67 research outputs found
Multifunctional Chiral pi-Conjugated Polymer Microspheres: Production and Confinement of NLO signal, Detection of Circularly Polarized Light, and Display of Laser-Triggered NLO Emission Shifts
ChemInform Abstract: A Combined-Redox Synthesis of 2-Alkylbenzimidazoles from 2-Nitroanilines by Semiconductor Photocatalysis.
A Combined-Redox Synthesis of 2-Alkylbenzimidazoles from 2-Nitroanilines by Semiconductor Photocatalysis
Elucidating the Origins of a Range of Diverse Flexible Responses in Crystalline Coordination Polymers
Micromanipulation of Mechanically Compliant Organic Single-Crystal Optical Microwaveguides
Flexible organic single crystals are evolving as new materials for optical waveguides that can be used for transfer of information in organic optoelectronic microcircuits. Integration in microelectronics of such crystalline waveguides requires downsizing and precise spatial control over their shape and size at the microscale, however that currently is not possible due to difficulties with manipulation of these small, brittle objects that are prone to cracking and disintegration. Here we demonstrate that atomic force microscopy (AFM) can be used to reshape, resize and relocate single-crystal microwaveguides in order to attain spatial control over their light output. Using an AFM cantilever tip, mechanically compliant acicular microcrystals of three N-benzylideneanilines were bent to an arbitrary angle, sliced out from a bundle into individual crystals, cut into shorter crystals of arbitrary length, and moved across and above a solid surface. When excited by using laser light, such bent microcrystals act as active optical microwaveguides that transduce their fluorescence, with the total intensity of transduced light being dependent on the optical path length. This micromanipulation of the crystal waveguides using AFM is non-invasive, and after bending their emissive spectral output remains unaltered. The approach reported here effectively overcomes the difficulties that are commonly encountered with reshaping and positioning of small delicate objects (the “thick fingers” problem), and can be applied to mechanically reconfigure organic optical waveguides in order to attain spatial control over their output in two and three dimensions in optical microcircuits
Green Synthesized Silver and Gold Nanoparticles for Colorimetric Detection of Hg<sup>2+</sup>, Pb<sup>2+</sup>, and Mn<sup>2+</sup> in Aqueous Medium
In
this study, we report a simple and green method for the synthesis
of l-tyrosine-stabilized silver (AgNPs) and gold nanoparticles
(AuNPs) in aqueous medium under ambient sunlight irradiation. The
nanoparticles (NPs) are characterized by UV–visible spectroscopy,
high-resolution transmission electron microscopy (HR-TEM), Fourier
transform infrared spectroscopy (FT-IR), cyclic voltammetry (CV),
and dynamic light scattering (DLS) techniques. The size and shape
of the metal NPs could be controlled by changing the concentration
of the substrate, metal precursors, and pH of the medium. The synthesized
AgNPs are found to be highly sensitive to Hg<sup>2+</sup> and Mn<sup>2+</sup> ions with the detection limit for both ions as low as 16
nM under optimized conditions. However AuNPs are found to be sensitive
to Hg<sup>2+</sup> and Pb<sup>2+</sup> ions with a detection limit
as low as 53 and 16 nM, respectively. The proposed method was found
to be useful for colorimetric detection of heavy metal ions in aqueous
medium
Micromanipulation of Mechanically Compliant Organic Single‐Crystal Optical Microwaveguides
Micromanipulation of Mechanically Compliant Organic Single‐Crystal Optical Microwaveguides
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