 1.305 ± 0.123, is comparable to that of membranes used for selective transport of ethanol, despite the fact that lactic acid is a much larger molecule than ethanol. Selective transport of lactic acid in our membrane is governed mainly by differences in solubility; lactic acid is 18 times more soluble in the membrane than water.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"89 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462985","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}
Pub Date : 2025-02-20DOI: 10.1021/acs.macromol.4c02970
Mengjia Yin, Zhigang Xue
Polymer organic electrodes with unique electron storage and ion storage mechanisms have achieved remarkable development in recent years. However, the specific capacity and rate capability of organic electrodes are still unsatisfactory due to the slow ion and electron transport. Most importantly, some measures used to improve electron or ion transport come at the expense of slowing down the transport of the other. Therefore, achieving a balance between ion and electron transport and accelerating electrode reaction kinetics through underlying molecular design remain a formidable task. Herein, we adopted a measure of combining the rigidity and flexibility of the polymer backbone to realize fast electron and ion transport simultaneously. When the prepared polymer Fc-EDA was used as the cathode for lithium-ion batteries, it provided a high capacity of 160 mA h g–1 at 0.1 A g–1, corresponding to an active site utilization of up to 83%. Fc-EDA had excellent rate capability, with the capacities at 2 A g–1 and 10 A g–1 being 60% and 40% of that at 0.1 A g–1, respectively. In addition, it could be cycled over 3500 times at 2 A g–1 with a capacity retention of 60%.
{"title":"Balance of Ion and Electron Transport in Ferrocene-Based Polymer Organic Cathode for High-Performance Lithium-Ion Batteries","authors":"Mengjia Yin, Zhigang Xue","doi":"10.1021/acs.macromol.4c02970","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02970","url":null,"abstract":"Polymer organic electrodes with unique electron storage and ion storage mechanisms have achieved remarkable development in recent years. However, the specific capacity and rate capability of organic electrodes are still unsatisfactory due to the slow ion and electron transport. Most importantly, some measures used to improve electron or ion transport come at the expense of slowing down the transport of the other. Therefore, achieving a balance between ion and electron transport and accelerating electrode reaction kinetics through underlying molecular design remain a formidable task. Herein, we adopted a measure of combining the rigidity and flexibility of the polymer backbone to realize fast electron and ion transport simultaneously. When the prepared polymer Fc-EDA was used as the cathode for lithium-ion batteries, it provided a high capacity of 160 mA h g<sup>–1</sup> at 0.1 A g<sup>–1</sup>, corresponding to an active site utilization of up to 83%. Fc-EDA had excellent rate capability, with the capacities at 2 A g<sup>–1</sup> and 10 A g<sup>–1</sup> being 60% and 40% of that at 0.1 A g<sup>–1</sup>, respectively. In addition, it could be cycled over 3500 times at 2 A g<sup>–1</sup> with a capacity retention of 60%.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"22 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462988","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}
Pub Date : 2025-02-20DOI: 10.1021/acs.macromol.4c02925
Zitan Huang, Sol Mi Oh, Karen I. Winey, Michael A. Hickner
Proton exchange membranes (PEMs) with high conductivity are of critical importance for the development of fuel cells, electrolyzers, and other electrochemical technologies. In this research, poly(1,1,2,2-tetrafluoro-2-phenoxyethane-1-sulfonic acid) (PTPS) with an aromatic polymer main chain and a perfluorinated superacidic polymer side chain was synthesized. The water dynamics of PTPS were characterized across various length scales using a combination of Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) and compared with Nafion, a standard perfluorinated PEM, and sulfonated poly(ether sulfone) (SPES 40), an aromatic PEM without perfluorinated superacid side chains. The T1 and T2 relaxation times of water in the samples probed by NMR increase from SPES 40 to PTPS to Nafion, indicating that the local motion of the water molecules becomes faster. This trend corresponds well with the relative fraction of bulk-like water determined using FTIR. At larger length scales, the diffusion coefficient of water was characterized using pulsed-field gradient NMR (PFG-NMR). At a longer diffusion time (Δ = 100 ms), PTPS has a smaller diffusion coefficient compared with both Nafion and SPES 40, due to restricted diffusion, and this effect is also evident in the proton conductivity of the hydrated membranes. From this comparison, it is apparent that the aromatic backbone and side chain type greatly influence the water dynamics in PEMs at various length scales and the water dynamics significantly impact the bulk proton conductivity. These insights will lead to new designs for aromatic PEMs and help to identify bottlenecks in current materials.
{"title":"Water Dynamics of Superacid Aromatic Proton Exchange Membranes for Fuel Cell Applications","authors":"Zitan Huang, Sol Mi Oh, Karen I. Winey, Michael A. Hickner","doi":"10.1021/acs.macromol.4c02925","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02925","url":null,"abstract":"Proton exchange membranes (PEMs) with high conductivity are of critical importance for the development of fuel cells, electrolyzers, and other electrochemical technologies. In this research, poly(1,1,2,2-tetrafluoro-2-phenoxyethane-1-sulfonic acid) (PTPS) with an aromatic polymer main chain and a perfluorinated superacidic polymer side chain was synthesized. The water dynamics of PTPS were characterized across various length scales using a combination of Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) and compared with Nafion, a standard perfluorinated PEM, and sulfonated poly(ether sulfone) (SPES 40), an aromatic PEM without perfluorinated superacid side chains. The <i>T</i><sub>1</sub> and <i>T</i><sub>2</sub> relaxation times of water in the samples probed by NMR increase from SPES 40 to PTPS to Nafion, indicating that the local motion of the water molecules becomes faster. This trend corresponds well with the relative fraction of bulk-like water determined using FTIR. At larger length scales, the diffusion coefficient of water was characterized using pulsed-field gradient NMR (PFG-NMR). At a longer diffusion time (Δ = 100 ms), PTPS has a smaller diffusion coefficient compared with both Nafion and SPES 40, due to restricted diffusion, and this effect is also evident in the proton conductivity of the hydrated membranes. From this comparison, it is apparent that the aromatic backbone and side chain type greatly influence the water dynamics in PEMs at various length scales and the water dynamics significantly impact the bulk proton conductivity. These insights will lead to new designs for aromatic PEMs and help to identify bottlenecks in current materials.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"209 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462986","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}
Pub Date : 2025-02-20DOI: 10.1021/acs.macromol.4c02187
Matteo Chamchoum, Orsolya Czakkel, Özge Azeri, Bin Dai, Sylvain Prévost, Olga Kuzminskaya, Olga Matsarskaia, Andrew E. Whitten, Michael Gradzielski
The formation of interpolyelectrolyte complexes (IPECs) by mixing oppositely charged polyelectrolytes has been studied extensively over the last few years. In this article, we show how the structure of IPECs formed by a double-hydrophilic anionic block copolymer and hydrophobically modified poly (2-(dimethylamino)ethyl methacrylate) (PDMAEMA) is affected by the mixing ratio and the type and quantity of hydrophobic modifications of the PDMAEMA. Static and dynamic light scattering as well as small-angle neutron scattering (SANS) reveal the role of hydrophobic modifications on large-scale aggregation behavior. Modeling SANS data with a cluster of hydrated spheres formed by the polymeric species enabled us to see that the aggregates become less hydrated upon switching from polycation to polyanion excess, and larger and more well-defined aggregates are formed with hydrophobically modified PDMAEMA.
{"title":"Formation of Interpolyelectrolyte Complexes (IPECs) between Double-Hydrophilic Block Copolymers and Polysoaps: The Role of Hydrophobic Modification and Mixing Ratio as Structural Control Parameters","authors":"Matteo Chamchoum, Orsolya Czakkel, Özge Azeri, Bin Dai, Sylvain Prévost, Olga Kuzminskaya, Olga Matsarskaia, Andrew E. Whitten, Michael Gradzielski","doi":"10.1021/acs.macromol.4c02187","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02187","url":null,"abstract":"The formation of interpolyelectrolyte complexes (IPECs) by mixing oppositely charged polyelectrolytes has been studied extensively over the last few years. In this article, we show how the structure of IPECs formed by a double-hydrophilic anionic block copolymer and hydrophobically modified poly (2-(dimethylamino)ethyl methacrylate) (PDMAEMA) is affected by the mixing ratio and the type and quantity of hydrophobic modifications of the PDMAEMA. Static and dynamic light scattering as well as small-angle neutron scattering (SANS) reveal the role of hydrophobic modifications on large-scale aggregation behavior. Modeling SANS data with a cluster of hydrated spheres formed by the polymeric species enabled us to see that the aggregates become less hydrated upon switching from polycation to polyanion excess, and larger and more well-defined aggregates are formed with hydrophobically modified PDMAEMA.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"25 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462983","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}
Pub Date : 2025-02-20DOI: 10.1021/acs.macromol.4c02988
Xintong Zhao, Ninghua He, Ying Lu, Yongfeng Men
The kinetics of crystallization, lamellar long period, and melting temperatures (Tm) of hydrogenous isotactic polybutene-1 (hPB-1) and its fully deuterated counterpart (deuterated isotactic polybutene-1, dPB-1) with similar molecular weight at different isothermal crystallization temperatures (Tc) were investigated by means of fast scanning chip calorimetry and synchrotron microfocus small-angle X-ray scattering techniques. The Hoffman–Weeks plot where Tm was plotted as a function of Tc was used to determine the equilibrium melting point by extrapolating the data to Tm = Tc. Moreover, following the Gibbs–Thomoson equation and Strobl’s multistage crystallization model, the melting line and crystallization line where Tm or Tc is plotted as a function of inversed lamellar long period (1/dac) were constructed to determine the equilibrium melting temperature and equilibrium crystallization temperature by extrapolating the corresponding lines to infinite lamellar long period. The hPB-1 displays faster crystallization rates across the entire temperature range, suggesting a higher supercooling driving its crystallization than in dPB-1. However, hPB-1 possesses a lower equilibrium melting point/temperature but a higher equilibrium crystallization temperature than dPB-1. This peculiar isotope effect on the crystallization behavior of isotactic polybutene-1 provides a unique example supporting the crystallization mechanism proposed by Strobl where the supercooling with respect to the equilibrium crystallization temperature determines the crystallization kinetics.
{"title":"Crystallization Kinetics, Crystallization and Melting Lines of Deuterated and Hydrogenous Isotactic Polybutene-1","authors":"Xintong Zhao, Ninghua He, Ying Lu, Yongfeng Men","doi":"10.1021/acs.macromol.4c02988","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02988","url":null,"abstract":"The kinetics of crystallization, lamellar long period, and melting temperatures (<i>T</i><sub>m</sub>) of hydrogenous isotactic polybutene-1 (hPB-1) and its fully deuterated counterpart (deuterated isotactic polybutene-1, dPB-1) with similar molecular weight at different isothermal crystallization temperatures (<i>T</i><sub>c</sub>) were investigated by means of fast scanning chip calorimetry and synchrotron microfocus small-angle X-ray scattering techniques. The Hoffman–Weeks plot where <i>T</i><sub>m</sub> was plotted as a function of <i>T</i><sub>c</sub> was used to determine the equilibrium melting point by extrapolating the data to <i>T</i><sub>m</sub> = <i>T</i><sub>c</sub>. Moreover, following the Gibbs–Thomoson equation and Strobl’s multistage crystallization model, the melting line and crystallization line where <i>T</i><sub>m</sub> or <i>T</i><sub>c</sub> is plotted as a function of inversed lamellar long period (1/<i>d</i><sub>ac</sub>) were constructed to determine the equilibrium melting temperature and equilibrium crystallization temperature by extrapolating the corresponding lines to infinite lamellar long period. The hPB-1 displays faster crystallization rates across the entire temperature range, suggesting a higher supercooling driving its crystallization than in dPB-1. However, hPB-1 possesses a lower equilibrium melting point/temperature but a higher equilibrium crystallization temperature than dPB-1. This peculiar isotope effect on the crystallization behavior of isotactic polybutene-1 provides a unique example supporting the crystallization mechanism proposed by Strobl where the supercooling with respect to the equilibrium crystallization temperature determines the crystallization kinetics.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"25 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462990","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}
Pub Date : 2025-02-20DOI: 10.1021/acs.macromol.4c02435
M. S. Rumyantsev, I. Yu Kalagaev, I. N. Senchikhin
The search for chemical and technological solutions to process cheap and available elemental sulfur to produce valuable multifunctional materials is one of the current challenging tasks. Instead of extensively used low-molecular-weight monomers, we proposed to use the original reactive polyalkylene sulfide resin as an alternative reagent containing pendant methacrylic groups. The use of a reactive viscous resin instead of monomers allows the syntheses to be carried out under reduced pressure conditions and high temperature, which allows volatile impurities and byproducts to be removed from the reaction zone. Peculiarities in the glass transition temperatures, heat capacities, and onsets of thermal degradation were addressed in the paper. Two glass transition temperatures were demonstrated to be the unique feature of the synthesized materials. This phenomenon was attributed to the enhanced chain mobility of the polyalkylene sulfide resin used, which was consequently expressed as a specific chain organization in the systems studied. Assuming the analysis of the literature data and the results presented in this work, it was concluded that in order to obtain more homogeneous materials less susceptible to undesirable aging, it is preferred to use the ratio of double bonds to sulfur, providing the formation of short cross-links consisting of 2–3 sulfur atoms. The materials obtained showed relatively high values of the onset of thermal degradation exceeding 270 °C and very high adhesion to glass and steel. In both cases, the adhesion tensile strength values exceeded 10 MPa. Furthermore, the obtained materials showed high chemical resistance to basic organic solvents.
{"title":"Thioglycidyl Methacrylate-Based Reactive Polyalkylene Sulfide Resin as an Alternative Substrate for the Reaction with Elemental Sulfur: Peculiarities of Synthesis, Thermodynamic and Mechanical Properties of Sulfur-Rich Plastics with High Adhesive Tensile Strength and Chemical Resistance","authors":"M. S. Rumyantsev, I. Yu Kalagaev, I. N. Senchikhin","doi":"10.1021/acs.macromol.4c02435","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c02435","url":null,"abstract":"The search for chemical and technological solutions to process cheap and available elemental sulfur to produce valuable multifunctional materials is one of the current challenging tasks. Instead of extensively used low-molecular-weight monomers, we proposed to use the original reactive polyalkylene sulfide resin as an alternative reagent containing pendant methacrylic groups. The use of a reactive viscous resin instead of monomers allows the syntheses to be carried out under reduced pressure conditions and high temperature, which allows volatile impurities and byproducts to be removed from the reaction zone. Peculiarities in the glass transition temperatures, heat capacities, and onsets of thermal degradation were addressed in the paper. Two glass transition temperatures were demonstrated to be the unique feature of the synthesized materials. This phenomenon was attributed to the enhanced chain mobility of the polyalkylene sulfide resin used, which was consequently expressed as a specific chain organization in the systems studied. Assuming the analysis of the literature data and the results presented in this work, it was concluded that in order to obtain more homogeneous materials less susceptible to undesirable aging, it is preferred to use the ratio of double bonds to sulfur, providing the formation of short cross-links consisting of 2–3 sulfur atoms. The materials obtained showed relatively high values of the onset of thermal degradation exceeding 270 °C and very high adhesion to glass and steel. In both cases, the adhesion tensile strength values exceeded 10 MPa. Furthermore, the obtained materials showed high chemical resistance to basic organic solvents.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"4 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462984","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}
Pub Date : 2025-02-20DOI: 10.1021/acs.macromol.4c03124
Mariano E. Brito, Ellen Höpner, David Beyer, Christian Holm
Combining a mean-field swelling model─which incorporates the Poisson–Boltzmann cell model for describing the electrostatics of microgels and a Flory–Rehner-based model for describing the polymer network─with the law of mass action to account for chemical reactions, we present a comprehensive swelling model for weakly charged microgels. This model provides an expression for the microgel osmotic pressure, used to determine the equilibrium swelling and, consequently, the net charge of the microgel as a function of reservoir pH, salt concentration, degree of polymerization, and other suspension and microscopic network properties. The model allows us to relate microscopic microgel features with the equilibrium swelling properties. The weak-field limiting case of the Poisson–Boltzmann theory is analyzed, yielding closed formulas. We validate the model against state-of-the-art coarse-grained simulations of a microgel, utilizing molecular dynamics to explore configurational degrees of freedom and the Monte Carlo grand-reaction method to simulate chemical reactions in equilibrium with a pH and salt reservoir. We test the model predictions for equilibrium ionization, size, and net charge against particle-based simulations and experiments. Our findings show that the model accurately describes microgel swelling and net charge over a wide range of pH levels. Although the accuracy decreases for larger salt concentrations, its overall qualitative accuracy makes it a reliable tool for parameter exploration and data interpretation, aiding in the rational design of microgel suspensions.
{"title":"Modeling Swelling of pH-Responsive Microgels: Theory and Simulations","authors":"Mariano E. Brito, Ellen Höpner, David Beyer, Christian Holm","doi":"10.1021/acs.macromol.4c03124","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c03124","url":null,"abstract":"Combining a mean-field swelling model─which incorporates the Poisson–Boltzmann cell model for describing the electrostatics of microgels and a Flory–Rehner-based model for describing the polymer network─with the law of mass action to account for chemical reactions, we present a comprehensive swelling model for weakly charged microgels. This model provides an expression for the microgel osmotic pressure, used to determine the equilibrium swelling and, consequently, the net charge of the microgel as a function of reservoir pH, salt concentration, degree of polymerization, and other suspension and microscopic network properties. The model allows us to relate microscopic microgel features with the equilibrium swelling properties. The weak-field limiting case of the Poisson–Boltzmann theory is analyzed, yielding closed formulas. We validate the model against state-of-the-art coarse-grained simulations of a microgel, utilizing molecular dynamics to explore configurational degrees of freedom and the Monte Carlo grand-reaction method to simulate chemical reactions in equilibrium with a pH and salt reservoir. We test the model predictions for equilibrium ionization, size, and net charge against particle-based simulations and experiments. Our findings show that the model accurately describes microgel swelling and net charge over a wide range of pH levels. Although the accuracy decreases for larger salt concentrations, its overall qualitative accuracy makes it a reliable tool for parameter exploration and data interpretation, aiding in the rational design of microgel suspensions.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"25 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462987","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}
Pub Date : 2025-02-19DOI: 10.1021/acs.macromol.4c03090
Jeffrey C. Foster, Isaiah T. Dishner, Joshua T. Damron, Vilmos Kertesz, Ilja Popovs, Tomonori Saito
Traditional chemical recycling approaches for condensation polymers suffer compounding energy losses and CO2 emissions across multiple polymerization and depolymerization cycles. Entropic recycling can address these energy losses by entrapping free energy within the deconstruction products. Entropic recycling involves depolymerization to macrocyclic monomers, but such processes have not been feasible due to the high dilutions typically required to generate macrocyclic compounds. Here, we leverage selective catalysis to allow entropic recycling at concentrations 20–2000× higher than typical for macrocyclization reactions. We find that Ru-based olefin metathesis catalysts containing bulky iodine ligands significantly bias the ring–chain kinetic product distribution during ring-closing metathesis (RCM) toward the formation of oligomeric cycloalkenes. Further improvements in reaction concentration and macrocycle yield are obtained by using high catalyst loadings and by predisposing the alkene substrates to undergo favorable macrocyclization. These RCM optimizations translate effectively to cyclodepolymerization (CDP) of an olefin-containing polymer, with RCM and CDP affording similar macrocycle product distributions under identical reaction conditions. Macrocycle polymerization by entropy-driven ring-opening metathesis provides much higher molecular weight polymers than condensation polymerization of linear analogues, reducing the time to achieve high molecular weight from hours to minutes and enabling polymerization at room temperature. Our findings re-emphasize the importance of energy consumption during a polymer’s lifecycle and provide a framework for the design of efficient entropic recycling systems.
{"title":"Toward Efficient Entropic Recycling by Mastering Ring–Chain Kinetics","authors":"Jeffrey C. Foster, Isaiah T. Dishner, Joshua T. Damron, Vilmos Kertesz, Ilja Popovs, Tomonori Saito","doi":"10.1021/acs.macromol.4c03090","DOIUrl":"https://doi.org/10.1021/acs.macromol.4c03090","url":null,"abstract":"Traditional chemical recycling approaches for condensation polymers suffer compounding energy losses and CO<sub>2</sub> emissions across multiple polymerization and depolymerization cycles. Entropic recycling can address these energy losses by entrapping free energy within the deconstruction products. Entropic recycling involves depolymerization to macrocyclic monomers, but such processes have not been feasible due to the high dilutions typically required to generate macrocyclic compounds. Here, we leverage selective catalysis to allow entropic recycling at concentrations 20–2000× higher than typical for macrocyclization reactions. We find that Ru-based olefin metathesis catalysts containing bulky iodine ligands significantly bias the ring–chain kinetic product distribution during ring-closing metathesis (RCM) toward the formation of oligomeric cycloalkenes. Further improvements in reaction concentration and macrocycle yield are obtained by using high catalyst loadings and by predisposing the alkene substrates to undergo favorable macrocyclization. These RCM optimizations translate effectively to cyclodepolymerization (CDP) of an olefin-containing polymer, with RCM and CDP affording similar macrocycle product distributions under identical reaction conditions. Macrocycle polymerization by entropy-driven ring-opening metathesis provides much higher molecular weight polymers than condensation polymerization of linear analogues, reducing the time to achieve high molecular weight from hours to minutes and enabling polymerization at room temperature. Our findings re-emphasize the importance of energy consumption during a polymer’s lifecycle and provide a framework for the design of efficient entropic recycling systems.","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"4 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462997","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}
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