Degumming with an aqueous alkaline solution, such as sodium carbonate (Na2CO3), is the initial step in purifying a silk fibroin (SF) aqueous solution from Bombyx mori silkworm cocoons. While essential for sericin removal, this process affects the molecular state of the SF, impacting factors such as the molecular chain length and weight distribution. In this study, we aimed to investigate the physical and biological properties of films prepared from different aqueous SF solutions obtained through degumming with Na2CO3 at various concentrations, followed by water solubilization and dialysis. Higher concentrations of Na2CO3 resulted in broader distributions of molecular weights in the purified SF aqueous solutions. An SF film containing a greater proportion of low-molecular-weight chains (below 100 kDa) exhibited a faster degradation rate and lower fibroblast adhesion compared with a film containing predominantly high-molecular-weight chains. In a rat abdominal adhesion model, the former inhibited postoperative adhesion, whereas the latter promoted adhesion at wound sites. These results highlight the importance of the initial degumming process in regulating the functionality of resulting SF products for medical applications. Aqueous SF solution is purified through degumming with Na2CO3 aqueous solution, followed by water solubilization and dialysis. In the preparation of SF film, the aqueous SF solution is cast into a mold and subjected to a drying process. Throughout this process, intermolecular interactions played a crucial role in film formation. The molecular state of the SF, including its chain length and molecular weight distribution, affected the properties of the resulting film.
{"title":"The effect of degumming conditions on the functionality of silk fibroin films","authors":"Masaya Harada, Wei Xu, Yusuke Kambe, Tsunenori Kameda, Shoji Nagaoka, Makoto Sasaki, Takuro Niidome","doi":"10.1038/s41428-025-01019-7","DOIUrl":"10.1038/s41428-025-01019-7","url":null,"abstract":"Degumming with an aqueous alkaline solution, such as sodium carbonate (Na2CO3), is the initial step in purifying a silk fibroin (SF) aqueous solution from Bombyx mori silkworm cocoons. While essential for sericin removal, this process affects the molecular state of the SF, impacting factors such as the molecular chain length and weight distribution. In this study, we aimed to investigate the physical and biological properties of films prepared from different aqueous SF solutions obtained through degumming with Na2CO3 at various concentrations, followed by water solubilization and dialysis. Higher concentrations of Na2CO3 resulted in broader distributions of molecular weights in the purified SF aqueous solutions. An SF film containing a greater proportion of low-molecular-weight chains (below 100 kDa) exhibited a faster degradation rate and lower fibroblast adhesion compared with a film containing predominantly high-molecular-weight chains. In a rat abdominal adhesion model, the former inhibited postoperative adhesion, whereas the latter promoted adhesion at wound sites. These results highlight the importance of the initial degumming process in regulating the functionality of resulting SF products for medical applications. Aqueous SF solution is purified through degumming with Na2CO3 aqueous solution, followed by water solubilization and dialysis. In the preparation of SF film, the aqueous SF solution is cast into a mold and subjected to a drying process. Throughout this process, intermolecular interactions played a crucial role in film formation. The molecular state of the SF, including its chain length and molecular weight distribution, affected the properties of the resulting film.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 6","pages":"689-697"},"PeriodicalIF":2.3,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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: 10.1038/s41428-024-01007-3
Hiroyoshi Kawakami
Solid electrolyte membranes based on polymers have shown promise owing to their high-energy demand and the sustainable and cost-effective nature of these materials. However, polymer electrolyte membranes composed of a polymer matrix have not progressed for the following reasons: (1) the low ion conductivity of polymer materials cannot achieve the level required for practical use, and (2) it is difficult to satisfy both battery performance and membrane durability simultaneously because of the trade-offs between ion conductivity and membrane stability. In recent years, research on composite electrolyte membranes composed of polymer nanofibers and a polymer matrix has attracted significant interest because of their improved ion conductivity, excellent membrane durability, and ability to fabricate thinner membranes. Polymeric nanofiber-containing polymer electrolyte membranes are expected to be applied not only to electrolyte membranes for fuel cells and water electrolysis, including alkaline-type electrolyte membranes for water electrolysis, but also to all-solid-state Li-ion batteries and all-solid-state Li-air batteries. This focus review presents the latest information on these topics. Research on composite electrolyte membranes composed of polymer nanofibers and a polymer matrix has attracted significant interest because of their improved ion conductivity, excellent membrane durability, and ability to fabricate thinner membranes. Polymeric nanofiber-containing polymer electrolyte membranes are expected to be applied not only to electrolyte membranes for fuel cells and water electrolysis but also to all-solid-state Li-ion batteries. This focus review presents the latest information on these topics.
{"title":"Development of composite electrolyte membranes with functional polymer nanofiber frameworks","authors":"Hiroyoshi Kawakami","doi":"10.1038/s41428-024-01007-3","DOIUrl":"10.1038/s41428-024-01007-3","url":null,"abstract":"Solid electrolyte membranes based on polymers have shown promise owing to their high-energy demand and the sustainable and cost-effective nature of these materials. However, polymer electrolyte membranes composed of a polymer matrix have not progressed for the following reasons: (1) the low ion conductivity of polymer materials cannot achieve the level required for practical use, and (2) it is difficult to satisfy both battery performance and membrane durability simultaneously because of the trade-offs between ion conductivity and membrane stability. In recent years, research on composite electrolyte membranes composed of polymer nanofibers and a polymer matrix has attracted significant interest because of their improved ion conductivity, excellent membrane durability, and ability to fabricate thinner membranes. Polymeric nanofiber-containing polymer electrolyte membranes are expected to be applied not only to electrolyte membranes for fuel cells and water electrolysis, including alkaline-type electrolyte membranes for water electrolysis, but also to all-solid-state Li-ion batteries and all-solid-state Li-air batteries. This focus review presents the latest information on these topics. Research on composite electrolyte membranes composed of polymer nanofibers and a polymer matrix has attracted significant interest because of their improved ion conductivity, excellent membrane durability, and ability to fabricate thinner membranes. Polymeric nanofiber-containing polymer electrolyte membranes are expected to be applied not only to electrolyte membranes for fuel cells and water electrolysis but also to all-solid-state Li-ion batteries. This focus review presents the latest information on these topics.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 6","pages":"623-633"},"PeriodicalIF":2.3,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-01007-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-20DOI: 10.1038/s41428-025-01023-x
Kakeru Obayashi, Ken Kojio
Cured epoxy resin (CER) adhesives are known to have excellent properties due to their strong strength and ability to interact with adherends. The high chemical cross-linking density structure of CERs plays an important role in their properties. In this study, a low cross-linking density cured epoxy resin (CER-L) was prepared with diglycidyl ether bisphenol A (average degree of polymerization (n = 1.1) (EPON) and phenyl ethyl amine (PEA)), and a high cross-linking density cured epoxy resin (CER-H) was prepared with diglycidyl ether bisphenol A (n = 1) (DGEBA) and 4,4’-diaminodiphenyl methane (DDM). Then, the mechanical properties of the bulk and adhesive properties of the single-lap joint (SLJ) were investigated, and the internal structure was evaluated. The resulting CER-L and CER-H showed similar Young’s moduli and yield stresses, whereas the elongation at break of CER-L was ten times larger than that of CER-H. The shear modulus and strength of the SLJs with CER-L were also comparable to those with CER-H. The failure modes of the SLJs with CER-L and CER-H were cohesive failure and interfacial failure, respectively. In situ small-angle X-ray scattering measurements at various positions in the adhesive during deformation revealed that crazes formed in CER-L during both uniaxial deformation and shear deformation and that plastic deformation occurred at the submillimeter scale. The stress concentration portion at the edge of the adhesive in the SLJ sample was relaxed by the plastic deformation of CER-L; this resulted in a comparable adhesive strength with CER-H. These novel results showed excellent adhesive strength even for the SLJ with CER-L and could be used to provide new guidelines for the design of adhesive materials. The adhesive properties of single-lap joint (SLJ) with low and high cross-linking density cured epoxy resin (CER-L and CER-H) were investigated and the internal structures during shear deformation were evaluated. Failure modes of the SLJs with CER-L and CER-H were cohesive failure and interfacial failure, respectively. Small-angle X-ray scattering measurements at various positions in adhesive revealed that crazes were formed for CER-L during shear deformation. The stress concentration portion at the edge of adhesive in the SLJ sample was relaxed by plastic deformation of CER-L, resulting in preventing interfacial failure.
{"title":"Adhesive properties of low-cross-linking density cured epoxy resin","authors":"Kakeru Obayashi, Ken Kojio","doi":"10.1038/s41428-025-01023-x","DOIUrl":"10.1038/s41428-025-01023-x","url":null,"abstract":"Cured epoxy resin (CER) adhesives are known to have excellent properties due to their strong strength and ability to interact with adherends. The high chemical cross-linking density structure of CERs plays an important role in their properties. In this study, a low cross-linking density cured epoxy resin (CER-L) was prepared with diglycidyl ether bisphenol A (average degree of polymerization (n = 1.1) (EPON) and phenyl ethyl amine (PEA)), and a high cross-linking density cured epoxy resin (CER-H) was prepared with diglycidyl ether bisphenol A (n = 1) (DGEBA) and 4,4’-diaminodiphenyl methane (DDM). Then, the mechanical properties of the bulk and adhesive properties of the single-lap joint (SLJ) were investigated, and the internal structure was evaluated. The resulting CER-L and CER-H showed similar Young’s moduli and yield stresses, whereas the elongation at break of CER-L was ten times larger than that of CER-H. The shear modulus and strength of the SLJs with CER-L were also comparable to those with CER-H. The failure modes of the SLJs with CER-L and CER-H were cohesive failure and interfacial failure, respectively. In situ small-angle X-ray scattering measurements at various positions in the adhesive during deformation revealed that crazes formed in CER-L during both uniaxial deformation and shear deformation and that plastic deformation occurred at the submillimeter scale. The stress concentration portion at the edge of the adhesive in the SLJ sample was relaxed by the plastic deformation of CER-L; this resulted in a comparable adhesive strength with CER-H. These novel results showed excellent adhesive strength even for the SLJ with CER-L and could be used to provide new guidelines for the design of adhesive materials. The adhesive properties of single-lap joint (SLJ) with low and high cross-linking density cured epoxy resin (CER-L and CER-H) were investigated and the internal structures during shear deformation were evaluated. Failure modes of the SLJs with CER-L and CER-H were cohesive failure and interfacial failure, respectively. Small-angle X-ray scattering measurements at various positions in adhesive revealed that crazes were formed for CER-L during shear deformation. The stress concentration portion at the edge of adhesive in the SLJ sample was relaxed by plastic deformation of CER-L, resulting in preventing interfacial failure.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 6","pages":"679-687"},"PeriodicalIF":2.3,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-025-01023-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-18DOI: 10.1038/s41428-025-01018-8
Jin Iwasaki, Yuzuki Kasahara, Tomoyuki Toda, Katsuhiko Takenaka
Ligands in homogeneous complex polymerization catalysts are crucial not only for influencing polymerization activity but also for controlling the stereoselectivity of the resulting polymers. We designed ligands on the basis of the dibenzophosphole skeleton and investigated the structure and ethylene polymerization activity of titanium and zirconium complexes activated by dried modified methylaluminoxane. In this investigation, we selected 1-octene as an α-olefin monomer and polymerized it using five types of titanium and zirconium complexes. Then, we obtained information regarding the ligand structure, polymerization activity toward 1-octene, and tacticity control. The [NPN]-Zr complex, which exhibited the highest activity for ethylene polymerization, demonstrated negligible polymerization activity for 1-octene. Conversely, titanium and zirconium complexes with [PN] ligands as auxiliary ligands exhibited activity toward 1-octene, yielding isotactic-rich polyoctene. The [PN] and [NPN] Ligands with a dibenzophosphole backbone were investigated in titanium and zirconium complexes for their roles in 1-octene polymerization. The [NPN]-Zr complex showed low activity toward 1-octene. In contrast, [PN]-ligated complexes demonstrated catalytic activity for 1-octene polymerization, with the [PN]-Zr and [PN]2Zr complexes producing oligomers at 70 °C and the [PN]2Ti complex yielding isotactic-rich polyoctene ([mm] = 66%) at −20 °C. These results highlight the critical role of ligand design in tuning polymerization activity and stereoselectivity, advancing the development of α-olefin polymerization catalysts.
{"title":"1-octene polymerization catalyzed by titanium and zirconium complexes supported by [PN] or [NPN] ligands","authors":"Jin Iwasaki, Yuzuki Kasahara, Tomoyuki Toda, Katsuhiko Takenaka","doi":"10.1038/s41428-025-01018-8","DOIUrl":"10.1038/s41428-025-01018-8","url":null,"abstract":"Ligands in homogeneous complex polymerization catalysts are crucial not only for influencing polymerization activity but also for controlling the stereoselectivity of the resulting polymers. We designed ligands on the basis of the dibenzophosphole skeleton and investigated the structure and ethylene polymerization activity of titanium and zirconium complexes activated by dried modified methylaluminoxane. In this investigation, we selected 1-octene as an α-olefin monomer and polymerized it using five types of titanium and zirconium complexes. Then, we obtained information regarding the ligand structure, polymerization activity toward 1-octene, and tacticity control. The [NPN]-Zr complex, which exhibited the highest activity for ethylene polymerization, demonstrated negligible polymerization activity for 1-octene. Conversely, titanium and zirconium complexes with [PN] ligands as auxiliary ligands exhibited activity toward 1-octene, yielding isotactic-rich polyoctene. The [PN] and [NPN] Ligands with a dibenzophosphole backbone were investigated in titanium and zirconium complexes for their roles in 1-octene polymerization. The [NPN]-Zr complex showed low activity toward 1-octene. In contrast, [PN]-ligated complexes demonstrated catalytic activity for 1-octene polymerization, with the [PN]-Zr and [PN]2Zr complexes producing oligomers at 70 °C and the [PN]2Ti complex yielding isotactic-rich polyoctene ([mm] = 66%) at −20 °C. These results highlight the critical role of ligand design in tuning polymerization activity and stereoselectivity, advancing the development of α-olefin polymerization catalysts.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 6","pages":"635-643"},"PeriodicalIF":2.3,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-025-01018-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Five-membered cyclic carbonate 5 was synthesized from myo-inositol via a four-step reaction. The structures of the obtained single crystals of 5 were investigated via X-ray structural analysis. The results showed that 5 has torsional and angular strains similar to those of previously reported 5-membered carbonates that undergo ring-opening polymerization. However, the anionic homopolymerization of 5 did not produce any polymeric products. On the other hand, the copolymerization of 5 with some lactones yielded polymeric products. Among the lactones used, ε-caprolactone (CL) produced a homogeneous mixture with 5 at a mole fraction of 5 (f5) up to 30 mol%. The copolymerization of the homogeneous mixtures produced copolymers with a mole fraction of 5 (F5) similar to that of f5. The glass transition temperature (Tg) of the copolymers was determined by a differential scanning calorimetory (DSC). The copolymer with F5 = 0.14 had a Tg of −26.1 °C, which increased with increasing F5 and reached a value of 0.65 °C at F5 = 0.29. 5-membered cyclic carbonate (5) was synthesized via 4-steps from myo-inositol which is mainly contained from grains. X-ray crystallographic analysis of 5 showed that 5 is largely twisted compared to non-polymerizable ethylene carbonate. However, the homopolymerization of 1 did not proceed. The copolymerization of 5 with CL, on the other hand, proceeded successfully to yield methanol-insoluble products. By changing the feed ratio, the content of 5 in the resulting copolymers increased up to 29%.
{"title":"Anionic ring-opening polymerization of a 5-membered cyclic carbonate with a myo-inositol structure","authors":"Yuto Oshima, Hiroshi Katagiri, Osamu Haba, Tatsuro Toda, Hisanari Yoneda","doi":"10.1038/s41428-025-01021-z","DOIUrl":"10.1038/s41428-025-01021-z","url":null,"abstract":"Five-membered cyclic carbonate 5 was synthesized from myo-inositol via a four-step reaction. The structures of the obtained single crystals of 5 were investigated via X-ray structural analysis. The results showed that 5 has torsional and angular strains similar to those of previously reported 5-membered carbonates that undergo ring-opening polymerization. However, the anionic homopolymerization of 5 did not produce any polymeric products. On the other hand, the copolymerization of 5 with some lactones yielded polymeric products. Among the lactones used, ε-caprolactone (CL) produced a homogeneous mixture with 5 at a mole fraction of 5 (f5) up to 30 mol%. The copolymerization of the homogeneous mixtures produced copolymers with a mole fraction of 5 (F5) similar to that of f5. The glass transition temperature (Tg) of the copolymers was determined by a differential scanning calorimetory (DSC). The copolymer with F5 = 0.14 had a Tg of −26.1 °C, which increased with increasing F5 and reached a value of 0.65 °C at F5 = 0.29. 5-membered cyclic carbonate (5) was synthesized via 4-steps from myo-inositol which is mainly contained from grains. X-ray crystallographic analysis of 5 showed that 5 is largely twisted compared to non-polymerizable ethylene carbonate. However, the homopolymerization of 1 did not proceed. The copolymerization of 5 with CL, on the other hand, proceeded successfully to yield methanol-insoluble products. By changing the feed ratio, the content of 5 in the resulting copolymers increased up to 29%.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 6","pages":"645-652"},"PeriodicalIF":2.3,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-025-01021-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High-frequency electronic applications increasingly require polymer-based insulators with low dielectric constants (Dk) and dissipation factors (Df). Reducing molecular mobility effectively decreases the Df of polyimides (PIs), which are widely used as interlayer dielectrics in semiconductor integrated circuits. In this study, we reduced molecular mobility by synthesizing smectic liquid crystalline polyimides (LC-PIs) via the use of diamines with phenyl benzoate structures and alkyl chains, and promoting mesogen stacking in LC structures. Self-supporting films were fabricated, and their dielectric properties were evaluated, revealing significantly lower Df values than those of conventional PI. The functional groups responsible for increasing Df are visualized via molecular dynamics simulations performed by applying a virtual alternating electric field to 3D models of the LC-PIs whose structure was confirmed via wide-angle X-ray diffraction. This study highlights the potential of smectic LC-PIs in the molecular design of polymeric materials with lower Df. This study demonstrates the synthesis of smectic liquid crystalline polyimides (LC-PIs) with reduced dissipation factors (Df) by incorporating phenyl benzoate units and alkyl chains into the polyimide backbone to promote mesogen stacking. Compared to conventional polyimides derived from pyromellitic dianhydride and 4,4′-oxydianiline, the LC-PIs exhibited significantly lower Df. The functional groups responsible for increasing Df were visualized via molecular dynamics simulations, applying a virtual alternating electric field to 3D models of the LC-PIs, the structures of which were confirmed using wide-angle X-ray diffraction.
{"title":"Smectic liquid crystalline poly(ester imide)s with low dielectric dissipation factors for high-frequency applications","authors":"Hayato Maeda, Yucheng Liang, Ryohei Hosoya, Rika Marui, Erina Yoshida, Yuqian Chen, Kan Hatakeyama-Sato, Yuta Nabae, Shiori Nakagawa, Junko Morikawa, Masatoshi Tokita, Ririka Sawada, Shinji Ando, Yoshihiro Hayashi, Ryo Yoshida, Hidemine Furuya, Teruaki Hayakawa","doi":"10.1038/s41428-025-01020-0","DOIUrl":"10.1038/s41428-025-01020-0","url":null,"abstract":"High-frequency electronic applications increasingly require polymer-based insulators with low dielectric constants (Dk) and dissipation factors (Df). Reducing molecular mobility effectively decreases the Df of polyimides (PIs), which are widely used as interlayer dielectrics in semiconductor integrated circuits. In this study, we reduced molecular mobility by synthesizing smectic liquid crystalline polyimides (LC-PIs) via the use of diamines with phenyl benzoate structures and alkyl chains, and promoting mesogen stacking in LC structures. Self-supporting films were fabricated, and their dielectric properties were evaluated, revealing significantly lower Df values than those of conventional PI. The functional groups responsible for increasing Df are visualized via molecular dynamics simulations performed by applying a virtual alternating electric field to 3D models of the LC-PIs whose structure was confirmed via wide-angle X-ray diffraction. This study highlights the potential of smectic LC-PIs in the molecular design of polymeric materials with lower Df. This study demonstrates the synthesis of smectic liquid crystalline polyimides (LC-PIs) with reduced dissipation factors (Df) by incorporating phenyl benzoate units and alkyl chains into the polyimide backbone to promote mesogen stacking. Compared to conventional polyimides derived from pyromellitic dianhydride and 4,4′-oxydianiline, the LC-PIs exhibited significantly lower Df. The functional groups responsible for increasing Df were visualized via molecular dynamics simulations, applying a virtual alternating electric field to 3D models of the LC-PIs, the structures of which were confirmed using wide-angle X-ray diffraction.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 6","pages":"665-677"},"PeriodicalIF":2.3,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-025-01020-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-10DOI: 10.1038/s41428-025-01022-y
Sagar Umesh Patil, Josh Kemppainen, Marianna Maiaru, Gregory M. Odegard
High-performance epoxy systems are extensively used in structural polymer‒matrix composites for aerospace vehicles. The evolution of the thermomechanical properties of these epoxies significantly impacts the evolution of process-induced residual stresses. The corresponding process parameters need to be optimized via multiscale process modeling to minimize the residual stresses and maximize the composite strength and durability. In this study, the thermomechanical properties of a multicomponent epoxy system are predicted via molecular dynamics (MD) simulation as a function of the degree of cure to provide critical property evolution data for process modeling. In addition, the experimentally validated results of this study provide critical insight into MD modeling protocols. Among these insights, harmonic- and Morse-bond-based force fields predict similar mechanical properties. However, simulations with the Morse-bond potential fail at intermediate strain values because of cross-term energy dominance. Additionally, crosslinking simulations should be conducted at the corresponding processing temperature, because the simulation temperature impacts shrinkage evolution significantly. Multiple analysis methods are utilized to process MD heating/cooling data for glass transition temperature prediction, and the results indicate that neither method has a significant advantage. These results are important for effective and comprehensive process modeling within the ICME (Integrated Computational Materials Engineering) and Materials Genome Initiative frameworks. Molecular dynamics simulations were utilized to model and predict thermomechanical properties of a multi-component high-performance epoxy. Virtual curing between the molecules is simulated using REACTER protocol in LAMMPS and LUNAR tool is utilized to assign force field parameters and post-processing of simulated data. Insights into the predicted properties using harmonic- and morse-bond-based force fields, strain-rate sensitivity, glass transition temperature predicted from heating and cooling simulations are provided. The comprehensive set of properties are predicted as a function of processing temperature and crosslinking density required for multi-scale process modeling high-performance epoxy.
{"title":"High-performance, multi-component epoxy resin simulation for predicting thermo-mechanical property evolution during curing","authors":"Sagar Umesh Patil, Josh Kemppainen, Marianna Maiaru, Gregory M. Odegard","doi":"10.1038/s41428-025-01022-y","DOIUrl":"10.1038/s41428-025-01022-y","url":null,"abstract":"High-performance epoxy systems are extensively used in structural polymer‒matrix composites for aerospace vehicles. The evolution of the thermomechanical properties of these epoxies significantly impacts the evolution of process-induced residual stresses. The corresponding process parameters need to be optimized via multiscale process modeling to minimize the residual stresses and maximize the composite strength and durability. In this study, the thermomechanical properties of a multicomponent epoxy system are predicted via molecular dynamics (MD) simulation as a function of the degree of cure to provide critical property evolution data for process modeling. In addition, the experimentally validated results of this study provide critical insight into MD modeling protocols. Among these insights, harmonic- and Morse-bond-based force fields predict similar mechanical properties. However, simulations with the Morse-bond potential fail at intermediate strain values because of cross-term energy dominance. Additionally, crosslinking simulations should be conducted at the corresponding processing temperature, because the simulation temperature impacts shrinkage evolution significantly. Multiple analysis methods are utilized to process MD heating/cooling data for glass transition temperature prediction, and the results indicate that neither method has a significant advantage. These results are important for effective and comprehensive process modeling within the ICME (Integrated Computational Materials Engineering) and Materials Genome Initiative frameworks. Molecular dynamics simulations were utilized to model and predict thermomechanical properties of a multi-component high-performance epoxy. Virtual curing between the molecules is simulated using REACTER protocol in LAMMPS and LUNAR tool is utilized to assign force field parameters and post-processing of simulated data. Insights into the predicted properties using harmonic- and morse-bond-based force fields, strain-rate sensitivity, glass transition temperature predicted from heating and cooling simulations are provided. The comprehensive set of properties are predicted as a function of processing temperature and crosslinking density required for multi-scale process modeling high-performance epoxy.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 5","pages":"539-552"},"PeriodicalIF":2.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-025-01022-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143914778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Much effort has been devoted to developing organic scintillators because of their wide versatility in the liquid and solid states. Recently, near-infrared (NIR) scintillators have attracted much attention owing to their ability to sensitively detect radiation doses. Herein, we report that NIR fluorescent π-conjugated polymers containing hypervalent tin(IV) compounds can be utilized for generating liquid and film-type organic scintillators. By incorporating tin, a heavy element known to have excellent radiation absorption properties, into the fluorescent π-conjugated framework, intense scintillations were observed upon X-ray irradiation. The polymer films exhibited NIR fluorescence in the region from 700 to 1250 nm, and the scintillation signals were enhanced as the irradiation dose increased. These results demonstrate that incorporating heavy elements into π-conjugated skeletons is an effective strategy to fabricate organic scintillators based on luminescent polymers. The performances of liquid and film-type NIR scintillation detectors based on π-conjugated polymers containing hypervalent tin(IV) compounds are evaluated. Taking advantage of the high radiation absorption of tin (Sn) and highly efficient NIR fluorescence from the π-conjugated polymers in both solution and on a film, the polymers can be used as both liquid and film-type NIR scintillators. Moreover, the radioluminescence showed good linearity across the dose rate range of 50 to 5000 mGy h−1, suggesting their practical use as NIR scintillation detectors.
{"title":"Liquid and film-type organic scintillators based on near-infrared fluorescent π-conjugated polymers containing hypervalent tin(IV) compounds","authors":"Masayuki Gon, Kazuya Tanimura, Kai Okazaki, Takumi Kato, Daisuke Nakauchi, Noriaki Kawaguchi, Takayuki Yanagida, Kazuo Tanaka","doi":"10.1038/s41428-025-01017-9","DOIUrl":"10.1038/s41428-025-01017-9","url":null,"abstract":"Much effort has been devoted to developing organic scintillators because of their wide versatility in the liquid and solid states. Recently, near-infrared (NIR) scintillators have attracted much attention owing to their ability to sensitively detect radiation doses. Herein, we report that NIR fluorescent π-conjugated polymers containing hypervalent tin(IV) compounds can be utilized for generating liquid and film-type organic scintillators. By incorporating tin, a heavy element known to have excellent radiation absorption properties, into the fluorescent π-conjugated framework, intense scintillations were observed upon X-ray irradiation. The polymer films exhibited NIR fluorescence in the region from 700 to 1250 nm, and the scintillation signals were enhanced as the irradiation dose increased. These results demonstrate that incorporating heavy elements into π-conjugated skeletons is an effective strategy to fabricate organic scintillators based on luminescent polymers. The performances of liquid and film-type NIR scintillation detectors based on π-conjugated polymers containing hypervalent tin(IV) compounds are evaluated. Taking advantage of the high radiation absorption of tin (Sn) and highly efficient NIR fluorescence from the π-conjugated polymers in both solution and on a film, the polymers can be used as both liquid and film-type NIR scintillators. Moreover, the radioluminescence showed good linearity across the dose rate range of 50 to 5000 mGy h−1, suggesting their practical use as NIR scintillation detectors.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 5","pages":"567-573"},"PeriodicalIF":2.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-025-01017-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143914779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Materials with J-shaped stress-strain behavior under uniaxial stretching have been developed using various designs; in these materials, the strength increases as the deformation progresses. On the other hand, polymer materials that progressively stiffen under bending are far less explored, and a systematic approach to achieving this behavior has not yet been developed. To address this gap, membrane tensegrity structures, which achieve structural stability by balancing compressive forces in rods and tensile forces in membranes, were examined. Notably, some of these structures exhibit increased stiffness under bending. Using a multipolymer patterning technique, we developed a functional polymer film exhibiting membrane tensegrity-like properties that stiffened under bending. This effect resulted from the membrane tension generated by rod protrusions and a likely increase in the second moment of area at regions with maximum curvature. In this study, the membrane tensegrity concept and multipolymer patterning were used to design functional polymer films that progressively stiffened under bending. This behavior was achieved through the rod protrusions generating tensile forces in the membrane and likely changes in the second moment of the area in the maximum curvature regions. The use of these films can provide a systematic approach to dynamic stiffness under nonuniaxial deformation, enabling applications in soft robotics, adaptive supports, and devices requiring tailored mechanical responses.
{"title":"Tensegrity-inspired polymer films: progressive bending stiffness through multipolymeric patterning","authors":"Rikima Kuwada, Shuto Ito, Yuta Shimoda, Haruka Fukunishi, Ryota Ohnishi, Daisuke Ishii, Mikihiro Hayashi","doi":"10.1038/s41428-025-01015-x","DOIUrl":"10.1038/s41428-025-01015-x","url":null,"abstract":"Materials with J-shaped stress-strain behavior under uniaxial stretching have been developed using various designs; in these materials, the strength increases as the deformation progresses. On the other hand, polymer materials that progressively stiffen under bending are far less explored, and a systematic approach to achieving this behavior has not yet been developed. To address this gap, membrane tensegrity structures, which achieve structural stability by balancing compressive forces in rods and tensile forces in membranes, were examined. Notably, some of these structures exhibit increased stiffness under bending. Using a multipolymer patterning technique, we developed a functional polymer film exhibiting membrane tensegrity-like properties that stiffened under bending. This effect resulted from the membrane tension generated by rod protrusions and a likely increase in the second moment of area at regions with maximum curvature. In this study, the membrane tensegrity concept and multipolymer patterning were used to design functional polymer films that progressively stiffened under bending. This behavior was achieved through the rod protrusions generating tensile forces in the membrane and likely changes in the second moment of the area in the maximum curvature regions. The use of these films can provide a systematic approach to dynamic stiffness under nonuniaxial deformation, enabling applications in soft robotics, adaptive supports, and devices requiring tailored mechanical responses.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 5","pages":"587-594"},"PeriodicalIF":2.3,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-025-01015-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143914780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stable, tough, and functional adhesion systems are urgently needed for a sustainable society. As a resolution, supramolecular scientists have introduced reversible and movable crosslinked materials into adhesion systems. Reversible crosslinks can repeatedly associate and dissociate. Therefore, reversible crosslinked materials show self-healing and stimuli-responsive properties. Moreover, movable crosslinks are topological crosslinks in which the polymer chains penetrate the cavities of cyclic molecules. The sliding of the movable crosslinks with deformation enabled the achievement of materials showing high toughness and self-relaxation. Adhesion systems with reversible and movable crosslinks have improved adhesion and cohesion, stability, and functionality. This novel concept for the design of adhesion systems is expected to increase the lifetime of adhesives and ameliorate environmental problems. This review paper summarizes various works on supramolecular materials with reversible and movable crosslinks and their application as adhesives. Reversible crosslinks can repeatedly associate and dissociate. Therefore, The reversible crosslinked materials show self-healing and stimuli-responsive properties. The slide of the movable crosslinks with deformation resulted in high toughness and self-relaxing of the materials. The adhesion systems with reversible and movable crosslinks show improved adhesion and cohesion properties, stability, and functionality. This new concept for designing adhesion systems is expected to enhance the lifetime of adhesives and reduce environmental problems.
{"title":"Design of functional and stable adhesion systems using reversible and movable crosslinked materials","authors":"Yunpeng Qian, Sho Kosaba, Ryohei Ikura, Kenji Yamaoka, Yoshinori Takashima","doi":"10.1038/s41428-024-01011-7","DOIUrl":"10.1038/s41428-024-01011-7","url":null,"abstract":"Stable, tough, and functional adhesion systems are urgently needed for a sustainable society. As a resolution, supramolecular scientists have introduced reversible and movable crosslinked materials into adhesion systems. Reversible crosslinks can repeatedly associate and dissociate. Therefore, reversible crosslinked materials show self-healing and stimuli-responsive properties. Moreover, movable crosslinks are topological crosslinks in which the polymer chains penetrate the cavities of cyclic molecules. The sliding of the movable crosslinks with deformation enabled the achievement of materials showing high toughness and self-relaxation. Adhesion systems with reversible and movable crosslinks have improved adhesion and cohesion, stability, and functionality. This novel concept for the design of adhesion systems is expected to increase the lifetime of adhesives and ameliorate environmental problems. This review paper summarizes various works on supramolecular materials with reversible and movable crosslinks and their application as adhesives. Reversible crosslinks can repeatedly associate and dissociate. Therefore, The reversible crosslinked materials show self-healing and stimuli-responsive properties. The slide of the movable crosslinks with deformation resulted in high toughness and self-relaxing of the materials. The adhesion systems with reversible and movable crosslinks show improved adhesion and cohesion properties, stability, and functionality. This new concept for designing adhesion systems is expected to enhance the lifetime of adhesives and reduce environmental problems.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":"57 4","pages":"491-512"},"PeriodicalIF":2.3,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-01011-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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