百欧林简报-KSV NIMA LB膜分析仪文献-2021年第9期

1. Name：Unambiguous Determination of Electrostatically Driven Molecular Packing in a Triphenylene–Surfactant Complex Monolayer

Authors：Samapika Mallik, Shakkira Erimban, Swamynathan Kaleeswaran, Sandeep Kumar, Snehasis Daschakraborty, Alpana Nayak

Journal： Advanced Materials Interfaces

DOI: 10.1002/admi.202100187

Abstract：Emergence of ordered structures during molecular self-assembly at interfaces is influenced by a variety of thermodynamic ａnd kinetic factors that are not well understood. Experiments alone can only inform about the final architecture keeping self-assembly pathways inaccessible. Here with the help of molecular dynamic simulations, the intricate details of the self-assembly processes ａnd resultant ordered structures of a triphenylene–surfactant complex monolayer at air–water interface are reported. The monolayer is observed to be stable ａnd reversible using surface manometry ａnd real-time Brewster angle microscopy. Not only that the simulated isotherm ａnd 2D density profiles are in good agreement with experimental observations, the simulation results bespeak the crucial role of specific electrostatic interactions forming the nanostructures at the interface analyzed via orientational structural profiles, radial distribution, ａnd Z-density profiles. Moreover, real-space visualization using atomic force microscopy suggests that the molecular packing is preserved in the monolayer even after transferring onto a silicon substrate. Since the rational designing of organic electronics requires nanoscale control of molecular structures on solid substrates, it is anticipated that these results will be of fundamental importance.

Link：https://onlinelibrary.wiley.com/doi/abs/10.1002/admi.202100187

2. Name：Multiscale Modeling Strategy of 2D Covalent Organic Frameworks Confined at an Air–Water Interface

Authors：Andres Ortega-Guerrero, Hafeesudeen Sahabudeen, Alexander Croy, Arezoo Dianat, Renhao Dong, Xinliang Feng, ａnd Gianaurelio Cuniberti

Journal：ACS Applied Materials & Interfaces

DOI: 10.1021/acsami.1c05967

Abstract：Two-dimensional covalent organic frameworks (2D COFs) have attracted attention as versatile active materials in many applications. Recent advances have demonstrated the synthesis of monolayer 2D COF via an air–water interface. However, the interfacial 2D polymerization mechanism has been elusive. In this work, we have used a multiscale modeling strategy to study dimethylmethylene-bridged triphenylamine building blocks confined at the air–water interface to form a 2D COF via Schiff-base reaction. A synergy between the computational investigations ａnd experiments allowed the synthesis of a 2D-COF with one of the linkers considered. Our simulations complement the experimental characterization ａnd show the preference of the building blocks to be at the interface with a favorable orientation for the polymerization. The air–water interface is shown to be a key factor to stabilize a flat conformation when a dimer molecule is considered. The structural ａnd electronic properties of the monolayer COFs based on the two monomers are calculated ａnd show a semiconducting nature with direct bandgaps. Our strategy provides a first step toward the in silico polymerization of 2D COFs at air–water interfaces capturing the initial steps of the synthesis up to the prediction of electronic properties of the 2D material.

Link: https://pubs.acs.org/doi/abs/10.1021/acsami.1c05967

3. Name：Cholesterol modulates the interaction between paclitaxel ａnd Langmuir monolayers simulating cell membranesAuthors：Andressa R.Pereira, Flavio M.Shimizu, Osvaldo N.OliveiraJr.

Journal：Colloids ａnd Surfaces B: Biointerfaces

DOI: 10.1016/j.colsurfb.2021.111889

Abstract：The composition of Langmuir monolayers used as cell membrane models is an essential factor for the interaction with biologically-relevant molecules, including pharmaceutical drugs. In this paper, we report the modulation of effects from the antineoplastic drug paclitaxel by the relative concentration of cholesterol in the Langmuir monolayers of ternary mixtures of dipalmitoylphosphatidylcholine, sphingomyelin, ａnd cholesterol. Since the dependence on cholesterol concentration for these monolayers simulating lipid rafts is non-monotonic, we analyzed the surface pressure ａnd compressibility modulus data with the multidimensional projection technique referred to as interactive document mapping (IDMAP). The maximum expansion induced by paclitaxel in surface pressure isotherms was observed for 27% cholesterol, while the compressibility modulus decreased most strongly for the monolayer with 48% cholesterol. Therefore, the physiological action of paclitaxel may vary depending on whether it is associated with penetration in the membrane or with changes in the membrane elasticity.

Link：https://www.sciencedirect.com/science/article/abs/pii/S0927776521003337

4. Name：Exploring Langmuir-Blodgett technique to investigate effect of various subphase conditions on monolayers formed by amphiphilic block co-polymers tetronic 701 ａnd tetronic 90R4Authors: DipaliRoy, BappadityaNaskar, TanushreeBal

Journal：Colloids ａnd Surfaces A: Physicochemical ａnd Engineering Aspects

DOI: 10.1016/j.colsurfa.2021.126924

Abstract：Tetronics are X-shaped octa block amphiphilic copolymer having multi-stimuli sensitive chemical ａnd physical properties due to the presence of central ethylenediamine, polyethylene oxide (PEO) ａnd polypropylene oxide (PPO) groups. Langmuir monolayers formed at the air-water interface by two tetronics namely tetronic 701 with normal sequence ａnd reverse sequential tetronic 90R4, were studied on a comparative basis. The effects of different subphase conditions on the monolayer at the air-water interface were systematically investigated. Different spreading volumes of tetronics, different pH, temperature ａnd ionic strength of the subphase were the parameters considered in this study. The corresponding Langmuir-Blodgett films were characterized with scanning electron microscopy (SEM). The SEM images of the films at different pH, temperature ａnd salt environment showed a diversity of the copolymer arrangement at the air-water interface which corroborated with the explanation obtained from π-A isotherms analyses. The study revealed that the sequence of the block did not affect the nature of isotherm, instead the ratio of PPO/PEO ａnd molecular weight played significant role in determining the characteristics of the films. This basic interfacial study on tetronics was not only a part of fundamental property-study but would definitely be helpful to design potential application involving tetronics in various fields.

Link：https://www.sciencedirect.com/science/article/abs/pii/S0927775721007937

5. Name：Reversible Photoisomerization in Thin Surface Films from Azo-Functionalized Guanosine DerivativesAuthors：Matjaž LičenMatjaž, Stefano Masiero, Silvia Pieraccini, ａnd Irena Drevenšek-Olenik

Journal：ACS Omega

DOI: 10.1021/acsomega.1c01879

Abstract：Two novel azo-functionalized guanosine derivatives were synthesized, ａnd their photoisomerization process was investigated in molecular monolayers at the air–water interface ａnd in the Langmuir–Blodgett (LB) films on solid substrates. Measurements of surface pressure vs area isotherms, surface potential measurements, UV–visible (vis) absorption spectroscopy, Brewster angle microscopy (BAM), ａnd atomic force microscopy (AFM) were performed. Despite not having a typical amphiphilic molecular structure, the derivatives formed stable films on the water surface. They could also undergo repeated photoisomerization in all of the investigated thin-film configurations. The observations suggest that in the films at the air–water interface, the molecules first exhibit a conformational change, ａnd then they reorient to an energetically more favored orientation. In the LB films transferred onto solid substrates, the isomerization process occurs on a similar time scale as in solution. However, the isomerization efficiency is about an order of magnitude lower than that in solution. Our results show that DNA nucleobases functionalized with azobenzene moieties are suitable candidates for the fabrication of photoactive two-dimensional (2D) materials that can provide all beneficial functionalities of DNA-based compounds.

Link：https://pubs.acs.org/doi/abs/10.1021/acsomega.1c01879

6. Name: Facile fabrication of ultra-large graphene film with high photothermal effect ａnd hermal conductivity

Authors: Chenglong Cai, Ting Wang, Yixin Zhang, Nongyue He

Journal: Applied Surface Science

DOI: 10.1016/j.apsusc.2021.150354

Abstract: A macro-scopic ensembles of graphene was considered to be very important for their extensive use. A macro-scopic ensembles of graphene was considered to be very important for their extensive use. Such as electromagnetic-interference shielding, thermal control ａnd sensor. In this work, we developed a facile one-step strategy for ultra-large neat graphene oxide (UN-GO) film with excellent thermal conduction ａnd photothermal conversion property. A Langmuir Blodgett was used as the reactor for self-assembling aqueous graphite oxide (GO) suspensions onto the glass slice to form UN-GO film. The wrinkling density ａnd degree of the close-packed flat UN-GO monolayer were determined by the size of GO sheets. The defect on UN-GO film 2D structure determined the thermal conductivities of the close-packed flat UN-GO. To avoid defect on UN-GO film 2D structure, we modified the substrate with different concentration of (3-aminopropyl) triethoxysilane (APTEs). The internal structure of self-assembled monolayers (SAMs) of APTES fabricated on a glass substrate determined the defect of UN-GO film. Flat APTES-SAMs with integrated molecular structure was a determinant for UN-GO film to form 2D structure with rare defect. Graphene on the of the substrate was 4 layers. With rare detect on 2D structure, thermal conductivity of GO film reached at 2514 W·m -1 ·K-1. One-step process will be with a high potential for large scale production.

Link：https://www.sciencedirect.com/science/article/pii/S0169433221014288

7. Name: Surface Chemistry Studies on the Formation of Mixed Stearic Acid/Phenylalanine Dehydrogenase Langmuir ａnd Langmuir–Blodgett Films

Authors: Rafael Leonardo Cruz Gomes da Silva, Shiv K. Sharma, Suraj Paudyal, Keenan J. Mintz, Roger M. Leblanc, ａnd Luciano Caseli

Journal: Langmuir

DOI: 10.1021/acs.langmuir.1c00934

Abstract:This work investigates the physicochemical properties of mixed stearic acid (HSt)/phenylalanine dehydrogenase enzyme (PheDH) Langmuir films ａnd their immobilization onto solid supports as Langmuir–Blodgett (LB) films. PheDH from the aqueous subphase enters the surfactant matrix up to an exclusion surface pressure of 25.3 mN/m, leading to the formation of stable ａnd highly condensed mixed Langmuir monolayers. Hydrophobic interactions between the enzyme ａnd HSt nonpolar groups tuned the secondary structure of PheDH, evidenced by the presence of β-sheet structures as demonstrated by infrared ａnd circular dichroism spectra. The floating monolayers were successfully transferred to solid quartz supports, yielding Y-type LB films, ａnd then characterized employing fluorescence, circular dichroism, ａnd microscopic techniques, which indicated that PheDH was co-immobilized with HSt proportionally to the number of transferred layers. The enzyme fluidized the HSt monolayers, reducing their maximum dipoles when condensed to their maximum, ａnd disorganized the alkyl chains of the fatty acid, as detected with infrared spectroscopy. The stability of the mixed floating monolayers enabled their transfer to solid supports as LB films, which is important for producing optical ａnd electrochemical sensors for phenylalanine whose molecular architecture can be controlled with precision.

Link: https://pubs.acs.org/doi/abs/10.1021/acs.langmuir.1c00934

8. Name: A bactericide peptide changing the static ａnd dilatational surface elasticity properties of zwitterionic lipids at the air-water interface: Relationship with the thermodynamic, structural ａnd morphological properties

Authors: Heung Jin Alves Santana , Luciano Caseli

Journal: Biophysical Chemistry

DOI: 10.1016/j.bpc.2021.106638

Abstract: In this paper, we studied how different hydrophilicity degrees of the polar groups of the lipids dipalmitoylphosphatidylcholine (DPPC) ａnd dipalmitoyl phosphatidylethanolamine (DPPE) influence the interaction of the antibiotic peptide vancomycin (VC), affecting the physicochemical properties of the monolayers, including thermodynamic, rheological, structural ａnd morphological ones. Lipid Langmuir monolayers were prepared at air-water interfaces with VC aqueous solution as subphase ａnd characterized with tensiometry, Brewster angle microscopy, infrared spectroscopy, dilatational, ａnd interfacial shear rheology. The presence of PC or PE groups as polar head groups of the phospholipid monolayers modulated the interaction of VC adsorbing from the aqueous subphase since for DPPC, vancomycin condenses the monolayer, making it less stable, fluid, ａnd more disordered. In contrast, for DPPE, vancomycin expands the monolayer, making it more stable, keeping the compressibility, ａnd leading to the formation of interfacial aggregates, which are not observed for DPPC. We concluded thatelectrostatic interactions induced the insertion of the peptide into the polar heads of the monolayers (DPPE), while hydrophobic interactions, in addition to ion-dipole interactions, induced the adsorption of the peptide onto the polar head of the monolayers (DPPC).

Link: https://www.sciencedirect.com/science/article/pii/S0301462221001204

9. Name: Effect of Cu₂O Substrate on Photoinduced Hydrophilicity of TiO₂ and ZnO Nanocoatings

Authors: Maria V. Maevskaya, Aida V. Rudakova, Alexei V. Emeline ａnd Detlef W. Bahnemann

Journal: Nanomaterials

DOI: 10.3390/nano11061526

Abstract: The effect of a Cu2O substrate on the photoinduced alteration of the hydrophilicity of TiO2 ａnd ZnO surfaces was studied. It was demonstrated that the formation of heterostructures Cu2O/TiO2 ａnd Cu2O/ZnO strongly changed the direction of the photoinduced alteration of surface hydrophilicity: while both TiO2 ａnd ZnO demonstrate surface transition to superhydrophilic state under UV irradiation ａnd no significant alteration of the surface hydrophilicity under visible light irradiation, the formation of Cu2O/TiO2 ａnd Cu2O/ZnO heterostructures resulted in photoinduced decay of the surface hydrophilicity caused by both UV ａnd visible light irradiation. All observed photoinduced changes of the surface hydrophilicity were compared ａnd analyzed in terms of photoinduced alteration of the surface free energy ａnd its polar ａnd dispersive components. Alteration of the photoinduced hydrophilic behavior of TiO2 ａnd ZnO surfaces caused by formation of the corresponding heterostructures with Cu2O are explained within the mechanism of electron transfer ａnd increasing of the electron concentration on the TiO2 ａnd ZnO surfaces.

Link: https://www.mdpi.com/2079-4991/11/6/1526

10. Name: Determining the Dependence of Interfacial Tension on Molecular Area for Phospholipid Monolayers Formed at Silicone Oil–Water ａnd Tricaprylin–Water Interfaces by Vesicle Fusion

Authors: Chiho Kataoka-Hamai ａnd Kohsaku Kawakami

Journal: Langmuir

DOI: 10.1021/acs.langmuir.1c01021

Abstract:Phospholipid monolayers formed at oil–water interfaces have been used to explore biological interface properties. Thus, monolayer systems need to be quantitatively understood. Previously, we investigated the formation of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) monolayers at silicone oil–water interfaces to determine the dependence of interfacial tension, γ, on the area per lipid, a, compared to that of the closely packed monolayers, acp. This study aims to develop a method to obtain the γ–a relationship from the γ–a/acp data by investigating POPC monolayers at the silicone oil–water ａnd tricaprylin–water interfaces. Pendant ｄrop tensiometry was used to obtain the dependence of γ on a/acp. Furthermore, by calculating the surface pressure, Π, from γ ａnd multiplying a/acp with an estimated acp value, the dependence of Π on a was obtained. When a value approximately equal to the a of POPC bilayers was assigned to acp, the resultant Π–a profile partially or approximately completely overlapped with the Π–a isotherms obtained for the monolayers at the air–water interface using a Langmuir trough. The overlap for the silicone oil–water interface occurred at a ≤ 77 Å2, while that for the tricaprylin–water interface occurred in approximately the entire a region. The results indicate that the Π of the condensed monolayers is little affected by bulk oil. Thus, the γ–a relationship for the oil–water interface can be determined by comparing the compression isotherm with the one obtained for the air–water interface.

Link: https://pubs.acs.org/doi/abs/10.1021/acs.langmuir.1c01021

11. Name: Construction of Multifunctional ａnd Adjustable Langmuir–Blodgett Composite Films Containing Black Phosphorus with High Stability for Optically Electrical Applications

Authors: Ran Wang, Na Li, Chongling Wang, Jing Gao, Liting Guo, Zhihui Qin, Jianmin Gu, Mingli Wang, Zhiwei Liu, ａnd Tifeng Jiao

Journal: Langmuir

DOI: 10.1021/acs.langmuir.1c01260

Abstract: Fabrication of composite thin-film materials based on black phosphorus (BP) will greatly broaden the applications of BP in various areas. However, it is still a challenge to prepare a BP-based composite film with good stability ａnd controllable structure. In this work, a series of BP-based composite Langmuir–Blodgett (LB) films are prepared by the self-assembly of polyethyleneimine (PEI)-modified BP nanosheets (BPNSs) (BPNS-PEI) ａnd dye molecules. The presence of PEI greatly improves the stability of BPNSs. As for BPNS-PEI ａnd dye molecules, the electrostatic interactions or π–π stacking interactions ensure the formation of stable composite LB films. Due to the protonation ａnd deprotonation of amino groups, the synthesized BPNS-PEI/dye composite films show a sensitive response to acid ａnd alkali gases, which shows wide application prospects as a highly sensitive gas sensor. Furthermore, surface-enhanced Raman scattering (SERS) proves that the prepared LB films exhibit good reproducibility ａnd obvious Raman enhancement effect on rhodamine 6G molecules. In addition, due to the high carrier transfer rate of the obtained composite films, they possess enhanced photocurrent generation performance than pure BPNS-PEI ａnd pure dye films. The current work demonstrates an effective method for preparing the ordered self-assembled BP-based composite LB films with good SERS ａnd photoelectric conversion performance.

Link：https://pubs.acs.org/doi/abs/10.1021/acs.langmuir.1c01260

12. Name：Towards the systematic design of multilayer O/W emulsions with tannic acid as an interfacial antioxidant

Authors：Savvia Alexandraki ａnd Epameinondas Leontidis

Journal： The Royal Society of Chemistry

DOI: 10.1039/D1RA03512F

Abstract：This work discusses the possibility of designing multilayer oil-in-water emulsions to introduce the maximum possible amount of an antioxidant at the droplet interfaces for the optimal protection of a linseed oil core against oxidation, using a systematic three-step colloidal procedure. An antioxidant (here Tannic Acid – TA) is chosen ａnd its interactions with a primary emulsifier (here Bovine Serum Albumin – BSA) ａnd several polysaccharides are first examined in solution using turbidity measurements. As a second step, LbL deposition on solid surfaces is used to determine which of the polysaccharides to combine with BSA ａnd tannic acid in a multilayer system to ensure maximum presence of tannic acid in the films. From UV-vis ａnd polarization modulation infrared reflection–absorption (PM-IRRAS) spectroscopic measurements it is suggested that the best components to use in a multilayer emulsion droplet, together with BSA ａnd TA, are chitosan ａnd pectin. BSA, chitosan ａnd pectin are subsequently used for the formation of three-layer linseed oil emulsions, ａnd tannic acid is introduced into any of the three layers as an antioxidant. The effect of the exact placement of tannic acid on the oxidative stabilization of linseed oil is assessed by monitoring the fluorescence of Nile red, dissolved in the oil droplets, under the attack of radicals generated in the aqueous phase of the emulsion. From the results it appears that the three-stage procedure presented here can serve to identify successful combinations of interfacial components of multilayer emulsions. It is also concluded that the exact interfacial placement of the antioxidant plays an important role in the oxidative stabilization of the valuable oil core.

Link：https://pubs.rsc.org/en/content/articlehtml/2021/ra/d1ra03512f

13. Name：Direct causality between film formation ａnd water-retaining effect of surfactant-based film-forming curing compound for concrete

Authors：Yoko Ito, Yuya Sakai, Rie Makiura, Seunghyun Na, TaroToyota

Journal：Journal of Building Engineering

DOI: 10.1016/j.jobe.2021.102930

Abstract：Surfactant-based film-forming curing compounds (SFCCs) are widely used to retain water on fresh concrete by forming multilayered films. However, the water-retaining mechanism is not yet fully understood; therefore, we aimed to clarify this mechanism, thereby potentially aiding in evaluating the effect of SFCC or to develop more effective SFCCs. It was confirmed that SFCC does not hinder the setting ａnd hardening properties or strength development. Thus, we examined water evaporation from cement pastes on which SFCC was sprayed. Consequently, the water-retaining effect lasted up to 8 h, which indicating that 8 h after spraying SFCC is enough time for suppression of plastic cracking. We then observed the water surface on which SFCC was spread under a Brewster angle microscope ａnd discovered that SFCC on the water surface forms continuous thin film ａnd agglomerates. The water-retaining effect was higher when a continuous thin film was formed; thus, the observation of this thin film facilitated the evaluation of the effect of SFCC.

Link:https://www.sciencedirect.com/science/article/pii/S2352710221007889

14. Name：Insight into the Ionizing Surface Potential Method ａnd Aqueous Sodium Halide SurfacesAuthors：Tehseen Adel, Ka Chon Ng, Maria G. Vazquez de Vasquez, Juan Velez-Alvarez, ａnd Heather C. Allen

Journal：Langmuir

DOI: 10.1021/acs.langmuir.1c00465

Abstract：Complementing the microscopic picture of the surface structure of electrolyte solutions set out by previous theoretical ａnd experimental studies, the ionizing surface potential technique offers a unique approach to quantifying the impact of aqueous inorganic ions upon the interfacial electric field of the air–aqueous interface. In this Feature Article, we review the vulnerability of theoretical ａnd empirically derived χwater values as a normative reference for aqueous ion surface potentials. Instead, we recognize ａnd evaluate aqueous ion surface potentials relative to well-known ionic surfactants cetyltrimethylammonium bromide (CTAB) ａnd sodium dodecyl sulfate (SDS). Additionally, we also explore factors that impact the magnitude of the measured surface potentials using the ionizing method, particularly in the type of reference electrode ａnd ionizing gas environment. With potential measurements of sodium halide solutions, we show that iodide has a dominant effect on the air–aqueous electric field. Compared to chloride ａnd bromide, iodide is directly observed with a net negatively charged surface electric field at all salt concentrations measured (0.2 to 3.0 mol/kg water). Also, above the 2 M region, bromide is observed with a net negatively charged surface. Although several scenarios contribute to this effect, it is most likely due to the surface enrichment of bromide ａnd iodide. While the results of this study are pertinent to determining the specific interfacial reactivity of aqueous halides, these anions seldom transpire as single-halide systems in the natural environment. Therefore, we also provide an outlook on future research concerning surface potential methods ａnd more complex aqueous electrolyte systems.

Link：https://pubs.acs.org/doi/abs/10.1021/acs.langmuir.1c00465

15. Name：Interactions of fungal phospholipase Lecitase ultra with phospholipid Langmuir monolayers – Search for substrate specificity ａnd structural factors affecting the activity of the enzymeAuthors: Paulina Perczyk, Roksana Gawlak, Marcin Broniatowski

Journal：Biochimica et Biophysica Acta (BBA) - Biomembranes

DOI: 10.1016/j.bbamem.2021.183687

Abstract：Inoculation of selected microbial species into the soils is one of the most effective means of bioremediation of soils polluted by persistent organic pollutants as well as of biocontrol of plant pests. However, this procedure turns out frequently to be ineffective due to the membrane-destructive enzymes secreted to the soil by the autochthonous microorganisms. Especial role play here phospholipases ａnd among them phospholipase A1 (PLA1), Therefore, to explain the interactions of microbial membranes ａnd PLA1 at molecular level ａnd to find the correlation between the composition of the membrane ａnd its resistance to PLA1 action we applied phospholipid Langmuir monolayers as model microbial membranes. As a representative soil extracellular PLA1 we applied Lecitase ultra which is a commercially available hybrid enzyme of PLA1 activity. With the application of specific sn1-ether-sn2-ester phospholipids we proved that Lecitase ultra has solely PLA1 activity; thus, can be applied as an effective model of soil PLA1s. Our studies proved that this enzyme has vast substrate specificity ａnd can hydrolyze structural phospholipids regardless the structure of their polar headgroup. It turned out that the hydrolysis rate was controlled by the condensation of the model membranes. These built of the phospholipids with long saturated fatty acid chains were especially resistant to the action of this enzyme, whereas these formed by the 1-saturated-2-unsaturated-sn-glycero-3-phospholipids were readily degraded.Regarding the polar headgroup we proposed the following row of substrate preference of Lecitase ultra: phosphatidylglycerols > phosphatidylcholines > phosphatidylethanolamines > cardiolipins.

Link：https://www.sciencedirect.com/science/article/pii/S0005273621001371

原创作者：瑞典百欧林科技有限公司