Pub Date : 2024-06-26DOI: 10.1007/s10118-024-3150-4
Jia-Jia Wu, Fei Wang, Peng-Qi Wan, Li Pan, Chun-Sheng Xiao, Zhe Ma, Yue-Sheng Li
Owing to its high production volume and wide range of applications, polyethylene has gained a great deal of attention, but its low surface energy and non-polar nature have limited its application in some important fields. In this study, ethylene/11-iodo-1-undecene copolymers were prepared and used as the intermediates to afford a series of imidazolium-based ionomers bearing methanesulfonate (CH3SO3−), trifluoromethanesulfonate (CF3SO3−), or bis(trifluoromethane)sulfonimide (Tf2N−) counteranions. The tensile test results showed that the stress-at-break (7.8–25.6 MPa) and the elongation-at-break (445%–847%) of the ionomers could be adjusted by changing the counterion species and the ionic group contents. Most importantly, the ionomers exhibited marvelous antibacterial activities against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The ionomers bearing Tf2N− exhibited antibacterial activities >99% against both S. aureus and E. coli when ionic content reached 9.1%. The imidazolium-based ionomers prepared in this work demonstrated excellent comprehensive properties, especially high-efficient and broad-spectrum antibacterial ability, exhibiting the potential for the application as the antibacterial materials in packaging, medical, and other fields.
{"title":"Synthesis, Characterization of Polyethylene Ionomers and Their Antibacterial Properties","authors":"Jia-Jia Wu, Fei Wang, Peng-Qi Wan, Li Pan, Chun-Sheng Xiao, Zhe Ma, Yue-Sheng Li","doi":"10.1007/s10118-024-3150-4","DOIUrl":"10.1007/s10118-024-3150-4","url":null,"abstract":"<div><p>Owing to its high production volume and wide range of applications, polyethylene has gained a great deal of attention, but its low surface energy and non-polar nature have limited its application in some important fields. In this study, ethylene/11-iodo-1-undecene copolymers were prepared and used as the intermediates to afford a series of imidazolium-based ionomers bearing methanesulfonate (CH<sub>3</sub>SO<sub>3</sub><sup>−</sup>), trifluoromethanesulfonate (CF<sub>3</sub>SO<sub>3</sub><sup>−</sup>), or bis(trifluoromethane)sulfonimide (Tf<sub>2</sub>N<sup>−</sup>) counteranions. The tensile test results showed that the stress-at-break (7.8–25.6 MPa) and the elongation-at-break (445%–847%) of the ionomers could be adjusted by changing the counterion species and the ionic group contents. Most importantly, the ionomers exhibited marvelous antibacterial activities against <i>Staphylococcus aureus</i> (<i>S. aureus</i>) and <i>Escherichia coli</i> (<i>E. coli</i>). The ionomers bearing Tf<sub>2</sub>N<sup>−</sup> exhibited antibacterial activities >99% against both <i>S. aureus</i> and <i>E. coli</i> when ionic content reached 9.1%. The imidazolium-based ionomers prepared in this work demonstrated excellent comprehensive properties, especially high-efficient and broad-spectrum antibacterial ability, exhibiting the potential for the application as the antibacterial materials in packaging, medical, and other fields.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 8","pages":"1077 - 1084"},"PeriodicalIF":4.1,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141523333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-26DOI: 10.1007/s10118-024-3155-z
Jian Wang, Ke Liang, Jian Li, Yun-Xiu Zhang, Xiao-Kuang Xue, Tie-Jin Chen, Yong-Liang Hao, Jia-Sheng Wu, Jie-Chao Ge
Photodynamic therapy (PDT) has been emerged as a promising modality for cancer treatment. However, the development of drug delivery system enabling continuous release of photosensitizers (PSs) for long-term PDT treatment still remains challenges. Herein, a H2O2-responsive injectable hydrogel, covalently crosslinked by N1-(4-boronobenzyl)-N3-(4-boronophenyl)-N1,N1,N3,N3-tetramethylpropane-1,3-diaminium (TSPBA) with PVA containing polythiophene quaternary ammonium salt (PT2) polymer dots (PDots) as a photosensitizer was fabricated. Under the stimulation of H2O2, the obtained injectable hydrogel gradually degrades and releases PDots. In vitro experiments suggested that the released PDots could realize efficient tumor cells inhibition through its robust singlet oxygen generation capability upon 577 nm laser irradiation. In vivo studies demonstrated a sustained retention of PDots for at least 7 days following single-dose administration, facilitating efficient tumor inhibition with light treatments for 3 times without apparent biotoxicity. This work presents an innovative polymer dots-based composite local drug delivery system for long-term PDT in cancer treatment.
{"title":"H2O2-Responsive Injectable Polymer Dots Hydrogel for Long-term Photodynamic Therapy of Tumors","authors":"Jian Wang, Ke Liang, Jian Li, Yun-Xiu Zhang, Xiao-Kuang Xue, Tie-Jin Chen, Yong-Liang Hao, Jia-Sheng Wu, Jie-Chao Ge","doi":"10.1007/s10118-024-3155-z","DOIUrl":"10.1007/s10118-024-3155-z","url":null,"abstract":"<div><p>Photodynamic therapy (PDT) has been emerged as a promising modality for cancer treatment. However, the development of drug delivery system enabling continuous release of photosensitizers (PSs) for long-term PDT treatment still remains challenges. Herein, a H<sub>2</sub>O<sub>2</sub>-responsive injectable hydrogel, covalently crosslinked by N<sup>1</sup>-(4-boronobenzyl)-N<sup>3</sup>-(4-boronophenyl)-N<sup>1</sup>,N<sup>1</sup>,N<sup>3</sup>,N<sup>3</sup>-tetramethylpropane-1,3-diaminium (TSPBA) with PVA containing polythiophene quaternary ammonium salt (PT2) polymer dots (PDots) as a photosensitizer was fabricated. Under the stimulation of H<sub>2</sub>O<sub>2</sub>, the obtained injectable hydrogel gradually degrades and releases PDots. <i>In vitro</i> experiments suggested that the released PDots could realize efficient tumor cells inhibition through its robust singlet oxygen generation capability upon 577 nm laser irradiation. <i>In vivo</i> studies demonstrated a sustained retention of PDots for at least 7 days following single-dose administration, facilitating efficient tumor inhibition with light treatments for 3 times without apparent biotoxicity. This work presents an innovative polymer dots-based composite local drug delivery system for long-term PDT in cancer treatment.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 11","pages":"1690 - 1698"},"PeriodicalIF":4.1,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141496239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-26DOI: 10.1007/s10118-024-3153-1
Hui Liu, Rui Hu, Zi-Qing Hu, Xiao-Fan Ji
Supramolecular polymers, as a type of dynamic polymers, are subordinate to the interdisciplinary field of polymer chemistry and supramolecular chemistry, whose development has greatly promoted the prosperity of new materials. Notably, molecular weight is one of the most important parameters of supramolecular polymers, which affects the physical/chemical properties and processing applications of materials. Developing new methods for characterizing the molecular weight of supramolecular polymers is crucial for advancing the development of supramolecular polymers. In this review, we elaborate and summarize three strategies for characterizing the molecular weight of supramolecular polymers that recently reported by our research group according to the characteristics of supramolecular polymers, including (1) the molecular weight distinction corresponding to variable fluorescence colors, (2) matching different molecular weights with different fluorescence lifetime, (3) transforming supramolecular polymers into mechanically interlocked polymers or covalent polymers. Besides, we also discuss the limitations of current methods for characterizing supramolecular polymers. We hope that this review can promote the development of supramolecular polymers and significantly inspire to exploit new methods to characterizing molecular weight of supramolecular polymers.
{"title":"The New Methods for Characterization of Molecular Weight of Supramolecular Polymers","authors":"Hui Liu, Rui Hu, Zi-Qing Hu, Xiao-Fan Ji","doi":"10.1007/s10118-024-3153-1","DOIUrl":"10.1007/s10118-024-3153-1","url":null,"abstract":"<div><p>Supramolecular polymers, as a type of dynamic polymers, are subordinate to the interdisciplinary field of polymer chemistry and supramolecular chemistry, whose development has greatly promoted the prosperity of new materials. Notably, molecular weight is one of the most important parameters of supramolecular polymers, which affects the physical/chemical properties and processing applications of materials. Developing new methods for characterizing the molecular weight of supramolecular polymers is crucial for advancing the development of supramolecular polymers. In this review, we elaborate and summarize three strategies for characterizing the molecular weight of supramolecular polymers that recently reported by our research group according to the characteristics of supramolecular polymers, including (1) the molecular weight distinction corresponding to variable fluorescence colors, (2) matching different molecular weights with different fluorescence lifetime, (3) transforming supramolecular polymers into mechanically interlocked polymers or covalent polymers. Besides, we also discuss the limitations of current methods for characterizing supramolecular polymers. We hope that this review can promote the development of supramolecular polymers and significantly inspire to exploit new methods to characterizing molecular weight of supramolecular polymers.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 10","pages":"1403 - 1413"},"PeriodicalIF":4.1,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the mechanical stability of PP layer, the PP/HDPE double-layer microporous membrane could be prepared at a higher heat-setting temperature than that of PE monolayer membrane. In this work, the effects of heat-setting temperature on the pore structure and properties of PP/HDPE double-layer membrane were studied. With the increase of heat-setting temperature from 120 °C to 130 °C, the length of connecting bridge crystal and crystallinity in the PE layer increase due to the melting of thin lamellae and the stability of connecting bridge structure during heat-setting. The corresponding air permeability, porosity, wettability of liquid electrolyte and mechanical property of the heat-set microporous membrane increase, exhibiting better electrochemical performance. However, when the heat-setting temperature is further increased to 140 °C, higher than the melting point of PE resin, some pores are closed since the lamellae and connecting bridges melt and shrink during heat-setting, resulting in a decrease of air permeability and porosity. In contrast, there is negligible change in the PP layer within the above heat-setting temperature region. This study successfully builds the relationship between the stable pore structure and property of microporous membrane during heat-setting, which is helpful to guide the production of high-performance PP/PE/PP lithium batteries separator.
由于 PP 层的机械稳定性,PP/HDPE 双层微孔膜可以在比 PE 单层膜更高的热固温度下制备。本文研究了热固温度对 PP/HDPE 双层膜孔结构和性能的影响。随着热固温度从 120 °C 升至 130 °C,PE 层中的连接桥晶体长度和结晶度增加,这是由于薄层片熔化以及热固过程中连接桥结构的稳定性所致。相应地,热固微孔膜的透气性、孔隙率、液体电解质的润湿性和机械性能都会增加,从而表现出更好的电化学性能。然而,当热固温度进一步升高到 140 ℃(高于聚乙烯树脂的熔点)时,由于片层和连接桥在热固过程中熔化和收缩,部分孔隙被封闭,导致透气性和孔隙率下降。相反,在上述热固温度区域内,聚丙烯层的变化可以忽略不计。该研究成功地建立了微孔膜在热固过程中稳定的孔结构与性能之间的关系,有助于指导高性能 PP/PE/PP 锂电池隔膜的生产。
{"title":"Influence of Heat-setting Temperature on the Microporous Structure and Properties of PP/HDPE Bilayer Microporous Membranes","authors":"Jie Xie, Yong-Shi Wu, Jia-Yi Xie, Rui-Jie Xu, Cai-Hong Lei, Sai-Nan Song, Guang-Quan Li, An-Ping Huang","doi":"10.1007/s10118-024-3157-x","DOIUrl":"10.1007/s10118-024-3157-x","url":null,"abstract":"<div><p>Due to the mechanical stability of PP layer, the PP/HDPE double-layer microporous membrane could be prepared at a higher heat-setting temperature than that of PE monolayer membrane. In this work, the effects of heat-setting temperature on the pore structure and properties of PP/HDPE double-layer membrane were studied. With the increase of heat-setting temperature from 120 °C to 130 °C, the length of connecting bridge crystal and crystallinity in the PE layer increase due to the melting of thin lamellae and the stability of connecting bridge structure during heat-setting. The corresponding air permeability, porosity, wettability of liquid electrolyte and mechanical property of the heat-set microporous membrane increase, exhibiting better electrochemical performance. However, when the heat-setting temperature is further increased to 140 °C, higher than the melting point of PE resin, some pores are closed since the lamellae and connecting bridges melt and shrink during heat-setting, resulting in a decrease of air permeability and porosity. In contrast, there is negligible change in the PP layer within the above heat-setting temperature region. This study successfully builds the relationship between the stable pore structure and property of microporous membrane during heat-setting, which is helpful to guide the production of high-performance PP/PE/PP lithium batteries separator.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 8","pages":"1243 - 1252"},"PeriodicalIF":4.1,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-26DOI: 10.1007/s10118-024-3146-0
Wen-Jun Feng, Yan-He Wu, Xiao-Yang Liu, Zheng-Ke Wang
Shear-thinning hydrogels have emerged for endoscopic submucosal dissection, while wound intervention after surgery has rarely been mentioned. Herein, a catechol-modified chitosan hydrogel with shear-thinning property was developed for simultaneously facilitating endoscopic submucosal dissection and postoperative wound healing. Benefiting from the shear-thinning and self-healing characteristics, the asprepared hydrogel showed easily endoscopic injectability. It also performed very well as submucosal cushion, which could remain above 70% after injection for 120 min in ex vivo porcine large intestine model. In fact, the cushion height of normal saline dramatically decreased to 46% of the initial height at 30 min. Ag nanoparticles encapsulated into the network endowed the hydrogel with almost reached 100% antibacterial effect against E. coli and S. aureus. The hemolysis ratio of the hydrogel was calculated to be as low as 0.8%. Combined with good hemocompatibility and cytocompatibility, the as-prepared hydrogel displayed much higher in vivo wound closure and healing efficacy than normal saline. These results demonstrated the superiority of the shear-thinning chitosan hydrogel in facilitating clinical endoscopic submucosal dissection surgery.
{"title":"Shear-thinning Catechol-modified Chitosan Hydrogel Loaded with Silver Nanoparticles for Endoscopic Submucosal Dissection","authors":"Wen-Jun Feng, Yan-He Wu, Xiao-Yang Liu, Zheng-Ke Wang","doi":"10.1007/s10118-024-3146-0","DOIUrl":"10.1007/s10118-024-3146-0","url":null,"abstract":"<div><p>Shear-thinning hydrogels have emerged for endoscopic submucosal dissection, while wound intervention after surgery has rarely been mentioned. Herein, a catechol-modified chitosan hydrogel with shear-thinning property was developed for simultaneously facilitating endoscopic submucosal dissection and postoperative wound healing. Benefiting from the shear-thinning and self-healing characteristics, the asprepared hydrogel showed easily endoscopic injectability. It also performed very well as submucosal cushion, which could remain above 70% after injection for 120 min in <i>ex vivo</i> porcine large intestine model. In fact, the cushion height of normal saline dramatically decreased to 46% of the initial height at 30 min. Ag nanoparticles encapsulated into the network endowed the hydrogel with almost reached 100% antibacterial effect against <i>E. coli</i> and <i>S. aureus</i>. The hemolysis ratio of the hydrogel was calculated to be as low as 0.8%. Combined with good hemocompatibility and cytocompatibility, the as-prepared hydrogel displayed much higher <i>in vivo</i> wound closure and healing efficacy than normal saline. These results demonstrated the superiority of the shear-thinning chitosan hydrogel in facilitating clinical endoscopic submucosal dissection surgery.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 8","pages":"1147 - 1155"},"PeriodicalIF":4.1,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141523332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Toughening the petroleum-based epoxy resin blends with bio-based modifiers without compromising their modulus, mechanical strength, and other properties is still a big challenge in view of the sustainability. In this study, a bio-based liquid crystal epoxy resin (THMT-EP) with an s-triazine ring structure was utilized to modify a petroleum-based bisphenol A epoxy resin (E51) with 4,4′-diaminodiphenylsulfone (DDS) as a curing agent, and the blended systems were evaluated for their thermal stability, mechanical properties, and flame retardancy. The results showed that the impact strength of the blended system initially increased and then decreased with the increase in THMT-EP content, and it reached the a maximum value of 26.5 kJ/m2 when the THMT-EP content was 5%, which was 31.2% higher than that of E51/DDS. Notably, the flexural strength, modulus, and glass transition temperature of the blended system were all simultaneously improved with the addition of THMT-EP. At the same time, the addition of THMT-EP enhanced the flame retardancy of the system by increasing the char yield at 700 °C and decreasing the peak heat release rate and total heat release rate. This work paves the way for a more sustainable improvement in the comprehensive performance of epoxy resin.
{"title":"Unleashing the Power of Bio-based Thermotropic Liquid Crystal Modifiers: Toughening and Reinforcing Petroleum-based Epoxy Resin without Compromising Other Properties","authors":"Qing-Yun Lu, Hong-Wei Gu, Jia-Hui Li, Qian-Qian Fan, Bei-Tao Liu, Yan Kou, Xi-Gao Jian, Zhi-Huan Weng","doi":"10.1007/s10118-024-3149-x","DOIUrl":"10.1007/s10118-024-3149-x","url":null,"abstract":"<div><p>Toughening the petroleum-based epoxy resin blends with bio-based modifiers without compromising their modulus, mechanical strength, and other properties is still a big challenge in view of the sustainability. In this study, a bio-based liquid crystal epoxy resin (THMT-EP) with an <i>s</i>-triazine ring structure was utilized to modify a petroleum-based bisphenol A epoxy resin (E51) with 4,4′-diaminodiphenylsulfone (DDS) as a curing agent, and the blended systems were evaluated for their thermal stability, mechanical properties, and flame retardancy. The results showed that the impact strength of the blended system initially increased and then decreased with the increase in THMT-EP content, and it reached the a maximum value of 26.5 kJ/m<sup>2</sup> when the THMT-EP content was 5%, which was 31.2% higher than that of E51/DDS. Notably, the flexural strength, modulus, and glass transition temperature of the blended system were all simultaneously improved with the addition of THMT-EP. At the same time, the addition of THMT-EP enhanced the flame retardancy of the system by increasing the char yield at 700 °C and decreasing the peak heat release rate and total heat release rate. This work paves the way for a more sustainable improvement in the comprehensive performance of epoxy resin.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 8","pages":"1093 - 1102"},"PeriodicalIF":4.1,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141503320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-07DOI: 10.1007/s10118-024-3154-0
Fang-Hua Luo, Zhi-Tao Dong, Guo-Hua Chen, Chen Ma, Huai-Yuan Wang
Janus films with asymmetric physical/chemical properties have attracted considerable attention due to their promising applications in personal thermal management, electronic skins, sensors, actuators, etc. However, traditional methods for fabricating Janus films conventionally need the assistance of an interface or auxiliary equipment, which are usually complex and time-consuming. Herein, flexible poly(vinyl alcohol) (PVA)/graphene oxide (GO)/h-BN (recorded as PVA/GO/h-BN) Janus films with thermally, optically, and electrically anisotropic properties are fabricated by a simple density deposition self-assembly method, which just utilizes the density difference between GO and h-BN during water evaporation. Experimental results show that the two sides of the acquired Janus films have obvious asymmetric characteristics. In the original state of the PVA/GO/h-BN Janus films, the thermal conductivity of the GO side (10.06 W·m−1·K−1) is generally lower than that of the h-BN side (10.48 W·m−1·K−1). But after GO is reduced, the thermal conductivity of the rGO side reaches 12.17 W·m−1·K−1, surpassing that of the h-BN side. In addition, the relative reflectance of the h-BN side of Janus film is also significantly higher than that of the rGO side, and the surface resistance difference between the two sides is about 4 orders of magnitude. The prepared PVA/GO/h-BN Janus films show great application potential in human thermal management, light conversion switches, and electronic skins. This study provides a simple and versatile strategy for fabricating Janus films with multifunctional (such as thermal, optical, and electrical) anisotropies.
{"title":"Preparation of PVA/GO/h-BN Janus Film with High Thermal Conductivity and Excellent Flexibility via a Density Deposition Self-assembly Method","authors":"Fang-Hua Luo, Zhi-Tao Dong, Guo-Hua Chen, Chen Ma, Huai-Yuan Wang","doi":"10.1007/s10118-024-3154-0","DOIUrl":"10.1007/s10118-024-3154-0","url":null,"abstract":"<div><p>Janus films with asymmetric physical/chemical properties have attracted considerable attention due to their promising applications in personal thermal management, electronic skins, sensors, actuators, etc. However, traditional methods for fabricating Janus films conventionally need the assistance of an interface or auxiliary equipment, which are usually complex and time-consuming. Herein, flexible poly(vinyl alcohol) (PVA)/graphene oxide (GO)/h-BN (recorded as PVA/GO/h-BN) Janus films with thermally, optically, and electrically anisotropic properties are fabricated by a simple density deposition self-assembly method, which just utilizes the density difference between GO and h-BN during water evaporation. Experimental results show that the two sides of the acquired Janus films have obvious asymmetric characteristics. In the original state of the PVA/GO/h-BN Janus films, the thermal conductivity of the GO side (10.06 W·m<sup>−1</sup>·K<sup>−1</sup>) is generally lower than that of the h-BN side (10.48 W·m<sup>−1</sup>·K<sup>−1</sup>). But after GO is reduced, the thermal conductivity of the rGO side reaches 12.17 W·m<sup>−1</sup>·K<sup>−1</sup>, surpassing that of the h-BN side. In addition, the relative reflectance of the h-BN side of Janus film is also significantly higher than that of the rGO side, and the surface resistance difference between the two sides is about 4 orders of magnitude. The prepared PVA/GO/h-BN Janus films show great application potential in human thermal management, light conversion switches, and electronic skins. This study provides a simple and versatile strategy for fabricating Janus films with multifunctional (such as thermal, optical, and electrical) anisotropies.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 8","pages":"1217 - 1226"},"PeriodicalIF":4.1,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141371110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polyelectrolyte (PE) gels, distinguished by their unique stimuli-responsive swelling behavior, serve as the basis of broad applications, such as artificial muscles and drug delivery. In this work, we present a theoretical model to analyze the electrostatics and its contribution to the swelling behavior of PE gels in salt solutions. By minimizing the free energy of PE gels, we obtain two distinct scaling regimes for the swelling ratio at equilibrium with respect to the salt concentration. We compare our predictions for the swelling ratio with experimental measurements, which show excellent agreement. In addition, we employ a finite element method to assess the applicability range of our theoretical model and assumptions. We anticipate that our model will also provide valuable insights into drug adsorption and release, deformation of red blood cells, 4D printing and soft robotics, where the underlying mechanism of swelling remains enigmatic.
{"title":"Swelling of Spherical Polyelectrolyte Gels","authors":"Ming-Yu Duan, Jia-Dong Chen, Yi-Ming Liu, Zhao-Feng Peng, Guang Chen","doi":"10.1007/s10118-024-3152-2","DOIUrl":"10.1007/s10118-024-3152-2","url":null,"abstract":"<div><p>Polyelectrolyte (PE) gels, distinguished by their unique stimuli-responsive swelling behavior, serve as the basis of broad applications, such as artificial muscles and drug delivery. In this work, we present a theoretical model to analyze the electrostatics and its contribution to the swelling behavior of PE gels in salt solutions. By minimizing the free energy of PE gels, we obtain two distinct scaling regimes for the swelling ratio at equilibrium with respect to the salt concentration. We compare our predictions for the swelling ratio with experimental measurements, which show excellent agreement. In addition, we employ a finite element method to assess the applicability range of our theoretical model and assumptions. We anticipate that our model will also provide valuable insights into drug adsorption and release, deformation of red blood cells, 4D printing and soft robotics, where the underlying mechanism of swelling remains enigmatic.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 9","pages":"1386 - 1392"},"PeriodicalIF":4.1,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141379356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-06DOI: 10.1007/s10118-024-3145-1
Yuan-Xin Zhou, Xian Kong
Salt-doped block copolymers have widespread applications in batteries, fuel cells, semiconductors, and various industries, where their properties crucially depend on phase separation behavior. Traditionally, investigations into salt-doped diblock copolymers have predominantly focused on microphase separation, overlooking the segregation between ionic and polymeric species. This study employs weak segregation theory to explore the interplay between phase separation dominated by the polymer-modulated mode and the salt-out-modulated mode, corresponding to microscopic and macroscopic phase separations, respectively. By comparing diblock copolymers doped with salts to those doped with neutral solvents, we elucidate the significant role of charged species in modulating phase behavior. The phase separation mode exhibits a transition between the polymer-modulated and salt-out-modulated modes at different wavenumbers. In systems doped with neutral solvents, this transition is stepwise, while in salt-ion-doped systems, it is continuous. With a sufficiently large Flory-Huggins parameter between ions and polymers, the salt-out-modulated mode becomes dominant, promoting macrophase separation. Due to the solvation effect of salt ions, salt-doped systems are more inclined to undergo microphase separation. Furthermore, we explore factors influencing the critical wavenumber of phase separation, including doping level and the Flory-Huggins parameters between two blocks and between ions and polymeric species. Our findings reveal that in a neutral solvent environment, these factors alter only the boundary between micro- and macro-phase separations, leaving the critical wavenumber unchanged in microphase separation cases. However, in a salt-doped environment, the critical wavenumber of microphase separation varies with these parameters. This provides valuable insights into the pivotal role of electrostatics in the phase separation of salt-doped block copolymers.
{"title":"Competition of Composition Fluctuation Modes in Weakly Segregated Salt-doped Symmetric Diblock Copolymers","authors":"Yuan-Xin Zhou, Xian Kong","doi":"10.1007/s10118-024-3145-1","DOIUrl":"10.1007/s10118-024-3145-1","url":null,"abstract":"<div><p>Salt-doped block copolymers have widespread applications in batteries, fuel cells, semiconductors, and various industries, where their properties crucially depend on phase separation behavior. Traditionally, investigations into salt-doped diblock copolymers have predominantly focused on microphase separation, overlooking the segregation between ionic and polymeric species. This study employs weak segregation theory to explore the interplay between phase separation dominated by the polymer-modulated mode and the salt-out-modulated mode, corresponding to microscopic and macroscopic phase separations, respectively. By comparing diblock copolymers doped with salts to those doped with neutral solvents, we elucidate the significant role of charged species in modulating phase behavior. The phase separation mode exhibits a transition between the polymer-modulated and salt-out-modulated modes at different wavenumbers. In systems doped with neutral solvents, this transition is stepwise, while in salt-ion-doped systems, it is continuous. With a sufficiently large Flory-Huggins parameter between ions and polymers, the salt-out-modulated mode becomes dominant, promoting macrophase separation. Due to the solvation effect of salt ions, salt-doped systems are more inclined to undergo microphase separation. Furthermore, we explore factors influencing the critical wavenumber of phase separation, including doping level and the Flory-Huggins parameters between two blocks and between ions and polymeric species. Our findings reveal that in a neutral solvent environment, these factors alter only the boundary between micro- and macro-phase separations, leaving the critical wavenumber unchanged in microphase separation cases. However, in a salt-doped environment, the critical wavenumber of microphase separation varies with these parameters. This provides valuable insights into the pivotal role of electrostatics in the phase separation of salt-doped block copolymers.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 9","pages":"1375 - 1385"},"PeriodicalIF":4.1,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141377372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-05DOI: 10.1007/s10118-024-3151-3
Qi Liao
We present the results of molecular dynamics simulations of steady shear between a pair of neutral polymer brushes, as well as a pair of charged polymer brushes in the strongly compressed regime. The results of the molecular dynamic simulations of neutral and polyelectrolyte brushes in implicit solvent including normal forces, shear forces, viscosities and friction coefficients as a function of separation between brushes, are presented in the study. The comparison of the simulation results of neutral and charged brushes shows that the charged brushes is in the quasi-neutral regime, and the dependence of viscosity on the separation distance show the similar power law of neutral brushes. Our simulation results confirm that the implicit solvent simulations of polyelectrolyte brushes that ignore hydrodynamics interaction are in agreement with the scaling predictions qualitatively because of screening of hydrodynamic interaction and long-range electrostatic interactions on the correlation length scale. Both of neutral and charged brushes show the lubrication properties that the friction coefficient decreases with the separation decreases at enough large loads. However, a maximum of friction coefficients is observed for polyelectrolyte brushes, which is in contrast to the neutral brushes with monotonical dependence.
{"title":"Friction between Strongly Compressed Polymer Brushes","authors":"Qi Liao","doi":"10.1007/s10118-024-3151-3","DOIUrl":"10.1007/s10118-024-3151-3","url":null,"abstract":"<div><p>We present the results of molecular dynamics simulations of steady shear between a pair of neutral polymer brushes, as well as a pair of charged polymer brushes in the strongly compressed regime. The results of the molecular dynamic simulations of neutral and polyelectrolyte brushes in implicit solvent including normal forces, shear forces, viscosities and friction coefficients as a function of separation between brushes, are presented in the study. The comparison of the simulation results of neutral and charged brushes shows that the charged brushes is in the quasi-neutral regime, and the dependence of viscosity on the separation distance show the similar power law of neutral brushes. Our simulation results confirm that the implicit solvent simulations of polyelectrolyte brushes that ignore hydrodynamics interaction are in agreement with the scaling predictions qualitatively because of screening of hydrodynamic interaction and long-range electrostatic interactions on the correlation length scale. Both of neutral and charged brushes show the lubrication properties that the friction coefficient decreases with the separation decreases at enough large loads. However, a maximum of friction coefficients is observed for polyelectrolyte brushes, which is in contrast to the neutral brushes with monotonical dependence.</p></div>","PeriodicalId":517,"journal":{"name":"Chinese Journal of Polymer Science","volume":"42 9","pages":"1368 - 1374"},"PeriodicalIF":4.1,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141386191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}