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Luminescent materials of covalent grafting lanthanide complexes to the synthetic clays
摘要： Lanthanide complex-based luminescent organic-inorganic hybrid materials are highly interesting for a broad range of application fields. The combination of lanthanide complexes with the synthetic clay, Laponite, is now attracting the interest of scientists due to the unique features of the synthetic clay. However, most of the reported literatures are involved with the adsorption of lanthanide complexes on the clay particles. Taking the covalent incorporation of lanthanide complex into clay and satisfying the further coordinate with central lanthanide ion into account, herein, we reported a facile strategy of covalent grafting lanthanide complexes to the clay via the reaction of the terminal triethoxy groups of triethoxysilylated ligand (phenSi) and the surface OH groups of the clay. The successful grafting of the complexes was confirmed by the FT-IR spectra, 29Si solid-state NMR spectra and the luminescent data. And the nitrogen atoms of Phen moieties which are covalently grafted to the clay provide the chance to prepare luminescent hybrid materials with larger coordination number.
关键词： covalent grafting,lanthanide complexes,Laponite,luminescent materials
更新于2025-11-14 15:18:02
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Robust conductive micropatterns on PTFE achieved via selective UV- induced graft copolymerization for flexible electronic applications
摘要： Fabrication of stable and functional patterns on the surface of polytetrafluoroethylene (PTFE) remains a great technical challenge owing to its inertness and high hydrophobicity. Here, we report for the first time the fabrication of functional micro-patterns on the PTFE surface by selectively irradiating plasma-treated PTFE coated with the monomer solution. A series of uniform, highly dense polydopamine methacrylamide (denoted as PDMA) line patterns with the line/pitch width 20μm/20μm and 50μm/50μm were fabricated on the surface of PTFE (denoted as PDMA-p/PTFE) using dopamine methacrylamide (DMA) as the monomer. The surface graft copolymerization occurs attributed to the universal adsorption of DMA and the low grafting energy barrier, comparing with the polymerization energy barrier, which is also demonstrated by the density functional theory (DFT) calculations. Further, robust, well-defined metal Ag or Cu patterns with the strong adhesion strength are fabricated on the surface the PTFE film by electroless deposition, and demonstrated for applications in flexible electronics. The approach is demonstrated to be versatile for fabrication of PDMA micropatterns onto a wide range of polymeric substrates including polypropylene (PP), and acrylonitrile butadiene styrene (ABS).
关键词： dopamine methacrylamide,UV irradiation,graft copolymerization,metal patterns,Surface grafting,PTFE
更新于2025-09-23 15:23:52
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Synergistic effect of carboxylated-MWCNTs on the performance of acrylic acid UV-grafted polyamide nanofiltration membranes
摘要： Surface modification of a commercial polyamide nanofiltration membrane was achieved by UV induced graft polymerization of acrylic acid and incorporation of carboxylated-MWCNTs (COOH-MWCNTs). The grafting process was done under different monomer concentrations and UV exposure times. The modified membranes were characterized through scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle and zeta-potential analysis, and cross-flow filtration experiments. Changes in the surface hydrophilicity, negative charge and roughness of the modified membranes improved their permeability and fouling resistance significantly. The membrane grafted with 50 g/L acrylic acid under 5 min UV exposure showed the best filtration performance including pure water flux of 38.8 L/m2 h, salt rejections of 97.43% (Na2SO4) and 93.4% (NaCl), and flux recovery ratio (FRR) of 80.2% during bovine serum albumin (BSA) filtration. After optimizing grafting condition, different amounts of COOH-MWCNTs were dispersed in the monomer solution for embedding in the grafting layer. By adding 0.2 wt% COOH-MWCNTs to the grafting layer, a water flux improvement of around 30% was observed. But, excess loading of the COOH-MWCNTs led to compaction of the grafting layer and made it inflexible and subsequently, reduced the hydrophilicity and permeability of the membrane. Fouling tests with BSA aqueous solution showed that antifouling ability of the modified membranes was remarkably improved at all concentrations of the COOH-MWCNTs. Furthermore, salt rejection results displayed that simultaneous surface modification through grafting and COOH-MWCNTs embedding could effectively improve the nanofiltration performance of the membranes in the term of permeability, desalination and fouling resistance.
关键词： Acrylic acid,Nanofiltration,Antifouling,Surface modification,Multiwalled carbon nanotube,Grafting
更新于2025-09-23 15:23:52
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Prediction models for different plaque morphology in non-significantly stenosed regions of saphenous vein grafts assessed with optical coherence tomography
摘要： Introduction: Coronary artery bypass grafting (CABG) is a method of choice in treatment of diffuse coronary artery disease (CAD), although it has some limitations such as late saphenous vein graft (SVG) patency loss, which occurs in one fifth of all conduits at 5 years. Since atherosclerosis in SVG has diffuse characteristics, it appears that significantly and non-significantly stenosed lesions may have an equal impact on worse prognosis. Aim: To assess non-significant lesions of SVG by the use of optical coherence tomography (OCT) and investigate the clinical and laboratory findings with the potential impact on plaque composition. Material and methods: Twenty-nine patients with 43 non-significant lesions were enrolled in the study. All variables were assessed using uni- and multivariable logistic regression analysis with each plaque morphology as a dependent variable. Odds ratio (OR) and 95% confidence interval (CI) were computed. Results: Plaque rupture (PRT) was independently associated with age (OR = 1.49, 95% CI: 1.09–2.04, p = 0.015) and lower rates of high-density lipoproteins (HDL) cholesterol (OR = 0.67, 95% CI: 0.49–0.92, p = 0.016). Intimal tearing or rupture (ITR) was related to reduced GFR (OR = 0.52, 95% CI: 0.38–0.72, p = 0.0004). Lipid-rich plaque (LRP) was associated with raised platelet count (PLT) (OR = 1.51, 95% CI: 1.16–1.96, p = 0.004) and increased frequency of smoking (OR = 1.45, 95% CI: 1.12–1.89, p = 0.007). Conclusions: Atherosclerosis of SVG is not restricted to significantly stenosed lesions. Plaque composition is independently associated with different types of clinical and laboratory findings, mostly recognized as risk factors of CAD.
关键词： coronary artery disease,optical coherence tomography,saphenous vein graft coronary artery bypass grafting
更新于2025-09-23 15:22:29
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Harnessing polymer grafting to control the shape of plasmonic nanoparticles
摘要： Matrix-free polymer grafted nanoparticles (NPs) are single component polymer nanocomposites (PNCs) for which the often reported severe aggregation of the conventional PNCs can be suppressed. For a given particle core, the size and shape of the polymer grafted nanoparticles can be controlled by the molecular weight of the polymer and its grafting density. However, the degree of homogeneity of one-component PNCs depends on the grafted chain molecular weight and grafting density, as well as on the shape of grafted NPs. Surface plasmon resonance enhanced dynamic light scattering from very dilute solutions, yielding both translational and rotational transport coefficients, complemented by UV–Vis extinction spectra, can detect deviations from spheres. Here, we report that poly(isobutylene)-grafted Ag NPs strongly deviate from the spherical shape and are modeled as prolate spheroids. This NP asphericity, due to inhomogeneous grafting, can impact the structure and properties of plasmonic PNCs in the solid state. Thus, characterizing this behavior is a crucial step prior to the formation of one-component PNCs.
关键词： shape control,polymer grafting,dynamic light scattering,UV–Vis extinction spectra,plasmonic nanoparticles
更新于2025-09-23 15:21:01
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Peripheral RAFT Polymerization on a Covalent Organic Polymer with Enhanced Aqueous Compatibility for Controlled Generation of Singlet Oxygen
摘要： A covalent organic polymer (COP) is prepared by 4,4’,4’’,4’’’-(porphyrin-5,10,15,20-tetrayl)tetraaniline (TAPP) with 4,4’-(anthracene-9,10-diyl)dibenzoic acid (ADDA) via 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/4-dimethylaminopyridine coupling. The COP is further modified with a hydrophilic polymer, poly(poly(ethylene glycol) methyl ether methacrylate) by grafting-from reversible-addition-fragmentation chain transfer (RAFT) polymerization to enhance its solubility in various solvents. The modified COP can bind singlet oxygen through the formation of endoperoxide by ADDA upon the exposure to red light irradiation. Singlet oxygen can be then released via the photodynamic mechanism or the cycloreversion by endoperoxide when heated at 110 8C. These results open new possibilities for simultaneous generation of singlet oxygen by the photodynamic route and singlet oxygen carriers, demonstrating promise for treating hypoxic tumors.
关键词： endoperoxides,grafting-from,covalent organic polymers,singlet oxygen,photodynamic mechanism
更新于2025-09-23 15:21:01
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Peripheral RAFT polymerization on covalent organic polymer with enhanced aqueous compatibility for controlled generation of singlet oxygen
摘要： The efficient generation of singlet oxygen has attracted a great deal of interest in various fields such as medicine, synthetic chemistry and materials science. In this study, a covalent organic polymer (COP) is prepared by crosslinking the photosensitizer 4,4',4'',4'''-(porphyrin-5,10,15,20-tetrayl)tetraaniline (TAPP) with 4,4'-(anthracene-9,10-diyl)dibenzoic acid (ADDA) via the 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC)/4-dimethylaminopyridine (DMAP) coupling method. The COP is further modified with a hydrophilic polymer i.e. poly(poly(ethylene glycol) methyl ether methacrylate) through grafting-from reversible addition–fragmentation chain transfer (RAFT) polymerization to enhance its solubility in various solvent systems. The modified COP can bind with singlet oxygen through the formation of endoperoxide by ADDA upon the exposure to the red light irradiation. The singlet oxygen incorporated in COP can be then released via the photodynamic mechanism or the cycloreversion by endoperoxide when heated at 110 ℃. Our results have opened new possibilities for simultaneous generation of singlet oxygen by the dual mechanisms, i.e. photodynamic route and singlet oxygen carrier, which demonstrates the promising potential for treating hypoxic tumors.
关键词： RAFT,red LED,photodynamic,grafting from,singlet oxygen,covalent organic polymer,endoperoxides
更新于2025-09-23 15:19:57
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Fluorescent patterns by Selective Grafting of a Telechelic Polymer
摘要： The preparation of patterned ultrathin films (sub-10 nm) composed of end-anchored fluorescently-labeled poly(methyl methacrylate) (PMMA) is presented. Telechelic PMMA was synthesized utilizing activator regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) and consecutively end-functionalized with alkynylated fluorescein by Cu-catalyzed azide-alkyne cycloaddition (CuAAC) 'click' chemistry. The polymers were grafted via the α-carboxyl groups to silica or glass substrates pre-treated with (3-aminopropyl)triethoxysilane (APTES). Patterned surfaces were prepared by inkjet printing of APTES onto glass substrates and selectively grafted with fluorescently end-labeled PMMA to obtain emissive arrays on the surface.
关键词： ATRP,inkjet printing,click chemistry,grafting to,polymer brushes
更新于2025-09-19 17:15:36
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Mussel‐Inspired Polymer Grafting on CsPbBr <sub/>3</sub> Perovskite Quantum Dots Enhancing the Environmental Stability
摘要： Mussel-inspired chemistry, motivated by the adhesive proteins secreted by mussels for attachment to wet surfaces, is an emerging technique for manipulating the surface properties of a variety of materials. Here, a facile mussel-inspired poly(N-vinyl pyrrolidone) (PVP) polymer encapsulation with trivial influence on inherent optical properties of perovskite quantum dots (QDs) is demonstrated to efficiently combat the low intrinsic thermal, chemical, and photostability of CsPbBr3 QDs. The suitability of photopolymer-processed PVP-CsPbBr3 QDs flexible films as color components in white light–emitting devices is substantiated.
关键词： perovskite quantum dots,stability,white light-emitting diodes,photoluminescence,polymer grafting
更新于2025-09-12 10:27:22
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Dimensional Impact of Metal-Organic Frameworks in Catalyzing Photo-Induced Hydrogen Evolution and Cyanosilylation Reactions
摘要： Metal-organic frameworks (MOFs) have been widely studied as heterogeneous catalysts. Compared to the MOFs with three dimensional (3D) topologies, two dimensional (2D) MOF nanosheets can allow facile access to the active sites on their external surface, thus having huge potentials in catalysis. Herein, we fabricate 2D MOF nanosheets, UiO-67-NS, as photocatalyst for H2 evolution reaction, and study their photocatalytic performance in relation to their 3D bulk counterparts (UiO-67). The UiO-67-NS exhibit an 84-fold increase in photocatalytic efficiency compared to UiO-67. Postsynthetic cation grafting of the UiO-67-NS with titanium leads to further enhancement in photocatalytic efficiency, giving a hydrogen evolution rate of up to 393 μmol g-1 h-1, which is 13-times higher than that of the non-grafting nanosheets under the same condition. Our results indicate that the 3D-to-2D dimensionality reduction can be a viable strategy for the development of MOFs as efficient photocatalysts. In addition, we have demonstrated that the improvement of catalytic performance based on the strategy of 3D-to-2D framework dimensionality reduction can be easily extended to heterogeneous cyanosilylation reaction.
关键词： Post-Synthetic Grafting,Metal-Organic Frameworks,Dimensional Impact,Photo-Induced Hydrogen Evolution,Metal-Organic Nanosheets
更新于2025-09-10 09:29:36