scholarly journals Wet-spun graphene filaments: effect of temperature of coagulation bath and type of reducing agents on mechanical & electrical properties

RSC Advances ◽  
2018 ◽  
Vol 8 (31) ◽  
pp. 17443-17452 ◽  
Author(s):  
Melik Oksuz ◽  
H. Yildirim Erbil
Keyword(s):  
Tensile Strength ◽  
Acetic Acid ◽  
Electrical Properties ◽  
Hydriodic Acid ◽  
Reducing Agents ◽  
Effect Of Temperature ◽  
Coagulation Bath ◽  
Acid Reduction

Cold isopropanol coagulation bath and use of acetic acid/hydriodic acid reduction resulted in better tensile strength for wet-spun graphene filaments.

scholarly journals Probing the Catalytic Efficiency of Supported Heteropoly Acids for Esterification: Effect of Weak Catalyst Support Interactions

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ali Alsalme ◽  
Aliyah A. Alsharif ◽  
Hamda Al-Enizi ◽  
Mujeeb Khan ◽  
Saad G. Alshammari ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Active Sites ◽  
Catalyst Support ◽  
Supported Catalyst ◽  
Catalytic Efficiency ◽  
Biodiesel Production ◽  
Effect Of Temperature ◽  
Heteropoly Acids ◽  
Catalyst Loading ◽  
Esterification Activity

Supported heteropoly acids are an interesting class of solid acid catalysts which possess flexible structure and super acidic properties essentially required for the oil-based biodiesel production. In this study, a series of catalysts containing 25 wt.% of heteropolytungstate (HPW) supported on various clays or SiO2 were prepared, and their catalytic efficiency was evaluated for esterification of acetic acid with heptanol. The as-prepared catalysts were characterized by various techniques including FT-IR spectroscopy, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, and BET. The catalytic efficiency of both bulk and supported HPW catalysts for the esterification activity strongly depends on the type of support and amount of catalyst; the bulk HPW catalyst and the catalyst supported by kaolinite with 25 wt.% of HPW exhibited highest activity. In order to study the effect of temperature on conversion, all the catalysts were subjected to different reaction temperatures. It was revealed that esterification activity of both bulk and supported HPW catalysts strongly depends upon the temperature variations of the reaction. Besides, the effect of leaching of active sites on the catalysts performance for biodiesel production was also evaluated by inductively coupled plasma studies (ICP). The kaolinite-supported catalyst (25% HPW/kaolinite) demonstrated higher amount of leaching which is also confirmed by the significant decrease in its catalytic activity when it is used for the second time. However, the higher activity demonstrated by HPW/kaolinite maybe because of some homogeneous reaction indicating a weak catalyst support interaction (WCSI) resulting in the leaching of the catalyst during the test. Furthermore, the effects of other reaction variables such as catalyst loading and reaction time on the conversion of acetic acid were also studied.

The effect of temperature and strain rate on the tensile strength of a fast-gas-cooled uranium-2 wt% molybdenum alloy

1985 ◽  
Vol 132 (2) ◽  
pp. 181-191 ◽  
Author(s):  
G.A.C. Boyd ◽  
J. Harding ◽  
P.A. Bleasdale ◽  
K. Dunn ◽  
G.I. Turner
Keyword(s):  
Tensile Strength ◽  
Strain Rate ◽  
Molybdenum Alloy ◽  
Effect Of Temperature

scholarly journals Effects of reducing reagents and temperature on conversion of nitrite and nitrate to nitric oxide and detection of NO by chemiluminescence

1997 ◽  
Vol 43 (4) ◽  
pp. 657-662 ◽  
Author(s):  
Fan Yang ◽  
Eric Troncy ◽  
Martin Francœur ◽  
Bernard Vinet ◽  
Patrick Vinay ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Effect Of Temperature ◽  
Fixed Amount ◽  
Increased Temperature

Abstract To measure the concentration of nitrites and nitrates by chemiluminescence, we examined the efficiency of five reducing agents [V(III), Mo(VI) + Fe(II), NaI, Ti(III), and Cr(III)] to reduce nitrite (NO2−) and (or) nitrate (NO3−) to nitric oxide (NO). The effect of each reducing agent on the conversion of different amounts of NO2− and (or) NO3−(100–500 pmol, representing concentrations of 0.4 to 2 μmolar) to NO was determined at 20 °C for NO2− and at 80 °C for NO3−. The effect of temperature from 20 to 90 °C on the conversion of a fixed amount of NO2− or NO3− (400 pmol or 1.6 μmolar) to NO was also determined. These five reducing agents are similarly efficient for the conversion of NO2− to NO at 20 °C. V(III) and Mo(VI) + Fe(II) can completely reduce NO3− to NO at 80 °C. NaI and Cr(III) were unable to convert NO3− to NO. Increased temperature facilitated the conversion of NO3− to NO, rather than that of NO2− to NO. We evaluated the recovery of NO2− and NO3− from plasmas of pig and of dog. Recovery from plasma of both animals was reproducible and near quantitative.

Preparation and Characterization of Alginate/Polyvinyl Alcohol Composite Fibers Containing Copper Ions

2013 ◽  
Vol 652-654 ◽  
pp. 1562-1565 ◽  
Author(s):  
Jing Guo ◽  
Qian He Chen ◽  
Yu Yan Zhang ◽  
Yu Mei Gong ◽  
Hong Zhang
Keyword(s):  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
Copper Ions ◽  
Fiber Surface ◽  
Coagulation Bath ◽  
Wet Spinning ◽  
Composite Fibers ◽  
Pseudoplastic Fluid ◽  
Cu Ions

Alginate/polyvinyl alcohol (PVA) composite fibers containing copper ions were prepared by wet spinning. The spinning solution and manufacturing process were researched. The composite fibers were characterized by Tensile Strength Tester, SEM and TGA. This report shows that the spinning solution is a typical kind of pseudoplastic fluid. Adding boric acid to coagulation bath and putting Cu ions into composite fibers can improve the strength. The structure of composite fibers with Cu ions is denser and there are grooves on the fiber surface. In addition, the thermal property of composite fibers is steady.

scholarly journals Temperature Coagulant Tub Variation Effect on the Characteristic of Hollow Fiber Dialyser from Cellulose Acetate Composite D-Glucose Monohydrate

2017 ◽  
Vol 31 ◽  
pp. 53-60
Author(s):  
Rizki Firsta Wahyuliswari ◽  
Siswanto ◽  
Prihartini Widiyanti
Keyword(s):  
Tensile Strength ◽  
Creatinine Clearance ◽  
Cellulose Acetate ◽  
Hollow Fiber ◽  
Bath Temperature ◽  
Hollow Fibers ◽  
Coagulation Bath ◽  
Temperature Variations ◽  
Swelling Rate ◽  
Coagulation Bath Temperature

Polysulfone is synthetic polymer widely used as basic material for dialyzer membrane and hydrophobic so it tends to cause fouling. Cellulose acetate is non-synthetic, hydrophilic polymer which has low tendency of fouling and has good thermal stability and permeability so it is considered as alternative material for hollow fiber dialyzer. A proper hollow fiber can be achieved by setting a proper temperature of coagulation bath along the spinning process. This research aims to understand the effect of coagulation bath temperature variations on the physical characteristic such as pore size, tensile strength, swelling rate and creatinine clearance of cellulose acetate – D-glucose monohydrate hollow fibers. Hollow fibers were fabricated using spinneret at temperature variations 5°C, 10°C, 15°C dan 20°C. Physical characteristics were estimated by doing morphology test using SEM, tensile test, swelling test towards Simulated Body Fluid (SBF) and filtration test towards creatinine. Result revealed that the hollow fibers from 5°C coagulation bath temperature gives the best characteristic and performance with tensile strength 27,421 N mm-2, pore size 0,0295–0,0858 nm, swelling rate 4,18%, elongation rate 4,4 %, flux rate 1,6032–1,7956 mL cm-2 min-1 and creatinine clearance rate 40,14–48,30% so it is potential to be applied as dialyzer membrane.

Effect of temperature on the electrical properties of copolymer/carbon black mixtures

2010 ◽  
Vol 356 (31-32) ◽  
pp. 1536-1541 ◽  
Author(s):  
M. El Hasnaoui ◽  
M.P.F. Graça ◽  
M.E. Achour ◽  
L.C. Costa ◽  
A. Outzourhit ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Carbon Black ◽  
Effect Of Temperature
Sign in / Sign up

Export Citation Format

Share Document