Two types of lamellar stacking model were proposed for the inner structure of the melt-grown spherulites of isotactic polypropylene (iPP): the edge-on structure (flat lamellar planes stand on the spherulite plane, and a*-axis // growth direction of spherulite, b-axis ┴ spherulite plane, and c-axis // spherulite plane) and the flat-on structure (flat lamellar planes lay on the spherulite plane, a*-axis // growth direction, b-axis // spherulite plane, and c-axis ┴ spherulite plane). After a literature review was performed, the observed X-ray scattering data were not high quality and could not be used to establish these bimodal structures; moreover, the X-ray data analyses were not performed satisfactorily. As a result, the derivations of actual structures were still debatable. We performed simultaneous time-resolved WAXD/SAXS measurements using a synchrotron X-ray microbeam technique. The collected data were classified into three sets of completely different WAXD/SAXS patterns. Detailed quantitative analysis enabled the determination of the spatial orientations of the stacked lamellae and related crystallographic axes. Although the bimodal structure of iPP spherulites was considered to be a well-known and already-established concept for long years, the bimodal structure was successfully confirmed for the first time in the present study, making the concrete discussions on the growth mechanism of the iPP spherulites possible. The in situ wide-angle (WAXD) and small-angle X-ray scattering (SAXS) measurements have been performed using a synchrotron microbeam technique for the melt-isothermally-growing iPP spherulites. The thus-collected data were found to be classified into three sets of totally different WAXD/SAXS patterns, from which the three different orientation modes of the stacked lamellae and related crystallographic axes were deduced. These structural information allowed us to discuss the growth mechanism of stacked lamellae in the iPP spherulites from the microscopic point of view.
针对熔融生长的异方性聚丙烯（iPP）球粒的内部结构，提出了两种层状堆积模型：边缘结构（扁平片层平面位于球粒体平面上，球粒体的生长方向为 a*轴//球粒体平面、b 轴┴球粒体平面和 c 轴//球粒体平面）和平面结构（扁平片层平面位于球粒体平面上，生长方向为 a*轴//球粒体平面、b 轴//球粒体平面和 c 轴┴球粒体平面）。在查阅文献后发现，观测到的 X 射线散射数据质量不高，无法用于确定这些双模结构；此外，X 射线数据分析的效果也不理想。因此，实际结构的推导仍有争议。我们使用同步辐射 X 射线微束技术同时进行了时间分辨 WAXD/SAXS 测量。收集到的数据被分为三组完全不同的 WAXD/SAXS 模式。通过详细的定量分析，确定了叠层的空间取向和相关的晶体学轴线。尽管 iPP 球粒的双峰结构多年来一直被认为是一个众所周知且早已确立的概念，但本研究首次成功证实了其双峰结构，从而使对 iPP 球粒的生长机制进行具体讨论成为可能。
{"title":"Three representative types of WAXD/SAXS patterns to establish the bimodal structure concept of stacked lamellae in isotactic polypropylene spherulites","authors":"Kohji Tashiro, Hiroko Yamamoto, Ken-ichi Funaki, Hiroyasu Masunaga, Yuichi Miyake","doi":"10.1038/s41428-024-00893-x","DOIUrl":"10.1038/s41428-024-00893-x","url":null,"abstract":"Two types of lamellar stacking model were proposed for the inner structure of the melt-grown spherulites of isotactic polypropylene (iPP): the edge-on structure (flat lamellar planes stand on the spherulite plane, and a*-axis // growth direction of spherulite, b-axis ┴ spherulite plane, and c-axis // spherulite plane) and the flat-on structure (flat lamellar planes lay on the spherulite plane, a*-axis // growth direction, b-axis // spherulite plane, and c-axis ┴ spherulite plane). After a literature review was performed, the observed X-ray scattering data were not high quality and could not be used to establish these bimodal structures; moreover, the X-ray data analyses were not performed satisfactorily. As a result, the derivations of actual structures were still debatable. We performed simultaneous time-resolved WAXD/SAXS measurements using a synchrotron X-ray microbeam technique. The collected data were classified into three sets of completely different WAXD/SAXS patterns. Detailed quantitative analysis enabled the determination of the spatial orientations of the stacked lamellae and related crystallographic axes. Although the bimodal structure of iPP spherulites was considered to be a well-known and already-established concept for long years, the bimodal structure was successfully confirmed for the first time in the present study, making the concrete discussions on the growth mechanism of the iPP spherulites possible. The in situ wide-angle (WAXD) and small-angle X-ray scattering (SAXS) measurements have been performed using a synchrotron microbeam technique for the melt-isothermally-growing iPP spherulites. The thus-collected data were found to be classified into three sets of totally different WAXD/SAXS patterns, from which the three different orientation modes of the stacked lamellae and related crystallographic axes were deduced. These structural information allowed us to discuss the growth mechanism of stacked lamellae in the iPP spherulites from the microscopic point of view.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140147929","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}
Water-insoluble micropatterned films were prepared from poly(vinyl alcohol) (PVA) (or ethylene-vinyl alcohol copolymer (EVOH)) and poly(methacrylic acid) (poly(MAAc)). The carboxy groups in poly(MAAc) underwent dehydration reactions with the hydroxy groups in the vinyl alcohol units during heating at 135 °C, which resulted in crosslinking with ester bonds and formation of a polymeric network in the micropatterned films. The surface structures of the micropatterned films and the shapes of the peeled microplastics in the supernatant were measured after decomposition in an oxidizing environment, after ultrasonic irradiation, and with both. The results revealed that the micropatterns could be peeled off from the films after they were subjected to appropriate decomposition conditions and maintained their patterned shapes. Water-insoluble micropatterned films were prepared from poly(vinyl alcohol) (PVA) (or ethylene-vinyl alcohol copolymer (EVOH)) and poly(methacrylic acid) (poly(MAAc)). The carboxy groups in poly(MAAc) underwent dehydration reactions with the hydroxy groups in the vinyl alcohol units during heating at 135 °C, which resulted in the introduction of a crosslinked structure with ester bonds into the polymeric network of the micropatterned films. The micropatterns could be peeled off from the films after decomposition and maintained their patterned shapes.
用聚（乙烯醇）（PVA）（或乙烯-乙烯醇共聚物（EVOH））和聚（甲基丙烯酸）（poly(MAAc)）制备了不溶于水的微图案薄膜。在 135 °C 的加热过程中，聚（甲基丙烯酸）中的羧基与乙烯醇单元中的羟基发生脱水反应，从而与酯键交联，在微图案薄膜中形成聚合物网络。测量了微图案薄膜在氧化环境中分解后、超声波辐照后以及两者同时分解后的表面结构和上清液中剥离的微塑料的形状。结果表明，在适当的分解条件下，微图案可以从薄膜上剥离，并保持其图案形状。
{"title":"Micropatterned microplastic generation via degradation of polymeric films with micropatterned structures","authors":"Haruki Uchida, Wakako Uchiyama, Erika Kurita, Masayuki Kirihara, Yohei Kotsuchibashi","doi":"10.1038/s41428-024-00897-7","DOIUrl":"10.1038/s41428-024-00897-7","url":null,"abstract":"Water-insoluble micropatterned films were prepared from poly(vinyl alcohol) (PVA) (or ethylene-vinyl alcohol copolymer (EVOH)) and poly(methacrylic acid) (poly(MAAc)). The carboxy groups in poly(MAAc) underwent dehydration reactions with the hydroxy groups in the vinyl alcohol units during heating at 135 °C, which resulted in crosslinking with ester bonds and formation of a polymeric network in the micropatterned films. The surface structures of the micropatterned films and the shapes of the peeled microplastics in the supernatant were measured after decomposition in an oxidizing environment, after ultrasonic irradiation, and with both. The results revealed that the micropatterns could be peeled off from the films after they were subjected to appropriate decomposition conditions and maintained their patterned shapes. Water-insoluble micropatterned films were prepared from poly(vinyl alcohol) (PVA) (or ethylene-vinyl alcohol copolymer (EVOH)) and poly(methacrylic acid) (poly(MAAc)). The carboxy groups in poly(MAAc) underwent dehydration reactions with the hydroxy groups in the vinyl alcohol units during heating at 135 °C, which resulted in the introduction of a crosslinked structure with ester bonds into the polymeric network of the micropatterned films. The micropatterns could be peeled off from the films after decomposition and maintained their patterned shapes.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00897-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140054004","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}
Semiconducting polymers have garnered considerable attention from researchers, as these polymers are potentially applicable to flexible/stretchable organic electronics. However, although the adhesiveness of these materials on substrates is an important characteristic, it has rarely been investigated. Herein, we synthesized and characterized a novel block copolymer, poly(3-hexylthiophene)-b-poly(vinyl catechol) (P3HT-b-PVC), with improved adhesion properties. P3HT-b-PVC was successfully synthesized via a copper-catalyzed azide–alkyne cycloaddition reaction between chain-end-functionalized P3HT with an alkyne group (P3HT-Alkyne) and chain-end-functionalized poly(3,4-di-tert-butyldimethylsilyloxystyrene) with an azide group (PSVC-Azide), followed by deprotection of tert-butyldimethylsilyloxy groups from the PSVC-Azide segment. Tape test results showed that the adhesion property of the P3HT-b-PVC film was considerably better than that of the corresponding P3HT film. Furthermore, despite the presence of an insulating PVC block in P3HT-b-PVC, the P3HT-b-PVC thin film exhibited a hole mobility of 1.1 × 10−5 cm2V−1s−1, which was comparable to that of the corresponding P3HT thin film (1.8 × 10−5 cm2V−1s−1). To the best of our knowledge, this is the first study to elucidate the primitive adhesion properties and charge mobility of P3HT-based block copolymers. The proposed synthetic approach may be extended to develop various block copolymers with other π-conjugated polymer segments, providing new avenues for various applications that require highly-adhesive materials. A novel block copolymer, poly(3-hexylthiophene)-b-poly(vinyl catechol) (P3HT-b-PVC) was successfully synthesized via a Click reaction between chain-endfunctionalized P3HT with an alkyne group (P3HT-Alkyne) and chain-end-functionalized poly(3,4-di-tert-butyldimethylsilyloxystyrene) with an azide group (PSVC-Azide), followed by deprotection of tert-butyldimethylsilyloxy groups from the PSVC-Azide segment. Tape test results showed that the adhesion property of the P3HT-b-PVC film was considerably better than that of the corresponding P3HT film. Furthermore, despite the presence of an insulating PVC block in P3HT-b-PVC, the P3HT-b-PVC thin film exhibited a hole mobility comparable to that of the corresponding P3HT thin film.
{"title":"Click synthesis of an adhesive block copolymer with poly(3-hexylthiophene) and poly(vinyl catechol) segments","authors":"Shin Inagaki, Kazuhiro Nakabayashi, Tomoya Higashihara","doi":"10.1038/s41428-024-00898-6","DOIUrl":"10.1038/s41428-024-00898-6","url":null,"abstract":"Semiconducting polymers have garnered considerable attention from researchers, as these polymers are potentially applicable to flexible/stretchable organic electronics. However, although the adhesiveness of these materials on substrates is an important characteristic, it has rarely been investigated. Herein, we synthesized and characterized a novel block copolymer, poly(3-hexylthiophene)-b-poly(vinyl catechol) (P3HT-b-PVC), with improved adhesion properties. P3HT-b-PVC was successfully synthesized via a copper-catalyzed azide–alkyne cycloaddition reaction between chain-end-functionalized P3HT with an alkyne group (P3HT-Alkyne) and chain-end-functionalized poly(3,4-di-tert-butyldimethylsilyloxystyrene) with an azide group (PSVC-Azide), followed by deprotection of tert-butyldimethylsilyloxy groups from the PSVC-Azide segment. Tape test results showed that the adhesion property of the P3HT-b-PVC film was considerably better than that of the corresponding P3HT film. Furthermore, despite the presence of an insulating PVC block in P3HT-b-PVC, the P3HT-b-PVC thin film exhibited a hole mobility of 1.1 × 10−5 cm2V−1s−1, which was comparable to that of the corresponding P3HT thin film (1.8 × 10−5 cm2V−1s−1). To the best of our knowledge, this is the first study to elucidate the primitive adhesion properties and charge mobility of P3HT-based block copolymers. The proposed synthetic approach may be extended to develop various block copolymers with other π-conjugated polymer segments, providing new avenues for various applications that require highly-adhesive materials. A novel block copolymer, poly(3-hexylthiophene)-b-poly(vinyl catechol) (P3HT-b-PVC) was successfully synthesized via a Click reaction between chain-endfunctionalized P3HT with an alkyne group (P3HT-Alkyne) and chain-end-functionalized poly(3,4-di-tert-butyldimethylsilyloxystyrene) with an azide group (PSVC-Azide), followed by deprotection of tert-butyldimethylsilyloxy groups from the PSVC-Azide segment. Tape test results showed that the adhesion property of the P3HT-b-PVC film was considerably better than that of the corresponding P3HT film. Furthermore, despite the presence of an insulating PVC block in P3HT-b-PVC, the P3HT-b-PVC thin film exhibited a hole mobility comparable to that of the corresponding P3HT thin film.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00898-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140054097","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}
Heptaisobutyl-norbornenylethyl-substituted cage octasilsesquioxane (POSS) (1a) and heptaphenyl-norbornenylethyl-substituted POSS (1b) were subjected to ring-opening metathesis polymerizations (ROMP) at room temperature with the Grubbs 2nd generation catalyst. The metathesis polymerizations of 1a and 1b were performed at room temperature for 3 h with initial monomer molar concentrations of [1a, 1b] = 10 mM, and the number average molecular weights (Mn) of 2a and 2b were 82,000 g/mol and 87,000 g/mol, respectively. Dynamic light scattering (DLS) and static light scattering (SLS) measurements showed that the Rg/Rh value for 2a was 4.91, suggesting the formation of polydisperse rod-shaped particles. Chloroform solutions of 2a and 2b were cast onto glass substrates and dried at room temperature to obtain optically transparent free-standing films. X-ray diffraction (XRD) analyses of the casted films revealed their amorphous natures. Thermogravimetric analyses (TGA) of 2a and 2b under N2 atmospheres showed 5 wt% losses (Td5) at 416 °C and 451 °C, respectively. The POSS-pendant polynorbornenenes connected with short spacers exhibited showed high optical transparencies owing to the prevention of POSS crystallization and the excellent thermal stability. Side-chain typed POSS-based polynorbornenes connecting with a short spacer exhibiting optical transparency owing to prevention of POSS crystallization to provide amorphous character. In addition, the resulting amorphous polymers exhibited excellent thermal stability.
{"title":"Cage octasilsesquioxane-pendant polynorbornenes connected with short spacers exhibiting optical transparency","authors":"Yu Tomioka, Ryota Tanaka, Thu Thao Pham, Shin-ichi Yusa, Hiroaki Imoto, Kensuke Naka","doi":"10.1038/s41428-024-00903-y","DOIUrl":"10.1038/s41428-024-00903-y","url":null,"abstract":"Heptaisobutyl-norbornenylethyl-substituted cage octasilsesquioxane (POSS) (1a) and heptaphenyl-norbornenylethyl-substituted POSS (1b) were subjected to ring-opening metathesis polymerizations (ROMP) at room temperature with the Grubbs 2nd generation catalyst. The metathesis polymerizations of 1a and 1b were performed at room temperature for 3 h with initial monomer molar concentrations of [1a, 1b] = 10 mM, and the number average molecular weights (Mn) of 2a and 2b were 82,000 g/mol and 87,000 g/mol, respectively. Dynamic light scattering (DLS) and static light scattering (SLS) measurements showed that the Rg/Rh value for 2a was 4.91, suggesting the formation of polydisperse rod-shaped particles. Chloroform solutions of 2a and 2b were cast onto glass substrates and dried at room temperature to obtain optically transparent free-standing films. X-ray diffraction (XRD) analyses of the casted films revealed their amorphous natures. Thermogravimetric analyses (TGA) of 2a and 2b under N2 atmospheres showed 5 wt% losses (Td5) at 416 °C and 451 °C, respectively. The POSS-pendant polynorbornenenes connected with short spacers exhibited showed high optical transparencies owing to the prevention of POSS crystallization and the excellent thermal stability. Side-chain typed POSS-based polynorbornenes connecting with a short spacer exhibiting optical transparency owing to prevention of POSS crystallization to provide amorphous character. In addition, the resulting amorphous polymers exhibited excellent thermal stability.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140045925","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}
An important method for plant genetic modification is using peptide/pDNA complexes to transfer genes into plant cells. With conventional carrier peptides, the peptide sequence must contain a high amount of cationic amino acids to condense and introduce pDNA. As a result, the dissociation of pDNA from the complex is inefficient, often causing problems. Herein, we designed a new peptide carrier that mimics the basic leucine zipper (bZIP) domain of DNA-binding proteins, in which (LU)4 is the leucine zipper motif and (KUA)3 is the basic DNA-binding and cell-penetrating motif (U = α-aminoisobutyric acid). After (KUA)3-(LU)4 peptide was mixed with pDNA, DNA molecules were condensed to form nanoparticles of approximately 130 nm. Furthermore, when complexes of (KUA)3-(LU)4 peptide and pDNA were introduced into the leaves of Arabidopsis thaliana (A. thaliana), expression of the reporter protein was detected in the plant cells. Thus, (KUA)3-(LU)4 peptide that mimics the bZIP domain is a novel and efficient carrier for pDNA with high dissociation efficiency. A new peptide carrier that mimics the basic leucine zipper domain (bZIP) of DNA-binding proteins was designed, in which (LU)4 is the leucine zipper motif and (KUA)3 is the basic DNA-binding motif (U = α-aminoisobutyric acid). When mixed with pDNA, (KUA)3-(LU)4 peptide condensed DNA molecules to form nanoparticles. Furthermore, when complexes of the (KUA)3-(LU)4 peptide and pDNA were introduced into the leaves of Arabidopsis thaliana (A. thaliana), the reporter protein was expressed in plant cells. Thus, (KUA)3-(LU)4 is an efficient carrier of pDNA with high dissociation efficiency.
{"title":"Construction of peptide/plasmid DNA complexes for plant gene transfection via the basic leucine zipper domain","authors":"Kota Nomura, Seiya Fujita, Yuki Shimatani, Taichi Kurita, Chonprakun Thagun, Naoya Abe, Kazusato Oikawa, Kousuke Tsuchiya, Hirotaka Uji, Keiji Numata","doi":"10.1038/s41428-024-00901-0","DOIUrl":"10.1038/s41428-024-00901-0","url":null,"abstract":"An important method for plant genetic modification is using peptide/pDNA complexes to transfer genes into plant cells. With conventional carrier peptides, the peptide sequence must contain a high amount of cationic amino acids to condense and introduce pDNA. As a result, the dissociation of pDNA from the complex is inefficient, often causing problems. Herein, we designed a new peptide carrier that mimics the basic leucine zipper (bZIP) domain of DNA-binding proteins, in which (LU)4 is the leucine zipper motif and (KUA)3 is the basic DNA-binding and cell-penetrating motif (U = α-aminoisobutyric acid). After (KUA)3-(LU)4 peptide was mixed with pDNA, DNA molecules were condensed to form nanoparticles of approximately 130 nm. Furthermore, when complexes of (KUA)3-(LU)4 peptide and pDNA were introduced into the leaves of Arabidopsis thaliana (A. thaliana), expression of the reporter protein was detected in the plant cells. Thus, (KUA)3-(LU)4 peptide that mimics the bZIP domain is a novel and efficient carrier for pDNA with high dissociation efficiency. A new peptide carrier that mimics the basic leucine zipper domain (bZIP) of DNA-binding proteins was designed, in which (LU)4 is the leucine zipper motif and (KUA)3 is the basic DNA-binding motif (U = α-aminoisobutyric acid). When mixed with pDNA, (KUA)3-(LU)4 peptide condensed DNA molecules to form nanoparticles. Furthermore, when complexes of the (KUA)3-(LU)4 peptide and pDNA were introduced into the leaves of Arabidopsis thaliana (A. thaliana), the reporter protein was expressed in plant cells. Thus, (KUA)3-(LU)4 is an efficient carrier of pDNA with high dissociation efficiency.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00901-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140033263","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}
In this study, we utilized tetra-armed polyethylene glycol (Tetra-PEG) slimes, which are model transient networks with well-controlled structures, to predict the effects of long-term degradation on the viscoelastic properties of liquids. Viscoelastic liquids, such as sodium hyaluronate, are frequently used in biomedical applications within the human body. However, precisely controlling the viscoelastic properties of these liquids in the long-term is challenging, as the main chains of the liquids undergo stochastic degradation. To establish a predictable model for studying long-term degradation effects, we employed Tetra-PEG slime, and modifications were performed to introduce specific cleavage sites in areas with connections. The Tetra-PEG slimes were characterized by single relaxation modes, and these modes were independent from the degree of degradation, which was determined by hydrolyzing the cleavage sites. Overall, this work provides a universal design for viscoelastic liquids with precisely-controllable degradation. This study explores the effects of long-term degradation on the viscoelastic properties of viscoelastic liquids using tetra-armed polyethylene glycol (Tetra-PEG) slimes as model material. It aims to enhance control over the viscoelasticity of biomedical materials, like sodium hyaluronate, by introducing specific cleavage sites into the Tetra-PEG slimes to simulate degradation. The study reveals that despite degradation, the slimes maintain a single relaxation mode, offering a method to design viscoelastic liquids with predictable and controllable degradation for biomedical applications.
{"title":"Predicting the effects of degradation on viscoelastic relaxation time using model transient networks","authors":"Ryunosuke Kobayashi, Mitsuru Naito, Kanjiro Miyata, Takamasa Sakai, Ung-il Chung, Takuya Katashima","doi":"10.1038/s41428-024-00902-z","DOIUrl":"10.1038/s41428-024-00902-z","url":null,"abstract":"In this study, we utilized tetra-armed polyethylene glycol (Tetra-PEG) slimes, which are model transient networks with well-controlled structures, to predict the effects of long-term degradation on the viscoelastic properties of liquids. Viscoelastic liquids, such as sodium hyaluronate, are frequently used in biomedical applications within the human body. However, precisely controlling the viscoelastic properties of these liquids in the long-term is challenging, as the main chains of the liquids undergo stochastic degradation. To establish a predictable model for studying long-term degradation effects, we employed Tetra-PEG slime, and modifications were performed to introduce specific cleavage sites in areas with connections. The Tetra-PEG slimes were characterized by single relaxation modes, and these modes were independent from the degree of degradation, which was determined by hydrolyzing the cleavage sites. Overall, this work provides a universal design for viscoelastic liquids with precisely-controllable degradation. This study explores the effects of long-term degradation on the viscoelastic properties of viscoelastic liquids using tetra-armed polyethylene glycol (Tetra-PEG) slimes as model material. It aims to enhance control over the viscoelasticity of biomedical materials, like sodium hyaluronate, by introducing specific cleavage sites into the Tetra-PEG slimes to simulate degradation. The study reveals that despite degradation, the slimes maintain a single relaxation mode, offering a method to design viscoelastic liquids with predictable and controllable degradation for biomedical applications.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00902-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140033266","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 : 2024-02-28DOI: 10.1038/s41428-024-00900-1
Ryotaro Makita, Aya M. Akimoto, Takafumi Enomoto, Taihei Nishimoto, Xiang Li, Mitsuhiro Shibayama, Ryo Yoshida
This manuscript presents the humidity responsiveness of a poly(N-isopropylacrylamide) (PNIPAAm) gel, which was capable of exhibiting volume changes. The strategy for inducing volume changes in the gel capitalized on the differences in PNIPAAm solubility, which stemmed from variations in the polyethylene glycol (PEG) proportions of PEG/water solvent mixtures. Due to the hygroscopic nature of PEG, PNIPAAm gels using PEG as the solvent (weight fraction of PEG, φPEG = 1.00) absorbed ambient moisture, resulting in a decrease in φPEG over time. In concert with this moisture absorption process, the PNIPAAm gel contracted owing to phase separation at a consistent room temperature, which was attributed to the diminished solubility of PNIPAAm in the solvent. During this investigation, we scrutinized the temperature dependency of the optical transmittance and conducted differential scanning calorimetry (DSC) assessments on free PNIPAAm in water across various φPEG values to substantiate phase separation of the system. We then demonstrated that a PNIPAAm gel with a PEG/water mixed solvent underwent volume changes in response to humidity changes. Additionally, humidity-induced shape deformations were realized with a PNIPAAm and poly(N,N-dimethylacrylamide) (PDMAAm) composite gel. This study introduces, for the first time, a humidity-responsive PNIPAAm gel with a PEG/water mixed solvent. We report the humidity-responsive volume changes of a poly(N-isopropylacrylamide) (PNIPAAm) gel and bending deformation of a PNIPAAm and poly(N,N-dimethylacrylamide) (PDMAAm) complex gel.
{"title":"Humidity responsiveness of a poly(N-isopropylacrylamide) gel with a PEG/water mixed solvent","authors":"Ryotaro Makita, Aya M. Akimoto, Takafumi Enomoto, Taihei Nishimoto, Xiang Li, Mitsuhiro Shibayama, Ryo Yoshida","doi":"10.1038/s41428-024-00900-1","DOIUrl":"10.1038/s41428-024-00900-1","url":null,"abstract":"This manuscript presents the humidity responsiveness of a poly(N-isopropylacrylamide) (PNIPAAm) gel, which was capable of exhibiting volume changes. The strategy for inducing volume changes in the gel capitalized on the differences in PNIPAAm solubility, which stemmed from variations in the polyethylene glycol (PEG) proportions of PEG/water solvent mixtures. Due to the hygroscopic nature of PEG, PNIPAAm gels using PEG as the solvent (weight fraction of PEG, φPEG = 1.00) absorbed ambient moisture, resulting in a decrease in φPEG over time. In concert with this moisture absorption process, the PNIPAAm gel contracted owing to phase separation at a consistent room temperature, which was attributed to the diminished solubility of PNIPAAm in the solvent. During this investigation, we scrutinized the temperature dependency of the optical transmittance and conducted differential scanning calorimetry (DSC) assessments on free PNIPAAm in water across various φPEG values to substantiate phase separation of the system. We then demonstrated that a PNIPAAm gel with a PEG/water mixed solvent underwent volume changes in response to humidity changes. Additionally, humidity-induced shape deformations were realized with a PNIPAAm and poly(N,N-dimethylacrylamide) (PDMAAm) composite gel. This study introduces, for the first time, a humidity-responsive PNIPAAm gel with a PEG/water mixed solvent. We report the humidity-responsive volume changes of a poly(N-isopropylacrylamide) (PNIPAAm) gel and bending deformation of a PNIPAAm and poly(N,N-dimethylacrylamide) (PDMAAm) complex gel.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140011481","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}
The effects of the cyclic molecules within polyrotaxanes moving over axial molecules serving as cross-linking points in a polymeric network preclude observation of the cyclic effects in polymer networks composed of conventional cross-linking agents. As a result, polymer networks with movable cross-linking points behave more gently and stretch better than conventional polymer networks. These polymer networks can be composed of various polymers when using cross-linkers obtained by modifying the vinyl groups on the polyrotaxanes. In this study, the effects of the polyrotaxane cross-linker concentration and solvent content on elastomer preparation were investigated to obtain elastomers with high toughnesses due to the properties of the polyrotaxane cross-linking agent. If elastomers were prepared in a state in which the cyclic effect of the polyrotaxane was easily expressed by the concentration of the polyrotaxane cross-linker and the amount of solvent, the elastomers obtained elongated more and were tougher than elastomers made from conventional cross-linkers. In this study, the effects of the polyrotaxane cross-linker concentration and solvent content on elastomer preparation were investigated to obtain elastomers with high toughnesses due to the properties of the polyrotaxane cross-linking agent. If elastomers were prepared in a state in which the slide-ring effect of the polyrotaxane was easily expressed by the concentration of the polyrotaxane cross-linker and the amount of solvent, the elastomers obtained elongated more and were tougher than elastomers made from conventional cross-linkers.
{"title":"Optimal conditions for the use of polyrotaxane as a cross-linker in preparing elastomers with high toughnesses","authors":"Sizhe Liu, Tomoya Hayashi, Mitsuo Hara, Takahiro Seki, Kohzo Ito, Yukikazu Takeoka","doi":"10.1038/s41428-024-00896-8","DOIUrl":"10.1038/s41428-024-00896-8","url":null,"abstract":"The effects of the cyclic molecules within polyrotaxanes moving over axial molecules serving as cross-linking points in a polymeric network preclude observation of the cyclic effects in polymer networks composed of conventional cross-linking agents. As a result, polymer networks with movable cross-linking points behave more gently and stretch better than conventional polymer networks. These polymer networks can be composed of various polymers when using cross-linkers obtained by modifying the vinyl groups on the polyrotaxanes. In this study, the effects of the polyrotaxane cross-linker concentration and solvent content on elastomer preparation were investigated to obtain elastomers with high toughnesses due to the properties of the polyrotaxane cross-linking agent. If elastomers were prepared in a state in which the cyclic effect of the polyrotaxane was easily expressed by the concentration of the polyrotaxane cross-linker and the amount of solvent, the elastomers obtained elongated more and were tougher than elastomers made from conventional cross-linkers. In this study, the effects of the polyrotaxane cross-linker concentration and solvent content on elastomer preparation were investigated to obtain elastomers with high toughnesses due to the properties of the polyrotaxane cross-linking agent. If elastomers were prepared in a state in which the slide-ring effect of the polyrotaxane was easily expressed by the concentration of the polyrotaxane cross-linker and the amount of solvent, the elastomers obtained elongated more and were tougher than elastomers made from conventional cross-linkers.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140003115","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}
Postpolymerization modifications of poly(2-methoxyethoxycarbonylmethylene) (pMEDA’) and poly(2-phenoxyethoxycarbonylmethylene) (pPEDA’) are described. The reactions of these polymers with mixtures of chlorotrimethylsilane (Me3SiCl) and lithium diisopropylamide (LDA) efficiently transformed the alkoxycarbonylmethylene repeating units to ketene silyl acetals to yield a product with up to 93 mol% composition of the latter unit. The ketene silyl acetal composition of the product was controlled by changing the feed ratio of Me3SiCl/LDA with respect to the alkoxycarbonylmethylene unit. Tetrabutylammonium fluoride (TBAF)-mediated benzylation of the highly silylated polymer with benzyl bromide yielded a polymer containing side chain O (major)- and main chain C (minor)-benzylated units along with the unreacted ketene silyl acetal unit. Postpolymerization modifications of poly(2-methoxyethoxycarbonylmethylene) and poly(2-phenoxyethoxycarbonylmethylene) with mixtures of Me3SiCl and LDA efficiently transformed the alkoxycarbonylmethylene repeating units to ketene silyl acetals to yield a product with up to 93 mol% composition of the latter unit. TBAF-mediated benzylation of the highly silylated polymer with benzyl bromide yielded a polymer containing side chain O (major)- and main chain C (minor)-benzylated units along with the unreacted ketene silyl acetal unit.
{"title":"Postpolymerization modification of poly(2-alkoxyethoxycarbonylmethylene)s: Efficient formation and reactivity of the ketene silyl acetal repeating units in the polymer main chain","authors":"Hiroaki Shimomoto, Shota Inouchi, Tomomichi Itoh, Eiji Ihara","doi":"10.1038/s41428-024-00891-z","DOIUrl":"10.1038/s41428-024-00891-z","url":null,"abstract":"Postpolymerization modifications of poly(2-methoxyethoxycarbonylmethylene) (pMEDA’) and poly(2-phenoxyethoxycarbonylmethylene) (pPEDA’) are described. The reactions of these polymers with mixtures of chlorotrimethylsilane (Me3SiCl) and lithium diisopropylamide (LDA) efficiently transformed the alkoxycarbonylmethylene repeating units to ketene silyl acetals to yield a product with up to 93 mol% composition of the latter unit. The ketene silyl acetal composition of the product was controlled by changing the feed ratio of Me3SiCl/LDA with respect to the alkoxycarbonylmethylene unit. Tetrabutylammonium fluoride (TBAF)-mediated benzylation of the highly silylated polymer with benzyl bromide yielded a polymer containing side chain O (major)- and main chain C (minor)-benzylated units along with the unreacted ketene silyl acetal unit. Postpolymerization modifications of poly(2-methoxyethoxycarbonylmethylene) and poly(2-phenoxyethoxycarbonylmethylene) with mixtures of Me3SiCl and LDA efficiently transformed the alkoxycarbonylmethylene repeating units to ketene silyl acetals to yield a product with up to 93 mol% composition of the latter unit. TBAF-mediated benzylation of the highly silylated polymer with benzyl bromide yielded a polymer containing side chain O (major)- and main chain C (minor)-benzylated units along with the unreacted ketene silyl acetal unit.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00891-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139950594","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 : 2024-02-21DOI: 10.1038/s41428-024-00894-w
Ming Ge, Lidong Zhang
Hydrogels can be stretched to several tens or even hundreds of times their original lengths, making them suitable for various applications. They have shown great potential for use in sensors and wearable devices. Although many attempts have been made to develop highly stretchable hydrogels, combining high stretchability and excellent damping remains a challenge. This study reports a method that significantly improved the stretchability and damping properties of hydrogels. The innovation is the replacement of traditional short-chain crosslinkers, such as N,N-methylenebis(acrylamide) (MBA), with long-chain crosslinkers. With increasing chain lengths, the spaces in the networks became larger, which reduced the interactions between the molecular chains in the network. As a result, the molecular chains of the network could slide when stretched, which greatly increased the mechanical elongation and enabled damping by the hydrogel (up to 85%). The maximum elongation reached 21800%, with a toughness of 11.32 MJ m−3. To the best of our knowledge, this elongation is superior to those in all previous reports. Our results provide a new approach for the development of highly stretchable and damping hydrogels. This study reports a method that significantly improved the stretchability and damping properties of hydrogels. The innovation is the replacement of traditional short-chain crosslinkers, such as N,N-methylenebis(acrylamide) (MBA), with long-chain crosslinkers. As a result, the molecular chains of the network could slide when stretched, which greatly increased the mechanical elongation and enabled damping by the hydrogel (up to 85%). The maximum elongation reached 21800%, with a toughness of 11.32 MJ m−3. This study provides a new approach for the development of highly stretchable and damping hydrogels.
{"title":"Ultrastretchable hydrogels with strong damping effects","authors":"Ming Ge, Lidong Zhang","doi":"10.1038/s41428-024-00894-w","DOIUrl":"10.1038/s41428-024-00894-w","url":null,"abstract":"Hydrogels can be stretched to several tens or even hundreds of times their original lengths, making them suitable for various applications. They have shown great potential for use in sensors and wearable devices. Although many attempts have been made to develop highly stretchable hydrogels, combining high stretchability and excellent damping remains a challenge. This study reports a method that significantly improved the stretchability and damping properties of hydrogels. The innovation is the replacement of traditional short-chain crosslinkers, such as N,N-methylenebis(acrylamide) (MBA), with long-chain crosslinkers. With increasing chain lengths, the spaces in the networks became larger, which reduced the interactions between the molecular chains in the network. As a result, the molecular chains of the network could slide when stretched, which greatly increased the mechanical elongation and enabled damping by the hydrogel (up to 85%). The maximum elongation reached 21800%, with a toughness of 11.32 MJ m−3. To the best of our knowledge, this elongation is superior to those in all previous reports. Our results provide a new approach for the development of highly stretchable and damping hydrogels. This study reports a method that significantly improved the stretchability and damping properties of hydrogels. The innovation is the replacement of traditional short-chain crosslinkers, such as N,N-methylenebis(acrylamide) (MBA), with long-chain crosslinkers. As a result, the molecular chains of the network could slide when stretched, which greatly increased the mechanical elongation and enabled damping by the hydrogel (up to 85%). The maximum elongation reached 21800%, with a toughness of 11.32 MJ m−3. This study provides a new approach for the development of highly stretchable and damping hydrogels.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139920408","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}
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