Marek Nemec, Stefanie B. Hauser, Daniel Rentsch, Gabriel M. Pagotti João, Lilli C. Kuerten, Nour Adilien, Lukas Huber, Ana Stojanovic, Wim J. Malfait* and Matthias M. Koebel*,
Functional silanes are multifaceted cross-linkers, compatibilizers, coupling agents, and surface modifiers. Herein, we present organofunctional polysiloxane building blocks that offer great versatility in terms of molecular weight, degree of condensation, and the choice and loading of organic substituent groups. The organofunctional polyethoxysilanes (funPEOS) are prepared in a one-pot, two-step process: synthesis of the PEOS carrier/substrate, followed by grafting a functional silane “shell”, both based on condensation with acetic anhydride. The reaction was optimized at the lab scale and scaled up to a 7 L reactor. The acetylation, condensation, and hyperbranched structure of the carrier were confirmed by 29Si NMR, while 29Si–29Si 2D INADEQUATE NMR provides strong evidence for the grafting of functional silanes onto the carrier (Q–T coupling). IR, 1H, and 13C NMR spectroscopy demonstrate that the functional groups remain intact. The molar mass can be tailored by stoichiometric control of the acetic anhydride to silane monomer ratio (Mn 3500–20,000 g/mol). The compounds are stable organic liquids with a long shelf life. Selected applications are presented: scratch-resistant coatings with water contact angles of ∼90°, stable water emulsions, and surfactant-free, mesoporous silica foams.
{"title":"Hyperbranched, Functional Polyethoxysiloxanes: Tunable Molecular Building Blocks","authors":"Marek Nemec, Stefanie B. Hauser, Daniel Rentsch, Gabriel M. Pagotti João, Lilli C. Kuerten, Nour Adilien, Lukas Huber, Ana Stojanovic, Wim J. Malfait* and Matthias M. Koebel*, ","doi":"10.1021/acsapm.4c00758","DOIUrl":"10.1021/acsapm.4c00758","url":null,"abstract":"<p >Functional silanes are multifaceted cross-linkers, compatibilizers, coupling agents, and surface modifiers. Herein, we present organofunctional polysiloxane building blocks that offer great versatility in terms of molecular weight, degree of condensation, and the choice and loading of organic substituent groups. The organofunctional polyethoxysilanes (funPEOS) are prepared in a one-pot, two-step process: synthesis of the PEOS carrier/substrate, followed by grafting a functional silane “shell”, both based on condensation with acetic anhydride. The reaction was optimized at the lab scale and scaled up to a 7 L reactor. The acetylation, condensation, and hyperbranched structure of the carrier were confirmed by <sup>29</sup>Si NMR, while <sup>29</sup>Si–<sup>29</sup>Si 2D INADEQUATE NMR provides strong evidence for the grafting of functional silanes onto the carrier (Q–T coupling). IR, <sup>1</sup>H, and <sup>13</sup>C NMR spectroscopy demonstrate that the functional groups remain intact. The molar mass can be tailored by stoichiometric control of the acetic anhydride to silane monomer ratio (<i>M</i><sub><i>n</i></sub> 3500–20,000 g/mol). The compounds are stable organic liquids with a long shelf life. Selected applications are presented: scratch-resistant coatings with water contact angles of ∼90°, stable water emulsions, and surfactant-free, mesoporous silica foams.</p>","PeriodicalId":7,"journal":{"name":"ACS Applied Polymer Materials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsapm.4c00758","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141344281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dacheng Li, Liangdong Ye, Hongbo Liu, Dongming Chen, Qiaoyan Wei, Xianhui Zhang, Ziwei Li* and Shaorong Lu*,
Despite the potential of polylactic acid (PLA) as a biodegradable polymer, widespread applications have been limited by its inherent flammability and brittleness. To overcome these issues, PLA was combined with a composite-reinforced flame-retardant filler (A-MBC/PA/A-TiO2) consisting of γ-aminopropyl triethoxysilane (APTES)-grafted microcrystalline bagasse cellulose (A-MBC), phytic acid (PA), and APTES-silylated titanium dioxide nanoparticles (A-TiO2). When 10 wt % A-MBC/PA/A-TiO2 was incorporated, the tensile and impact strengths of the PLA composite increased by 15 and 22%, respectively, relative to those of pristine PLA. The addition of 10 wt % A-MBC/PA/A-TiO2 resulted in PLA composites with a UL-94 V-0 rating and a high limiting oxygen index of 29% owing to a synergistic flame-retardant mechanism in the gas and condensed phases. The presence of A-MBC/PA/A-TiO2 contributed to the formation of a solid carbon layer containing P and Ti in the condensed phase as well as the release of PO· free radicals and N-containing noncombustible gases in the gas phase, which reduced the flammable gas and oxygen concentrations, thus providing a synergistic flame-retardant effect. In addition, molecular dynamics simulations of the PLA/(A-MBC/PA/A-TiO2) composite system were performed. The numerical and analytical results showed that A-MBC and A-TiO2 in the filler interacted strongly with the PLA matrix, which was beneficial for distributing the flame retardant in PLA and improving its mechanical and flame-retardant properties. This work demonstrates a strategy for simultaneously improving the flame retardancy and mechanical properties of PLA composites using a biobased composite flame retardant.
尽管聚乳酸(PLA)作为一种可生物降解的聚合物潜力巨大,但其固有的易燃性和脆性限制了其广泛应用。为了克服这些问题,我们将聚乳酸与由γ-氨基丙基三乙氧基硅烷(APTES)接枝的微晶甘蔗渣纤维素(A-MPC)、植酸(PA)和APTES硅烷化二氧化钛纳米颗粒(A-TiO2)组成的复合增强阻燃填料(A-MPC/PA/A-TiO2)结合在一起。当加入 10 wt % 的 A-MBC/PA/A-TiO2 时,聚乳酸复合材料的拉伸强度和冲击强度比原始聚乳酸分别提高了 15% 和 22%。加入 10 wt % A-MBC/PA/A-TiO2 后,由于气相和凝结相中的协同阻燃机制,聚乳酸复合材料达到了 UL-94 V-0 级,极限氧指数高达 29%。A-MBC/PA/A-TiO2 的存在有助于在凝聚相中形成含 P 和 Ti 的固态碳层,并在气相中释放出 PO 自由基和含 N 的不可燃气体,从而降低了可燃气体和氧气的浓度,因此产生了协同阻燃效果。此外,还对聚乳酸/(A-MBC/PA/A-TiO2)复合体系进行了分子动力学模拟。数值和分析结果表明,填料中的 A-MBC 和 A-TiO2 与聚乳酸基体相互作用强烈,有利于阻燃剂在聚乳酸中的分布,并改善其机械和阻燃性能。这项工作展示了一种利用生物基复合阻燃剂同时提高聚乳酸复合材料阻燃性和机械性能的策略。
{"title":"Enhanced Flame Retardancy and Mechanical Properties of Polylactic Acid Composites with Phytate-Chelated Nanotitanium Dioxide-Modified Bagasse Cellulose","authors":"Dacheng Li, Liangdong Ye, Hongbo Liu, Dongming Chen, Qiaoyan Wei, Xianhui Zhang, Ziwei Li* and Shaorong Lu*, ","doi":"10.1021/acsapm.4c00340","DOIUrl":"10.1021/acsapm.4c00340","url":null,"abstract":"<p >Despite the potential of polylactic acid (PLA) as a biodegradable polymer, widespread applications have been limited by its inherent flammability and brittleness. To overcome these issues, PLA was combined with a composite-reinforced flame-retardant filler (A-MBC/PA/A-TiO<sub>2</sub>) consisting of γ-aminopropyl triethoxysilane (APTES)-grafted microcrystalline bagasse cellulose (A-MBC), phytic acid (PA), and APTES-silylated titanium dioxide nanoparticles (A-TiO<sub>2</sub>). When 10 wt % A-MBC/PA/A-TiO<sub>2</sub> was incorporated, the tensile and impact strengths of the PLA composite increased by 15 and 22%, respectively, relative to those of pristine PLA. The addition of 10 wt % A-MBC/PA/A-TiO<sub>2</sub> resulted in PLA composites with a UL-94 V-0 rating and a high limiting oxygen index of 29% owing to a synergistic flame-retardant mechanism in the gas and condensed phases. The presence of A-MBC/PA/A-TiO<sub>2</sub> contributed to the formation of a solid carbon layer containing P and Ti in the condensed phase as well as the release of PO· free radicals and N-containing noncombustible gases in the gas phase, which reduced the flammable gas and oxygen concentrations, thus providing a synergistic flame-retardant effect. In addition, molecular dynamics simulations of the PLA/(A-MBC/PA/A-TiO<sub>2</sub>) composite system were performed. The numerical and analytical results showed that A-MBC and A-TiO<sub>2</sub> in the filler interacted strongly with the PLA matrix, which was beneficial for distributing the flame retardant in PLA and improving its mechanical and flame-retardant properties. This work demonstrates a strategy for simultaneously improving the flame retardancy and mechanical properties of PLA composites using a biobased composite flame retardant.</p>","PeriodicalId":7,"journal":{"name":"ACS Applied Polymer Materials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141338395","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}
Lipid accumulation is a prominent pathologic feature of nonalcoholic fatty liver disease (NAFLD), which is due to imbalances in triglycerides metabolism. However, none of the available therapeutic strategies have been able to achieve the effective removal of triglycerides from the lesion site. Herein, MIP@QUE, a mimetic transporter with a high affinity for triglycerides, was synthesized using molecular imprinting. The physicochemical features of MIP@QUE are such that it binds to triglycerides and releases the drug in an affinity-driven reaction. In vivo and in vitro experiments showed that the metabolism of triglycerides was promoted by dual activation of the autophagy-lysosomal pathway through the size effect of the molecularly imprinted polymer (MIP) and the pharmacological action of quercetin (QUE). Moreover, MIP@QUE not only reduced triglyceride accumulation to reverse hepatic steatosis but also effectively lowered the level of oxidative stress to reduce hepatocellular damage. Targeting the key causative factors of NAFLD, MIP@QUE offers an effective therapeutic strategy to control the disease process by promoting the lysosomal transport and metabolism of triglycerides in hepatocytes; it also serves as a platform for the treatment of triglyceride-related metabolic syndrome.
{"title":"Triglyceride-Targeted Molecularly Imprinted Polymers Activate Lipophagy via Cargo Exchange for Nonalcoholic Fatty Liver Disease Treatment","authors":"Yilin Wen, Ping Weng, Yueyue Li, Liming Yang, Chengju Li, Qingyang Chen, Yanni He, Wanping Zhang, Hui Hu, Zhiyi Yuan* and Chao Yu*, ","doi":"10.1021/acsapm.4c01222","DOIUrl":"10.1021/acsapm.4c01222","url":null,"abstract":"<p >Lipid accumulation is a prominent pathologic feature of nonalcoholic fatty liver disease (NAFLD), which is due to imbalances in triglycerides metabolism. However, none of the available therapeutic strategies have been able to achieve the effective removal of triglycerides from the lesion site. Herein, MIP@QUE, a mimetic transporter with a high affinity for triglycerides, was synthesized using molecular imprinting. The physicochemical features of MIP@QUE are such that it binds to triglycerides and releases the drug in an affinity-driven reaction. <i>In vivo</i> and <i>in vitro</i> experiments showed that the metabolism of triglycerides was promoted by dual activation of the autophagy-lysosomal pathway through the size effect of the molecularly imprinted polymer (MIP) and the pharmacological action of quercetin (QUE). Moreover, MIP@QUE not only reduced triglyceride accumulation to reverse hepatic steatosis but also effectively lowered the level of oxidative stress to reduce hepatocellular damage. Targeting the key causative factors of NAFLD, MIP@QUE offers an effective therapeutic strategy to control the disease process by promoting the lysosomal transport and metabolism of triglycerides in hepatocytes; it also serves as a platform for the treatment of triglyceride-related metabolic syndrome.</p>","PeriodicalId":7,"journal":{"name":"ACS Applied Polymer Materials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141338304","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}
Conductive polymer composites with a segregated structure have been developed for flexible piezoresistive sensors, but segregated composites usually suffer from the problem of poor interfacial bonding. In this work, ethylene-vinyl acetate copolymer (EVA)/carbon nanotube (CNT)/hydroxylated carbon nanotube (CNT-OH) composites with segregated structures were prepared by ball-milled coating and the following hot-press molding, in which dynamic boron-centered three-dimensional cross-linking networks were constructed in EVA granules. The interfacial bonding was significantly improved by molecular bridges at the interface based on thermo-activated transesterification between CNT-OH and EVA vitrimer granules. As a result, the composites with the ratio of CNT to CNT-OH of 3:1 showed a superior elongation-at-break of 563.69%, strength of 12.6 MPa, and conductivity of 13.6 S/m. Furthermore, a 3D porous structure was constructed in the EVA composites by supercritical carbon dioxide foaming. Benefiting from the segregated conductive structure and strong interfacial bonding, the segregated conductive EVA foams exhibited an excellent piezoresistive sensing sensitivity with a GF of −23.6 and compression stability. It provided an approach for interface strengthening of segregated conductive polymer composites, and the resulting conductive foams exhibited great potential for the application as a flexible piezoresistive sensor.
目前已开发出具有离析结构的导电聚合物复合材料,可用于柔性压阻传感器,但离析复合材料通常存在界面结合力差的问题。本研究通过球磨涂覆和热压成型制备了具有离析结构的乙烯-醋酸乙烯共聚物(EVA)/碳纳米管(CNT)/羟基碳纳米管(CNT-OH)复合材料,在 EVA 颗粒中构建了以硼为中心的动态三维交联网络。基于 CNT-OH 和 EVA 维聚物颗粒之间热激活的酯交换反应,界面上的分子桥显著改善了界面粘合。结果,CNT 与 CNT-OH 的比例为 3:1,复合材料的断裂伸长率达到 563.69%,强度达到 12.6 兆帕,导电率达到 13.6 S/m。此外,还通过超临界二氧化碳发泡在 EVA 复合材料中构建了三维多孔结构。得益于离析导电结构和强大的界面结合力,离析导电 EVA 泡沫表现出卓越的压阻传感灵敏度(GF 为 -23.6)和压缩稳定性。该研究为离析导电聚合物复合材料的界面强化提供了一种方法,所制备的导电泡沫在用作柔性压阻传感器方面具有巨大潜力。
{"title":"Enhanced Interface Bonding of Segregated Conductive Elastomeric Foams by Dynamic Cross-Linking Reshuffling: Toward Highly Sensitive Piezoresistive Sensors","authors":"Lihong Geng, Yufeng Liu, Pinchuan Ma, Jianming Wu, Xin Chen, Chunlin Deng* and Xiangfang Peng*, ","doi":"10.1021/acsapm.4c01083","DOIUrl":"10.1021/acsapm.4c01083","url":null,"abstract":"<p >Conductive polymer composites with a segregated structure have been developed for flexible piezoresistive sensors, but segregated composites usually suffer from the problem of poor interfacial bonding. In this work, ethylene-vinyl acetate copolymer (EVA)/carbon nanotube (CNT)/hydroxylated carbon nanotube (CNT-OH) composites with segregated structures were prepared by ball-milled coating and the following hot-press molding, in which dynamic boron-centered three-dimensional cross-linking networks were constructed in EVA granules. The interfacial bonding was significantly improved by molecular bridges at the interface based on thermo-activated transesterification between CNT-OH and EVA vitrimer granules. As a result, the composites with the ratio of CNT to CNT-OH of 3:1 showed a superior elongation-at-break of 563.69%, strength of 12.6 MPa, and conductivity of 13.6 S/m. Furthermore, a 3D porous structure was constructed in the EVA composites by supercritical carbon dioxide foaming. Benefiting from the segregated conductive structure and strong interfacial bonding, the segregated conductive EVA foams exhibited an excellent piezoresistive sensing sensitivity with a GF of −23.6 and compression stability. It provided an approach for interface strengthening of segregated conductive polymer composites, and the resulting conductive foams exhibited great potential for the application as a flexible piezoresistive sensor.</p>","PeriodicalId":7,"journal":{"name":"ACS Applied Polymer Materials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141344948","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}
Yi Li, Siyang Wang, Tianyu Wu*, Xiaoyu Meng and Hai-Mu Ye*,
Self-nucleation behavior is a critical phenomenon in polymer crystallization, and the impact of the chemical structure on this behavior has been extensively investigated. However, the underlying mechanism has not been fully elucidated. In this study, the self-nucleation behavior of a series of polyolefins with varying degrees of fluorine substitutions is comprehensively surveyed. Incorporation of fluorine atoms, which increase the polarity of polyolefin chains, considerably improves the self-nucleation ability, resulting in an apparent expansion of the temperature widths of Domain II for poly(vinyl fluoride) and poly(vinylidene fluoride) in comparison with polyethylene. However, further fluorine substitution diminishes the self-nucleation ability of fluoropolyolefins. Then, the correlation between the self-nucleation ability and dielectric constant is studied. It is found that the width of Domain IIb increases monotonously with respect to dielectric constant, expect for poly(vinylidene fluoride) which exhibits a slightly narrow Domain IIb than poly(vinyl fluoride). However, a rather wide Domain IIa appears in poly(vinylidene fluoride). Based on the intermolecular interactions, a correlation between the width of Domain II and the dielectric constant is reasonably established. Further, Fourier transformation infrared spectroscopy directly reveals that the hydrogen-bonding interactions between C–F and C–H are the essential reason for the self-nucleation behavior of fluoropolyolefins. However, in combination with the intriguing disappearance of self-nucleation behavior for the ethylene–tetrafluoroethylene alternating copolymer, the isomer of poly(vinylidene fluoride), and ethylene–chlorotrifluoroethylene alternating copolymer, it is unveiled that the possible scattering, isolated F···H–C hydrogen bonds in fluoropolyolefin are not a sufficient condition for endowing self-nucleation behavior. Thus, an interacting mechanism of long-range continuous structure of hydrogen bond is speculated for the display of the self-nucleation ability of fluoropolyolefins. This work deepens the understanding of self-nucleation crystallization in fluoropolyolefins and provides guidance for the melt processing.
自核行为是聚合物结晶中的一个关键现象,化学结构对这种行为的影响已得到广泛研究。然而,其内在机理尚未完全阐明。本研究全面考察了一系列氟取代程度不同的聚烯烃的自核行为。氟原子的加入增加了聚烯烃链的极性,从而大大提高了自核能力,与聚乙烯相比,聚(氟乙烯)和聚(偏氟乙烯)的域 II 温度宽度明显扩大。然而,氟的进一步取代会降低含氟聚烯烃的自成核能力。然后,研究了自核能力与介电常数之间的相关性。研究发现,畴 IIb 的宽度随介电常数的增加而单调增加,但聚(偏氟乙烯)的畴 IIb 比聚(氟乙烯)略窄。然而,在聚(偏氟乙烯)中却出现了相当宽的领域 IIa。根据分子间的相互作用,可以合理地确定域 II 宽度与介电常数之间的相关性。此外,傅立叶变换红外光谱直接揭示了 C-F 和 C-H 之间的氢键相互作用是氟聚烯烃自核行为的根本原因。然而,结合乙烯-四氟乙烯交替共聚物、聚偏氟乙烯异构体和乙烯-氯三氟乙烯交替共聚物自核行为消失的现象,揭示了氟聚烯烃中可能存在的散射、孤立的 F-H-C 氢键并不是赋予自核行为的充分条件。因此,推测氢键长程连续结构的相互作用机制是氟聚烯烃显示自核能力的关键。这项工作加深了人们对氟聚烯烃自核结晶的理解,为熔融加工提供了指导。
{"title":"Self-Nucleation Ability and Intermolecular Interactions Mechanism in Fluoropolyolefins","authors":"Yi Li, Siyang Wang, Tianyu Wu*, Xiaoyu Meng and Hai-Mu Ye*, ","doi":"10.1021/acsapm.4c00860","DOIUrl":"10.1021/acsapm.4c00860","url":null,"abstract":"<p >Self-nucleation behavior is a critical phenomenon in polymer crystallization, and the impact of the chemical structure on this behavior has been extensively investigated. However, the underlying mechanism has not been fully elucidated. In this study, the self-nucleation behavior of a series of polyolefins with varying degrees of fluorine substitutions is comprehensively surveyed. Incorporation of fluorine atoms, which increase the polarity of polyolefin chains, considerably improves the self-nucleation ability, resulting in an apparent expansion of the temperature widths of Domain II for poly(vinyl fluoride) and poly(vinylidene fluoride) in comparison with polyethylene. However, further fluorine substitution diminishes the self-nucleation ability of fluoropolyolefins. Then, the correlation between the self-nucleation ability and dielectric constant is studied. It is found that the width of Domain IIb increases monotonously with respect to dielectric constant, expect for poly(vinylidene fluoride) which exhibits a slightly narrow Domain IIb than poly(vinyl fluoride). However, a rather wide Domain IIa appears in poly(vinylidene fluoride). Based on the intermolecular interactions, a correlation between the width of Domain II and the dielectric constant is reasonably established. Further, Fourier transformation infrared spectroscopy directly reveals that the hydrogen-bonding interactions between C–F and C–H are the essential reason for the self-nucleation behavior of fluoropolyolefins. However, in combination with the intriguing disappearance of self-nucleation behavior for the ethylene–tetrafluoroethylene alternating copolymer, the isomer of poly(vinylidene fluoride), and ethylene–chlorotrifluoroethylene alternating copolymer, it is unveiled that the possible scattering, isolated F···H–C hydrogen bonds in fluoropolyolefin are not a sufficient condition for endowing self-nucleation behavior. Thus, an interacting mechanism of long-range continuous structure of hydrogen bond is speculated for the display of the self-nucleation ability of fluoropolyolefins. This work deepens the understanding of self-nucleation crystallization in fluoropolyolefins and provides guidance for the melt processing.</p>","PeriodicalId":7,"journal":{"name":"ACS Applied Polymer Materials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141344579","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}
Moirangthem Anita Chanu, Laxmi Raman Adil and Parameswar Krishnan Iyer*,
Pendimethalin (PDM) is a chemically synthesized herbicide and is primarily employed to control broadleaf weeds and woody plants. It enters our environment from production industries and from human activity in farming. Pendimethalin residues in edible foodstuffs and water sources are a serious worldwide problem as they are linked to various health issues. As such, there is an urgent need for the construction of a portable point-of-care (PoC) testing device for the detection of pendimethalin residues from food and vegetables before being consumed. Considering this challenge, an aggregation-induced enhance emission (AIEE) polymer PF2CN is developed by modifying the conjugated backbone of polyfluorene-based polymer PFP. The insertion of an M2CN monomer into the conjugated backbone of PF2CN plays a key role in tuning the photophysical property of the PF2CN polymer where it shows AIEE activity with red-shifted emission. Further, the PF2CN polymer shows remarkable sensitivity and selectivity toward PDM with a limit of detection (LOD) of 2.8 nM, which is much less than the standard maximum residual limits for pesticides in food. Notably, the simultaneous occurrence of PET and FRET serves as a “receptor-free” selective sensor for PDM. Furthermore, the designed PF2CN conjugated polymer-based PDM detection process is miniaturized into a prototype smartphone device, thereby providing a rapid and practical solution for on-site toxic analyte detection, thereby providing higher environmental safety and protection.
{"title":"Receptor-Free AIEE-Conjugated Polymer Nanoparticle-Based PoC Device for Amplified Detection of Pendimethalin","authors":"Moirangthem Anita Chanu, Laxmi Raman Adil and Parameswar Krishnan Iyer*, ","doi":"10.1021/acsapm.4c00546","DOIUrl":"10.1021/acsapm.4c00546","url":null,"abstract":"<p >Pendimethalin (PDM) is a chemically synthesized herbicide and is primarily employed to control broadleaf weeds and woody plants. It enters our environment from production industries and from human activity in farming. Pendimethalin residues in edible foodstuffs and water sources are a serious worldwide problem as they are linked to various health issues. As such, there is an urgent need for the construction of a portable point-of-care (PoC) testing device for the detection of pendimethalin residues from food and vegetables before being consumed. Considering this challenge, an aggregation-induced enhance emission (AIEE) polymer PF2CN is developed by modifying the conjugated backbone of polyfluorene-based polymer PFP. The insertion of an M2CN monomer into the conjugated backbone of PF2CN plays a key role in tuning the photophysical property of the PF2CN polymer where it shows AIEE activity with red-shifted emission. Further, the PF2CN polymer shows remarkable sensitivity and selectivity toward PDM with a limit of detection (LOD) of 2.8 nM, which is much less than the standard maximum residual limits for pesticides in food. Notably, the simultaneous occurrence of PET and FRET serves as a “receptor-free” selective sensor for PDM. Furthermore, the designed PF2CN conjugated polymer-based PDM detection process is miniaturized into a prototype smartphone device, thereby providing a rapid and practical solution for on-site toxic analyte detection, thereby providing higher environmental safety and protection.</p>","PeriodicalId":7,"journal":{"name":"ACS Applied Polymer Materials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141340397","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}
Thomas J. Kolibaba*, Benjamin W. Caplins, Callie I. Higgins, Elisabeth Mansfield, Samantha L. Miller, Caleb Chandler and Jason P. Killgore*,
Polyelectrolyte complexes (PECs) have wide ranging applications spanning medicine, fire safety, and electronic materials. For years, PECs presented processing challenges owing to their ionic bonds, which limited them to use as coatings. Chemistry was recently developed to additively manufacture PECs of polyethylenimine and poly(methacrylic acid) through vat photopolymerization, but the use of solvent compromised the mechanical properties and vat stability of the parts. Here, two reactive diluents, hydroxyethyl methacrylate and dimethyl acrylamide, are substituted for the solvent used in prior work on printable PEC resins. Parts printed with these reactive diluents have nearly identical processing parameters but exhibit significantly increased storage modulus, especially at elevated temperatures, when compared to that of the control resin. Thermally driven amidization of the carboxylate and ammonium groups yields further control over the properties of the parts. The combination of spatial, thermomechanical, and hydrophilic control promises to dramatically expand the application space of polyelectrolyte materials.
{"title":"Tailoring Properties of 3D-Printable Polyelectrolyte Photopolymer Complexes with Reactive Diluents","authors":"Thomas J. Kolibaba*, Benjamin W. Caplins, Callie I. Higgins, Elisabeth Mansfield, Samantha L. Miller, Caleb Chandler and Jason P. Killgore*, ","doi":"10.1021/acsapm.4c00441","DOIUrl":"10.1021/acsapm.4c00441","url":null,"abstract":"<p >Polyelectrolyte complexes (PECs) have wide ranging applications spanning medicine, fire safety, and electronic materials. For years, PECs presented processing challenges owing to their ionic bonds, which limited them to use as coatings. Chemistry was recently developed to additively manufacture PECs of polyethylenimine and poly(methacrylic acid) through vat photopolymerization, but the use of solvent compromised the mechanical properties and vat stability of the parts. Here, two reactive diluents, hydroxyethyl methacrylate and dimethyl acrylamide, are substituted for the solvent used in prior work on printable PEC resins. Parts printed with these reactive diluents have nearly identical processing parameters but exhibit significantly increased storage modulus, especially at elevated temperatures, when compared to that of the control resin. Thermally driven amidization of the carboxylate and ammonium groups yields further control over the properties of the parts. The combination of spatial, thermomechanical, and hydrophilic control promises to dramatically expand the application space of polyelectrolyte materials.</p>","PeriodicalId":7,"journal":{"name":"ACS Applied Polymer Materials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141338795","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}
Maria Chiara Cabua, Maria Vittoria Piras, Debora Dessi, Giorgia Sarais, Francesco Corrias, Michael Zanon, Keivan Guido Kahnamoei, Alberto Martis, Guido Ennas, Ignazio Roppolo, Candido Fabrizio Pirri, Alessandra Cabizza, Annalisa Chiappone and Francesco Secci*,
Aloe represents a valuable resource for the Mediterranean economy; the pharmaceutical and nutraceutical industries exploit the Aloe gel for several applications, but about 45 wt % of the Aloe plant, i.e., the leaf peel, is waste. This waste is usually disposed off in a landfill or used as a fertilizer. The possibility to give added value and a second life to the portions of Aloe Vera waste will help this growing market enter a circular economy perspective. In this work, waste collected from the local Sardinian cultivation of Aloe Vera was employed to prepare microcrystalline cellulose (MCC). Cellulose was purified from anthraquinones, lignin, and hemicellulose through hydrolytic procedures using eco-friendly solvents. Anthraquinone biocomponents, as well as lignin and hemicellulose, were quantified and intended for other valorization processes. At the same time, the cellulose fraction was further converted into MCC and characterized by NMR and infrared spectroscopy and X-ray analyses. TGA-IR and SEM microscopy analyses were performed to investigate the structural changes of MCC during the extraction and postfunctionalization processes. MCC derivatives were finally used as cross-linkers in the photopolymerization and light-induced 3D printing (VAT printing) of acrylic monomers and hydrogels.
芦荟是地中海经济的宝贵资源;制药和保健品行业将芦荟凝胶用于多种用途,但芦荟植物的约 45 重量%(即叶片果皮)是废物。这些废物通常被填埋或用作肥料。为芦荟废料赋予附加值和第二次生命的可能性将有助于这一不断增长的市场进入循环经济视角。在这项工作中,从撒丁岛当地芦荟种植中收集的废弃物被用来制备微晶纤维素(MCC)。通过使用环保溶剂进行水解,从蒽醌、木质素和半纤维素中提纯出纤维素。对蒽醌类生物成分以及木质素和半纤维素进行了量化,并准备用于其他价值化过程。同时,纤维素部分被进一步转化为 MCC,并通过核磁共振、红外光谱和 X 射线分析进行表征。为了研究 MCC 在提取和后功能化过程中的结构变化,还进行了 TGA-IR 和 SEM 显微镜分析。MCC 衍生物最终被用作交联剂,用于丙烯酸单体和水凝胶的光聚合和光诱导三维打印(VAT 打印)。
{"title":"Microcrystalline Cellulose from Aloe Plant Waste as a Platform for Green Materials: Preparation, Chemical Functionalization, and Application in 3D Printing","authors":"Maria Chiara Cabua, Maria Vittoria Piras, Debora Dessi, Giorgia Sarais, Francesco Corrias, Michael Zanon, Keivan Guido Kahnamoei, Alberto Martis, Guido Ennas, Ignazio Roppolo, Candido Fabrizio Pirri, Alessandra Cabizza, Annalisa Chiappone and Francesco Secci*, ","doi":"10.1021/acsapm.4c00409","DOIUrl":"10.1021/acsapm.4c00409","url":null,"abstract":"<p >Aloe represents a valuable resource for the Mediterranean economy; the pharmaceutical and nutraceutical industries exploit the Aloe gel for several applications, but about 45 wt % of the Aloe plant, i.e., the leaf peel, is waste. This waste is usually disposed off in a landfill or used as a fertilizer. The possibility to give added value and a second life to the portions of Aloe Vera waste will help this growing market enter a circular economy perspective. In this work, waste collected from the local Sardinian cultivation of Aloe Vera was employed to prepare microcrystalline cellulose (MCC). Cellulose was purified from anthraquinones, lignin, and hemicellulose through hydrolytic procedures using eco-friendly solvents. Anthraquinone biocomponents, as well as lignin and hemicellulose, were quantified and intended for other valorization processes. At the same time, the cellulose fraction was further converted into MCC and characterized by NMR and infrared spectroscopy and X-ray analyses. TGA-IR and SEM microscopy analyses were performed to investigate the structural changes of MCC during the extraction and postfunctionalization processes. MCC derivatives were finally used as cross-linkers in the photopolymerization and light-induced 3D printing (VAT printing) of acrylic monomers and hydrogels.</p>","PeriodicalId":7,"journal":{"name":"ACS Applied Polymer Materials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141339801","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}
Yi-Huan Lee*, Chia-Hsing Lin, Chia-Wei Lee and Lyu-Ying Wang,
In this study, a polyamide elastomer system with excellent foamability was synthesized. Single-walled carbon nanotube (SWCNT) fillers were combined to fabricate a series of nanocomposites. Following supercritical carbon dioxide (sc-CO2) foaming, a high-quality nanocomposite foam system was successfully manufactured. With the incorporation of only 2.5 wt % SWCNT, the foamed product exhibited excellent absorption-dominated electromagnetic interference (EMI) shielding performance with a specific shielding effectiveness (SSE) value of 209.8 dB cm3 g–1, which was resulted from the synergistic effect induced by the three-dimensional conductive network of SWCNT and multiple reflections inside the micropores. Deformation tests were conducted, in which the nanocomposite foam was bent or twisted 1000 times; the foam stably retained its EMI shielding capacity at more than 95% of the original performance. The nanocomposite foam was both recyclable and refoamable, indicating its higher sustainability than traditional foaming products with chemical residues or cross-linking. This study provides insights into the development of high-efficiency EMI shielding foams for lightweight electronic applications.
{"title":"Lightweight, Highly Efficient, and Recyclable Absorption-Dominated Electromagnetic Interference Shielding Foams Based on Molecularly Designed Polyamide Elastomer/Carbon Nanotube Nanocomposites","authors":"Yi-Huan Lee*, Chia-Hsing Lin, Chia-Wei Lee and Lyu-Ying Wang, ","doi":"10.1021/acsapm.4c00577","DOIUrl":"10.1021/acsapm.4c00577","url":null,"abstract":"<p >In this study, a polyamide elastomer system with excellent foamability was synthesized. Single-walled carbon nanotube (SWCNT) fillers were combined to fabricate a series of nanocomposites. Following supercritical carbon dioxide (sc-CO<sub>2</sub>) foaming, a high-quality nanocomposite foam system was successfully manufactured. With the incorporation of only 2.5 wt % SWCNT, the foamed product exhibited excellent absorption-dominated electromagnetic interference (EMI) shielding performance with a specific shielding effectiveness (SSE) value of 209.8 dB cm<sup>3</sup> g<sup>–1</sup>, which was resulted from the synergistic effect induced by the three-dimensional conductive network of SWCNT and multiple reflections inside the micropores. Deformation tests were conducted, in which the nanocomposite foam was bent or twisted 1000 times; the foam stably retained its EMI shielding capacity at more than 95% of the original performance. The nanocomposite foam was both recyclable and refoamable, indicating its higher sustainability than traditional foaming products with chemical residues or cross-linking. This study provides insights into the development of high-efficiency EMI shielding foams for lightweight electronic applications.</p>","PeriodicalId":7,"journal":{"name":"ACS Applied Polymer Materials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsapm.4c00577","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141349779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fluorescent polyimide films were manufactured using colorless, transparent polyimide (PI) as a matrix material and perylenediimide (PDI) as a covalently incorporated fluorophore. The matrix polymer was manufactured using fluorinated monomers of 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 2,2-bis(trifluoromethyl)benzidine. A slight excess of 6FDA was used to produce an acid anhydride-terminated polyamic acid (PAA) precursor. Amine-terminated PDI was prepared in advance through a high-temperature condensation reaction between perylene-3,4,9,10-tetracarboxylic acid dianhydride and two equivalent cycloaliphatic diamines. The acid anhydride-terminated precursor PAA was treated with the amine-terminated PDI to simultaneously extend the chain and confer fluorescence (FL), followed by chemical imidization to obtain fluorescent PIs. Well-featured PI films with a thickness of approximately 50 μm were fabricated via casting on glass slides and convection drying. The prepared PI films showed an elastic modulus of more than 4.4 GPa, a tensile strength of more than 81 MPa, a thermal decomposition temperature of more than 500 °C, at which a weight loss of 5% was observed, and a glass transition temperature of more than 306 °C. Moreover, the polymer films showed FL quantum efficiency of 5.74% or higher, with the FL color slightly differing depending on the cycloaliphatic diamine used in the synthesis of the PDI unit.
{"title":"Fluorescent Polyimide Films with Covalently Incorporated Perylenediimide","authors":"Heesang Kim, and , Giseop Kwak*, ","doi":"10.1021/acsapm.4c01308","DOIUrl":"10.1021/acsapm.4c01308","url":null,"abstract":"<p >Fluorescent polyimide films were manufactured using colorless, transparent polyimide (PI) as a matrix material and perylenediimide (PDI) as a covalently incorporated fluorophore. The matrix polymer was manufactured using fluorinated monomers of 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 2,2-bis(trifluoromethyl)benzidine. A slight excess of 6FDA was used to produce an acid anhydride-terminated polyamic acid (PAA) precursor. Amine-terminated PDI was prepared in advance through a high-temperature condensation reaction between perylene-3,4,9,10-tetracarboxylic acid dianhydride and two equivalent cycloaliphatic diamines. The acid anhydride-terminated precursor PAA was treated with the amine-terminated PDI to simultaneously extend the chain and confer fluorescence (FL), followed by chemical imidization to obtain fluorescent PIs. Well-featured PI films with a thickness of approximately 50 μm were fabricated via casting on glass slides and convection drying. The prepared PI films showed an elastic modulus of more than 4.4 GPa, a tensile strength of more than 81 MPa, a thermal decomposition temperature of more than 500 °C, at which a weight loss of 5% was observed, and a glass transition temperature of more than 306 °C. Moreover, the polymer films showed FL quantum efficiency of 5.74% or higher, with the FL color slightly differing depending on the cycloaliphatic diamine used in the synthesis of the PDI unit.</p>","PeriodicalId":7,"journal":{"name":"ACS Applied Polymer Materials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141353254","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}