Arsenocholine-containing methacrylate (MTAsB) inspired by marine organisms was synthesized by the reaction of 2-bromoethyl methacrylate and trimethylarsine to investigate its polymerization behavior and the fundamental properties of the resulting polymer. Controlled radical polymerization of MTAsB proceeded in the presence of a copper catalyst and imidazolium chloride at 60 °C for 8 h to give a water-soluble polycation with a 94% yield. The smaller amount of nonfreezing water and intermediate water of poly(MTAsB) was observed compared with that of the ammonium-containing polycations. A poly(MTAsB) brush was also prepared on a silicon substrate to investigate its swelling structure in aqueous salt solution by scanning probe microscopy and neutron reflectivity measurements. The brush chains adopted a relatively extended conformation in pure water because of the Coulombic repulsion among the arsenic cation groups of the polyelectrolyte, while the brush formed a collapsed structure in aqueous solutions of Hofmeister series anions as a result of the screening effect by salt ions. In particular, thiocyanate ions induced a significant reduction in the swollen thickness of the brush, probably caused by the attractive interaction between arsenic cations and chaotropic thiocyanate ions. The salt concentration dependency of the poly(MTAsB) brush was similar to that of the ammonium-cation-type polyelectrolyte brushes.
{"title":"Synthesis of Arsenocholine-Type Polycation Brush and Its Hydration Structure in Aqueous Solution","authors":"Takumi Komiya, Itsuki Watanabe, Raita Goseki, Motoyasu Kobayashi","doi":"10.1021/acs.langmuir.4c04541","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04541","url":null,"abstract":"Arsenocholine-containing methacrylate (MTAsB) inspired by marine organisms was synthesized by the reaction of 2-bromoethyl methacrylate and trimethylarsine to investigate its polymerization behavior and the fundamental properties of the resulting polymer. Controlled radical polymerization of MTAsB proceeded in the presence of a copper catalyst and imidazolium chloride at 60 °C for 8 h to give a water-soluble polycation with a 94% yield. The smaller amount of nonfreezing water and intermediate water of poly(MTAsB) was observed compared with that of the ammonium-containing polycations. A poly(MTAsB) brush was also prepared on a silicon substrate to investigate its swelling structure in aqueous salt solution by scanning probe microscopy and neutron reflectivity measurements. The brush chains adopted a relatively extended conformation in pure water because of the Coulombic repulsion among the arsenic cation groups of the polyelectrolyte, while the brush formed a collapsed structure in aqueous solutions of Hofmeister series anions as a result of the screening effect by salt ions. In particular, thiocyanate ions induced a significant reduction in the swollen thickness of the brush, probably caused by the attractive interaction between arsenic cations and chaotropic thiocyanate ions. The salt concentration dependency of the poly(MTAsB) brush was similar to that of the ammonium-cation-type polyelectrolyte brushes.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"13 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986939","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, we demonstrate a novel and efficient fabrication methodology for nonclose-packed, two-dimensional (2D) colloidal crystals exhibiting square lattice structures. In our recent work, we detailed the formation of 2D colloidal crystals via the electrostatic adsorption of three-dimensional (3D) charged colloidal crystals onto oppositely charged substrates. These 3D colloidal crystals possessed a face-centered cubic (FCC) lattice structure with their (111) planes aligned parallel to the substrate, facilitating the formation of 2D crystals with triangular lattice arrangements upon adsorption. This work presents the synthesis of 2D crystals with square lattices─a configuration widely used in photonics. We prepared 3D colloidal crystals of silica particles with four-fold symmetry in a micrometer-scale gap between two coverslips. The bottom glass surface is modified with a cationic silane coupling reagent, aminopropyltriethoxysilane, generating pH-responsive charge characteristics with an isoelectric point (iep) near pH 8. When the pH is greater than iep, the surface is charged negatively. As pH decreases below iep, the sign of the surface charge reverses to positive. Controlled pH lowering below the iep induces adsorption of the lowermost lattice plane of 3D crystals onto the substrate, yielding 2D crystals with a distinct square lattice. We further synthesized three-layer body-centered cubic (BCC) structures by stacking alternating layers of the 2D square lattices of silica and polystyrene particles. By aligning the refractive index of the surrounding medium (aqueous solution of ethylene glycol) with that of silica particles, we successfully fabricated a structure that is optically identical to a simple cubic lattice. These findings advance the development of 2D crystalline materials for photonic and plasmonic applications.
{"title":"Two-Dimensional Square Lattice of Colloidal Particles Formed by Electrostatic Adsorption in Confined Space","authors":"Yurina Aoyama, Akiko Toyotama, Tohru Okuzono, Tatsuya Ishikawa, Koichiro Hyodo, Masaya Nishida, Junpei Yamanaka","doi":"10.1021/acs.langmuir.4c04480","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04480","url":null,"abstract":"In this study, we demonstrate a novel and efficient fabrication methodology for nonclose-packed, two-dimensional (2D) colloidal crystals exhibiting square lattice structures. In our recent work, we detailed the formation of 2D colloidal crystals via the electrostatic adsorption of three-dimensional (3D) charged colloidal crystals onto oppositely charged substrates. These 3D colloidal crystals possessed a face-centered cubic (FCC) lattice structure with their (111) planes aligned parallel to the substrate, facilitating the formation of 2D crystals with triangular lattice arrangements upon adsorption. This work presents the synthesis of 2D crystals with square lattices─a configuration widely used in photonics. We prepared 3D colloidal crystals of silica particles with four-fold symmetry in a micrometer-scale gap between two coverslips. The bottom glass surface is modified with a cationic silane coupling reagent, aminopropyltriethoxysilane, generating pH-responsive charge characteristics with an isoelectric point (iep) near pH 8. When the pH is greater than iep, the surface is charged negatively. As pH decreases below iep, the sign of the surface charge reverses to positive. Controlled pH lowering below the iep induces adsorption of the lowermost lattice plane of 3D crystals onto the substrate, yielding 2D crystals with a distinct square lattice. We further synthesized three-layer body-centered cubic (BCC) structures by stacking alternating layers of the 2D square lattices of silica and polystyrene particles. By aligning the refractive index of the surrounding medium (aqueous solution of ethylene glycol) with that of silica particles, we successfully fabricated a structure that is optically identical to a simple cubic lattice. These findings advance the development of 2D crystalline materials for photonic and plasmonic applications.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"24 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981717","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 : 2025-01-15DOI: 10.1021/acs.langmuir.4c04320
Anca Mazare, Mahmut Hakan Ulubas, Hyesung Kim, Iana Fomicheva, George Sarau, Silke H. Christiansen, Wolfgang H. Goldmann, Alexander B. Tesler
The term “aerophilic surface” is used to describe superhydrophobic surfaces in the Cassie–Baxter wetting state that can trap air underwater. To create aerophilic surfaces, it is essential to achieve a synergy between a low surface energy coating and substrate surface roughness. While a variety of techniques have been established to create surface roughness, the development of rapid, scalable, low-cost, waste-free, efficient, and substrate-geometry-independent processes for depositing low surface energy coatings remains a challenge. This study demonstrates that fluorinated phosphate ester, with a surface tension as low as 15.31 mN m–1, can form a self-assembled monolayer on metal oxide substrates within seconds using a facile wet-chemical approach. X-ray photoelectron spectroscopy was used to analyze the formed self-assembled monolayers. Using nanotubular morphology as a rough substrate, we demonstrate the rapid formation of a superhydrophobic surface with a trapped air layer underwater.
{"title":"Binding Kinetics of Self-Assembled Monolayers of Fluorinated Phosphate Ester on Metal Oxides for Underwater Aerophilicity","authors":"Anca Mazare, Mahmut Hakan Ulubas, Hyesung Kim, Iana Fomicheva, George Sarau, Silke H. Christiansen, Wolfgang H. Goldmann, Alexander B. Tesler","doi":"10.1021/acs.langmuir.4c04320","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04320","url":null,"abstract":"The term “aerophilic surface” is used to describe superhydrophobic surfaces in the Cassie–Baxter wetting state that can trap air underwater. To create aerophilic surfaces, it is essential to achieve a synergy between a low surface energy coating and substrate surface roughness. While a variety of techniques have been established to create surface roughness, the development of rapid, scalable, low-cost, waste-free, efficient, and substrate-geometry-independent processes for depositing low surface energy coatings remains a challenge. This study demonstrates that fluorinated phosphate ester, with a surface tension as low as 15.31 mN m<sup>–1</sup>, can form a self-assembled monolayer on metal oxide substrates within seconds using a facile wet-chemical approach. X-ray photoelectron spectroscopy was used to analyze the formed self-assembled monolayers. Using nanotubular morphology as a rough substrate, we demonstrate the rapid formation of a superhydrophobic surface with a trapped air layer underwater.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"118 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981712","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}
Nontraditional luminogens (NTLs) without large π-conjugated aromatic structures have attracted a great deal of attention in recent years. Developing NTLs with red-shifted and enhanced emissions remains a great challenge. In this work, we developed a NTL composed of three components, i.e., polymaleic acid (PMA), arginine (Arg), and polyacrylamide (PAM), and investigated its photoluminescent behavior and mechanism. Compared with the single components and binary components, the PMA/Arg/PAM solid exhibited two red-shifted emission peaks at 510 and 562 nm and higher quantum yields. Structural characterizations demonstrated that hydrogen bonds formed between the nonconventional chromophores in PMA and Arg lead to more extended through-space conjugation and rigidified conformations, which is the fundamental reason for the red-shifted emission and higher quantum yield of the PMA/Arg/PAM solid. In addition, theoretical calculations proved that excited-state proton transfer occurs between the carboxyl groups of PMA and amino groups of Arg via photoexcitation, resulting in dual emissions in the PMA/Arg/PAM solid. This work provides a deeper understanding of the photoluminescence mechanism of NTLs based on multiple hydrogen bonds and is helpful in guiding the design of NTLs with red-shifted and enhanced emissions.
{"title":"Red-Shifted and Enhanced Photoluminescence Emissions from Hydrogen-Bonded Multicomponent Nontraditional Luminogens","authors":"Yunhao Bai, Jipeng Zhang, Yixu Wang, Xiangye Guo, Junwen Deng, Xuanshu Zhong, Wendi Xie, Jinsheng Xiao, Huiliang Wang","doi":"10.1021/acs.langmuir.4c04572","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04572","url":null,"abstract":"Nontraditional luminogens (NTLs) without large π-conjugated aromatic structures have attracted a great deal of attention in recent years. Developing NTLs with red-shifted and enhanced emissions remains a great challenge. In this work, we developed a NTL composed of three components, i.e., polymaleic acid (PMA), arginine (Arg), and polyacrylamide (PAM), and investigated its photoluminescent behavior and mechanism. Compared with the single components and binary components, the PMA/Arg/PAM solid exhibited two red-shifted emission peaks at 510 and 562 nm and higher quantum yields. Structural characterizations demonstrated that hydrogen bonds formed between the nonconventional chromophores in PMA and Arg lead to more extended through-space conjugation and rigidified conformations, which is the fundamental reason for the red-shifted emission and higher quantum yield of the PMA/Arg/PAM solid. In addition, theoretical calculations proved that excited-state proton transfer occurs between the carboxyl groups of PMA and amino groups of Arg via photoexcitation, resulting in dual emissions in the PMA/Arg/PAM solid. This work provides a deeper understanding of the photoluminescence mechanism of NTLs based on multiple hydrogen bonds and is helpful in guiding the design of NTLs with red-shifted and enhanced emissions.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"8 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981718","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}
Self-assembly of amino acids and short-peptide derivatives attracted significant curiosity worldwide due to their unique self-assembly process and wide variety of applications. Amino acid is considered one of the important synthons in supramolecular chemistry. Self-assembly processes and applications of unfunctionalized native amino acids have been less reported in the literature. In this article, we are first-time reporting the self-assembly process of tyrosine (Tyr), an aromatic amino acid, in dimethyl sulfoxide (DMSO) solvent. Most of the studies related to Tyr self-assembly were reported in different aqueous solutions. In our work, we studied the self-assembly in several common organic solvents and found that Tyr could self-assemble into a supramolecular gel in dimethyl sulfoxide (DMSO) solvent. The self-assembly process was investigated by several techniques, such as UV–vis, fluorescence, FTIR, and NMR spectroscopy. Morphological features on the nanoscale were investigated through scanning electron microscopy (SEM). SEM images indicated the formation of nanofibrils with high aspect ratios. The supramolecular gel property was investigated by different rheological experiments. Computational study on the self-assembly process of Tyr in DMSO medium suggested that noncovalent interactions like hydrogen bonding and π–π stacking among the Tyr molecules played a prominent role. Finally, the charge-transfer complex formation ability of electron-rich Tyr with electron-deficient 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) was studied. In the presence of DDQ due to the charge-transfer complex formation, the supramolecular gel converted into a reddish color solution, and their fibrillar nanoscale morphologies collapsed.
{"title":"Supramolecular Gelation Based on Native Amino Acid Tyrosine and Its Charge-Transfer Complex Formation","authors":"Pijush Singh, Manju Siyaram Yadav, Soumen Kuila, Amit Kumar Paul, Debes Ray, Souvik Misra, Jishu Naskar, Vinod Kumar Aswal, Jayanta Nanda","doi":"10.1021/acs.langmuir.4c03708","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c03708","url":null,"abstract":"Self-assembly of amino acids and short-peptide derivatives attracted significant curiosity worldwide due to their unique self-assembly process and wide variety of applications. Amino acid is considered one of the important synthons in supramolecular chemistry. Self-assembly processes and applications of unfunctionalized native amino acids have been less reported in the literature. In this article, we are first-time reporting the self-assembly process of tyrosine (Tyr), an aromatic amino acid, in dimethyl sulfoxide (DMSO) solvent. Most of the studies related to Tyr self-assembly were reported in different aqueous solutions. In our work, we studied the self-assembly in several common organic solvents and found that Tyr could self-assemble into a supramolecular gel in dimethyl sulfoxide (DMSO) solvent. The self-assembly process was investigated by several techniques, such as UV–vis, fluorescence, FTIR, and NMR spectroscopy. Morphological features on the nanoscale were investigated through scanning electron microscopy (SEM). SEM images indicated the formation of nanofibrils with high aspect ratios. The supramolecular gel property was investigated by different rheological experiments. Computational study on the self-assembly process of Tyr in DMSO medium suggested that noncovalent interactions like hydrogen bonding and π–π stacking among the Tyr molecules played a prominent role. Finally, the charge-transfer complex formation ability of electron-rich Tyr with electron-deficient 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) was studied. In the presence of DDQ due to the charge-transfer complex formation, the supramolecular gel converted into a reddish color solution, and their fibrillar nanoscale morphologies collapsed.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981715","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 : 2025-01-15DOI: 10.1021/acs.langmuir.4c04867
Ma. Laura Martí, Viviana Cano Aristizábal, Rubén Motrich, Laura E. Valenti, Carla E. Giacomelli
Surface biofunctionalization with structurally perturbed albumin, as well as with other plasmatic proteins, inhibits the initial bacterial adhesion and biofilm formation, involved in numerous healthcare-associated infections. In fact, we have reported this protective effect with thermally treated plasmatic proteins, such as albumin and fibrinogen, adsorbed on flat silica surfaces. Here, we show that albumin biofunctionalization also works properly on flat Ti6Al4V substrates, which are widely used to fabricate medical devices. The protective effect is conserved even in biologically relevant fluids, containing other proteins that potentially adsorb onto and/or displace preadsorbed albumin from the biofunctionalized substrates. We further demonstrate that the presence of structurally perturbed albumin on the substrate does not trigger macrophage activation and the release of inflammatory mediators. Consequently, surface biofunctionalization with thermally perturbed albumin is a simple strategy to prepare antibacterial, nonimmunogenic medical devices.
{"title":"Defending Ti6Al4V against Biofilm Formation with Albumin Biofunctionalization","authors":"Ma. Laura Martí, Viviana Cano Aristizábal, Rubén Motrich, Laura E. Valenti, Carla E. Giacomelli","doi":"10.1021/acs.langmuir.4c04867","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04867","url":null,"abstract":"Surface biofunctionalization with structurally perturbed albumin, as well as with other plasmatic proteins, inhibits the initial bacterial adhesion and biofilm formation, involved in numerous healthcare-associated infections. In fact, we have reported this protective effect with thermally treated plasmatic proteins, such as albumin and fibrinogen, adsorbed on flat silica surfaces. Here, we show that albumin biofunctionalization also works properly on flat Ti6Al4V substrates, which are widely used to fabricate medical devices. The protective effect is conserved even in biologically relevant fluids, containing other proteins that potentially adsorb onto and/or displace preadsorbed albumin from the biofunctionalized substrates. We further demonstrate that the presence of structurally perturbed albumin on the substrate does not trigger macrophage activation and the release of inflammatory mediators. Consequently, surface biofunctionalization with thermally perturbed albumin is a simple strategy to prepare antibacterial, nonimmunogenic medical devices.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"18 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981744","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 : 2025-01-15DOI: 10.1021/acs.langmuir.4c04114
Tianhao Ren, Dehai Liang
Coacervation is generally treated as a liquid–liquid phase separation process and is controlled mainly by thermodynamics. However, kinetics could make a dominant contribution, especially in systems containing multiple interactions. In this work, using peptides of (XXLY)6SSSGSS to tune the charge density and the degree of hydrophobicity, as well as to introduce secondary structures, we evaluated the effect of kinetics on biphasic coacervates formed by peptides with single-stranded oligonucleotides and quaternized dextran at varying pH values. Only in the case where the charge density is constant and the electrostatic interaction is the major driving force for Coacervation is the effect of kinetics negligible. When pH-dependent electrostatic interaction and hydrophobic interaction are involved or the peptides form secondary structures, the Coacervation process is then path-dependent, indicating that the kinetics controls the phase separation process. The Coacervation by combining two different peptides suggests that the peptide with a higher charge density plays a leading role in the early stage, while the cooperation of both peptides takes over afterward. Our work demonstrates that it is normal to observe coacervates with different morphologies and functions due to kinetic control, especially in living cells. Peptides with minimized sequences are a practical approach to reveal the mechanism of Coacervation processes controlled by kinetics.
{"title":"Biphasic Coacervation Controlled by Kinetics as Studied by De Novo-Designed Peptides","authors":"Tianhao Ren, Dehai Liang","doi":"10.1021/acs.langmuir.4c04114","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04114","url":null,"abstract":"Coacervation is generally treated as a liquid–liquid phase separation process and is controlled mainly by thermodynamics. However, kinetics could make a dominant contribution, especially in systems containing multiple interactions. In this work, using peptides of (XXLY)<sub>6</sub>SSSGSS to tune the charge density and the degree of hydrophobicity, as well as to introduce secondary structures, we evaluated the effect of kinetics on biphasic coacervates formed by peptides with single-stranded oligonucleotides and quaternized dextran at varying pH values. Only in the case where the charge density is constant and the electrostatic interaction is the major driving force for Coacervation is the effect of kinetics negligible. When pH-dependent electrostatic interaction and hydrophobic interaction are involved or the peptides form secondary structures, the Coacervation process is then path-dependent, indicating that the kinetics controls the phase separation process. The Coacervation by combining two different peptides suggests that the peptide with a higher charge density plays a leading role in the early stage, while the cooperation of both peptides takes over afterward. Our work demonstrates that it is normal to observe coacervates with different morphologies and functions due to kinetic control, especially in living cells. Peptides with minimized sequences are a practical approach to reveal the mechanism of Coacervation processes controlled by kinetics.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"26 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981716","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 : 2025-01-15DOI: 10.1021/acs.langmuir.4c04104
Kenta Kakiuchi, Mark Andrew Borden
Lipid-coated oxygen microbubbles (OMBs) are being investigated for biomedical applications to alleviate hypoxia such as systemic oxygenation and image-guided radiosensitization therapy. Additionally, they hold potential for boarder application as oxygen carriers beyond the biomedical filed. Understanding the stability and oxygen release properties of OMBs in dynamic aqueous environments is critical for these applications. In this study, we found that OMBs composed of longer acyl chain phospholipids (DSPC and DBPC) were stable in storage for at least 1 week, unlike the shorter acyl chain phospholipid (DPPC). OMBs were also more stable with a diacyl PEG–PE emulsifier compared with single-chain PEG-40 stearate. Dilution of OMBs did not alter the average diameter. While previous studies have examined the theoretical and experimental aspects of oxygen release from OMBs under static conditions, quantitative evaluations of OMB dispersions under dynamic stirring conditions remain limited. Here, we introduce a novel oxygen measurement method that quantitatively tracks the transition of the dissolved oxygen concentration in an aqueous medium upon mixing with a bolus of OMBs. Our results indicate that a 50 vol % OMB dispersion releases more than 330 mg/L of oxygen, surpassing arterial oxygen levels, and that more than 95% of this oxygen is released within 30 s. The rate of oxygenation of the OMB dispersions was comparable to that of a bolus injection of oxygen-saturated water under sufficient agitation, indicating that convection in the aqueous medium is the limiting transport mechanism. However, the lipid shell had a measurable effect on the oxygen release rate, which correlated with its oxygen permeability. Increasing the stirring speed increased both oxygen release rate and total amount of oxygen released. Overall, this study elucidates the fundamental stability and mass transport properties of the OMB dispersions under practical stirring conditions.
{"title":"Effect of Lipid Composition and Stirring Dynamics on Oxygen Microbubble Stability and Oxygen Release","authors":"Kenta Kakiuchi, Mark Andrew Borden","doi":"10.1021/acs.langmuir.4c04104","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04104","url":null,"abstract":"Lipid-coated oxygen microbubbles (OMBs) are being investigated for biomedical applications to alleviate hypoxia such as systemic oxygenation and image-guided radiosensitization therapy. Additionally, they hold potential for boarder application as oxygen carriers beyond the biomedical filed. Understanding the stability and oxygen release properties of OMBs in dynamic aqueous environments is critical for these applications. In this study, we found that OMBs composed of longer acyl chain phospholipids (DSPC and DBPC) were stable in storage for at least 1 week, unlike the shorter acyl chain phospholipid (DPPC). OMBs were also more stable with a diacyl PEG–PE emulsifier compared with single-chain PEG-40 stearate. Dilution of OMBs did not alter the average diameter. While previous studies have examined the theoretical and experimental aspects of oxygen release from OMBs under static conditions, quantitative evaluations of OMB dispersions under dynamic stirring conditions remain limited. Here, we introduce a novel oxygen measurement method that quantitatively tracks the transition of the dissolved oxygen concentration in an aqueous medium upon mixing with a bolus of OMBs. Our results indicate that a 50 vol % OMB dispersion releases more than 330 mg/L of oxygen, surpassing arterial oxygen levels, and that more than 95% of this oxygen is released within 30 s. The rate of oxygenation of the OMB dispersions was comparable to that of a bolus injection of oxygen-saturated water under sufficient agitation, indicating that convection in the aqueous medium is the limiting transport mechanism. However, the lipid shell had a measurable effect on the oxygen release rate, which correlated with its oxygen permeability. Increasing the stirring speed increased both oxygen release rate and total amount of oxygen released. Overall, this study elucidates the fundamental stability and mass transport properties of the OMB dispersions under practical stirring conditions.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"59 1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987058","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 : 2025-01-15DOI: 10.1021/acs.langmuir.4c04259
Mohammad Awashra, Seyed Mehran Mirmohammadi, Lingju Meng, Sami Franssila, Ville Jokinen
Superhydrophobic surfaces find applications in numerous biomedical scenarios, requiring the repellence of biofluids and biomolecules. Plastron, the trapped air between a superhydrophobic surface and a wetting liquid, plays a pivotal role in biofluid repellency. A key challenge, however, is the often short-lived plastron stability in biofluids and the lack of knowledge surrounding it. Plastron stability refers to the duration for which a surface remains in the Cassie state before transitioning to the fully wetting Wenzel state. Here, a submersion test with real-time optical monitoring is used to determine the plastron lifetime of different superhydrophobic surfaces upon immersion in various biofluids. We find that biofluids of all types exhibit shorter plastron lifetimes compared to pure water, which is attributed to their lower surface tension and biomolecular adsorption through hydrophobic–hydrophobic interactions. Proteins and glucose are identified as the major contributors to plastron dissipation in fetal bovine serum-based biofluids. Plastron minimizes the solid–liquid interface, reducing biomolecular adsorption, making its stability crucial for biofluid repellence. Thus, the effects of surface texture, feature size, Cassie solid fraction, Wenzel dimensionless roughness, and surface chemistry on plastron stability are investigated. Our key findings indicate that prolonged plastron stability and thus enhanced biofluid repellency are achieved through a combination of larger plastron volumes, increased Wenzel roughness degrees, greater Cassie solid fractions, and smaller feature sizes. We demonstrate that with optimized parameters, our surface design can maintain plastron stability and sustain a consistent solid–liquid area fraction for over 120 h in complex biofluids containing high levels of protein and glucose, underscoring a robust design for long-term use in biomedical and antifouling applications. This research is essential for advancing the design of superhydrophobic surfaces that effectively resist biofouling in diverse medical and engineering settings.
{"title":"Stable Air Plastron Prolongs Biofluid Repellency of Submerged Superhydrophobic Surfaces","authors":"Mohammad Awashra, Seyed Mehran Mirmohammadi, Lingju Meng, Sami Franssila, Ville Jokinen","doi":"10.1021/acs.langmuir.4c04259","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04259","url":null,"abstract":"Superhydrophobic surfaces find applications in numerous biomedical scenarios, requiring the repellence of biofluids and biomolecules. Plastron, the trapped air between a superhydrophobic surface and a wetting liquid, plays a pivotal role in biofluid repellency. A key challenge, however, is the often short-lived plastron stability in biofluids and the lack of knowledge surrounding it. Plastron stability refers to the duration for which a surface remains in the Cassie state before transitioning to the fully wetting Wenzel state. Here, a submersion test with real-time optical monitoring is used to determine the plastron lifetime of different superhydrophobic surfaces upon immersion in various biofluids. We find that biofluids of all types exhibit shorter plastron lifetimes compared to pure water, which is attributed to their lower surface tension and biomolecular adsorption through hydrophobic–hydrophobic interactions. Proteins and glucose are identified as the major contributors to plastron dissipation in fetal bovine serum-based biofluids. Plastron minimizes the solid–liquid interface, reducing biomolecular adsorption, making its stability crucial for biofluid repellence. Thus, the effects of surface texture, feature size, Cassie solid fraction, Wenzel dimensionless roughness, and surface chemistry on plastron stability are investigated. Our key findings indicate that prolonged plastron stability and thus enhanced biofluid repellency are achieved through a combination of larger plastron volumes, increased Wenzel roughness degrees, greater Cassie solid fractions, and smaller feature sizes. We demonstrate that with optimized parameters, our surface design can maintain plastron stability and sustain a consistent solid–liquid area fraction for over 120 h in complex biofluids containing high levels of protein and glucose, underscoring a robust design for long-term use in biomedical and antifouling applications. This research is essential for advancing the design of superhydrophobic surfaces that effectively resist biofouling in diverse medical and engineering settings.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"54 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986938","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}
Slip flow, a fluid flow enhanced in comparison to that calculated using continuum equations, has been reported for many nanopores, mostly those with hydrophobic surfaces. We investigated the flow of water, hexane, and methanol through hydrophilic nanopores in silica colloidal crystals. Three silica sphere sizes were used to prepare the crystals: 150 ± 30, 500 ± 40, and 1500 ± 100 nm. The spheres were pressure-packed in a fused silica capillary with an inner diameter of 75 μm. The resulting colloidal crystals had an average pore radius of 18 ± 4, 66 ± 6, and 215 ± 14 nm for the three silica sphere sizes used. The colloidal crystals were demonstrated to possess almost perfect packing. The fluids were flown through the colloidal crystals, and the pressure drop was measured using a pressure transducer. The flow rates varied from 10 to 80 nL/min. Water showed no-slip Hagen–Poiseuille flow with no enhancement for all of the pore sizes. Hexane showed a 20-fold flow enhancement for the smallest pore size, and the enhancement diminished for the medium pore size and was absent for the largest pore size. Methanol also showed a 20-fold flow enhancement for the smallest pores, about a 15-fold enhancement for the medium pores, and no enhancement for the largest pore size. The reduction in flow enhancement was significantly steeper for hexane than for methanol with an increasing pore size. These results demonstrate a significant slip flow in small (15 nm) hydrophilic nanopores for non-wetting fluids, which is size- and fluid-property-dependent. These observations are important for understanding fluid dynamics in liquid chromatography and naturally occurring nanoporous media.
{"title":"Slip Flow in Hydrophilic Nanopores of Silica Colloidal Crystals","authors":"Pranay Asai, Taylor Jordan, Viktoriya Semeykina, Thang Tran, Darryl Butt, Milind Deo, Ilya Zharov","doi":"10.1021/acs.langmuir.4c04369","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04369","url":null,"abstract":"Slip flow, a fluid flow enhanced in comparison to that calculated using continuum equations, has been reported for many nanopores, mostly those with hydrophobic surfaces. We investigated the flow of water, hexane, and methanol through hydrophilic nanopores in silica colloidal crystals. Three silica sphere sizes were used to prepare the crystals: 150 ± 30, 500 ± 40, and 1500 ± 100 nm. The spheres were pressure-packed in a fused silica capillary with an inner diameter of 75 μm. The resulting colloidal crystals had an average pore radius of 18 ± 4, 66 ± 6, and 215 ± 14 nm for the three silica sphere sizes used. The colloidal crystals were demonstrated to possess almost perfect packing. The fluids were flown through the colloidal crystals, and the pressure drop was measured using a pressure transducer. The flow rates varied from 10 to 80 nL/min. Water showed no-slip Hagen–Poiseuille flow with no enhancement for all of the pore sizes. Hexane showed a 20-fold flow enhancement for the smallest pore size, and the enhancement diminished for the medium pore size and was absent for the largest pore size. Methanol also showed a 20-fold flow enhancement for the smallest pores, about a 15-fold enhancement for the medium pores, and no enhancement for the largest pore size. The reduction in flow enhancement was significantly steeper for hexane than for methanol with an increasing pore size. These results demonstrate a significant slip flow in small (15 nm) hydrophilic nanopores for non-wetting fluids, which is size- and fluid-property-dependent. These observations are important for understanding fluid dynamics in liquid chromatography and naturally occurring nanoporous media.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"12 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142975586","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：