The Synergistic Effect of Polymer Composition, Solvent Volatility, and Collector Distance on Pullulan and PVA Fiber Production by Rotary Jet Spinning

Author(s):  
Leonardo de Souza ◽  
Alex Carvalho Alavarse ◽  
Marco Aurélio da Vinci ◽  
Jean-Jacques Bonvent
2019 ◽  
Vol 807 ◽  
pp. 171-175
Author(s):  
Chao Xiao ◽  
Xi Ke Xiong ◽  
Jun Sun ◽  
Li Xing Dai

Graphene oxide (GO) coated fiber via deposition of GO sheets on polyvinyl alcohol (PVA) fiber containing silver nanowires (AgNWs) was fabricated, and chemical reduction for GO on the fiber surface was carried out to obtain reduced GO (rGO) coated PVA-AgNWs (rGO/PVA-AgNWs) fiber. The results showed that the rGO sheets were closely adhered on the surface of fiber, the electrical conductivity of the fiber increased with coating times of GO, and the conductivity was high up to 2.05×10-3 S/m when GO was coated 3 times on the fiber and reduced. The synergistic effect of rGO and AgNWs for the conductivity was also clearly indicated.


The authors' methodic for assessing the role of chemical and physic-chemical factors during the structure formation of gypsum stone is presented in the article. The methodic is also makes it possible to reveal the synergistic effect and to determine the ranges of variation of controls factors that ensure maximum values of such effect. The effect of a micro-sized modifier based on zinc hydro-silicates on the structure formation of building gypsum is analyzed and corresponding dependencies are found. It is shown that effects of influence of modifier on the properties of gypsum compositions are determined by chemical properties of modifier. Among the mentioned properties are sorption characteristics (which depend on the amount of silicic acid and its state) and physicochemical properties - the ability to act as a substrate during crystal formation. The proposed method can also be extended to other binding substances and materials. This article contributes to the understanding of the processes that occur during the structure formation of composites, which will make it possible to control the structure formation in the future, obtaining materials with a given set of properties.


2012 ◽  
Vol 8 (1) ◽  
pp. 63
Author(s):  
Carlo Zivelonghi ◽  
Giulia Geremia ◽  
Michele Pighi ◽  
Flavio Ribichini ◽  
◽  
...  

Each component of a drug-eluting stent (DES) contributes to the safety of the device. Continuous efforts are being dedicated to the search of the optimal compromise between facility of use, safety and long-term efficacy. Shorter balloons reduce the vascular trauma beyond the stent struts; the metallic composition of the stent platform and the platform itself interact with the vascular wall in a long-lasting equilibrium between radial force, vessel patency and reparative cellular regrowth. The modality of drug elution is largely regulated by the chosen drug carrier, rather than by the chemical properties of the drug itself. Drug elution can be accomplished by permanent polymers that remain in the vessel wall forever, by biodegradable polymers that leave the naked metallic structure behind after their complete absorption, or even by direct release of the drug from stent reservoirs. The clinical performance of DESs has been exhaustively assessed in a large number of studies that have showed rapid and continuous improvements, from the first-generation DESs to the latest devices, based on substantial changes in stent design and polymer composition.


2005 ◽  
Vol 67 (3) ◽  
pp. 247-251 ◽  
Author(s):  
Motoi TAKENAKA ◽  
Sang Jae BAE ◽  
Shinichi SATO ◽  
Ichiro KATAYAMA

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