Molecularly aligned liquid-crystalline (LC) polymer films hold great promise for next-generation high-performance photonics, electronics, robotics, and medical devices. Photoalignment methods capable of achieving precise molecular alignment in a noncontact manner have been actively studied. Recently, we proposed the concept of using spatiotemporal photopolymerization to induce molecular diffusion and the resulting alignment, termed scanning wave photopolymerization (SWaP). The spatial gradient of the polymer concentration is the dominant factor in inducing the molecular diffusion and alignment of LCs. However, the effect of polymer concentration on molecular alignment behavior remains unclear. In this study, we performed SWaP at different exposure energies to modulate the polymer concentration during polymerization. We found that a certain polymer concentration was required to initiate the alignment. Furthermore, the phase diagram of the polymer/monomer mixtures and real-time observations during SWaP revealed that phase emergence and unidirectional molecular alignment occurred simultaneously when the polymer concentration exceeded 50%. Since SWaP achieves molecular alignment coincident with photopolymerization, it has the potential to revolutionize material fabrication by consolidating the multiple-step processes required to create functional materials in a single step. Schematic illustrations of the alignment behavior induced by SWaP. Photopolymerization was conducted with a scanned UV slit light. Uniaxial molecular alignment was induced when the polymer concentration in the exposure area was high, while it was random when the polymer concentration was low.
{"title":"Effect of polymer concentration on molecular alignment behavior during scanning wave photopolymerization","authors":"Takuto Ishiyama, Yoshiaki Kobayashi, Hirona Nakamura, Miho Aizawa, Kyohei Hisano, Shoichi Kubo, Atsushi Shishido","doi":"10.1038/s41428-024-00912-x","DOIUrl":"10.1038/s41428-024-00912-x","url":null,"abstract":"Molecularly aligned liquid-crystalline (LC) polymer films hold great promise for next-generation high-performance photonics, electronics, robotics, and medical devices. Photoalignment methods capable of achieving precise molecular alignment in a noncontact manner have been actively studied. Recently, we proposed the concept of using spatiotemporal photopolymerization to induce molecular diffusion and the resulting alignment, termed scanning wave photopolymerization (SWaP). The spatial gradient of the polymer concentration is the dominant factor in inducing the molecular diffusion and alignment of LCs. However, the effect of polymer concentration on molecular alignment behavior remains unclear. In this study, we performed SWaP at different exposure energies to modulate the polymer concentration during polymerization. We found that a certain polymer concentration was required to initiate the alignment. Furthermore, the phase diagram of the polymer/monomer mixtures and real-time observations during SWaP revealed that phase emergence and unidirectional molecular alignment occurred simultaneously when the polymer concentration exceeded 50%. Since SWaP achieves molecular alignment coincident with photopolymerization, it has the potential to revolutionize material fabrication by consolidating the multiple-step processes required to create functional materials in a single step. Schematic illustrations of the alignment behavior induced by SWaP. Photopolymerization was conducted with a scanned UV slit light. Uniaxial molecular alignment was induced when the polymer concentration in the exposure area was high, while it was random when the polymer concentration was low.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00912-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140672506","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}
The orientation of the crystalline lattice formed as a consequence of strain-induced crystallization (SIC) was revisited for a natural rubber (NR) sheet undergoing planar elongation by being stretched in one direction while keeping the other dimension unchanged. For this purpose, two-dimensional wide-angle X-ray diffraction patterns were measured by changing the inclination angle of the incident X-ray beam to the specimen sheet. The intensity of the reflection from the (120) plane of the orthorhombic crystal increased with increasing inclination angle from the normal direction of the specimen sheet; this result indicated that the orientation of the (120) planes was parallel to the surface of the specimen sheet. Moreover, the intensity of the (200) plane reflection reached a maximum at a slightly inclined angle from the normal of the specimen surface. WAXD measurements were also conducted using different X-ray wavelengths (0.06, 0.10, and 0.15 nm) to evaluate the inclined angle of the ac plane with respect to the surface of the specimen. By changing the X-ray wavelength, the distribution of reciprocal lattice points was altered such that the inclined angle of the incident X-ray beam to the specimen sheet needed to be changed to meet the diffraction condition. The inclined angle at the maximum intensity of the (200) reflection increased as a function of the X-ray wavelength. Based on this result, the preferential orientation of the ac planes was determined, whereby the ac plane was not completely parallel to the surface of the specimen sheet but was slightly inclined by 6.4°. Thus, a dual orientational state was deduced. Therefore, the preferential orientation of the ac plane was nearly parallel to the surface of the specimen sheet, with the inclined angle ranging from 6.4° to 19.6° within the volume of the specimen irradiated by the incident X-ray beam. Natural rubber exhibits the strain-induced crystallization (SIC). By using WAXD, the orientation of NR crystal formed by SIC under planar elongation was revisited. We found that the orientational state of the crystal lattice possesses a continuous margin of the orientation angle between 6.4 and 19.6° for the ac plane with respect to the surface of the specimen sheet in the real NR specimen. This orientational state could be accomplished as a result of balancing the preferential parallel orientation of (120) planes (the slip planes) and C = C planes with respect to the surface of the specimen sheet.
我们重新研究了天然橡胶（NR）薄片在保持其他尺寸不变的情况下，通过沿一个方向拉伸而发生平面伸长时，由于应变诱导结晶（SIC）而形成的晶格取向。为此，通过改变入射到试样片材的 X 射线束的倾斜角度，测量了二维广角 X 射线衍射图样。正方晶（120）面的反射强度随着与试样薄片法线方向的倾斜角增大而增大；这一结果表明（120）面的方向与试样薄片表面平行。此外，(200) 平面的反射强度在与试样表面的法线呈轻微倾斜角时达到最大值。还使用不同的 X 射线波长（0.06、0.10 和 0.15 纳米）进行了 WAXD 测量，以评估交流平面相对于试样表面的倾斜角度。通过改变 X 射线波长，倒易点阵点的分布发生了变化，因此需要改变入射 X 射线束与试样薄片的倾斜角度，以满足衍射条件。(200) 反射最大强度处的倾斜角随 X 射线波长的变化而增大。根据这一结果，确定了交流平面的优先取向，即交流平面并非完全平行于试样薄片表面，而是略微倾斜 6.4°。因此，可以推断出一种双重取向状态。因此，在入射 X 射线光束照射的试样体积内，交流平面的优先取向几乎与试样薄片表面平行，倾斜角度从 6.4°到 19.6°不等。
{"title":"Revisit of crystal orientation in a vulcanizate of natural rubber under planar elongation","authors":"Ruito Tanaka, Tomohiro Yasui, Hideaki Takagi, Nobutaka Shimizu, Noriyuki Igarashi, Hiroyasu Masunaga, Yuji Kitamura, Katsuhiko Tsunoda, Thanh-Tam Mai, Kenji Urayama, Shinichi Sakurai","doi":"10.1038/s41428-024-00910-z","DOIUrl":"10.1038/s41428-024-00910-z","url":null,"abstract":"The orientation of the crystalline lattice formed as a consequence of strain-induced crystallization (SIC) was revisited for a natural rubber (NR) sheet undergoing planar elongation by being stretched in one direction while keeping the other dimension unchanged. For this purpose, two-dimensional wide-angle X-ray diffraction patterns were measured by changing the inclination angle of the incident X-ray beam to the specimen sheet. The intensity of the reflection from the (120) plane of the orthorhombic crystal increased with increasing inclination angle from the normal direction of the specimen sheet; this result indicated that the orientation of the (120) planes was parallel to the surface of the specimen sheet. Moreover, the intensity of the (200) plane reflection reached a maximum at a slightly inclined angle from the normal of the specimen surface. WAXD measurements were also conducted using different X-ray wavelengths (0.06, 0.10, and 0.15 nm) to evaluate the inclined angle of the ac plane with respect to the surface of the specimen. By changing the X-ray wavelength, the distribution of reciprocal lattice points was altered such that the inclined angle of the incident X-ray beam to the specimen sheet needed to be changed to meet the diffraction condition. The inclined angle at the maximum intensity of the (200) reflection increased as a function of the X-ray wavelength. Based on this result, the preferential orientation of the ac planes was determined, whereby the ac plane was not completely parallel to the surface of the specimen sheet but was slightly inclined by 6.4°. Thus, a dual orientational state was deduced. Therefore, the preferential orientation of the ac plane was nearly parallel to the surface of the specimen sheet, with the inclined angle ranging from 6.4° to 19.6° within the volume of the specimen irradiated by the incident X-ray beam. Natural rubber exhibits the strain-induced crystallization (SIC). By using WAXD, the orientation of NR crystal formed by SIC under planar elongation was revisited. We found that the orientational state of the crystal lattice possesses a continuous margin of the orientation angle between 6.4 and 19.6° for the ac plane with respect to the surface of the specimen sheet in the real NR specimen. This orientational state could be accomplished as a result of balancing the preferential parallel orientation of (120) planes (the slip planes) and C = C planes with respect to the surface of the specimen sheet.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140609503","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 use of noncovalent intramolecular interactions constitutes a powerful design strategy for preparing π-conjugated polymers featuring high backbone coplanarities and thereby high crystallinities. Herein, we report the design and synthesis of an alkoxythiophene-flanked benzobisthiazole (BBTz) as a new building unit for π-conjugated polymers, which was subsequently copolymerized to give a simple BBTz-bithiophene copolymer with alkyl and alkoxy groups (PDBTz2). Owing to the S···O noncovalent intramolecular interactions between the alkoxy oxygens and thiazole sulfurs in BBTz, PDBTz2 showed greater coplanarity and crystallinity than its alkyl counterpart, PDBTz1. Interestingly, the backbone orientation was completely altered from the edge-on orientation observed for PDBTz1 to a face-on orientation for PDBTz2, which is preferable for organic photovoltaics (OPVs). In addition, the electron-donating nature of the alkoxy group increased the HOMO energy level of PDBTz2 compared to that of PDBTz1, which enabled photoinduced hole transfer from a nonfullerene acceptor, Y6, to the polymer. As a result, the short-circuit current density of an organic photovoltaic cell based on PDBTz2 and Y6 was significantly greater than that of a cell based on PDBTz1 and Y6. This study confirmed that alkoxythiophene-flanked BBTz is a promising building unit for high-performance π-conjugated polymers. We synthesized a new benzobisthiazole (BBTz) containing building unit in which two alkoxythiophenes were attached to the BBTz moiety so as to induce oxygen–sulfur noncovalent intramolecular interactions and thereby interlock the linkage. As a result, the π-conjugated polymer incorporating the new building unit, PDBTz2, had a more coplanar and rigid backbone than the alkyl counterpart, PDBTz1. Interestingly, the backbone orientation was completely altered from the edge-on orientation (PDBTz1) to the face-on orientation (PDBTz2), which is preferable for organic photovoltaics. Accordingly, PDBTz2 showed a much higher photovoltaic performance than PDBTz1.
{"title":"A highly crystalline face-on π-conjugated polymer based on alkoxythiophene-flanked benzobisthiazole for organic photovoltaics","authors":"Shuhei Doi, Tsubasa Mikie, Kodai Yamanaka, Yuki Sato, Hideo Ohkita, Masahiko Saito, Itaru Osaka","doi":"10.1038/s41428-024-00906-9","DOIUrl":"10.1038/s41428-024-00906-9","url":null,"abstract":"The use of noncovalent intramolecular interactions constitutes a powerful design strategy for preparing π-conjugated polymers featuring high backbone coplanarities and thereby high crystallinities. Herein, we report the design and synthesis of an alkoxythiophene-flanked benzobisthiazole (BBTz) as a new building unit for π-conjugated polymers, which was subsequently copolymerized to give a simple BBTz-bithiophene copolymer with alkyl and alkoxy groups (PDBTz2). Owing to the S···O noncovalent intramolecular interactions between the alkoxy oxygens and thiazole sulfurs in BBTz, PDBTz2 showed greater coplanarity and crystallinity than its alkyl counterpart, PDBTz1. Interestingly, the backbone orientation was completely altered from the edge-on orientation observed for PDBTz1 to a face-on orientation for PDBTz2, which is preferable for organic photovoltaics (OPVs). In addition, the electron-donating nature of the alkoxy group increased the HOMO energy level of PDBTz2 compared to that of PDBTz1, which enabled photoinduced hole transfer from a nonfullerene acceptor, Y6, to the polymer. As a result, the short-circuit current density of an organic photovoltaic cell based on PDBTz2 and Y6 was significantly greater than that of a cell based on PDBTz1 and Y6. This study confirmed that alkoxythiophene-flanked BBTz is a promising building unit for high-performance π-conjugated polymers. We synthesized a new benzobisthiazole (BBTz) containing building unit in which two alkoxythiophenes were attached to the BBTz moiety so as to induce oxygen–sulfur noncovalent intramolecular interactions and thereby interlock the linkage. As a result, the π-conjugated polymer incorporating the new building unit, PDBTz2, had a more coplanar and rigid backbone than the alkyl counterpart, PDBTz1. Interestingly, the backbone orientation was completely altered from the edge-on orientation (PDBTz1) to the face-on orientation (PDBTz2), which is preferable for organic photovoltaics. Accordingly, PDBTz2 showed a much higher photovoltaic performance than PDBTz1.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00906-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140570005","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}
A surface coated with a star polymer is believed to form a highly dense polymer brush-like architecture and inhibit biofouling. In this study, the surface properties of the star polymer coating were evaluated with their resistance to protein adsorption and surface zeta (ζ)-potential to clarify the mechanism for inhibition of cell adhesion. The surface of the star polymer coating with a high density of poly(2-hydroxyethyl methacrylate) (PHEMA) formed an electrically neutral diffuse brush structure in water and showed high resistance to protein adsorption. Considering the data obtained in the study, the surface ζ-potential and antibiofouling properties were correlated by controlling the molecular architecture of the coating material. The surface properties of the star polymer coating were evaluated with their resistance to protein adsorption and surface zeta (ζ)-potential to clarify the mechanism for inhibition of cell adhesion. The surface of the star polymer coating with a high density of poly(2-hydroxyethyl methacrylate) formed an electrically neutral diffuse brush structure in water and showed high resistance to protein adsorption. Considering the data obtained in the study, the surface ζ-potential and antibiofouling properties were correlated by controlling the molecular architecture of the coating material.
{"title":"Surface zeta potential and protein adsorption on the coating surface of a heteroarm star polymer with a controlled hydrophilic/hydrophobic arm ratio","authors":"Masayasu Totani, Hiroharu Ajiro, Jun-ichi Kadokawa, Masao Tanihara, Tsuyoshi Ando","doi":"10.1038/s41428-024-00911-y","DOIUrl":"10.1038/s41428-024-00911-y","url":null,"abstract":"A surface coated with a star polymer is believed to form a highly dense polymer brush-like architecture and inhibit biofouling. In this study, the surface properties of the star polymer coating were evaluated with their resistance to protein adsorption and surface zeta (ζ)-potential to clarify the mechanism for inhibition of cell adhesion. The surface of the star polymer coating with a high density of poly(2-hydroxyethyl methacrylate) (PHEMA) formed an electrically neutral diffuse brush structure in water and showed high resistance to protein adsorption. Considering the data obtained in the study, the surface ζ-potential and antibiofouling properties were correlated by controlling the molecular architecture of the coating material. The surface properties of the star polymer coating were evaluated with their resistance to protein adsorption and surface zeta (ζ)-potential to clarify the mechanism for inhibition of cell adhesion. The surface of the star polymer coating with a high density of poly(2-hydroxyethyl methacrylate) formed an electrically neutral diffuse brush structure in water and showed high resistance to protein adsorption. Considering the data obtained in the study, the surface ζ-potential and antibiofouling properties were correlated by controlling the molecular architecture of the coating material.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140323523","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}
Since anions play a significant role in various biological phenomena, developing fluorescence anion sensors is important. Previously, we focused on polyhedral oligomeric silsesquioxane (POSS) as a three-dimensional (3D) scaffold to design an anion receptor. In this study, we evaluated the anion binding properties of an POSS derivative with eight urea groups and applied the derivative to an anion fluorescence sensor utilizing its 3D structure. 1H NMR measurements revealed that the POSS derivative with urea groups can bind to sulfate ions. Compared to the model compound, the POSS derivative exhibits a greater binding ability due to the cooperative effects of multiple urea groups. Through the introduction of naphthyl urea groups, the POSS derivative can be used as a fluorescence sensor for quantifying sulfate ions. Developing fluorescence anion sensors is important because anions play a significant role in various biological phenomena. Herein, we evaluated the anion binding properties of a polyhedral oligomeric silsesquioxane (POSS) derivative with eight urea groups and a 3D structure. The results revealed that the POSS derivative with urea groups can bind to sulfate ions and exhibits a greater binding ability than that of the model compound because multiple urea groups exhibit cooperative effects. Through the introduction of naphthyl urea groups, the POSS derivative can be used as a fluorescence sensor for quantifying sulfate ions.
{"title":"Development of fluorescence sensors for quantifying anions based on polyhedral oligomeric silsesquioxane that contains flexible side chains with urea structures","authors":"Hayato Narikiyo, Masayuki Gon, Kazuo Tanaka, Yoshiki Chujo","doi":"10.1038/s41428-024-00909-6","DOIUrl":"10.1038/s41428-024-00909-6","url":null,"abstract":"Since anions play a significant role in various biological phenomena, developing fluorescence anion sensors is important. Previously, we focused on polyhedral oligomeric silsesquioxane (POSS) as a three-dimensional (3D) scaffold to design an anion receptor. In this study, we evaluated the anion binding properties of an POSS derivative with eight urea groups and applied the derivative to an anion fluorescence sensor utilizing its 3D structure. 1H NMR measurements revealed that the POSS derivative with urea groups can bind to sulfate ions. Compared to the model compound, the POSS derivative exhibits a greater binding ability due to the cooperative effects of multiple urea groups. Through the introduction of naphthyl urea groups, the POSS derivative can be used as a fluorescence sensor for quantifying sulfate ions. Developing fluorescence anion sensors is important because anions play a significant role in various biological phenomena. Herein, we evaluated the anion binding properties of a polyhedral oligomeric silsesquioxane (POSS) derivative with eight urea groups and a 3D structure. The results revealed that the POSS derivative with urea groups can bind to sulfate ions and exhibits a greater binding ability than that of the model compound because multiple urea groups exhibit cooperative effects. Through the introduction of naphthyl urea groups, the POSS derivative can be used as a fluorescence sensor for quantifying sulfate ions.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00909-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314645","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 : 2024-03-26DOI: 10.1038/s41428-024-00908-7
Tsukuru Masuda
Soft interfaces formed by polymer materials are important interfaces for biological systems (biointerfaces), and controlling their chemical and physical structures at the nanoscale plays an important role in understanding the mechanism and development of interface functionalities. Controlled radical polymerization (CRP) is highly suited for designing biointerfaces composed of polymer chains because it enables the formation of well-defined polymer brushes, block copolymers, and comb-type copolymers. This focus review describes the design of functional soft interfaces based on investigations of the structure-property relationships of CRPs. In particular, polymer brush surfaces showing autonomous property changes, 2D/3D transformations of lipid bilayers, and molecular interactions in bactericidal cationic polymer brushes are depicted. Soft interfaces formed by polymer materials are important interfaces for biological systems (biointerfaces). Controlled radical polymerization (CRP) is highly suited for designing biointerfaces composed of polymer chains because it enables precise control of the polymer architecture at the nanoscale. This focus review describes the design of functional soft interfaces based on investigations of the structure-property relationships of CRPs. In particular, polymer brush surfaces showing autonomous property changes, comb-type copolymer-driven 2D/3D transformations of lipid bilayers, and molecular interactions in bactericidal cationic polymer brushes are depicted.
{"title":"Design of functional soft interfaces with precise control of the polymer architecture","authors":"Tsukuru Masuda","doi":"10.1038/s41428-024-00908-7","DOIUrl":"10.1038/s41428-024-00908-7","url":null,"abstract":"Soft interfaces formed by polymer materials are important interfaces for biological systems (biointerfaces), and controlling their chemical and physical structures at the nanoscale plays an important role in understanding the mechanism and development of interface functionalities. Controlled radical polymerization (CRP) is highly suited for designing biointerfaces composed of polymer chains because it enables the formation of well-defined polymer brushes, block copolymers, and comb-type copolymers. This focus review describes the design of functional soft interfaces based on investigations of the structure-property relationships of CRPs. In particular, polymer brush surfaces showing autonomous property changes, 2D/3D transformations of lipid bilayers, and molecular interactions in bactericidal cationic polymer brushes are depicted. Soft interfaces formed by polymer materials are important interfaces for biological systems (biointerfaces). Controlled radical polymerization (CRP) is highly suited for designing biointerfaces composed of polymer chains because it enables precise control of the polymer architecture at the nanoscale. This focus review describes the design of functional soft interfaces based on investigations of the structure-property relationships of CRPs. In particular, polymer brush surfaces showing autonomous property changes, comb-type copolymer-driven 2D/3D transformations of lipid bilayers, and molecular interactions in bactericidal cationic polymer brushes are depicted.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41428-024-00908-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140303342","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 : 2024-03-25DOI: 10.1038/s41428-024-00904-x
Jun Araki, Shiori Yoda, Riku Kudo
Surface amino groups (SAGs) on chitin nanowhiskers and chitin nanofibers were rapidly and facilely quantified via spectrophotometry using three amino-labeling reagents (2,4,6-trinitrobenzensulfonic acid sodium salt (TNBS), o-phthalaldehyde (OPA) and ninhydrin) and two cationic dyes (reactive red 4 (RR4) and acid orange 7 (AO7)). After binding to the SAGs, the amounts of excess TNBS and OPA were determined via spectrophotometry and subtracted from the initial quantity. After ninhydrin was added to ChNWs/ChNFs, Ruhemann’s purple product was generated, which was quantified via spectrophotometry. When RR4 and AO7 were added in excess to the SAG of ChNWs/ChNFs, these dyes were adsorbed onto surface amino groups, and the excess amounts were similarly quantified. Each method yielded different amino group contents, which were compared with the titration values. Although the values obtained by labeling reagents were considerably underestimated, those obtained using TNBS and ninhydrin were proportional to those obtained by titration. The values obtained using AO7 adsorption at pH 2 or 3 corresponded well with the titration values for ChNWs but not ChNFs. Reliable results were attained using the two former labeling reagents with conversion equations or using AO7 adsorption. Surface amino groups (SAGs) on nanochitin materials were quantified using three amino-labeling reagents and two cationic dyes. After binding to SAGs, the excess labeling reagents or generated molecules were assessed by spectrophotometry. The dyes were adsorbed onto SAGs, and the excess was similarly quantified. The obtained values were compared with the titration values. Although the values by labeling reagents were underestimated, some of the values were proportional to those by titration. Reliable results were attained using the two labeling reagents with conversion equations or using Acid Orange 7 adsorption.
{"title":"Rapid and facile quantification of surface amino groups on chitin nanowhiskers and nanofibers via spectrophotometry","authors":"Jun Araki, Shiori Yoda, Riku Kudo","doi":"10.1038/s41428-024-00904-x","DOIUrl":"10.1038/s41428-024-00904-x","url":null,"abstract":"Surface amino groups (SAGs) on chitin nanowhiskers and chitin nanofibers were rapidly and facilely quantified via spectrophotometry using three amino-labeling reagents (2,4,6-trinitrobenzensulfonic acid sodium salt (TNBS), o-phthalaldehyde (OPA) and ninhydrin) and two cationic dyes (reactive red 4 (RR4) and acid orange 7 (AO7)). After binding to the SAGs, the amounts of excess TNBS and OPA were determined via spectrophotometry and subtracted from the initial quantity. After ninhydrin was added to ChNWs/ChNFs, Ruhemann’s purple product was generated, which was quantified via spectrophotometry. When RR4 and AO7 were added in excess to the SAG of ChNWs/ChNFs, these dyes were adsorbed onto surface amino groups, and the excess amounts were similarly quantified. Each method yielded different amino group contents, which were compared with the titration values. Although the values obtained by labeling reagents were considerably underestimated, those obtained using TNBS and ninhydrin were proportional to those obtained by titration. The values obtained using AO7 adsorption at pH 2 or 3 corresponded well with the titration values for ChNWs but not ChNFs. Reliable results were attained using the two former labeling reagents with conversion equations or using AO7 adsorption. Surface amino groups (SAGs) on nanochitin materials were quantified using three amino-labeling reagents and two cationic dyes. After binding to SAGs, the excess labeling reagents or generated molecules were assessed by spectrophotometry. The dyes were adsorbed onto SAGs, and the excess was similarly quantified. The obtained values were compared with the titration values. Although the values by labeling reagents were underestimated, some of the values were proportional to those by titration. Reliable results were attained using the two labeling reagents with conversion equations or using Acid Orange 7 adsorption.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140301481","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 effect of the ratio of divalent (Mg2+) to monovalent (Na+) cations on the mechanical and self-healing properties of polyisoprene (PI) ionomers co-neutralized with Na+ and Mg2+ was studied. Sodium carboxylates link polymer chains via electrostatic interactions, while magnesium carboxylates more strongly link polymer chains via ionic bonds. Therefore, Mg2+ considerably reinforces the PI ionomer. However, we found that the mechanical properties of the PI ionomers did not change proportionally to the ratio of Mg2+. The ionomer was significantly reinforced at over 25% of the Mg2+ ratio, where linkage via Mg2+ in the network was prevalent throughout the material. At the same time, the self-healing of the PI ionomer was disrupted. The morphology and physical properties of polyisoprene ionomers co-neutralized with Na+ and Mg2+ in different ratios have been studied. The mechanical and self-healing properties of the ionomer were reinforced and disturbed, respectively, at over 25 % of the Mg2+ ratio, where linkage via Mg2+ in the network is pervasive throughout the material.
研究了二价阳离子（Mg2+）和一价阳离子（Na+）的比例对与 Na+ 和 Mg2+ 共中性的聚异戊二烯（PI）离聚物的机械和自愈性能的影响。羧酸钠通过静电作用连接聚合物链，而羧酸镁则通过离子键更牢固地连接聚合物链。因此，Mg2+ 在很大程度上强化了 PI 离子聚合物。然而，我们发现 PI 离聚物的机械性能并没有随着 Mg2+ 的比例变化而成正比。当 Mg2+ 的比例超过 25% 时，离子聚合物得到明显增强，在这种情况下，通过 Mg2+ 在网络中的连接在整个材料中非常普遍。与此同时，PI 离子聚合物的自愈合能力被破坏。
{"title":"Effect of the Mg2+ ratio on the mechanical and self-healing properties of polyisoprene ionomers co-neutralized with Na+ and Mg2+","authors":"Rina Takahashi, Taro Udagawa, Kei Hashimoto, Shoichi Kutsumizu, Yohei Miwa","doi":"10.1038/s41428-024-00907-8","DOIUrl":"10.1038/s41428-024-00907-8","url":null,"abstract":"The effect of the ratio of divalent (Mg2+) to monovalent (Na+) cations on the mechanical and self-healing properties of polyisoprene (PI) ionomers co-neutralized with Na+ and Mg2+ was studied. Sodium carboxylates link polymer chains via electrostatic interactions, while magnesium carboxylates more strongly link polymer chains via ionic bonds. Therefore, Mg2+ considerably reinforces the PI ionomer. However, we found that the mechanical properties of the PI ionomers did not change proportionally to the ratio of Mg2+. The ionomer was significantly reinforced at over 25% of the Mg2+ ratio, where linkage via Mg2+ in the network was prevalent throughout the material. At the same time, the self-healing of the PI ionomer was disrupted. The morphology and physical properties of polyisoprene ionomers co-neutralized with Na+ and Mg2+ in different ratios have been studied. The mechanical and self-healing properties of the ionomer were reinforced and disturbed, respectively, at over 25 % of the Mg2+ ratio, where linkage via Mg2+ in the network is pervasive throughout the material.","PeriodicalId":20302,"journal":{"name":"Polymer Journal","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140199004","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 : 2024-03-14DOI: 10.1038/s41428-024-00899-5
Jose Jonathan Rubio Arias, Zijing Zhang, Manae Takahashi, Paramasivam Mahalingam, Pimjai Pimbaotham, Nuttapon Yodsin, Masafumi Unno, Yujia Liu, Siriporn Jungsuttiwong, Jason Azoulay, Matt Rammo, Aleksander Rebane, Richard M. Laine
We previously reported that functionalized phenyl- and vinyl-silsesquioxanes (SQs) and [RSiO1.5]8,10,12 (R = Ph or vinyl) exhibited redshifted absorption and emission, suggesting 3-D conjugation via a cage-centered lowest unoccupied molecular orbital (LUMO). The functionalized [PhSiO1.5]7(OSiMe3)3 with a missing corner and edge-opened, end-capped [PhSiO1.5]8(OSiMe2)2 (double decker, DD) analogs also exhibit emission redshifts, indicating 3-D conjugation. DD [PhSiO1.5]8(OSiMevinyl)2 and R-Ar-Br copolymers exhibit polymerization (DP)-dependent emission λmax and integer charge transfer (ICT) to 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TNCQ). The terpolymer-averaged redshifts all suggest conjugation with two (O-Si-O) endcaps, possibly via a cage-centered LUMO. In assessing conjugation limits, it was anticipated that copolymers of the ladder (LL) SQ, (vinylMeSiO2)[PhSiO1.5]4(O2SiMevinyl), with Br-Ar-Br and without a cage would eliminate LUMO formation and a redshift. The λmax values observed were greater for analogous copolymers, which requires a different explanation. Here, we assess the photophysical behavior of copolymers closer to polysiloxanes, namely, the expanded cage (MeVinylSiO)2[PhSiO1.5]8(OSiMeVinyl)2SQs. Copolymers with Br-Ar-Br exhibit redshifted absorption and emission, which supports conjugation via Si-O-Si bonds rather than cage-centered LUMOs, contrary to traditional views of Si-O-Si copolymers. One- and two-photon photophysical probes showed that XDD copolymers exhibit multiple fluorescence-emitting excited states, in violation of Kasha’s rule stating that emission should occur only from the lowest excited state. Finally, new modeling studies suggested that conjugation derives from Si-O-Si bond dπ-pπ interactions, an unexpected result for polysiloxanes that supports two forms of conjugation. a Column separation under black light illumination. b Calculated overlap of dπ-pπ orbitals demonstrating conjugation
{"title":"Conjugation in polysiloxane copolymers via unexpected Si-O-Si dπ-pπ overlap, a second mechanism?","authors":"Jose Jonathan Rubio Arias, Zijing Zhang, Manae Takahashi, Paramasivam Mahalingam, Pimjai Pimbaotham, Nuttapon Yodsin, Masafumi Unno, Yujia Liu, Siriporn Jungsuttiwong, Jason Azoulay, Matt Rammo, Aleksander Rebane, Richard M. Laine","doi":"10.1038/s41428-024-00899-5","DOIUrl":"10.1038/s41428-024-00899-5","url":null,"abstract":"We previously reported that functionalized phenyl- and vinyl-silsesquioxanes (SQs) and [RSiO1.5]8,10,12 (R = Ph or vinyl) exhibited redshifted absorption and emission, suggesting 3-D conjugation via a cage-centered lowest unoccupied molecular orbital (LUMO). The functionalized [PhSiO1.5]7(OSiMe3)3 with a missing corner and edge-opened, end-capped [PhSiO1.5]8(OSiMe2)2 (double decker, DD) analogs also exhibit emission redshifts, indicating 3-D conjugation. DD [PhSiO1.5]8(OSiMevinyl)2 and R-Ar-Br copolymers exhibit polymerization (DP)-dependent emission λmax and integer charge transfer (ICT) to 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TNCQ). The terpolymer-averaged redshifts all suggest conjugation with two (O-Si-O) endcaps, possibly via a cage-centered LUMO. In assessing conjugation limits, it was anticipated that copolymers of the ladder (LL) SQ, (vinylMeSiO2)[PhSiO1.5]4(O2SiMevinyl), with Br-Ar-Br and without a cage would eliminate LUMO formation and a redshift. The λmax values observed were greater for analogous copolymers, which requires a different explanation. Here, we assess the photophysical behavior of copolymers closer to polysiloxanes, namely, the expanded cage (MeVinylSiO)2[PhSiO1.5]8(OSiMeVinyl)2SQs. Copolymers with Br-Ar-Br exhibit redshifted absorption and emission, which supports conjugation via Si-O-Si bonds rather than cage-centered LUMOs, contrary to traditional views of Si-O-Si copolymers. One- and two-photon photophysical probes showed that XDD copolymers exhibit multiple fluorescence-emitting excited states, in violation of Kasha’s rule stating that emission should occur only from the lowest excited state. Finally, new modeling studies suggested that conjugation derives from Si-O-Si bond dπ-pπ interactions, an unexpected result for polysiloxanes that supports two forms of conjugation. a Column separation under black light illumination. b Calculated overlap of dπ-pπ orbitals demonstrating conjugation","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":"140148355","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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