Changes in the Morphology and Optical Absorption of Colloidal Silver Reduced with Formic Acid in the Polymer Matrix under UV Irradiation

1997 ◽  
Vol 101 (41) ◽  
pp. 8129-8132 ◽  
Author(s):  
Andrey L. Rogach ◽  
Gvidona P. Shevchenko ◽  
Zinaida M. Afanas'ev ◽  
Vadim V. Sviridov
Keyword(s):  
Optical Absorption ◽  
Formic Acid ◽  
Uv Irradiation ◽  
Polymer Matrix ◽  
Colloidal Silver

Antibacterial Activity of Biodegradable Particles based on Chitosan Containing Colloidal Silver

2020 ◽  
Vol 36 (4) ◽  
pp. 87-93
Author(s):  
V.Yu. Reshetova ◽  
A.F. Krivoshchepov ◽  
I.A. Butorova ◽  
N.B. Feldman ◽  
S.V. Lutsenko ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Polymer Matrix ◽  
Adipic Acid ◽  
Antibacterial Effect ◽  
Academic Excellence ◽  
Colloidal Silver ◽  
Scanning Electron Microscopy Data ◽  
Covalent Bonds ◽  
Agar Diffusion Test

Chitosan beads with colloidal silver nanoparticles inclued in the polymer matrix have been obtained by the introduction of chitosan into an acidified nanosilver sol. Dual interconnection of drops of the resulting solution was then carried out by ionotropic gelation at the first stage and covalent crosslinking of the polymer matrix with adipic acid at the second stage. The surface morphology of the obtained beads was studied by scanning electron microscopy. Data of Fourier transform IR spectroscopy confirmed the formation of covalent bonds between chitosan and adipic acid. The antibacterial activity of obtained beads against S. aureus and E. coli was evaluated using agar diffusion test. It was shown that the сhitosan beads modified with nanostructured silver exhibited an antibacterial effect against the tested strains, and they can be used as a basis for creating biodegradable wound healing dressings with a prolonged antibacterial effect. chitosan, silver nanoparticles, antibacterial activity, wound dressings This work was supported by the "Russian Academic Excellence Project 5-100". The study was carried out with the financial support of the Russian Foundation for Basic Research in the framework of the Scientific Project no. 18-29-18039.

Photochemistry of Nitrate Ion: Reduction by Formic Acid under UV Irradiation

2021 ◽  
Author(s):  
Na Tong ◽  
Zhonglei Xia ◽  
Tianzhu Xie ◽  
Xu Liu ◽  
Jinni Shen ◽  
...  
Keyword(s):  
Formic Acid ◽  
Uv Irradiation ◽  
Nitrate Ion

Photochromic Behavior of Spiropyrans: The Effect of Substituent

2014 ◽  
Vol 925 ◽  
pp. 323-328 ◽  
Author(s):  
Najiah Nadir ◽  
Zaharah Wahid ◽  
Mat Tamizi Zainuddin ◽  
Noor Zalikha Mohamed Islam
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Uv Irradiation ◽  
Rate Constant ◽  
Half Life ◽  
Diphenyl Ether ◽  
Life Time ◽  
Optical Absorption Spectra ◽  
Photochromic Behavior ◽  
Photochromic Effect

Spiropyrans are among the most promising organic photochromic dyes. However, spiropyrans are very sensitive dyes and there are many independent factors that can affect the performance of these dyes. The effect of substituent on the optical absorption spectra, fading kinetic, and also the dye stability of spiropyrans in diphenyl ether by UV irradiation has been investigated. The 6-nitro BIPS displayed greater absorbance intensity of 0.740% at 600nm compared to 8-ethoxy-6-nitro BIPS of 0.651% at 620nm. Furthermore, 6-nitro BIPS is less stable as it has higher rate constant of 0.1003s-1and thus lower half-life time (50% decay of the photochromic effect) of 6.9s, in contrast to 8-ethoxy-6-nitro BIPS of 0.0594s-1and 11.7s respectively.

Formic Acid of ppm Enhances LC-MS/MS Detection of UV Irradiation-Induced DNA Dimeric Photoproducts

2019 ◽  
Vol 92 (1) ◽  
pp. 1197-1204
Author(s):  
Ning Zhang ◽  
Wenchao Deng ◽  
Yao Li ◽  
Yangde Ma ◽  
Yan Liu ◽  
...  
Keyword(s):  
Formic Acid ◽  
Uv Irradiation ◽  
Ms Detection

Optical Absorption Study of the Biotin−Avidin Interaction on Colloidal Silver and Gold Particles

Langmuir ◽  
1998 ◽  
Vol 14 (15) ◽  
pp. 4138-4142 ◽  
Author(s):  
Murali Sastry ◽  
Neeta Lala ◽  
Vijaya Patil ◽  
S. P. Chavan ◽  
A. G. Chittiboyina
Keyword(s):  
Optical Absorption ◽  
Colloidal Silver ◽  
Absorption Study ◽  
Optical Absorption Study ◽  
Gold Particles

Photochemical transformation of lipoic acid-based ligands: probing the effects of solvent, ligand structure, oxygen and pH

2018 ◽  
Vol 20 (6) ◽  
pp. 3895-3902 ◽  
Author(s):  
Dinesh Mishra ◽  
Sisi Wang ◽  
Serge Michel ◽  
Goutam Palui ◽  
Naiqian Zhan ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Uv Irradiation ◽  
Lipoic Acid ◽  
Photochemical Transformation ◽  
Ligand Structure

We have combined optical absorption with the Ellman's test to identify the parameters that affect the transformation of the 5-membered dithiolanes to thiols in lipoic acid (LA) and its derivatives during UV-irradiation.

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