Surface-attached Polymer Networks

2000 ◽  
Vol 629 ◽  
Author(s):  
Oswald Prucker ◽  
Kristin Müller ◽  
Jürgen Rühe
Keyword(s):  
Uv Light ◽  
Polymer Networks ◽  
Covalent Bond ◽  
Thermal Polymerization ◽  
Synthetic Route ◽  
Present Evidence ◽  
The Third ◽  
Uv Illumination ◽  
Glass Surfaces

ABSTRACTIn this paper we present three novel routes for the preparation of surface-attached polymer networks. In one system the network is formed in situ at the surface by thermal polymerization in solution and from the surface. Another synthetic route starts with a surface that carries photoreactive groups. Onto this surface a polymer is deposited that also carries photoreactive groups and both the crosslinks of the network and the covalent bond to the surface are formed by UV illumination. The third approach start with the in situ formation of surface-attached copolymers that again carry photoreactive groups that are subsequently linked together by UV light. We present evidence for the successful synthesis of these networks and their superior adhesion on glass surfaces.

scholarly journals Irreversible inhibition of sodium current and batrachotoxin binding by a photoaffinity-derivatized local anesthetic.

1995 ◽  
Vol 105 (2) ◽  
pp. 267-287 ◽  
Author(s):  
J McHugh ◽  
W M Mok ◽  
G K Wang ◽  
G Strichartz
Keyword(s):  
Local Anesthetic ◽  
Uv Light ◽  
Sodium Current ◽  
Covalent Bond ◽  
Cell Voltage ◽  
Scorpion Venom ◽  
Gh3 Cells ◽  
Post Exposure ◽  
Irreversible Inhibition ◽  
Uv Illumination

We have synthesized a model local anesthetic (LA), N-(2-di-N-butyl-aminoethyl)-4-azidobenzamide (DNB-AB), containing the photoactivatable aryl azido moiety, which is known to form a covalent bond to adjacent molecules when exposed to UV light (Fleet, G.W., J.R. Knowles, and R.R. Porter. 1972. Biochemical Journal. 128:499-508. Ji, T.H. 1979. Biochimica et Biophysica Acta. 559:39-69). We studied the effects of DNB-AB on the sodium current (INa) under whole-cell voltage clamp in clonal mammalian GH3 cells and on 3[H]-BTX-B binding to sheep brain synaptoneurosomes. In the absence of UV illumination, DNB-AB behaved similarly to known LAs, producing both reversible block of peak INa (IC50 = 26 microM, 20 degrees C) and reversible inhibition of 3[H]-BTX-B (50 nM in the presence of 0.12 microgram/liter Leiurus quinquestriatus scorpion venom) binding (IC50 = 3.3 microM, 37 degrees C), implying a noncovalent association between DNB-AB and its receptor(s). After exposure to UV light, both block of INa and inhibition of 3[H]-BTX-B binding were only partially reversible (INa = 42% of control; 3[H]-BTX-B binding = 23% of control) showing evidence of a light-dependent, covalent association between DNB-AB and its receptor(s). In the absence of drug, UV light had less effect on INa (post exposure INa = 96% of control) or on 3[H]-BTX-B binding (post exposure binding = 70% of control). The irreversible block of INa was partially protected by coincubation of DNB-AB with 1 mM bupivacaine (IC50 = 45 microM, for INa inhibition at 20 degrees C, Wang, G.K., and S.Y. Wang. 1992. Journal of General Physiology. 100:1003-1020), (post exposure INa = 73% of control). The irreversible inhibition of 3[H]-BTX-B binding also was partially protected by coincubation with bupivacaine (500 microM, 37 degrees C) (post exposure binding = 51% of control), suggesting that the site of irreversible inhibition of both INa and 3[H]-BTX-B binding is shared with the clinical LA bupivacaine.

scholarly journals In situ reduction of chloroauric acid (HAuCl4) for generation of catalytic Au nanoparticle embedded triazine based covalent organic polymer networks

RSC Advances ◽  
2019 ◽  
Vol 9 (66) ◽  
pp. 38538-38546 ◽  
Author(s):  
Sami Dursun ◽  
Emine Yavuz ◽  
Zeynep Çetinkaya
Keyword(s):  
Real Time ◽  
Polymer Networks ◽  
Au Nanoparticle ◽  
Organic Polymer ◽  
Chloroauric Acid ◽  
Cell Analysis ◽  
In Situ Reduction ◽  
Synthetic Route ◽  
Good Biocompatibility

A facile synthetic route was applied to generate Au@COPN-1 hybrids via in situ reduction of Au3+ with no additional reducing agent. Au@COPN-1 is a promising catalyst platform and good biocompatibility confirmed by dynamic real-time cell analysis.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

scholarly journals Variability and improvement of optical and antimicrobial performances for CQDs/mesoporous SiO2/Ag NPs composites via in situ synthesis

2021 ◽  
Vol 10 (1) ◽  
pp. 403-411
Author(s):  
Youliang Cheng ◽  
Mingjie Wang ◽  
Changqing Fang ◽  
Ying Wei ◽  
Jing Chen ◽  
...  
Keyword(s):  
Uv Light ◽  
Carbon Quantum Dots ◽  
Diffusion Method ◽  
Ag Nps ◽  
Uniform Size ◽  
High Antibacterial Activity ◽  
Fluorescent Materials ◽  
Potential Applications ◽  
Mesoporous Sio2

Abstract To change the optical properties and improve the antibacterial performances of carbon quantum dots (CQDs) and Ag NPs, mesoporous SiO2 spheres were combined with them to form the composites. In this paper, CQDs with a uniform size of about 3.74 nm were synthesized using glucose as carbon source. Then, CQDs/mesoporous SiO2/Ag NPs composites were obtained in situ under UV light irradiating by using mesoporous SiO2 and Ag NO3 as the carrier and silver resource, respectively. The diameter of CQDs/mesoporous SiO2/Ag NPs particles was in the range of 200–250 nm. With the increase in irradiating time, the red-shift in the UV-Vis spectrum for as-prepared CQDs/mesoporous SiO2/Ag NPs composites was found, and the adsorption peak was widened. In addition, the composites showed a high antibacterial activity against Staphylococcus aureus and Escherichia coli via disc diffusion method. These results indicated that inhibition circles for Ag NPs/mesoporous SiO2/CQDs and mesoporous SiO2/Ag NPs were similar in diameter. Furthermore, the two composites had a better bactericidal performance compared with other particles. Therefore, as-prepared CQDs/mesoporous SiO2/Ag NPs composites in this paper have great potential applications for fluorescent materials and antibacterial materials.

57Fe Mössbauer Spectroscopic Study of the Geometrical Effects In the Catalytic Reactions with Intercalation Compounds

1982 ◽  
Vol 20 ◽  
Author(s):  
P.P. Vaishnava ◽  
P.A. Montano
Keyword(s):  
Ferric Chloride ◽  
Catalytic Reactions ◽  
Fischer Tropsch ◽  
Reaction Conditions ◽  
Intercalated Graphite ◽  
The Third ◽  
Intercalated Compounds ◽  
Catalytic Sites ◽  
Geometrical Effects

ABSTRACTIn situ 57Fe Mössbauer spectra are reported for the first-, higher-stage ferric chloride, and a mixed ferric chloride-potassium chloride intercalated graphite catalysts under reduction and Fischer-Tropsch reaction conditions. The mass spectroscopic measurements reveal a different catalytic selectivity for the three catalysts. The first two catalysts predominantly possess a higher selectivity for methane, whereas the third catalyst has higher selectivity for the formation of propane. The differences are attributed to geometrical effects in the catalytic sites of the intercalated compounds.

UV-light-actuated in-situ preparation of paper@ZnCd quantum dots for paper-based enzymatic nanoreactors

2021 ◽  
pp. 132508
Author(s):  
Nichakan Khunkitchai ◽  
Nantana Nuchtavorn ◽  
Tomas Rypar ◽  
Marcela Vlcnovska ◽  
Lukas Nejdl ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Uv Light ◽  
In Situ Preparation

Fabrication of a Metal Nanoparticles and Polymer Nanofibers Composite Material by an in Situ Chemical Synthetic Route

Langmuir ◽  
2005 ◽  
Vol 21 (17) ◽  
pp. 7964-7967 ◽  
Author(s):  
Kaushik Mallick ◽  
Mike J. Witcomb ◽  
Andy Dinsmore ◽  
Mike S. Scurrell
Keyword(s):  
Composite Material ◽  
Metal Nanoparticles ◽  
Synthetic Route ◽  
Polymer Nanofibers
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