Structure–Property Relationships of Polyethylene Glycol Modified Fluorophore as Near-Infrared Aβ Imaging Probes

2018 ◽  
Vol 90 (14) ◽  
pp. 8576-8582 ◽  
Author(s):  
Kaixiang Zhou ◽  
Yuying Li ◽  
Yi Peng ◽  
Xiaomei Cui ◽  
Jiapei Dai ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Near Infrared ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Imaging Probes

Catalyst Halogenation Enables Rapid and Efficient Polymerizations with Visible to Near-Infrared Light

2020 ◽  
Author(s):  
Alex Stafford ◽  
Dowon Ahn ◽  
Emily Raulerson ◽  
Kun-You Chung ◽  
Kaihong Sun ◽  
...  
Keyword(s):  
Near Infrared ◽  
Transient Absorption ◽  
Reaction Times ◽  
Infrared Light ◽  
Structure Property ◽  
Light Emitting ◽  
Structure Property Relationships ◽  
Nir Light ◽  
Light Intensities ◽  
Emission Quenching

Driving rapid polymerizations with visible to near-infrared (NIR) light will enable nascent technologies in the emerging fields of bio- and composite-printing. However, current photopolymerization strategies are limited by long reaction times, high light intensities, and/or large catalyst loadings. Improving efficiency remains elusive without a comprehensive, mechanistic evaluation of photocatalysis to better understand how composition relates to polymerization metrics. With this objective in mind, a series of methine- and aza-bridged boron dipyrromethene (BODIPY) derivatives were synthesized and systematically characterized to elucidate key structure-property relationships that facilitate efficient photopolymerization driven by visible to NIR light. For both BODIPY scaffolds, halogenation was shown as a general method to increase polymerization rate, quantitatively characterized using a custom real-time infrared spectroscopy setup. Furthermore, a combination of steady-state emission quenching experiments, electronic structure calculations, and ultrafast transient absorption revealed that efficient intersystem crossing to the lowest excited triplet state upon halogenation was a key mechanistic step to achieving rapid photopolymerization reactions. Unprecedented polymerization rates were achieved with extremely low light intensities (< 1 mW/cm<sup>2</sup>) and catalyst loadings (< 50 μM), exemplified by reaction completion within 60 seconds of irradiation using green, red, and NIR light-emitting diodes.

New Second-Order Nonlinear Optical Organic Crystals

1989 ◽  
Vol 173 ◽  
Author(s):  
D.S. Donald ◽  
L.-T. Cheng ◽  
G. Desiraju ◽  
G. R. Meredith ◽  
F. C. Zumsteg
Keyword(s):  
Nonlinear Optical ◽  
Near Infrared ◽  
Crystal Packing ◽  
Screening Program ◽  
Molecular Crystals ◽  
Molecular Properties ◽  
Organic Crystals ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Near Ultraviolet

ABSTRACTThe design of molecular crystals with specific optical properties, which are thought to arise from constituent molecules’ polarizability properties, is a desirable but currently unachievable goal. One can partially achieve this goal by choosing compounds with specific molecular attributes and empirically determining the manner in which these are translated into crystal properties. Besides the fact that there are no certain rules for prediction of crystal packing arrangements, there is also a problem in specifying molecular properties from what are today incomplete polarizability structure-property relationships. We have, realizing these limitations, identified new molecular crystals by a nonlinear optical (powder-SHG) scouting-screening program from lists of compounds chosen because of desirable molecular properties. Examination of successful materials has revealed interesting, new alignment motifs. Some of these materials, a set of halogen and cyano derivatives of aromatic compounds, are described relating properties and structures of molecules and crystals. In particular, the orientation directing influence of intermolecular halogen-cyano interactions and the use of heterocyclic compounds to improve transparency in the near infrared and in the blue and near ultraviolet spectral regions are demonstrated.

scholarly journals Catalyst Halogenation Enables Rapid and Efficient Polymerizations with Visible to Near-Infrared Light

2020 ◽  
Author(s):  
Alex Stafford ◽  
Dowon Ahn ◽  
Emily Raulerson ◽  
Kun-You Chung ◽  
Kaihong Sun ◽  
...  
Keyword(s):  
Near Infrared ◽  
Transient Absorption ◽  
Reaction Times ◽  
Infrared Light ◽  
Structure Property ◽  
Light Emitting ◽  
Structure Property Relationships ◽  
Nir Light ◽  
Light Intensities ◽  
Emission Quenching

Driving rapid polymerizations with visible to near-infrared (NIR) light will enable nascent technologies in the emerging fields of bio- and composite-printing. However, current photopolymerization strategies are limited by long reaction times, high light intensities, and/or large catalyst loadings. Improving efficiency remains elusive without a comprehensive, mechanistic evaluation of photocatalysis to better understand how composition relates to polymerization metrics. With this objective in mind, a series of methine- and aza-bridged boron dipyrromethene (BODIPY) derivatives were synthesized and systematically characterized to elucidate key structure-property relationships that facilitate efficient photopolymerization driven by visible to NIR light. For both BODIPY scaffolds, halogenation was shown as a general method to increase polymerization rate, quantitatively characterized using a custom real-time infrared spectroscopy setup. Furthermore, a combination of steady-state emission quenching experiments, electronic structure calculations, and ultrafast transient absorption revealed that efficient intersystem crossing to the lowest excited triplet state upon halogenation was a key mechanistic step to achieving rapid photopolymerization reactions. Unprecedented polymerization rates were achieved with extremely low light intensities (< 1 mW/cm<sup>2</sup>) and catalyst loadings (< 50 μM), exemplified by reaction completion within 60 seconds of irradiation using green, red, and NIR light-emitting diodes.

scholarly journals Silver/Polyethylene Glycol Nanocomposite Thin Films and its Biological Applications

2015 ◽  
Vol 11 (5) ◽  
pp. 3597-3608 ◽  
Author(s):  
Alaa Fahmy
Keyword(s):  
Thin Films ◽  
Antimicrobial Activity ◽  
Polyethylene Glycol ◽  
Average Particle Size ◽  
Average Particle ◽  
Structure Property ◽  
Ag Nps ◽  
Structure Property Relationships ◽  
Transmission Electron ◽  
Uv Visible

The synthesis of silver nanoparticles with different sizes and concentrations was carried out using NaBH4 as a reducing agent and polyethylene glycol (PEG) as a stabilizer. The thin films of PEG embedded with Ag nanoparticles (Ag NPs) were deposited by electrospray deposition technique (ESD) and the morphology of subsequent prepared films was studied by AFM. Structure-property relationships of the colloid and subsequent films were discussed in dependence on the concentration of NaBH4. The synthesized Ag/PEG nanocomposite solution was characterized by UV-visible spectroscopy and Transmission electron microscopy (TEM). Chemical composition in the whole and on the surface of films were investigated by Fourier transform infrared (ATR-IR) and X-ray photoelectron microscopy (XPS), respectively. The UV-visible results indicate to the formation of spherical Ag NPs where the absorption peak was observed at wavelengths around 395 nm. TEM images showed the well dispersion of Ag NPs in the PEG matrix with average particle size of 13 nm.  Furthermore, the antimicrobial activity of the nanocmposite was studied. The Ag NPs released from the polymer matrix proven to have a significant antimicrobial activity against S. Pneumonia, B. Subtilis, E. Coli, and A. Fumigates.

Enhancing NIR emission in ZnAl2O4:Nd,Ce nanofibers by co-doping with Ce and Nd: a promising biomarker material with low cytotoxicity

2021 ◽  
Author(s):  
Rocío Estefanía Rojas-Hernandez ◽  
Fernando Rubio-Marcos ◽  
Giulio Gorni ◽  
Carlo Marini ◽  
Mati Danilson ◽  
...  
Keyword(s):  
Near Infrared ◽  
Structure Property ◽  
Fundamental Structure ◽  
Co Doping ◽  
Structure Property Relationships ◽  
Nir Emission ◽  
Low Cytotoxicity

Development of new near infrared luminescent (NIR) emitters improves our understanding of their fundamental structure–property relationships.

Structure-property relationships of PE/PP sandwiched films

1987 ◽  
Vol 45 ◽  
pp. 454-455
Author(s):  
J. Petermann ◽  
G. Broza ◽  
U. Rieck ◽  
A. Jaballah ◽  
A. Kawaguchi
Keyword(s):  
Mechanical Tests ◽  
Polymer Materials ◽  
Ionic Crystals ◽  
Structure Property ◽  
Polymer Systems ◽  
Structure Property Relationships ◽  
Oriented Films ◽  
Materials Used ◽  
Polymer Laminates ◽  
Heated Glass

Oriented overgrowth of polymer materials onto ionic crystals is well known and recently it was demonstrated that this epitaxial crystallisation can also occur in polymer/polymer systems, under certain conditions. The morphologies and the resulting physical properties of such systems will be presented, especially the influence of epitaxial interfaces on the adhesion of polymer laminates and the mechanical properties of epitaxially crystallized sandwiched layers.Materials used were polyethylene, PE, Lupolen 6021 DX (HDPE) and 1810 D (LDPE) from BASF AG; polypropylene, PP, (PPN) provided by Höchst AG and polybutene-1, PB-1, Vestolen BT from Chemische Werke Hüls. Thin oriented films were prepared according to the method of Petermann and Gohil, by winding up two different polymer films from two separately heated glass-plates simultaneously with the help of a motor driven cylinder. One double layer was used for TEM investigations, while about 1000 sandwiched layers were taken for mechanical tests.

Approaches for TEM imaging of cavitation in toughened nylon

1989 ◽  
Vol 47 ◽  
pp. 352-353
Author(s):  
Barbara A. Wood
Keyword(s):  
Morphological Characteristics ◽  
Structure Property ◽  
Polymer Systems ◽  
Selective Staining ◽  
Structure Property Relationships ◽  
Rubber Toughened ◽  
Shear Yield ◽  
Controversial Topic ◽  
Selection Of ◽  
Diamond Knife

A controversial topic in the study of structure-property relationships of toughened polymer systems is the internal cavitation of toughener particles resulting from damage on impact or tensile deformation.Detailed observations of the influence of morphological characteristics such as particle size distribution on deformation mechanisms such as shear yield and cavitation could provide valuable guidance for selection of processing conditions, but TEM observation of damaged zones presents some experimental difficulties.Previously published TEM images of impact fractured toughened nylon show holes but contrast between matrix and toughener is lacking; other systems investigated have clearly shown cavitated impact modifier particles. In rubber toughened nylon, the physical characteristics of cavitated material differ from undamaged material to the extent that sectioning of heavily damaged regions by cryoultramicrotomy with a diamond knife results in sections of greater than optimum thickness (Figure 1). The detailed morphology is obscured despite selective staining of the rubber phase using the ruthenium trichloride route to ruthenium tetroxide.

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