Visible light-induced thione-ene cycloaddition reaction for the surface modification of polymeric materials

2018 ◽  
Vol 29 (1) ◽  
pp. 157-160 ◽  
Author(s):  
Li Wang ◽  
Yi Wang ◽  
Dong Chen ◽  
Wantai Yang
2020 ◽  
Vol 27 (10) ◽  
pp. 1616-1633 ◽  
Author(s):  
Oana Cristina Duta ◽  
Aurel Mihail Ţîţu ◽  
Alexandru Marin ◽  
Anton Ficai ◽  
Denisa Ficai ◽  
...  

Polymeric materials, due to their excellent physicochemical properties and versatility found applicability in multiples areas, including biomaterials used in tissue regeneration, prosthetics (hip, artificial valves), medical devices, controlled drug delivery systems, etc. Medical devices and their applications are very important in modern medicine and the need to develop new materials with improved properties or to improve the existent materials is increasing every day. Numerous reasearches are activated in this domain in order to obtain materials/surfaces that does not have drawbacks such as structural failure, calcifications, infections or thrombosis. One of the most used material is poly(vinylchloride) (PVC) due to its unique properties, availability and low cost. The most common method used for obtaining tubular devices that meet the requirements of medical use is the surface modification of polymers without changing their physical and mechanical properties, in bulk. PVC is a hydrophobic polymer and therefore many research studies were conducted in order to increase the hydrophilicity of the surface by chemical modification in order to improve biocompatibility, to enhance wettability, reduce friction or to make lubricious or antimicrobial coatings. Surface modification of PVC can be achieved by several strategies, in only one step or, in some cases, in two or more steps by applying several techniques consecutively to obtain the desired modification / performances. The most common processes used for modifying the surface of PVC devices are: plasma treatment, corona discharge, chemical grafting, electric discharge, vapour deposition of metals, flame treatment, direct chemical modification (oxidation, hydrolysis, etc.) or even some physical modification of the roughness of the surface.


Synlett ◽  
2019 ◽  
Vol 30 (15) ◽  
pp. 1725-1732 ◽  
Author(s):  
Ross W. Barber ◽  
Molly E. McFadden ◽  
Xiaoran Hu ◽  
Maxwell J. Robb

Mechanophores are molecules that undergo productive, covalent chemical transformations in response to mechanical force. Over the last decade, a variety of mechanochromic mechanophores have been developed that enable the direct visualization of stress in polymers and polymeric materials through changes in color and chemiluminescence. The recent introduction of mechanochemically gated photoswitching extends the repertoire of polymer mechanochromism by decoupling the mechanical activation from the visible response, enabling the mechanical history of polymers to be recorded and read on-demand using light. Here, we discuss advances in mechanochromic mechanophores and present our design of a cyclopentadiene–maleimide Diels–Alder adduct that undergoes a force-induced retro-[4+2] cycloaddition reaction to reveal a latent diarylethene photoswitch. Following mechanical activation, UV light converts the colorless diarylethene molecule into the colored isomer via a 6π-electrocyclic ring-closing reaction. Mechanically gated photoswitching expands on the fruitful developments in mechanochromic polymers and provides a promising platform for further innovation in materials applications including stress sensing, patterning, and information storage.1 Introduction to Polymer Mechanochemistry2 Mechanochromic Reactions for Stress Sensing3 Regiochemical Effects on Mechanophore Activation4 Mechanochemically Gated Photoswitching5 Conclusions


2008 ◽  
Vol 81 (8) ◽  
pp. 927-937 ◽  
Author(s):  
Kazuhiko Maeda ◽  
Hiroaki Terashima ◽  
Kentaro Kase ◽  
Masanobu Higashi ◽  
Masashi Tabata ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Min Liu ◽  
Hongmei Li ◽  
Yangsu Zeng

Tungsten trioxide (WO3) was surface modified with Cu(II) nanoclusters and titanium dioxide (TiO2) nanopowders by using a simple impregnation method followed by a physical combining method. The obtained nanocomposites were studied by scanning electron microscope, X-ray photoelectron spectroscopy spectra, UV-visible light spectra, and photoluminescence, respectively. Although the photocatalytic activity of WO3was negligible under visible light irradiation, the visible light photocatalytic activity of WO3was drastically enhanced by surface modification of Cu(II) nanoclusters and TiO2nanopowders. The enhanced photocatalytic activity is due to the efficient charge separation by TiO2and Cu(II) nanoclusters functioning as cocatalysts on the surface. Thus, this simple strategy provides a facile route to prepare efficient visible-light-active photocatalysts for practical application.


2000 ◽  
Vol 127 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Z. Iskanderova ◽  
J. Kleiman ◽  
Y. Gudimenko ◽  
R.C. Tennyson ◽  
W.D. Morison

2021 ◽  
Vol 7 (1) ◽  
pp. 9
Author(s):  
Cansu Esen ◽  
Baris Kumru

As a metal-free polymeric semiconductor with an absorption in the visible range, carbon nitride has numerous advantages for photo-based applications spanning hydrogen evolution, CO2 reduction, ion transport, organic synthesis and organic dye degradation. The combination of g-C3N4 and polymer networks grants mutual benefit for both platforms, as networks are upgraded with photoactivity or formed by photoinitiation, and g-C3N4 is integrated into novel applications. In the present contribution, some of the recently published projects regarding g-C3N4 and polymeric materials will be highlighted. In the first study, organodispersible g-C3N4 were incorporated into a highly commercialized porous resin called poly(styrene-co-divinylbenzene) through suspension photopolymerization, and performances of resulting beads were investigated as recyclable photocatalysts. In the other study, g-C3N4 nanosheets were embedded in porous hydrogel networks, and so-formed hydrogels with photoactivity were transformed either into a ‘hydrophobic hydrogel’ or pore-patched materials via secondary network introduction, where both processes were accomplished via visible light. Since g-C3N4 is an organic semiconductor exhibiting sufficient charge separation under visible light illumination, a novel method for the oxidative photopolymerization of EDOT was successfully accomplished. As a result of the absence of dissolved anions during polymerization, so-formed neutral PEDOT is a highly viscous liquid that can be processed and post-doped easily, and grants facile coating processes.


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