- 标题
- 摘要
- 关键词
- 实验方案
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Vacuum-UV of polyetheretherketone (PEEK) as a surface pre-treatment for structural adhesive bonding
摘要： Polyetheretherketone (PEEK) is known for its poor wettability and poor adhesive properties. Hence, for the creation of reliable high-strength structural adhesive bonded joints, surface treatment of PEEK is required. In this work high strength bondable PEEK surfaces were achieved through a vacuum-UV (VUV) treatment. Samples of amorphous and semi-crystalline PEEK films were exposed to different VUV radiation doses. Additionally oxygen low-pressure plasma (LPP) and untreated (as received) PEEK samples were investigated for comparison. Surfaces were characterized using x-ray photoelectron spectroscopy (XPS), contact angle measurements (CA), atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). Tensile tests of the PEEK films were carried out, to investigate changes in the mechanical properties in the bulk of the PEEK films due to the VUV exposure. The adhesive bond strength of treated specimen was determined through two different test methods (tensile and shear). These strengths were compared to the created surface properties. A strong correlation between the contact angle and the creation of functional groups was observed. VUV radiation appears as a suitable pre-treatment method for PEEK, as adhesive bonds of high strength were achieved after 5 seconds. Additionally, the usage of a VUV excimer lamp is simple, cheap and easy for automation.
关键词： X-ray photoelectron spectroscopy,Vacuum-UV (VUV),contact angles,chemical surface functionalization,structural adhesive bonding,Polyetheretherketone (PEEK),atomic force microscopy
更新于2025-09-11 14:12:44
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One-step bonding and hydrophobic surface modification method for rapid fabrication of polycarbonate-based droplet microfluidic chips
摘要： Chip bonding and hydrophobic surface modification are two critical processes for the fabrication of a droplet microfluidic chip from the thermoplastic polycarbonate (PC) material. In this paper, we describe a novel one-step method, which simultaneously bonded and modified two PC substrates. The mechanism of this one-step method is that n-pentane acts as a sacrificial solvent and acetone is the solvent that bonds the PC substrates. Additionally, entrapment functionalization and the Si-O-Si cross-linked network play a central role in the hydrophobic surface modification process. The method was optimized to achieve a high bonding strength, low surface roughness, and high optical transmittance. The naturally hydrophilic PC substrate surface was modified to become a hydrophobic surface, with surface tension decreased from 33.6 mN/m to 14.8 mN/m. Monodisperse droplets generated using a droplet generation chip fabricated by this method had an average diameter of 101.3 μm and coefficient of variation of 0.55%. A droplet digital polymerase chain reaction experiment was successfully carried out using droplets generated from this chip, which demonstrated the effectiveness of this method. This novel one-step method holds great potential for manufacturing droplet-based microfluidic chips using PC in large-scale, and it may have broad applications in microfluidic research fields.
关键词： chip bonding,droplet digital PCR,entrapment functionalization,droplet microfluidics,hydrophobic surface modification
更新于2025-09-10 09:29:36
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Direct β-Selective Styrylation of BODIPY Dyes via Palladium(II)-Catalyzed C-H Functionalization
摘要： A general and efficient method for direct β-selective styrylation of BODIPYs has been developed based on Palladium(II)-catalyzed oxidative C-H functionalization. The high β-regioselectivity was confirmed by X-ray analysis. The resulting dyes showed bathochromically shifted absorption and emission compared to that of the starting BODIPYs. This strategy, as a late-stage approach to rapidly assemble a diversity-oriented BODIPY library, provides a straightforward way to extend the conjugation of the BODIPY system at 2,6-positions.
关键词： oxidative C-H functionalization,Fluorescence,β-selective styrylation,BODIPY
更新于2025-09-10 09:29:36
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Gram Scale Synthesis of Isolated Monodisperse Gold Nanorods
摘要： While the gold nanorods (AuNRs) possess a strong potential application in nanotechnology, plasmonics and sensing, the scale-up synthesis of isolated AuNRs in gram quantity remains a challenge. Nearly all previously reported methods produce aqueous solutions of CTAB-coated AuNRs in milligram quantities with the yield of ~20-30 % in terms of Au (I) to Au (0) conversion. In addition, it is difficult to remove CTAB bilayer from the surface of AuNRs and yet make them soluble and functionalized for further processing and chemical modification. This report describes the synthesis of monodisperse functionalized AuNRs (σ~5%) in gram quantities. Our approach is to increase the concentration of HAuCl4.3H20 in the growth solution to produce larger quantities of starting AuNRs and further reduce the remaining Au (I) ions onto the surface of AuNRs. The slow and controlled addition of reducing agent ascorbic acid (AA) continues to Au (0) (via disproportionation reaction) onto the surface of nanorods maintaining their uniform morphology without creating any unwanted impurities of various shapes. In addition, this approach significantly narrows the size distribution due to the continuous growth of partially grown AuNRs during the initial stage of the synthesis. To isolate one-gram quantity of AuNRs and make them functionalized for further chemical reactions, a ligand exchange approach was utilized where surfactant CTAB was replaced with 4-mercaptophenol. The thiol group from 4-mercaptophenol forms a covalent bond to the surface of AuNRs leaving free functional OH groups available for further chemical coupling reactions. For the ligand exchange process, a concentrated solution of 4-mercaptophenol in tetrahydrofuran (THF) solution was introduced into the AuNRs solution. Pure AuNRs, functionalized with 4-mercaptophenol were isolated by dispersion and rinsing with excess of THF, followed by centrifugation.
关键词： Amplification,Surface Functionalization,Gram Scale,Monodisperse,Gold Nanorods
更新于2025-09-10 09:29:36
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Ionic liquid-mediated functionalization of graphene-based materials for versatile applications: a review
摘要： Industrial applications of the graphene (G) and graphene oxide (GO) can be further explored by making them more dispersible in the aqueous and organic environments. Several attempts have been performed to enhance the dispersity of the G and GO in which surface functionalization is one of the most effective methods. Recently, surface functionalization of G and GO using ionic liquids is gaining particular emphasis because of their high thermal and chemical stability, low volatility, very high ability to dissolve a wide range of compounds and more importantly their environmental-friendly behaviour. The covalent functionalization of G and GO is mostly being achieved by acylation, esterification, isocyanate formation, nucleophilic ring opening, amide formation, and diazotization and cycloaddition reactions. Non-covalent functionalization mostly involves electrostatic forces, hydrogen bonding, π–π interactions, van der Waals interaction and donor–acceptor interactions. Because of their high dipolar nature, ionic liquids strongly interact with the sp2-hydrodized carbon networks of G and GO sheets and make them more dispersible as compared to their native networks. In the present review article, we described the collection of reports available on covalent and non-covalent functionalization of G and GO using ionic liquids and their industrial applications. The ionic liquid-functionalized graphene (G-IL) and graphene oxide (GO-IL) are extensively used in pollutants decontamination, sensing and bio-sensing, lubrication, catalysis, and carbon dioxide capturing and hydrogen production. The G-IL and GO-IL represent an essential class of materials for versatile future applications.
关键词： Dispersibility,Functionalization,Nanomaterials,Ionic liquids,Graphene-based materials,Sustainable chemistry
更新于2025-09-10 09:29:36
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Construction of donor-acceptor type conjugated microporous polymers: a fascinating strategy for the development of efficient heterogeneous photocatalysts in organic synthesis
摘要： Metal-free, visible-light driven, solid organic photocatalysts provide a more green and environmentally friendly alternative to traditional metal-based photocatalysts. Donor-Acceepor (D-A) dyads possess a feature of easy to adjust the photoelectric properties, and enhance their photocatalytic performances. Here we report a fascinating strategy for screening excellent organic porous photocatalysts through oxidative coupling of single D-A based monomer, which has still an important advantage to ensure uniformity of polymer structure except for the inherent characteristics of D-A polymers. According to this strategy, three D-A typed conjugated microporous polymer (DA-CMP) photocatalysts consisting of alternating electron-rich (carbazole) and electron-deficient (benzene, 4,7-diphenyl-2,1,3-benzothiadiazole or anthraquinone) units have been synthesized, and their porosity and photoelectric properties including adsorption, emission, lifetime, optical bandgaps, energy levels and transient photocurrent response as well as photocatalytic activity, were conveniently tuned by selecting different D-A monomers with tunable electron-deficient moiety. These DA-CMPs were exploited as metal-free photocatalysts in the oxidative C-H functionalization reactions in the presence of visible-light and molecular oxygen. They showed excellent photocatalytic activity, extensive substrate adaptability and outstanding reusability, due to combining some key features like permanent porosity, outstanding stability and optoelectronic properties. In addition, the reaction mechanism for DA-CMP photocatalyzed C-H functionalization reactions under visible-light irradiation was investigated in detail. Moreover, to prove in depth the benefits of the heterogeneous photocatalysis, a continuous flow procedure has been conducted with an excellent yield.
关键词： flow chemistry,aerobic reaction,conjugated microporous polymers,C-H functionalization,heterogeneous photocatalysis
更新于2025-09-10 09:29:36
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[Topics in Organometallic Chemistry] || Green Cross-Coupling Using Visible Light for C–O and C–N Bond Formation
摘要： The development of green and sustainable approaches in organic synthesis can provide an environmentally friendly method in the industrial manufacture. Recently, visible-light-mediated photocatalysis has achieved great progress and been a powerful tool to the construction of new chemical bonds in the green synthetic community. This chapter provides an updated summary of visible-light-mediated cross-coupling for C–O and C–N bond formations. Compared with the traditional synthetic methods, the visible-light catalysis provides a new way for the useful compounds synthesis (O-containing and N-containing molecules).
关键词： Visible light,C–O bond,Photoredox catalysis,C–H functionalization,Cross-coupling,C–N bond
更新于2025-09-09 09:28:46
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Tunable multi-color luminescence and white emission in lanthanide ion functionalized polyoxometalate-based metal–organic frameworks hybrids and fabricated thin films
摘要： In this paper, luminescent hybrid material systems are prepared with porous polyoxometalate-based metal-organic framework (POM-based MOF)[La(H2O)4(pdc)]4}[SiMo12O40]$2H2O (1) through the introduction of lanthanide ions (Ln3+, Ln = Eu, Tb, Sm, Dy, Eu/Tb, Dy/Eu) by a solvothermal approach. The POM-based MOF serves as a host for protecting the luminescence of Ln3+ cations. The structure, thermal stability, ultraviolet absorption and visible light emission of the target hybrid materials are determined with powder X-rays diffraction patterns (PXRD), Fourier transform infrared spectra (FTIR), thermal-gravimetric analysis (TGA), inductively coupled plasma-mass spectrometry (ICP-MS) analysis, energy dispersive spectrometer (EDS), ultraviolet visible diffusion reflections spectra (UV-vis DRS) and especially luminescence spectra. The final luminescence of the Ln3+ hybrids can be adjusted by changing the composition of Ln3+ cations or converting the excitation wavelengths of them. Among [La0.95Dy0.045Eu0.005(H2O)4(pdc)]4}[SiMo12O40]$2H2O (Dy3+/Eu3+@1) emits white luminescence under the excitation at 295 nm and the Commission Internationale de L'Eclairage (CIE) chromaticity coordinate of it is (0.361, 0.3408). Moreover, we manufacture POM-based MOF thin films by using ethyl methacrylate (EMA) to assemble the POM-based MOF on a quartz plate as substrate. The hybrid thin films based on {La0.95Eu0.05(H2O)4(pdc)]4}[SiMo12O40]$2H2O (Eu3+@1) and La0.95Eu0.04Tb0.01(H2O)4(pdc)]4}[SiMo12O40]$2H2O (Eu3+/Tb3+@1) can also achieve white-light. The CIE chromaticity coordinates of them are (0.3425, 0.2548) and (0.3857, 0.3377), respectively.
关键词： Thin film,Lanthanide functionalization,Photofunctional hybrid material,Polyoxometallate based metal-organic frameworks,Luminescence
更新于2025-09-09 09:28:46
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Lewis-Acid-Catalyzed BODIPY Boron Functionalization Using Trimethylsilyl Nucleophiles
摘要： A novel and straightforward strategy for boron functionalization in boron dipyrromethenes (BODIPYs) is developed. In particular, this synthetic strategy provides new possibilities for the synthesis of sp2 N-substituted (B-NCS and -NCO), benzotriazole- and trifluoroacetamide-substituted BODIPYs that were hitherto unknown. These new BODIPYs display an array of highly desirable photophysical properties (0.04 < Φ f < 0.86), paving the road for further investigations in material applications.
关键词： photophysical properties,boron functionalization,trimethylsilyl nucleophiles,Lewis acid catalysis,BODIPY
更新于2025-09-09 09:28:46
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[Methods in Molecular Biology] Atomic Force Microscopy Volume 1886 (Methods and Protocols) || Molecular Recognition Force Spectroscopy for Probing Cell Targeted Nanoparticles In Vitro
摘要： In the development and design of cell targeted nanoparticle-based systems the density of targeting moieties plays a fundamental role in allowing maximal cell-specific interaction. Here, we describe the use of molecular recognition force spectroscopy as a valuable tool for the characterization and optimization of targeted nanoparticles toward attaining cell-specific interaction. By tailoring the density of targeting moieties at the nanoparticle surface, one can correlate the unbinding event probability between nanoparticles tethered to an atomic force microscopy tip and cells to the nanoparticle vectoring capacity. This novel approach allows for a rapid and cost-effective design of targeted nanomedicines reducing the need for long and tedious in vitro tests.
关键词： Targeted nanoparticles,Tailored nanomedicine,Tip functionalization,Single molecule force spectroscopy,Drug delivery
更新于2025-09-09 09:28:46