Pub Date : 2024-07-03DOI: 10.1021/acs.langmuir.4c01715
Jie Pan, Jinling Zhang, Yelei Li, Fanxi Yang, Yanchong Yu, Shebin Wang
Magnesium-based biodegradable metal bone implants exhibit superior mechanical properties compared to biodegradable polymers for orthopedic and cardiovascular stents. In this study, MgZZC-x (x = 1, 1.2) alloys were screened by in vitro biocompatibility tests in three simulated body fluids under nontoxic conditions. The MgZZC-1 alloys with better biocompatibility were selected to predict the days required for complete degradation. The evolution of degradation products was analyzed, and the mechanism of formation of the product film was inferred. A degradation kinetic model was established to investigate the effect of MEM components on the degradation of the alloys. The results demonstrate that the proteins in MEM can greatly retard the degradation progress by attaching to the surface of MgZZC-1 alloys, which are predicted to degrade completely within 341 days. The carbonate and phosphate buffers were adjusted to pH in MEM solution, delaying the degradation of magnesium alloys. This process in MEM more accurately reflects the actual degradation in the body and is superior to that in Hanks and SBF solutions. This study will promote the application of biodegradable materials in clinical medicine.
{"title":"Degradation Behavior of Medical MgZZC-1 in Various Simulated Body Fluids.","authors":"Jie Pan, Jinling Zhang, Yelei Li, Fanxi Yang, Yanchong Yu, Shebin Wang","doi":"10.1021/acs.langmuir.4c01715","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c01715","url":null,"abstract":"<p><p>Magnesium-based biodegradable metal bone implants exhibit superior mechanical properties compared to biodegradable polymers for orthopedic and cardiovascular stents. In this study, MgZZC-x (x = 1, 1.2) alloys were screened by in vitro biocompatibility tests in three simulated body fluids under nontoxic conditions. The MgZZC-1 alloys with better biocompatibility were selected to predict the days required for complete degradation. The evolution of degradation products was analyzed, and the mechanism of formation of the product film was inferred. A degradation kinetic model was established to investigate the effect of MEM components on the degradation of the alloys. The results demonstrate that the proteins in MEM can greatly retard the degradation progress by attaching to the surface of MgZZC-1 alloys, which are predicted to degrade completely within 341 days. The carbonate and phosphate buffers were adjusted to pH in MEM solution, delaying the degradation of magnesium alloys. This process in MEM more accurately reflects the actual degradation in the body and is superior to that in Hanks and SBF solutions. This study will promote the application of biodegradable materials in clinical medicine.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489988","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 : 2024-07-03DOI: 10.1021/acs.langmuir.4c02180
Wenfeng Hai, Yang Liu, YuJia Tian, Zhiran Chen, Yingsong Chen, Wenji Bao, Tingfang Bai, Jinghai Liu, Yushuang Liu
The antifouling properties of conductive polymers have received extensive attention for biosensor and bioelectronic applications. Polyethylene glycol (PEG) is a well-known antifouling material, but the controlled regulation of the surface topography of PEG without a template remains a challenge. Here, we show a columnar structure antifouling conductive polymer brush with enhanced antifouling properties and considerable conductivity. The method involves synthesizing the 3,4-ethylenedioxythiophene monomer modified with azide (EDOT-N3), the electropolymerization of PEDOT-N3, and the in situ growth of PEG polymer brushes on PEDOT through double-click reactions. The resultant columnar structure polymer brush exhibits high electrical conductivity (3.5 Ω·cm2), ultrahigh antifouling property, electrochemical stability (capacitance retention was 93.8% after 2000 cycles of CV scans in serum), and biocompatibility.
{"title":"In Situ Growth of Columnar PEG on PEDOT and Its Antifouling Properties.","authors":"Wenfeng Hai, Yang Liu, YuJia Tian, Zhiran Chen, Yingsong Chen, Wenji Bao, Tingfang Bai, Jinghai Liu, Yushuang Liu","doi":"10.1021/acs.langmuir.4c02180","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c02180","url":null,"abstract":"<p><p>The antifouling properties of conductive polymers have received extensive attention for biosensor and bioelectronic applications. Polyethylene glycol (PEG) is a well-known antifouling material, but the controlled regulation of the surface topography of PEG without a template remains a challenge. Here, we show a columnar structure antifouling conductive polymer brush with enhanced antifouling properties and considerable conductivity. The method involves synthesizing the 3,4-ethylenedioxythiophene monomer modified with azide (EDOT-N<sub>3</sub>), the electropolymerization of PEDOT-N<sub>3</sub>, and the in situ growth of PEG polymer brushes on PEDOT through double-click reactions. The resultant columnar structure polymer brush exhibits high electrical conductivity (3.5 Ω·cm<sup>2</sup>), ultrahigh antifouling property, electrochemical stability (capacitance retention was 93.8% after 2000 cycles of CV scans in serum), and biocompatibility.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489993","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}
In this study, a water-soluble quaternary ammonium salt (QAS)-functionalized montmorillonite (MMT) was fabricated using a mechanochemical method as a high-performance water lubrication additive. The intercalation of QAS into the MMT layer expands the layer spacing of MMT, but does not affect the hydrophilicity of MMT. The ultrathin layer QAS-functionalized montmorillonite (QAS-MMT) demonstrated excellent water-stable dispersion and can be used as a water-based lubrication additive. Only 0.1% addition can reduce the friction coefficient by more than 71.4% and the wear volume by about 58.8% when compared to water, demonstrating its excellent friction reduction and antiwear performance. The frictional mechanism indicates that the physical adsorption film, together with the chemical reaction film, endows the QAS-MMT additives with outstanding tribological performance, provides excellent lubrication for the contact of steel/steel pairs, and prevents the steel surface from being further worn.
{"title":"Tribological Effects of Quaternary Ammonium-Functionalized Montmorillonite as Water-Based Additives.","authors":"Zekun Kang, Xiaoxiao Du, Keying Hua, Xiangyu Zuo, Dongmei Xu, Xia Zhang","doi":"10.1021/acs.langmuir.4c01799","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c01799","url":null,"abstract":"<p><p>In this study, a water-soluble quaternary ammonium salt (QAS)-functionalized montmorillonite (MMT) was fabricated using a mechanochemical method as a high-performance water lubrication additive. The intercalation of QAS into the MMT layer expands the layer spacing of MMT, but does not affect the hydrophilicity of MMT. The ultrathin layer QAS-functionalized montmorillonite (QAS-MMT) demonstrated excellent water-stable dispersion and can be used as a water-based lubrication additive. Only 0.1% addition can reduce the friction coefficient by more than 71.4% and the wear volume by about 58.8% when compared to water, demonstrating its excellent friction reduction and antiwear performance. The frictional mechanism indicates that the physical adsorption film, together with the chemical reaction film, endows the QAS-MMT additives with outstanding tribological performance, provides excellent lubrication for the contact of steel/steel pairs, and prevents the steel surface from being further worn.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489996","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}
MXene has attracted considerable attention for supercapacitor applications in the past decade owing to its exceptional electrochemical properties. Although major research interests are focused on composite-based MXene, doping engineering of MXene has recently emerged as a promising alternative. This work unveils the potential of doped MXene for supercapacitor applications with a critical perspective. Various doping engineering strategies and synthesis methods adopted are explicitly delineated. Detailed discussions on the optimization of lattice, functionalization, substitution, and interface modification are provided. Further, it sheds light on recent developments with the asssociated mechanism of doped MXene supercapacitors, followed by the associated challenges. Finally, a roadmap for further progress of doped MXene for the realization of advanced and high-performing energy storage systems has been described. We envision that this Perspective will open up new avenues for the further exploration of this domain.
{"title":"Can Doped-MXene-Based Supercapacitors Be the Game-Changer for Future Energy Landscape? A Critical Perspective.","authors":"Ritik Mohanty, Amtul Nashim, Kaushik Parida, Kulamani Parida","doi":"10.1021/acs.langmuir.4c01242","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c01242","url":null,"abstract":"<p><p>MXene has attracted considerable attention for supercapacitor applications in the past decade owing to its exceptional electrochemical properties. Although major research interests are focused on composite-based MXene, doping engineering of MXene has recently emerged as a promising alternative. This work unveils the potential of doped MXene for supercapacitor applications with a critical perspective. Various doping engineering strategies and synthesis methods adopted are explicitly delineated. Detailed discussions on the optimization of lattice, functionalization, substitution, and interface modification are provided. Further, it sheds light on recent developments with the asssociated mechanism of doped MXene supercapacitors, followed by the associated challenges. Finally, a roadmap for further progress of doped MXene for the realization of advanced and high-performing energy storage systems has been described. We envision that this Perspective will open up new avenues for the further exploration of this domain.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489987","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 : 2024-07-03DOI: 10.1021/acs.langmuir.4c00910
Xinyi Zhao, Qian Sang, Mingzhe Dong, Jun Yao
Carbon dioxide (CO2) has been widely used to enhance the recovery of adsorbed hydrocarbons from the organic matter (OM) in shale formations. To reveal the driving force of replacing adsorbed hydrocarbons from OM by CO2, we performed molecular dynamics (MD) simulations of the replacement process and calculated the interaction forces between CO2 and hydrocarbons. In addition, based on the umbrella sampling method, steered MD simulations were performed, and the free energy profiles of hydrocarbons were obtained using the weighted histogram analysis method. Results show that the condition of the hydrocarbon replacement by CO2 requires the hydrocarbon to have sufficient kinetic energy or to have a sufficiently large attractive force exerted to ensure that the hydrocarbon escapes the potential well of the OM. The attractive forces exerted on hydrocarbon molecules by CO2 can significantly decrease the energy barrier associated with hydrocarbon movement away from the OM surface. Furthermore, both CO2 and supercritical CO2 can effectively displace adsorbed hydrocarbon gas (methane) on the OM, while supercritical CO2 is required to enhance the recovery of adsorbed hydrocarbon oil (n-dodecane). The results obtained in this study provide guidance for enhancing the recovery of adsorbed hydrocarbons by CO2 in shale formations.
二氧化碳(CO2)已被广泛用于提高页岩层中有机物(OM)吸附碳氢化合物的回收率。为了揭示 CO2 取代 OM 中吸附的碳氢化合物的驱动力,我们对取代过程进行了分子动力学(MD)模拟,并计算了 CO2 与碳氢化合物之间的相互作用力。此外,基于伞状采样方法,我们还进行了转向 MD 模拟,并利用加权直方图分析方法获得了碳氢化合物的自由能曲线。结果表明,碳氢化合物被二氧化碳置换的条件要求碳氢化合物具有足够的动能或施加足够大的吸引力,以确保碳氢化合物逃离 OM 的势阱。二氧化碳对碳氢化合物分子施加的吸引力可大大降低碳氢化合物远离 OM 表面的能量障碍。此外,二氧化碳和超临界二氧化碳都能有效地置换 OM 上吸附的烃类气体(甲烷),而要想提高吸附的烃类石油(正十二烷)的采收率,则需要超临界二氧化碳。本研究获得的结果为利用二氧化碳提高页岩层中吸附烃的采收率提供了指导。
{"title":"Investigation of the Driving Force of Replacing Adsorbed Hydrocarbons by CO<sub>2</sub> in Organic Matter from an Energy Perspective.","authors":"Xinyi Zhao, Qian Sang, Mingzhe Dong, Jun Yao","doi":"10.1021/acs.langmuir.4c00910","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c00910","url":null,"abstract":"<p><p>Carbon dioxide (CO<sub>2</sub>) has been widely used to enhance the recovery of adsorbed hydrocarbons from the organic matter (OM) in shale formations. To reveal the driving force of replacing adsorbed hydrocarbons from OM by CO<sub>2</sub>, we performed molecular dynamics (MD) simulations of the replacement process and calculated the interaction forces between CO<sub>2</sub> and hydrocarbons. In addition, based on the umbrella sampling method, steered MD simulations were performed, and the free energy profiles of hydrocarbons were obtained using the weighted histogram analysis method. Results show that the condition of the hydrocarbon replacement by CO<sub>2</sub> requires the hydrocarbon to have sufficient kinetic energy or to have a sufficiently large attractive force exerted to ensure that the hydrocarbon escapes the potential well of the OM. The attractive forces exerted on hydrocarbon molecules by CO<sub>2</sub> can significantly decrease the energy barrier associated with hydrocarbon movement away from the OM surface. Furthermore, both CO<sub>2</sub> and supercritical CO<sub>2</sub> can effectively displace adsorbed hydrocarbon gas (methane) on the OM, while supercritical CO<sub>2</sub> is required to enhance the recovery of adsorbed hydrocarbon oil (<i>n</i>-dodecane). The results obtained in this study provide guidance for enhancing the recovery of adsorbed hydrocarbons by CO<sub>2</sub> in shale formations.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489994","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 : 2024-07-03DOI: 10.1021/acs.langmuir.4c00649
Li Ma, Yilong Yao, Xiong Zhao, Junsheng Hou, Lei Huang, Zihan Ding, Xinlan Lu, Jinjia Wei, Nanjing Hao
Hydrogel microspheres are biocompatible materials widely used in biological and medical fields. Emulsification and stirring are the commonly used methods to prepare hydrogels. However, the size distribution is considerably wide, the monodispersity and the mechanical intensity are poor, and the stable operation conditions are comparatively narrow to meet some sophisticated applications. In this paper, a T-shaped stepwise microchannel combined with a simple side microchannel structure is developed to explore the liquid-liquid dispersion mechanism, interfacial evolution behavior, satellite droplet formation mechanism and separation, and the eventual successful synthesis of dextran hydrogel microspheres. The effect of the operation parameters on droplet and microsphere size is comprehensively studied. The flow pattern and the stable operation condition range are given, and mathematical prediction models are developed under three different flow regimes for droplet size prediction. Based on the stable operating conditions, a microdroplet-based method combined with UV light curing is developed to synthesize the dextran hydrogel microsphere. The highly uniform and monodispersed dextran microspheres with good mechanical intensity are synthesized in the developed microfluidic platform. The size of the microsphere could be tuned from 50 to 300 μm with a capillary number in the range of 0.006-0.742. This work not only provides a facile method for functional polymeric microsphere preparation but also offers important design guidelines for the development of a robust microreactor.
水凝胶微球是一种生物相容性材料,广泛应用于生物和医疗领域。乳化和搅拌是制备水凝胶的常用方法。但其粒度分布较广,单分散性和机械强度较差,稳定操作条件相对狭窄,难以满足一些复杂的应用。本文开发了一种结合简单侧微通道结构的 T 型阶梯式微通道,以探索液-液分散机理、界面演化行为、卫星液滴形成机理和分离,并最终成功合成右旋糖酐水凝胶微球。全面研究了操作参数对液滴和微球尺寸的影响。给出了流动模式和稳定操作条件范围,并建立了三种不同流动状态下的液滴粒度预测数学模型。在稳定操作条件的基础上,开发了一种基于微液滴并结合紫外光固化的方法来合成葡聚糖水凝胶微球。在所开发的微流控平台上合成了高度均匀、单分散且具有良好机械强度的葡聚糖微球。微球的尺寸可在 50 到 300 μm 之间调节,毛细管数在 0.006-0.742 之间。这项工作不仅为功能性聚合物微球的制备提供了简便的方法,还为开发坚固耐用的微反应器提供了重要的设计指南。
{"title":"Rational Design of Liquid-Liquid Microdispersion Droplet Microreactors for the Controllable Synthesis of Highly Uniform and Monodispersed Dextran Microspheres.","authors":"Li Ma, Yilong Yao, Xiong Zhao, Junsheng Hou, Lei Huang, Zihan Ding, Xinlan Lu, Jinjia Wei, Nanjing Hao","doi":"10.1021/acs.langmuir.4c00649","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c00649","url":null,"abstract":"<p><p>Hydrogel microspheres are biocompatible materials widely used in biological and medical fields. Emulsification and stirring are the commonly used methods to prepare hydrogels. However, the size distribution is considerably wide, the monodispersity and the mechanical intensity are poor, and the stable operation conditions are comparatively narrow to meet some sophisticated applications. In this paper, a T-shaped stepwise microchannel combined with a simple side microchannel structure is developed to explore the liquid-liquid dispersion mechanism, interfacial evolution behavior, satellite droplet formation mechanism and separation, and the eventual successful synthesis of dextran hydrogel microspheres. The effect of the operation parameters on droplet and microsphere size is comprehensively studied. The flow pattern and the stable operation condition range are given, and mathematical prediction models are developed under three different flow regimes for droplet size prediction. Based on the stable operating conditions, a microdroplet-based method combined with UV light curing is developed to synthesize the dextran hydrogel microsphere. The highly uniform and monodispersed dextran microspheres with good mechanical intensity are synthesized in the developed microfluidic platform. The size of the microsphere could be tuned from 50 to 300 μm with a capillary number in the range of 0.006-0.742. This work not only provides a facile method for functional polymeric microsphere preparation but also offers important design guidelines for the development of a robust microreactor.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489995","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}
Understanding mass transfer kinetics within individual porous particles is crucial for theoretically explaining the retention and elution behaviors in chromatography and drug delivery. Using laser trapping and fluorescence microspectroscopy, we investigated the diffusion mechanism of coumarin 102 (C102) into single octadecylsilyl particle in acetonitrile (ACN)/water, N,N-dimethylformamide (DMF)/water, and 1-butanol (BuOH)/water solutions. The intraparticle diffusion behavior of C102 was evaluated using the spherical diffusion equation, allowing us to determine the intraparticle diffusion coefficients (Dintra): (8-10) × 10-9 cm2 s-1 for ACN, (10-16) × 10-9 cm2 s-1 for DMF, and (4-6) × 10-9 cm2 s-1 for BuOH. The obtained Dintra values were further analyzed using a pore and surface diffusion model. Thus, we revealed that the diffusion mechanism of C102 differed depending on the organic solvent: surface diffusion for ACN and DMF and pore and surface diffusions for BuOH were observed. This difference is attributed to the formation of a concentrated liquid phase of ACN and DMF at the interface of the alkyl chain and the bulk solution in the pore.
{"title":"Effect of Organic Solvent on the Mass Transfer Mechanism of Coumarin 102 in a Single Octadecylsilyl Silica Gel/Organic Solvent-Water System by Laser Trapping and Fluorescence Microspectroscopy.","authors":"Kazuki Yamada, Akihisa Miyagawa, Ren Honma, Shigenori Nagatomo, Kiyoharu Nakatani","doi":"10.1021/acs.langmuir.4c00878","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c00878","url":null,"abstract":"<p><p>Understanding mass transfer kinetics within individual porous particles is crucial for theoretically explaining the retention and elution behaviors in chromatography and drug delivery. Using laser trapping and fluorescence microspectroscopy, we investigated the diffusion mechanism of coumarin 102 (C102) into single octadecylsilyl particle in acetonitrile (ACN)/water, <i>N</i>,<i>N</i>-dimethylformamide (DMF)/water, and 1-butanol (BuOH)/water solutions. The intraparticle diffusion behavior of C102 was evaluated using the spherical diffusion equation, allowing us to determine the intraparticle diffusion coefficients (<i>D</i><sub>intra</sub>): (8-10) × 10<sup>-9</sup> cm<sup>2</sup> s<sup>-1</sup> for ACN, (10-16) × 10<sup>-9</sup> cm<sup>2</sup> s<sup>-1</sup> for DMF, and (4-6) × 10<sup>-9</sup> cm<sup>2</sup> s<sup>-1</sup> for BuOH. The obtained <i>D</i><sub>intra</sub> values were further analyzed using a pore and surface diffusion model. Thus, we revealed that the diffusion mechanism of C102 differed depending on the organic solvent: surface diffusion for ACN and DMF and pore and surface diffusions for BuOH were observed. This difference is attributed to the formation of a concentrated liquid phase of ACN and DMF at the interface of the alkyl chain and the bulk solution in the pore.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489990","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 : 2024-07-03DOI: 10.1021/acs.langmuir.4c00907
Nitesh Kumar, Uvinduni I Premadasa, Dengpan Dong, Santanu Roy, Ying-Zhong Ma, Benjamin Doughty, Vyacheslav S Bryantsev
Amino acids make up a promising family of molecules capable of direct air capture (DAC) of CO2 from the atmosphere. Under alkaline conditions, CO2 reacts with the anionic form of an amino acid to produce carbamates and deactivated zwitterionic amino acids. The presence of the various species of amino acids and reactive intermediates can have a significant effect on DAC chemistry, the role of which is poorly understood. In this study, all-atom molecular dynamics (MD) based computational simulations and vibrational sum frequency generation (vSFG) spectroscopy studies were conducted to understand the role of competitive interactions at the air-aqueous interface in the context of DAC. We find that the presence of potassium bicarbonate ions, in combination with the anionic and zwitterionic forms of amino acids, induces concentration and charge gradients at the interface, generating a layered molecular arrangement that changes under pre- and post-DAC conditions. In parallel, an enhancement in the surface activity of both anionic and zwitterionic forms of amino acids is observed, which is attributed to enhanced interfacial stability and favorable intermolecular interactions between the adsorbed amino acids in their anionic and zwitterionic forms. The collective influence of these competitive interactions, along with the resulting interfacial heterogeneity, may in turn affect subsequent capture reactions and associated rates. These effects underscore the need to consider dynamic changes in interfacial chemical makeup to enhance DAC efficiency and to develop successful negative emission and storage technologies.
{"title":"Adsorption, Orientation, and Speciation of Amino Acids at Air-Aqueous Interfaces for the Direct Air Capture of CO<sub>2</sub>.","authors":"Nitesh Kumar, Uvinduni I Premadasa, Dengpan Dong, Santanu Roy, Ying-Zhong Ma, Benjamin Doughty, Vyacheslav S Bryantsev","doi":"10.1021/acs.langmuir.4c00907","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c00907","url":null,"abstract":"<p><p>Amino acids make up a promising family of molecules capable of direct air capture (DAC) of CO<sub>2</sub> from the atmosphere. Under alkaline conditions, CO<sub>2</sub> reacts with the anionic form of an amino acid to produce carbamates and deactivated zwitterionic amino acids. The presence of the various species of amino acids and reactive intermediates can have a significant effect on DAC chemistry, the role of which is poorly understood. In this study, all-atom molecular dynamics (MD) based computational simulations and vibrational sum frequency generation (vSFG) spectroscopy studies were conducted to understand the role of competitive interactions at the air-aqueous interface in the context of DAC. We find that the presence of potassium bicarbonate ions, in combination with the anionic and zwitterionic forms of amino acids, induces concentration and charge gradients at the interface, generating a layered molecular arrangement that changes under pre- and post-DAC conditions. In parallel, an enhancement in the surface activity of both anionic and zwitterionic forms of amino acids is observed, which is attributed to enhanced interfacial stability and favorable intermolecular interactions between the adsorbed amino acids in their anionic and zwitterionic forms. The collective influence of these competitive interactions, along with the resulting interfacial heterogeneity, may in turn affect subsequent capture reactions and associated rates. These effects underscore the need to consider dynamic changes in interfacial chemical makeup to enhance DAC efficiency and to develop successful negative emission and storage technologies.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489986","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}
Phase behavior in protein-nanoparticle systems in light of protein corona formation has been investigated. We report the formation of HSA thin films following the addition of a solid protein to a solution of CTAB-capped gold nanorods (AuNRs) via phase separation. The phase separation behavior was observed through UV-vis spectroscopy, turbidity assays, and DLS studies. UV-vis spectra for the protein-AuNR solution indicated a possible self-assembly formation by CTAB-HSA complexes and AuNR-HSA conjugates. The turbidity was found to increase linearly up to 30-50% v/v for each component. The growth phase slope is proportional to the concentration of the components, AuNRs, and HSA, with no lag phase. Dynamic light scattering (DLS) shows the formation of larger aggregates with time, implying a segregated phase of AuNR-HSA and a CTAB-HSA-AuNR network. ζ-potential values confirm surface modification, implying protein corona formation on nanorods. The thin films were also characterized using SEM, AFM, SAXS, XPS, FTIR, and TGA studies. SEM images show a smooth surface with a reduced number of pores, indicating the compactness of the deposited structure. AFM shows two different structural pattern formations with the deposition, indicating possible self-assembly of the protein-conjugated nanoparticles. FTIR studies indicate a change in the hydrogen bonding network and confirm the CTAB-HSA-AuNR complex network formation. The XPS studies indicate Au-S bond formation, along with Au-S-S-Au interactions. SAXS studies indicate the formation of aggregates (oligomers), as well as the presence of dominant attractive intermolecular interactions in the thin films.
{"title":"Thin Film Formation of HSA in the Presence of CTAB-Capped Gold Nanorods through Phase Separation.","authors":"Krishna Halder, Kabira Sabnam, Abhirup Das, Dipak K Goswami, Swagata Dasgupta","doi":"10.1021/acs.langmuir.4c00694","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c00694","url":null,"abstract":"<p><p>Phase behavior in protein-nanoparticle systems in light of protein corona formation has been investigated. We report the formation of HSA thin films following the addition of a solid protein to a solution of CTAB-capped gold nanorods (AuNRs) via phase separation. The phase separation behavior was observed through UV-vis spectroscopy, turbidity assays, and DLS studies. UV-vis spectra for the protein-AuNR solution indicated a possible self-assembly formation by CTAB-HSA complexes and AuNR-HSA conjugates. The turbidity was found to increase linearly up to 30-50% v/v for each component. The growth phase slope is proportional to the concentration of the components, AuNRs, and HSA, with no lag phase. Dynamic light scattering (DLS) shows the formation of larger aggregates with time, implying a segregated phase of AuNR-HSA and a CTAB-HSA-AuNR network. ζ-potential values confirm surface modification, implying protein corona formation on nanorods. The thin films were also characterized using SEM, AFM, SAXS, XPS, FTIR, and TGA studies. SEM images show a smooth surface with a reduced number of pores, indicating the compactness of the deposited structure. AFM shows two different structural pattern formations with the deposition, indicating possible self-assembly of the protein-conjugated nanoparticles. FTIR studies indicate a change in the hydrogen bonding network and confirm the CTAB-HSA-AuNR complex network formation. The XPS studies indicate Au-S bond formation, along with Au-S-S-Au interactions. SAXS studies indicate the formation of aggregates (oligomers), as well as the presence of dominant attractive intermolecular interactions in the thin films.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475434","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}