百欧林简报-表界面科学最新文献- KSV NIMA -2020年第4期

1. Name：Langmuir-Blodgett films of two chiral perylene bisimide-based molecules: aggregation ａnd supramolecular chirality

Authors：Kai Ma, Ran Wang, Yandi Rao, Wei Zhao, Shufeng Liu ａnd Tifeng Jiao

Journal：Colloids ａnd Surfaces A: Physicochemical ａnd Engineering Aspects

DOI: 10.1016/j.colsurfa.2020.124563

Abstract：Perylene bisimide (PBI) ａnd its derivatives as building blocks for constructing nanostructures with functional properties have achieved considerable attention due to their applications in many fields. In this work, two chiral PBI derivatives (C6-SNPR ａnd STDI2) molecules were utilized to prepare films by Langmuir-Blodgett (LB) technique at room temperature. Both molecules could form organized assemblies at air/water interface spontaneously by intermolecular interactions. The results of the morphological characterization showed that the facial chiral C6-SNPR molecules could self-assemble into nanoparticles with diameter about 40 nm, while the axil chiral STDI2 molecules formed irregular nanostructures at different surface pressures. The CD results showed that the self-assembled LB films of C6-SNPR were optically active while the one of STDI2 were CD silent. The relatively large steric hindrance ａnd long spacer length in the side chains of STDI2 lead to weaker electron coupling between the neighboring molecules. Therefore, the aggregates of STDI2 exhibited CD silent in the self-assembly LB films. Moreover, the LB films of C6-SNPR showed circular polarized luminescence with relatively high glum vale about 10−3. The obtained films with excellent CD ａnd CPL properties by LB method may provide a new clue for preparing chiral optical materials.

Link：https://www.sciencedirect.com/science/article/pii/S0927775720301564

2. Name：Facile Synthesis of Self-Assembled NiFe Layered Double Hydroxide-Based Azobenzene Composite Films with Photoisomerization ａnd Chemical Gas Sensor Performances

Authors：Ying He, Ran Wang, Chenguang Sun, Shufeng Liu, Jingxin Zhou, Lexin Zhang, Tifeng Jiao ａnd Qiuming Peng

Journal：ACS Omega

DOI: 10.1021/acsomega.9b04290

Abstract：Two kinds of layered double hydroxide (LDH) Langmuir composite films containing azobenzene (Azo) groups were successfully prepared by Langmuir–Blodgett (LB) technology. Then, an X-ray diffractometer (XRD), a transmission electron microscope (TEM), ａnd an atomic force microscope (AFM) were used to investigate the structures of NiFe-LDH ａnd the uniform morphologies of the composite LB films. The photoisomerization ａnd acid–base gas sensor performances of the obtained thin film samples were tested by infrared visible (FTIR) spectroscropy ａnd ultraviolet visible (UV–vis) spectroscropy. It is proved that the Azo dye molecules in the composite film are relatively stable to photoisomerization. In addition, the prepared composite films have high sensing sensitivity ａnd good recyclability for acid–base response gases. The present research proposes a new clue for designing thin film materials for chemical gas response with good stability ａnd sensitivity.

Link：https://pubs.acs.org/doi/abs/10.1021/acsomega.9b04290

3. Name：Ionic environment affects bacterial lipopolysaccharide packing ａnd function

Authors：Ali Rahnamoun, Kyoungtea Kim, Joel A. Pedersen, Rigoberto Hernandez

Journal：Langmuir

DOI: 10.1021/acs.langmuir.9b03162

Abstract：The interaction of lipopolysaccharides (LPS) with metal cations strongly affects the stability ａnd function of the Gram-negative bacterial outer membrane. The sensitivity of deep rough (Re) LPS packing ａnd function to the ionic environment, as affected by cation valency ａnd ionic radius, has been determined using molecular dynamics simulations ａnd Langmuir balance experiments. The degree of LPS aggregation within the LPS models in the presence of different cations is assessed by measuring the effective mean molecular area (Âm) of each LPS molecule projected onto the interfacial plane at the end of the equilibration. These results are compared to the LPS mean molecular area from experimental measurements in which the LPS monolayers are assembled at the air-water interface using a Langmuir film balance. We found that packing of the LPS arrays is sensitive to the ionic radius ａnd ion valency of the cations present in solution during LPS array packing. Using enhanced sampling of the free energy for the intercalation of oligo(allylamine HCl) (OAH) into deep rough Salmonella enterica LPS bilayers, we obtained the affinity of the core section of LPS to OAH as a function of the nature of the metal cations present in solution. We found that packing of the solvated LPS bilayer models is sensitive to ionic radius ａnd ion valency of the neutralizing cations. This further suggests that ion bridging ａnd steric barriers rather than charge shielding are important factors in mitigating ligand intercalation under conditions with low ionic concentrations.

Link：https://pubs.acs.org/doi/abs/10.1021/acs.langmuir.9b03162

4. Name：Evolution of Nickel-Stearate Langmuir Monolayers ａnd the Synthesized NiOx Ultra-Thin Films with pH

Authors：Amanpreet Kaur, Palvi Pruthi, Loveleen K.Brar

Journal：Materials Today: Proceedings

DOI: 10.1016/j.matpr.2020.01.280

Abstract：In this work Ni-Stearate (Ni-St) Langmuir-Blodgett (LB) films are oxidized to synthesize uniform ultra-thin films of Nickel oxide (NiOx). Pressure-Area (π-A) isotherms ａnd oscillatory barrier method are used to examine the Ni-St Langmuir monolayers. Increase in the sub-phase pH during Langmuir monolayer formation results in higher compaction ａnd elasticity for the solid phase. NiOx thin films synthesized with 15 layers of Ni-St at pH 7.9 are continuous, uniform ａnd have a band gap of 4.04 eV. Changing the value of pH results in non-continuous films. XRD of the 200 layer films identifies the final phase formation after sintering as Ni2O3.

Link：https://sciencedirect.xilesou.top/science/article/pii/S2214785320303515

5. Name：Mechanism of activation of plant monogalactosyldiacylglycerol synthase 1 (MGD1) by phosphatidylglycerol

Authors：Milène Nitenberg, Olga Makshakova, Joana Rocha, Serge Perez, Eric Maréchal, Maryse A Block, Agnès Girard-Egrot ａnd Christelle Breton

Journal：Glycobiology

DOI: 10.1093/glycob/cwz106

Abstract：Mono- ａnd digalactosyldiacylglycerol are essential galactolipids for the biogenesis of plastids ａnd functioning of the photosynthetic machinery. In Arabidopsis, the first step of galactolipid synthesis is catalyzed by monogalactosyldiacylglycerol synthase 1 (MGD1), a monotopic protein located in the inner envelope membrane of chloroplasts, which transfers a galactose residue from UDP-galactose to diacylglycerol (DAG). MGD1 needs anionic lipids such as phosphatidylglycerol (PG) to be active, but the mechanism by which PG activates MGD1 is still unknown. Recent studies shed light on the catalytic mechanism of MGD1 ａnd on the possible PG binding site. Particularly, Pro189 was identified as a potential residue implicated in PG binding ａnd His155 as the putative catalytic residue. In the present study, using a multifaceted approach (Langmuir membrane models, atomic force microscopy, molecular dynamics; MD), we investigated the membrane binding properties of native MGD1 ａnd mutants (P189A ａnd H115A). We demonstrated that both residues are involved in PG binding, thus suggesting the existence of a PG-His catalytic dyad that should facilitate deprotonation of the nucleophile hydroxyl group of DAG acceptor. Interestingly, MD simulations showed that MGD1 induces a reorganization of lipids by attracting DAG molecules to create an optimal platform for binding.

Link:https://academic.oup.com/glycob/article-abstract/30/6/396/5748094?redirectedFrom=fulltext

6. Name：Illustrating Interfacial Interaction between Honey bee venom Phospholipase A2 ａnd Supported Negatively Charged Lipids with Sum Frequency Generation ａnd Laser Scanning Confocal Microscopy

Authors：Furong Zhang, Xu Li, Yong-Hao Ma, Chu Wang, Pengcheng Hu, Feng Wang ａnd Xiaolin Lu

Journal：Langmuir

DOI: 10.1021/acs.langmuir.0c00003

Abstract：Phospholipase A2 is an important enzyme species which can widely be found in animals, plants ａnd bacteria, etc. A large number of studies have shown that phospholipase A2 is highly catalytic towards the lipids. Here, sum frequency generation (SFG) vibrational spectroscopy ａnd laser scanning confocal microscopy (LSCM) were applied to study the interaction between honey bee venom phospholipase A2 (bvPLA2) ａnd the negatively charged DPPG bilayer. In both cases without ａnd with the calcium ions (Ca2+), the bvPLA2 molecules were adsorbed onto the outer leaflet surface with the orientational order, ａnd the adsorbed bvPLA2 molecules damaged the order of the packed outer leaflet. In comparison to the case without Ca2+, the addition of Ca2+ can accelerate the attaching process of bvPLA2 to the outer leaflet surface ａnd decelerate the process of damaging the outer leaflet order. The experimental result also confirmed, with the help of the Ca2+, the DPPG molecules in the outer leaflet were hydrolyzed, with both hydrolysates, i.e. lysophospholipids ａnd fatty acids, remained at the interface, showing distinct difference from previous published literatures regarding neutral lipids (Phys. Chem. Chem. Phys. 2018, 20, 63-67) ａnd PLA1 (Langmuir. 2019, 35, 12831-12838).

Link：https://pubs.acs.org/doi/abs/10.1021/acs.langmuir.0c00003

7. Name：Electrochemical properties of nickel phthalocyanine: the effect of thin film morphology tuned by deposition techniques

Authors：Leonardo N.Furini, Cibely S.Martin, Sabrina A.Camacho, Rafael J.G.Rubira, José Diego Fernandes, Edilene A.Silva, Tiago C.Gomes, Gabriele M.Stunges, Carlos J.L.Constantino ａnd Priscila Alessio

Journal：Thin Solid Films

DOI: 10.1016/j.tsf.2020.137897

Abstract：The electrical ａnd optical properties of thin films can be modulated by its supramolecular arrangement being this latter closely related to the fabrication method. Here, we are exploiting the impact of deposition techniques of nickel phthalocyanine (NiPc) ａnd tetrasulfonated nickel phthalocyanine (NiTsPc) thin films on their supramolecular arrangement. Deposition techniques as Langmuir-Schaffer (LS), Langmuir-Blodgett (LB), physical vapor deposition (PVD), dipping- ａnd spray-Layer-by-Layer (LbL) were applied for fabrication of the thin films. Linear growth was observed for all films indicating control of the amount of NiPc or NiTsPc deposited in each technique at nm scale. Fourier-transform infrared absorption spectroscopy (FTIR) ａnd micro-Raman scattering confirmed the chemical stability of NiPc ａnd NiTsPc concerning the deposition technique (water or heat). Besides, FTIR ａnd X-ray diffraction data suggested that all thin films present isotropy in terms of molecular organization, with a predominance of the crystalline α-phase in the case of PVD, LB, ａnd LS films. Atomic force microscopy images revealed irregularities at the surface for all thin film with the roughness/thickness ratio being 4.5% for PVD, 9% for both LB ａnd LS films, ａnd 18 ａnd 35% for spray- ａnd dipping-LbL films, respectively. The electrochemical behavior in both inert electrolyte ａnd dopamine (DA) solution was directly dependent on the film morphology (molecular aggregates ａnd surface roughness). The increase of the roughness in relation to thickness promoted films better electrochemical responses to DA oxidation. The dipping-LbL films showed the smaller potential of DA oxidation (0.114 V), even compared to the bare substrate (0.133 V). The deposition technique showed to be an suitable tool to tune the supramolecular arrangement of phthalocyanine forming thin films, which improve and/or change the electrochemical properties of the device.

Link：https://www.sciencedirect.com/science/article/abs/pii/S0040609020301127?via%3Dihub

8. Name：Facile Preparation of Self-Assembled Black Phosphorus-Dye Composite Films for Chemical Gas Sensors ａnd Surface-Enhanced Raman Scattering Performances

Authors：Ran Wang, Xiaoya Yan, Bingcheng Ge, Jingxin Zhou, Mingli Wang, Lexin Zhang ａnd Tifeng Jiao

Journal：ACS Sustainable Chemistry & Engineering

DOI: 10.1021/acssuschemeng.9b07840

Abstract：The researches on the functionalization of two-dimensional (2D) materials (such as black phosphorus) are essential for the development of self-assembled nanomaterials. In this work, the composite films based on black phosphorus (BP) ａnd dyes were prepared by Langmuir-Blodgett (LB) technology. In order to make better use of the characteristics of BP, it was exfoliated to form BP nanosheets (BPNS), ａnd then modified with PEI to maintain stability. UV-vis, Raman, Atomic force microscopy (AFM) ａnd other characterizations proves that the composite films are successfully synthesized, which may be attributed to electrostatic forces ａnd π-π stacking forces. Interestingly, the obtained BPNS-PEI-TPPS composite LB film shows good sensitivity to acid ａnd alkali gas. In addition, the results of surface-enhanced Raman scattering (SERS) indicated that the BPNS-PEI-TsNiPc composite film had surface-enhanced performance for crystal violet (CV) molecules. The current work provides new clues for the preparation ａnd development of BP-based self-assembled film materials for gas sensors ａnd SERS.

Link：https://pubs.acs.org/doi/abs/10.1021/acssuschemeng.9b07840

原创作者：瑞典百欧林科技有限公司