Pub Date : 2022-08-03DOI: 10.1080/1539445X.2022.2108841
Guotong Du, Na Li, Qiwen Yong, Feng Jiang, Rui Wang, Yu-lin Li, Yao Xiao, Jinming Chang
ABSTRACT Covalent crosslinking can improve the water resistance of waterborne polyurethanes (WPUs), but the preparation time of WPUs will be greatly extended by the crosslinking process, and the long-term storage stability of WPU emulsions will decrease because the crosslinked molecular chains cannot disperse in any organic solvents or water. In this paper, a crosslinked WPU was prepared through a post metal-organic crosslinking toward a conventional linear WPU. This post crosslinking is quite fast since it is based on the ionic bond interaction between metal cations and organic anions. The crosslinked WPU emulsion has narrow particle size distribution and small average size, giving rise to excellent long-term storage stability. Additionally, the water absorptions of the crosslinked WPU at 25°C and 60°C are 6.3% and 8.6% respectively, which decrease by 47.9% and 39.4% compared with those of the linear counterpart, indicating that the post metal-organic crosslinking highly improves the water resistance of the WPU. The mechanical strength of the crosslinked WPU also improves compared with the linear WPU.
{"title":"Turning a linear waterborne polyurethane into a crosslinked counterpart with improved water resistance and mechanical strength through a fast post metal-organic crosslinking","authors":"Guotong Du, Na Li, Qiwen Yong, Feng Jiang, Rui Wang, Yu-lin Li, Yao Xiao, Jinming Chang","doi":"10.1080/1539445X.2022.2108841","DOIUrl":"https://doi.org/10.1080/1539445X.2022.2108841","url":null,"abstract":"ABSTRACT Covalent crosslinking can improve the water resistance of waterborne polyurethanes (WPUs), but the preparation time of WPUs will be greatly extended by the crosslinking process, and the long-term storage stability of WPU emulsions will decrease because the crosslinked molecular chains cannot disperse in any organic solvents or water. In this paper, a crosslinked WPU was prepared through a post metal-organic crosslinking toward a conventional linear WPU. This post crosslinking is quite fast since it is based on the ionic bond interaction between metal cations and organic anions. The crosslinked WPU emulsion has narrow particle size distribution and small average size, giving rise to excellent long-term storage stability. Additionally, the water absorptions of the crosslinked WPU at 25°C and 60°C are 6.3% and 8.6% respectively, which decrease by 47.9% and 39.4% compared with those of the linear counterpart, indicating that the post metal-organic crosslinking highly improves the water resistance of the WPU. The mechanical strength of the crosslinked WPU also improves compared with the linear WPU.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"471 - 478"},"PeriodicalIF":1.2,"publicationDate":"2022-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42283984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-20DOI: 10.1080/1539445X.2022.2082472
P. Mukherjee
ABSTRACT The smectic-A to chiral smectic-C* (SmA–SmC*) phase transition in the mixture of graphene nanoparticles and ferroelectric liquid crystal is studied. Combination of Flory–Huggins free energy of isotropic mixing and Landau theory is applied to explain the effects of graphene nanoparticles on the SmA–SmC* phase transition. The temperature and concentration of graphene nanoparticles dependence of tilt angle, spontaneous polarization and dielectric susceptibility in the smectic-C* phase of the SmA–SmC* phase transition are discussed. A qualitative agreement between theoretical results and experimental results is found.
{"title":"Effects of graphene on the smectic-A to chiral smectic-C* phase transition","authors":"P. Mukherjee","doi":"10.1080/1539445X.2022.2082472","DOIUrl":"https://doi.org/10.1080/1539445X.2022.2082472","url":null,"abstract":"ABSTRACT The smectic-A to chiral smectic-C* (SmA–SmC*) phase transition in the mixture of graphene nanoparticles and ferroelectric liquid crystal is studied. Combination of Flory–Huggins free energy of isotropic mixing and Landau theory is applied to explain the effects of graphene nanoparticles on the SmA–SmC* phase transition. The temperature and concentration of graphene nanoparticles dependence of tilt angle, spontaneous polarization and dielectric susceptibility in the smectic-C* phase of the SmA–SmC* phase transition are discussed. A qualitative agreement between theoretical results and experimental results is found.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"455 - 460"},"PeriodicalIF":1.2,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44332675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-05DOI: 10.1080/1539445X.2022.2083160
Shima Bahramizadeh-Sajadi, H. Katoozian, J. Nohava, M. Ariza-Gracia, P. Büchler
ABSTRACT Although corneal biomechanics plays an important role in ophthalmology, its characterization remains limited due to tissue availability. This problem is particularly critical when studying specific pathologic conditions such as keratoconus. A preservation method that maintains the mechanical response of the tissue over time allows the collection, transport, and storage of tissue samples from different, distant clinical sites and increases the number of samples available for testing. Therefore, the aim of this study was to quantify the change in mechanical response of porcine corneas after 6 days of storage either at −20°C or in standard culture medium. The viscoelastic response of porcine corneas was measured at different loading rates by nano-indentation. While the loading rate had a significant effect on the mechanical response (p < .0001), the results showed that the mechanical response were not altered by any of the preservation methods (p > .270). However, the standard deviation was up to 4.9 times larger when the samples were stored in the culture medium compared to the fresh and frozen samples. In addition, storage in culture medium resulted in significant swelling (+38%). In conclusion, although both preservation techniques provide equivalent mechanical response measured by nano-indentation, freezing the samples prevents swelling and provides more stable measurements.
{"title":"Effects of corneal preservation on the mechanical response of porcine corneas measured by nano-indentation","authors":"Shima Bahramizadeh-Sajadi, H. Katoozian, J. Nohava, M. Ariza-Gracia, P. Büchler","doi":"10.1080/1539445X.2022.2083160","DOIUrl":"https://doi.org/10.1080/1539445X.2022.2083160","url":null,"abstract":"ABSTRACT Although corneal biomechanics plays an important role in ophthalmology, its characterization remains limited due to tissue availability. This problem is particularly critical when studying specific pathologic conditions such as keratoconus. A preservation method that maintains the mechanical response of the tissue over time allows the collection, transport, and storage of tissue samples from different, distant clinical sites and increases the number of samples available for testing. Therefore, the aim of this study was to quantify the change in mechanical response of porcine corneas after 6 days of storage either at −20°C or in standard culture medium. The viscoelastic response of porcine corneas was measured at different loading rates by nano-indentation. While the loading rate had a significant effect on the mechanical response (p < .0001), the results showed that the mechanical response were not altered by any of the preservation methods (p > .270). However, the standard deviation was up to 4.9 times larger when the samples were stored in the culture medium compared to the fresh and frozen samples. In addition, storage in culture medium resulted in significant swelling (+38%). In conclusion, although both preservation techniques provide equivalent mechanical response measured by nano-indentation, freezing the samples prevents swelling and provides more stable measurements.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"461 - 470"},"PeriodicalIF":1.2,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45216217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-30DOI: 10.1080/1539445X.2022.2081580
Yan Bai, Shuaihang Bi, Weikang Wang, N. Ding, Yuyuan Lu, Mengyue Jiang, Cheng Ding, Weiwei Zhao, N. Liu, Jing Bian, Shu-juan Liu, Qiang Zhao
ABSTRACT With the booming growth of flexible human-computer interactions and telecommunications, it is desirable to fabricate a high-sensitivity strain sensor to monitor human movement and develop an electromagnetic interference (EMI) shielding materials to protect modern microelectronics and humans from electromagnetic damage. Herein, the biocompatible, stretchable, and compressible cellulose/MXene hydrogel has been prepared to first realize the dual-functional applications in strain sensor and EMI shielding. Two-dimensional MXene nanosheets serve as conductive sensing materials and fillers to construct conductive networks. The hydrogen bond interaction between them enhances the mechanical property of hydrogel. Benefiting from the excellent electrical conductivity and good mechanical property of the cellulose/MXene hydrogel, the resultant strain sensor displays excellent tensile strain (~144.4%), high sensitivity (gauge factor ~ -6.97), adjustable detection range (0-68.7%), fast response time (~100 ms), and great stability (~1000 cycles). It can monitor human motion, including pulse beating, speech recognition, writing sensing and pressure distribution induction of 4 × 4 sensor array platform. Moreover, the cellulose/MXene hydrogel presents an absorption-predominant EMI shielding performance in the frequency of X-band. This work provides a new inspiration for the development of multifunctional hydrogel in artificial intelligence, human-computer interaction, and EMI shielding technique.
{"title":"Biocompatible, stretchable, and compressible cellulose/MXene hydrogel for strain sensor and electromagnetic interference shielding","authors":"Yan Bai, Shuaihang Bi, Weikang Wang, N. Ding, Yuyuan Lu, Mengyue Jiang, Cheng Ding, Weiwei Zhao, N. Liu, Jing Bian, Shu-juan Liu, Qiang Zhao","doi":"10.1080/1539445X.2022.2081580","DOIUrl":"https://doi.org/10.1080/1539445X.2022.2081580","url":null,"abstract":"ABSTRACT With the booming growth of flexible human-computer interactions and telecommunications, it is desirable to fabricate a high-sensitivity strain sensor to monitor human movement and develop an electromagnetic interference (EMI) shielding materials to protect modern microelectronics and humans from electromagnetic damage. Herein, the biocompatible, stretchable, and compressible cellulose/MXene hydrogel has been prepared to first realize the dual-functional applications in strain sensor and EMI shielding. Two-dimensional MXene nanosheets serve as conductive sensing materials and fillers to construct conductive networks. The hydrogen bond interaction between them enhances the mechanical property of hydrogel. Benefiting from the excellent electrical conductivity and good mechanical property of the cellulose/MXene hydrogel, the resultant strain sensor displays excellent tensile strain (~144.4%), high sensitivity (gauge factor ~ -6.97), adjustable detection range (0-68.7%), fast response time (~100 ms), and great stability (~1000 cycles). It can monitor human motion, including pulse beating, speech recognition, writing sensing and pressure distribution induction of 4 × 4 sensor array platform. Moreover, the cellulose/MXene hydrogel presents an absorption-predominant EMI shielding performance in the frequency of X-band. This work provides a new inspiration for the development of multifunctional hydrogel in artificial intelligence, human-computer interaction, and EMI shielding technique.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"444 - 454"},"PeriodicalIF":1.2,"publicationDate":"2022-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45641441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-09DOI: 10.1080/1539445X.2022.2115514
Tomoki Sasada, Kento Yasuda, Yuto Hosaka, S. Komura
ABSTRACT We investigate the mechanical properties of a layered material with interlayer friction. We propose a model that contains lateral elasticity and interlayer friction to obtain the response function both in the Fourier and real spaces. By investigating how the internal deformation is laterally induced due to the applied surface displacement, we find that it is transmitted into the material with an apparent phase difference. We also obtain the effective complex modulus of the layered material and show that it exhibits an intermediate power-law behavior in the low-frequency regime. Our results can be used to estimate the internal deformation of layered materials that exists on various different scales.
{"title":"Lateral response of a layered material with interlayer friction","authors":"Tomoki Sasada, Kento Yasuda, Yuto Hosaka, S. Komura","doi":"10.1080/1539445X.2022.2115514","DOIUrl":"https://doi.org/10.1080/1539445X.2022.2115514","url":null,"abstract":"ABSTRACT We investigate the mechanical properties of a layered material with interlayer friction. We propose a model that contains lateral elasticity and interlayer friction to obtain the response function both in the Fourier and real spaces. By investigating how the internal deformation is laterally induced due to the applied surface displacement, we find that it is transmitted into the material with an apparent phase difference. We also obtain the effective complex modulus of the layered material and show that it exhibits an intermediate power-law behavior in the low-frequency regime. Our results can be used to estimate the internal deformation of layered materials that exists on various different scales.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"21 1","pages":"14 - 22"},"PeriodicalIF":1.2,"publicationDate":"2022-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48158732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-25DOI: 10.1080/1539445X.2022.2061513
C. Bauer, M. Ries, S. Pfaller
ABSTRACT In this contribution, molecular dynamics (MD) simulations in combination with continuum mechanical (CM) approaches are performed to investigate particle movements under uniaxial deformations of an amorphous polymer at particle resolution. A coarse-grained (CG) model of atactic polystyrene is used as an exemplary model system. We propose a hybrid molecular dynamics-continuum mechanical (MD-CM) approach to simulate the deformation behavior of the polymer. As a reference, purely molecular dynamics systems are used. The methods are compared with regard to the local displacement of the particles and the global stress-strain behavior of the overall system. The good reproducibility of the system’s mechanical behavior with the hybrid molecular dynamics-continuum mechanical method is shown. Furthermore, it is demonstrated that CPU time can be significantly reduced with the hybrid calculation model.
{"title":"Accelerating molecular dynamics simulations by a hybrid molecular dynamics-continuum mechanical approach","authors":"C. Bauer, M. Ries, S. Pfaller","doi":"10.1080/1539445X.2022.2061513","DOIUrl":"https://doi.org/10.1080/1539445X.2022.2061513","url":null,"abstract":"ABSTRACT In this contribution, molecular dynamics (MD) simulations in combination with continuum mechanical (CM) approaches are performed to investigate particle movements under uniaxial deformations of an amorphous polymer at particle resolution. A coarse-grained (CG) model of atactic polystyrene is used as an exemplary model system. We propose a hybrid molecular dynamics-continuum mechanical (MD-CM) approach to simulate the deformation behavior of the polymer. As a reference, purely molecular dynamics systems are used. The methods are compared with regard to the local displacement of the particles and the global stress-strain behavior of the overall system. The good reproducibility of the system’s mechanical behavior with the hybrid molecular dynamics-continuum mechanical method is shown. Furthermore, it is demonstrated that CPU time can be significantly reduced with the hybrid calculation model.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"428 - 443"},"PeriodicalIF":1.2,"publicationDate":"2022-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44495407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-25DOI: 10.1080/1539445X.2022.2049308
Suhela Tyeb, N. Kumar, Gorbel B, Ajay Kumar, Vivek Verma
ABSTRACT Microenvironment of majority chronic wounds exhibits pH in the range of 7.5 to 8.5, leading to poor healing prognosis. The elevated pH adds to dysregulation of healing cascade by creating hypoxia, elevating matrix metalloproteinase (MMP) activity and chances of infection. The current work focuses on fabrication of pH regulating agar-citric acid bi-layer dressing for effective management of chronic wounds. The desired pH in the range of 6 to 7 was achieved by unidirectional release of citric acid through bi-layer arrangement of agar-citric acid films in contact with wound simulating fluid of pH ~ 8.5. At lower pH (6.5), both MMP 9 and MMP 2 degraded lesser gelatin (0.11 µg/mg ± 0.003 µg/mg) as compared to higher pH (8.5) value (0.18 µg/mg ± 0.004 µg/mg). The dressing also exhibited bacteriostatic effect on Staphylococcus aureus and Pseudomonas aeruginosa bacteria cultured in-vitro. The bilayer dressing exhibited an average tensile strength of 27 MPa ± 2.5 MPa along with 52 ± 5% elongation at break. The percentage swelling and water vapor transmission rate of dressing was 112% ± 20% and 2156 g/m2/day ± 128 g/m2/day respectively.
{"title":"pH modulating agar dressing for chronic wounds","authors":"Suhela Tyeb, N. Kumar, Gorbel B, Ajay Kumar, Vivek Verma","doi":"10.1080/1539445X.2022.2049308","DOIUrl":"https://doi.org/10.1080/1539445X.2022.2049308","url":null,"abstract":"ABSTRACT Microenvironment of majority chronic wounds exhibits pH in the range of 7.5 to 8.5, leading to poor healing prognosis. The elevated pH adds to dysregulation of healing cascade by creating hypoxia, elevating matrix metalloproteinase (MMP) activity and chances of infection. The current work focuses on fabrication of pH regulating agar-citric acid bi-layer dressing for effective management of chronic wounds. The desired pH in the range of 6 to 7 was achieved by unidirectional release of citric acid through bi-layer arrangement of agar-citric acid films in contact with wound simulating fluid of pH ~ 8.5. At lower pH (6.5), both MMP 9 and MMP 2 degraded lesser gelatin (0.11 µg/mg ± 0.003 µg/mg) as compared to higher pH (8.5) value (0.18 µg/mg ± 0.004 µg/mg). The dressing also exhibited bacteriostatic effect on Staphylococcus aureus and Pseudomonas aeruginosa bacteria cultured in-vitro. The bilayer dressing exhibited an average tensile strength of 27 MPa ± 2.5 MPa along with 52 ± 5% elongation at break. The percentage swelling and water vapor transmission rate of dressing was 112% ± 20% and 2156 g/m2/day ± 128 g/m2/day respectively.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"379 - 393"},"PeriodicalIF":1.2,"publicationDate":"2022-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46392752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-22DOI: 10.1080/1539445X.2022.2054822
Jiahao Li, Xun Lu, Q. Bai, Zhaobo Wang
ABSTRACT In this work, we described a simple method to manufacture a novel nitrile butadiene rubber (NBR) filled with cupric sulfate (CuSO4) and tetramethylthiuram disulfide (TMTD) via simple mixing and heat pressing. Cure characteristics analysis, the motion capability of polymer segments, physical properties, micromorphology, swelling properties and dynamic characteristics were explored comprehensively. The results demonstrated that the three-dimensional network was cross-linked by the metal coordination interactions between the nitrile group and copper ion. The cure curve, tensile strength and crosslinking density exhibited a considerable increasing with the addition of TMTD in NBR/CuSO4 compounds, which was due to the synergistic effect between Cu2+ and Me2NCSn• (n = 1–2) radicals generated by the pyrolysis of TMTD, resulting in the formation of the hyperactive compounds [Cu(SnCNMe2)]•2+ and promoting the coordination crosslinking between -CN and Cu2+ significantly. The NBR/CuSO4/TMTD vulcanizates induced by the synergistic effect would play a crucial role in practical application for the excellent physical properties.
{"title":"Investigation on metal coordination crosslinking nitrile butadiene rubber induced by the synergistic effect between tetramethylthiuram disulfide and cupric sulfate","authors":"Jiahao Li, Xun Lu, Q. Bai, Zhaobo Wang","doi":"10.1080/1539445X.2022.2054822","DOIUrl":"https://doi.org/10.1080/1539445X.2022.2054822","url":null,"abstract":"ABSTRACT In this work, we described a simple method to manufacture a novel nitrile butadiene rubber (NBR) filled with cupric sulfate (CuSO4) and tetramethylthiuram disulfide (TMTD) via simple mixing and heat pressing. Cure characteristics analysis, the motion capability of polymer segments, physical properties, micromorphology, swelling properties and dynamic characteristics were explored comprehensively. The results demonstrated that the three-dimensional network was cross-linked by the metal coordination interactions between the nitrile group and copper ion. The cure curve, tensile strength and crosslinking density exhibited a considerable increasing with the addition of TMTD in NBR/CuSO4 compounds, which was due to the synergistic effect between Cu2+ and Me2NCSn• (n = 1–2) radicals generated by the pyrolysis of TMTD, resulting in the formation of the hyperactive compounds [Cu(SnCNMe2)]•2+ and promoting the coordination crosslinking between -CN and Cu2+ significantly. The NBR/CuSO4/TMTD vulcanizates induced by the synergistic effect would play a crucial role in practical application for the excellent physical properties.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"414 - 427"},"PeriodicalIF":1.2,"publicationDate":"2022-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44540386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-21DOI: 10.1080/1539445X.2022.2053542
Xiao-Peng Cheng, Xiaoting Xiong, Jianggang He, Wenhao Yu, C. Feng, Hai-liang Ni, P. Hu
ABSTRACT Nine new C3-symmetric 2,7,12-tris(decanoxy)-3,8,13-tris(alkoxy)truxene discogens were synthesized, and all exhibited only one three-dimensionally ordered hexagonal columnar mesophase with a wide mesogenic temperature range, as characterized by polarizing optical microscopy, differential scanning calorimetry, and X-ray diffractometry. Crucially, as the length of the alkoxy chain increased, the melting points first increased and then decreased, and, at the same time, the temperatures of the clearing point decreased gradually. In addition, these compounds were found to be highly thermally stable, having decomposition temperatures occurring well above 350°C, as determined by thermogravimetric analysis. The self-assembly behaviors in solution were studied using variable-concentration 1H-NMR, revealing that the truxenes self-aggregated in solution via the π–π facial interactions of the polycyclic aromatic units, and scanning tunneling microscopy results revealed that one of the discotic liquid crystal compounds periodically assembled in a hexagonal geometry at the liquid–solid interface of highly oriented pyrolytic graphite.
{"title":"C 3-symmetric truxene discotic liquid crystals with mixed ether chains: synthesis, mesomorphism, and self-assembly properties","authors":"Xiao-Peng Cheng, Xiaoting Xiong, Jianggang He, Wenhao Yu, C. Feng, Hai-liang Ni, P. Hu","doi":"10.1080/1539445X.2022.2053542","DOIUrl":"https://doi.org/10.1080/1539445X.2022.2053542","url":null,"abstract":"ABSTRACT Nine new C3-symmetric 2,7,12-tris(decanoxy)-3,8,13-tris(alkoxy)truxene discogens were synthesized, and all exhibited only one three-dimensionally ordered hexagonal columnar mesophase with a wide mesogenic temperature range, as characterized by polarizing optical microscopy, differential scanning calorimetry, and X-ray diffractometry. Crucially, as the length of the alkoxy chain increased, the melting points first increased and then decreased, and, at the same time, the temperatures of the clearing point decreased gradually. In addition, these compounds were found to be highly thermally stable, having decomposition temperatures occurring well above 350°C, as determined by thermogravimetric analysis. The self-assembly behaviors in solution were studied using variable-concentration 1H-NMR, revealing that the truxenes self-aggregated in solution via the π–π facial interactions of the polycyclic aromatic units, and scanning tunneling microscopy results revealed that one of the discotic liquid crystal compounds periodically assembled in a hexagonal geometry at the liquid–solid interface of highly oriented pyrolytic graphite.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"394 - 404"},"PeriodicalIF":1.2,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49570493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-14DOI: 10.1080/1539445X.2022.2053543
Javad B. M. Parambath, S. Kanan, Ahmed Abouzeed Mohamed
ABSTRACT Current research on coronavirus 2 disease (SARS-CoV-2) has been focused on developing reliable gold nanomaterials and methods for the detection of viral spike protein (S-proteins). Here, we describe the fluorescence quenching of spike proteins in the presence of robust gold-aryl nanoparticles. The obtained results demonstrated a strong binding affinity between S-proteins and tryptophan immobilized on gold-carbon nanoparticles (Trp-AuNPs) based on the binding constant value of 11.098 M−1. Förster non-radiative energy transfer (FRET) calculations showed an average binding distance of r = 3.06 nm and a critical energy transfer distance of R0 = 2.5 nm. Time-resolved fluorescence studies of conjugated S-proteins onto Trp-AuNPs revealed a short fluorescence lifetime and dynamic quenching.
{"title":"Tryptophan capped gold-aryl nanoparticles for energy transfer study with SARS-CoV-2 spike proteins","authors":"Javad B. M. Parambath, S. Kanan, Ahmed Abouzeed Mohamed","doi":"10.1080/1539445X.2022.2053543","DOIUrl":"https://doi.org/10.1080/1539445X.2022.2053543","url":null,"abstract":"ABSTRACT Current research on coronavirus 2 disease (SARS-CoV-2) has been focused on developing reliable gold nanomaterials and methods for the detection of viral spike protein (S-proteins). Here, we describe the fluorescence quenching of spike proteins in the presence of robust gold-aryl nanoparticles. The obtained results demonstrated a strong binding affinity between S-proteins and tryptophan immobilized on gold-carbon nanoparticles (Trp-AuNPs) based on the binding constant value of 11.098 M−1. Förster non-radiative energy transfer (FRET) calculations showed an average binding distance of r = 3.06 nm and a critical energy transfer distance of R0 = 2.5 nm. Time-resolved fluorescence studies of conjugated S-proteins onto Trp-AuNPs revealed a short fluorescence lifetime and dynamic quenching.","PeriodicalId":22140,"journal":{"name":"Soft Materials","volume":"20 1","pages":"405 - 413"},"PeriodicalIF":1.2,"publicationDate":"2022-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44409359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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