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Oxygen-vacancies-engaged efficient carrier utilization for the photocatalytic coupling reaction
摘要： Defects can greatly optimize the solar light harvesting capability and electronic structure of oxide materials. However, it remains challenging to achieve a defect engineering strategy under mild conditions. Meanwhile, the simultaneous exploitation of photogenerated holes (h+) and electrons (e?) to promote both photooxidation and photoreduction in a coupled system has rarely been reported. For the first time, we reveal an oxygen-vacancies-mediated photocatalytic strategy in which the electrons and holes are fully utilized for nitrobenzene reduction coupled with benzyl alcohol oxidation. The oxygen vacancies (OVs) generated in situ on the surface of TiO2 greatly extend light absorption into the visible region and promote the photogenerated electron transport for efficient photocatalysis. The experimental and theoretical results together indicate that chemisorption on the TiO2 surface decreases the oxidation potential of benzyl alcohol and causes an upward shift in its HOMO, which facilitates the oxidation reaction of benzyl alcohol to benzaldehyde. The in situ generated surface OVs also act as a bridge to enable the trapping and transferring of the photoinduced electrons to the nitrobenzene. This work provides a new perspective of utilizing the chemisorption between the reactant and catalyst to achieve a defect engineering strategy for synergetic photocatalysis.
关键词： Photocatalysis,Photoreduction,Surface complexation,Oxygen vacancies,Photooxidation
更新于2025-11-14 14:48:53
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Optically active crown ether-based fluorescent sensor molecules: A mini-review
摘要： This mini‐review focuses on fluorescent optically active crown ethers (polymeric derivatives are not included) reported in the literature (according to our knowledge), of which enantiomeric recognition ability, and in some cases, also inorganic cation complexation properties, were investigated by the sensitive and versatile fluorescence spectroscopy. These crown ether‐based chemosensors contain various fluorophore signaling units such as binaphthyl, anthracene, pyrene, tryptophan, benzimidazole, terpyridine, acridine, phenazine, acridone, BODIPY, and another conjugated aromatic one.
关键词： enantiomeric recognition,complexation,fluorophore,chemosensor,chiral crown ether
更新于2025-09-23 15:23:52
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Intricacies of the Determination of the Radiochemical Purity of 68Ga Preparations: Possibility of Sorption of Ionic 68Ga Species on Reversed-Phase Columns
摘要： The results of studying 68Ga radiopharmaceuticals using various TLC and HPLC procedures are compared. The data obtained reliably show that a part of 68Ga ionic species are irreversibly (under definite conditions) sorbed onto chromatographic columns packed with С18 reversed phase. The loss of 68Ga ionic species in the analysis can reach 90%. The 68Ga loss increases with an increase in pH of the preparation. At pH 2.5–3.0, the total loss of 68Ga ionic species on the chromatographic column does not exceed 15%. At pH 4.0, it is 65 ± 7% on the average, and at pH 6.0 it reaches 87 ± 8%. This effect should be taken into account in analysis of any 68Ga radiopharmaceuticals.
关键词： radiochemical purity,radiopharmaceuticals,sorption,complexation,HPLC,quality control,chromatography,gallium-68
更新于2025-09-23 15:22:29
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Nepafenac-Loaded Cyclodextrin/Polymer Nanoaggregates: A New Approach to Eye Drop Formulation
摘要： The topical administration route is commonly used for targeting therapeutics to the eye; however, improving the bioavailability of drugs applied directly to the eye remains a challenge. Different strategies have been studied to address this challenge. One of them is the use of aggregates that are formed easily by self-assembly of cyclodextrin (CD)/drug complexes in aqueous solution. The aim of this study was to design a new eye drop formulation based on aggregates formed between CD/drug complexes. For this purpose, the physicochemical properties of the aggregates associated with six CDs and selected water-soluble polymers were analysed. Complex formation was studied using differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR) and 1H nuclear magnetic resonance spectroscopy (1H-NMR). Results showed that HPβCD performed best in terms of solubilization, while γCD performed best in terms of enhancing nanoaggregate formation. Formation of inclusion complexes was con?rmed by DSC, FT-IR and 1H-NMR studies. A mixture of 15% (w/v) γCD and 8% (w/v) HPβCD was selected for formulation studies. It was concluded that formulations with aggregate sizes less than 1 μm and viscosity around 10–19 centipoises can be easily prepared using a mixture of CDs. Formulations containing polymeric drug/CD nanoaggregates represent an interesting strategy for enhanced topical delivery of nepafenac.
关键词： cyclodextrin,self-assemble,nepafenac,aggregate,polymer,complexation,ocular drug delivery
更新于2025-09-23 15:22:29
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Solutiona??Processed Polymer Solar Cells with over 17% Efficiency Enabled by an Iridium Complexation Approach
摘要： The commercially available PM6 as donor materials are used widely in highly efficient nonfullerene polymer solar cells (PSCs). In this work, different concentrations of iridium (Ir) complexes (0, 0.5, 1, 2.5, and 5 mol%) are incorporated carefully into the polymer conjugated backbone of PM6 (PM6-Ir0), and a set of π-conjugated polymer donors (named PM6-Ir0.5, PM6-Ir1, PM6-Ir2.5, and PM6-Ir5) are synthesized and characterized. It is demonstrated that the approach can rationally modify the molecular aggregations of polymer donors, effectively controlling the corresponding blend morphology and physical mechanisms, and finally improve the photovoltaic performance of the PM6-Irx-based PSCs. Among them, the best device based on PM6-Ir1:Y6 (1:1.2, w/w) exhibits outstanding power conversion efficiencies (PCEs) of 17.24% tested at Wuhan University and 17.32% tested at Institute of Chemistry, Chinese Academy of Sciences as well as a certified PCE of 16.70%, which are much higher than that of the control device based on the PM6-Ir0:Y6 blend (15.39%). This work affords an effective approach for further break through the reported champion PCE of the binary PSCs.
关键词： iridium complexation,morphology,polymer solar cells,power conversion efficiency
更新于2025-09-23 15:19:57
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[IEEE 2018 IEEE International Conference on Computational Science and Engineering (CSE) - Bucharest (2018.10.29-2018.10.31)] 2018 IEEE International Conference on Computational Science and Engineering (CSE) - An Overview of Image Engineering in Recent Years
摘要： A glucose-containing diblock copolymer was employed as nanocarrier in this study for delivery of the anticancer drug bortezomib (BTZ). Our system was based on pH-induced dynamical conjugation of boronic acid on BTZ to cis-diols on glucose-containing polymer. Diblock copolymer poly(ethylene glycol)-b-poly (gluconamidoethyl methacrylate) (PEG-PGAMA), was firstly synthesized via atom transfer radical polymerization(ATRP) by successive polymerization of monomer gluconamidoethyl methacrylate (GAMA) using a PEG-based ATRP macroinitiator. BTZ was then loaded in glucose-containing copolymer as chemical conjugation occurred of boronic acid to glucose groups and the drug-released behavior of this system was simulated in vitro. The results demonstrated that PEG-PGAMA copolymer had strong ability to bind BTZ at physiological pH of 7.4; it could also effectively release BTZ at acid pH of 5.5(close to environment of cancer tissue or the subcellular endosome) in a pH-dependent manner. In our study, a facile and interesting nanocarrier system for anti-cancer drug bortezomib (BTZ) was provided with a kind of glucose-containing block copolymer without any need of chemical modification, which only utilized dynamic chemical complexation to reach effective drug-loading and controlled release of BTZ upon responsiveness to external pH.
关键词： Dynamic chemical complexation,BTZ,Glucose,Diblock copolymer,pH-responsive
更新于2025-09-19 17:15:36
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Structural, morphological, optical and dielectric properties of M <sup>3+</sup> /PVA/PEG SPE Films (M = La, Y, Fe or Ir)
摘要： Low band gap polymer complexes are promising due to its flexibility, and exhibiting electronic and optical properties of inorganic semiconductors. The effect of PEG on the physical properties of PVA was evaluated. Then, blend (PVA: PEG = 50:50) doped with rare earth (La or Y) and transition metal (Fe or Ir) chlorides to obtain solid polymer electrolyte films. XRD shows that adding PEG to PVA results in a new peak, 2θ = 23o with increased intensity as PEG ratio increases. However, doping with La3+, Fe3+ or Ir3+ eliminate this peak and decrease the crystallinity. SEM exhibits significant changes in the morphology of films. FTIR confirms miscibility between PVA & PEG and the complexation of the salts. The optical band gap (Eg) of PVA ~ 5.37 eV, decreased slightly by blending with PEG. While it decreased significantly to 2.64 eV and 2.78 eV after doping with Fe3+ or Ir3+. There are a consistency between Eg values obtained by Tauc's model and that obtained from the optical dielectric loss. The dielectric constant and loss, in temperature range 303–405 K & frequency range 1.0 kHz ‐ 5.0 MHz, indicate one or two relaxation peak(s) depending on the film composition. Accordingly, conduction mechanism varied between correlated barrier hopping and large polaron tunneling. The DC conductivity was strongly depend on the dielectric loss. The transition metal salts appear to be more effective than the rare earth ones in increasing σac of films to higher values that candidates them in semiconductors industry.
关键词： conduction mechanism,low band gap polymers,activation energy,PVA/PEG blend,rare earth metal complexation,solid polymer electrolyte
更新于2025-09-09 09:28:46