Preparation of antibacterial down fibers by chemical grafting using novel guanidine salt oligomer

2021 ◽  
Author(s):  
Xuanyu Shentu ◽  
Yong Guan ◽  
Lili Wang ◽  
Jin Pan ◽  
Anna Zheng ◽  
...  
Keyword(s):  
Chemical Grafting

Surface Modification of Poly(Vinylchloride) for Manufacturing Advanced Catheters

2020 ◽  
Vol 27 (10) ◽  
pp. 1616-1633 ◽  
Author(s):  
Oana Cristina Duta ◽  
Aurel Mihail Ţîţu ◽  
Alexandru Marin ◽  
Anton Ficai ◽  
Denisa Ficai ◽  
...  
Keyword(s):  
Surface Modification ◽  
Chemical Modification ◽  
Medical Devices ◽  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Modern Medicine ◽  
Structural Failure ◽  
Chemical Grafting ◽  
One Step

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.

Biodegradable Microfluidic Device: Hydrolysis, Decomposition and Surface Modification

2010 ◽  
Vol 447-448 ◽  
pp. 755-759 ◽  
Author(s):  
Jia En Low ◽  
Wei Xiang Koh ◽  
Joon Kit Lai ◽  
Yan Jie Lee ◽  
Xu Li ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Microfluidic Device ◽  
Ph Value ◽  
Blood Compatibility ◽  
Blood Clot ◽  
Hydrophobic Surface ◽  
Poly Lactic Acid ◽  
Water Contact ◽  
Chemical Grafting ◽  
Poly Ethylene

Poly(lactic acid) (PLA) is a biodegradable and biocompatible aliphatic polyester whose lactic acid monomers are derived from renewable resources such as corn and sugar beet. As a thermal plastic it can be processed through compounding and injection. As such, we have developed a microfludic device using PLA aimed at blood dialysis application. To quantify the degradation of PLA, its hydrolysis at different pH value was studied. To study the bioresorbable property of these fabricated devices, its decomposition was tested by morphology observation and weight change measurements after embedding in soil under simulated environmental conditions. Upon contact with a hydrophobic surface, platelets and prothrombin are always activated to attach to the surface, resulting in blood clot. This would block the blood flow through the dialysis channels in the microfluidic device. To improve the hydrophilicity, hence the blood compatibility, chemical grafting of a hydrophilic polymer, poly(ethylene oxide) methacrylate (PEGmA), onto the surface of PLA microfluidic device was carried out and the changes in hydrophilicity was monitored through measuring the water contact angle. Our results indicate that chemical grafting of PEGmA significantly improves the hydrophilicity of the device surface.

Chemical grafting of Sepharose 6B and its use in the purification of PEGylated RNase A

2014 ◽  
Vol 136 ◽  
pp. 190-198 ◽  
Author(s):  
Agustín Hernández-Martínez ◽  
Oscar Aguilar
Keyword(s):  
Rnase A ◽  
Chemical Grafting

Chemical grafting of tin alkyl complexes on the external surface of mordenite: A method for controlling the size of the pore entrances of zeolites

1994 ◽  
Vol 2 (4) ◽  
pp. 251-259 ◽  
Author(s):  
C. Nédez ◽  
A. Theolier ◽  
F. Lefebvre ◽  
A. Choplin ◽  
J.M. Basset ◽  
...  
Keyword(s):  
External Surface ◽  
Alkyl Complexes ◽  
Chemical Grafting

Chemical Grafting of Biphenyl Self-Assembled Monolayers on Ultrananocrystalline Diamond

2006 ◽  
Vol 128 (51) ◽  
pp. 16884-16891 ◽  
Author(s):  
Simon Q. Lud ◽  
Marin Steenackers ◽  
Rainer Jordan ◽  
Paola Bruno ◽  
Dieter M. Gruen ◽  
...  
Keyword(s):  
Self Assembled Monolayers ◽  
Ultrananocrystalline Diamond ◽  
Chemical Grafting ◽  
Assembled Monolayers ◽  
Self Assembled

scholarly journals Polyacrylonitrile/Crown Ether Composite Nanofibres With High Efficiency for Adsorbing Li(I): Experiments and Theoretical Calculations

2021 ◽  
Vol 9 ◽  
Author(s):  
Tao Ding ◽  
Qian Wu ◽  
Mianping Zheng ◽  
Zhen Nie ◽  
Min Li ◽  
...  
Keyword(s):  
Crown Ether ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
High Efficiency ◽  
Theoretical Calculations ◽  
Salt Lakes ◽  
Maximum Adsorption Capacity ◽  
Chemical Grafting ◽  
Epoxy Groups

Lithium, as the lightest alkali metal, is widely used in military and new energy applications. With the rapid growth in demand for lithium resources, it has become necessary to improve the effectiveness of extraction thereof. By using chemical grafting and electrospinning techniques, nanofibres containing crown ether were developed for adsorbing Li(I) from the brine in salt lakes, so as to selectively adsorb Li(I) on the premise of retaining specific vacancies of epoxy groups in crown ether. In lithium-containing solution, the adsorbing materials can reach adsorption equilibrium within three hours, and the maximum adsorption capacity is 4.8 mg g−1. The adsorption mechanisms of the adsorbing materials for Li(I) were revealed by combining Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) with density functional theory (DFT) calculation. The results indicated that in crown ether, O in epoxy groups was coordinated with Li(I) to form Li–O and four O atoms in the epoxy groups were used as electron donors. After coordination, two O atoms protruded from the plane and formed a tetrahedral structure with Li(I), realising the specific capture of Li(I). By desorbing fibres that adsorbed Li(I) with 0.5-M HCl, the adsorption capacity only decreased by 10.4% after five cycles, proving ability to regenerate such materials. The nanofibres containing crown ether synthesised by chemical grafting and electrospinning have the potential to be used in extracting lithium resources from the brine in salt lakes.

Synthesis and Catalytic Applications of Chemically Grafted SiH-Functionalized Tripodal Ti-POSS Complexes in Crosslinked Hyperbranched Poly(siloxysilane)

2015 ◽  
Vol 68 (7) ◽  
pp. 1091 ◽  
Author(s):  
Emad H. Aish
Keyword(s):  
High Activity ◽  
Active Site ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Polar Environment ◽  
Hyperbranched Poly ◽  
Chemical Grafting ◽  
Synthesis Activity ◽  
Catalytic Applications ◽  
Oligomeric Silsesquioxane

This study investigated the synthesis, activity, epoxide selectivity, H2O2 efficiency, and recyclability of new heterogeneous alkene epoxidation catalysts prepared by chemical grafting of new SiH-functionalized tripodal Ti–polyhedral oligomeric silsesquioxane (Ti-POSS) complexes in hyperbranched poly(siloxysilane) via hydrosilation. Crosslinked hyperbranched poly(siloxysilane)-grafted [{(p-HSiMe2(CH2)2C6H4)(c-C6H11)6Si7O12}Ti(NMe2)] (11) and crosslinked hyperbranched poly(siloxysilane)-grafted [{(HSiMe2(CH2)3)(i-C4H9)6Si7O12}- Ti(NMe2)] (12) displayed high activity, epoxide selectivity (≥98 %), and H2O2 efficiency (≥97 %) in cyclohexene and 1-octene epoxidation with aqueous H2O2. Moreover, these catalysts were highly recyclable with retained activity and durability and proved to be truly heterogeneous. Using chemical grafting for the synthesis of 11 and 12 enhanced their recyclability and durability with retained activity. The high H2O2 efficiency can be attributed to the uniformly non-polar environment provided about Ti in 11 and 12 by the polymer; this results in low water concentrations and higher [alkene] : [H2O2] ratios at the Ti active site than in the rest of the solution. These effects enhance the epoxide selectivity and minimize leaching of titanium.

Improving the Fire Performance of Nylon 6,6 Fabric by Chemical Grafting with Acrylamide

2013 ◽  
Vol 52 (6) ◽  
pp. 2290-2296 ◽  
Author(s):  
Xueyan Li ◽  
Xiaoyu Gu ◽  
Sheng Zhang ◽  
Hongfei Li ◽  
Qingli Feng ◽  
...  
Keyword(s):  
Fire Performance ◽  
Nylon 6,6 ◽  
Chemical Grafting
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