scholarly journals Preparation of Nanoscale Urushiol/PAN Films to Evaluate Their Acid Resistance and Protection of Functional PVP Films

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 957
Author(s):  
Kunlin Wu ◽  
Bing-Chiuan Shiu ◽  
Ding Zhang ◽  
Zhenhao Shen ◽  
Minghua Liu ◽  
...  

Different amounts of urushiol were added to a fixed amount of polyacrylonitrile (PAN) to make nanoscale urushiol/PAN films by the electrospinning method. Electrospinning solutions were prepared by using dimethylformamide (DMF) as the solvent. Nanoscale urushiol/PAN films and conductive Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)/polyvinyl pyrrolidone (PVP) films were prepared by electrospinning. In order to prepare an electrospun sandwich nanoscale film, urushiol/PAN films were deposited as both the top and bottom layers and PEDOT:PSS/PVP film as the inner layer. When the PAN to urushiol ratio was 7:5, the fiber diameter ranged between 150 nm and 200 nm. The single-layer urushiol/PAN film could not be etched after being immersed into 60%, 80%, and 100% sulfuric acid (H2SO4) for 30 min, which indicated the improved acid resistance of the PAN film. The urushiol/PAN film was used to fabricate the sandwich nanoscale films. When the sandwich film was immersed into 80% and 100% H2SO4 solutions for 30 min, the structure remained intact, and the conductive PVP film retained its original properties. Thus, the working environment tolerability of the functional PVP film was increased.

1982 ◽  
Vol 55 (4) ◽  
pp. 1137-1151 ◽  
Author(s):  
R. R. Campbell ◽  
D. A. Stivers ◽  
R. E. Kolb

Abstract The effects of percent fluorine, filler, and cure systems on the thermal and acid resistance of fluoroelastomers were evaluated over temperature ranges that would be typical of actual flue duct installations and accelerated conditions such as 275°C for thermal resistance and 149°C for concentrated sulfuric acid resistance. FKM 2176, which contains 65% fluorine by weight, became hard and brittle after two weeks of accelerated air aging at 275°C. The balance of physical properties of FKM 2176 were good when aged at 200°C. FKM 4894, which contains 67% fluorine by weight, retained useful properties after six weeks of accelerated air aging at 275°C. This indicates this material has improved properties for flue duct applications compared to FKM 2176. FKM 4894 filled with MT carbon black had improved retention of tensile strength after aging at 232°C relative to the FKM 4894 filled with SRF/HAF black, Austin Black and litharge. FKM 2176 was totally degraded after aging three days at 149°C in concentrated sulfuric acid. Aging of FKM 4894 in concentrated sulfuric acid at 149°C resulted in a loss of approximately 75 percent of the original tensile and an increase in the elongation, and the appearance of the exposed surface did not indicate chemical attack. Although FKM 4894 was superior to FKM 2176 when aged in sulfuric acid at 149°C, there was little difference between FKM 4894 and FKM 2176 when aged at 121 °C for up to four weeks or after eight weeks at 100°C in concentrated sulfuric acid. Austin Black showed the best retention of tensile of the four filler systems evaluated after aging at 100°C in concentrated sulfuric acid. FKM 4826, which contains 69% fluorine and is vulcanized using organic peroxide and triallyl isocyanurate, has indicated a compatibility with fiberglass that is superior to all fluorocarbon elastomer gums that were tested.


Author(s):  
Paweena Jariyathitipong ◽  
Kazuyoshi Hosotani ◽  
Takashi Fujii ◽  
Toshiki Ayano

2014 ◽  
Vol 16 (1) ◽  
pp. 49-52
Author(s):  
Yelfira Sari ◽  
Muhamad Nasir ◽  
Chandra Risdian ◽  
Syukri Syukri

Sintesis nanofiber komposit Zn-PVDF kopolimer dengan metoda elektrospinning telah berhasil dilakukan. Proses pembuatan nanofiber komposit serta  morfologi yang terbentuk dipengaruhi oleh penambahan Zn-asetat dengan perubahan diameter rata-rata serat dari 357,13 nm menjadi 777,24 nm. Analisis FTIR menunjukkan bahwa struktur kristal nanofiber komposit Zn-PVDF kopolimer didominasi oleh strukturβ-phase, dengan bilangan gelombang 1190,08 cm-1 dan 487,99 cm-1 untuk struktur α-phase dan 1404,18 cm-1; 1280,73 cm-1; 1074,35 cm-1; 881,47 cm-1; dan 840,96 cm-1 untuk struktur β-phase.Kata kunci :nanofiber komposit, Zn-PVDF kopolimer komposit, elektrospinning,kristal struktur, morfologi, diameter fiber The fabrication of Zn-PVDF copolymer nanofiber composite has been investigated in this research study by using electrospinning method. Fabrication and morphology of nanofiber composite is influenced by the addition of Zn-acetate. The average diameter of nanofiber composites increase with an addition of Zn-acetate, from 357,13 to 777,24nm. FTIRanalysisshowedthat thecrystalstructure ofPVDFnanofiberis dominatedby β-phase , thewave number 1190,08 cm-1 and 487,99 cm-1 for α-phase structure and 1404,18cm-1; 1280,73cm-1; 1074,35cm-1; 881,47cm-1and840,96cm-1 for β-phase structure respectively.Key words : nanofiber composite, Zn-PVDF copolymer composite, electrospinning, crystal structure,  morphology, fiber diameter


2020 ◽  
Vol 54 (9-10) ◽  
pp. 953-965
Author(s):  
ÖMER ÖNAL ◽  
MUSTAFA YAZICI ◽  
ISMAIL TIYEK ◽  
KONUS OGUZHAN ◽  
MEHMET HAKKI ALMA ◽  
...  

In this study, in order to produce nanofibers from waste hazelnut shells, a lignocellulosic biomass, firstly, liquefied hazelnut shell (LHS) was obtained by liquefaction of waste hazelnut shells using phenol and some chemicals. Then, reduced graphene oxide (RGO) was produced by Hummers’ method. RGO and polyvinyl pyrrolidone (PVP) were added to LHS, in certain proportions, to form seven different LHS-RGO-PVP solutions with ethanol/dimethylformamide (EtOH/DMF). From these solutions, nanofiber surfaces were obtained by a semi-industrial electrospinning device. The morphology of the nanofibers and the properties of the electrospinning solution were investigated, and it was observed that the optimum nanofibers were obtained from 7.5% LHS/10% PVP/5.6% RGO solution by the electrospinning method. It has been determined that the conductivity is slightly reduced by the addition of RGO to the solution, the viscosity is greatly reduced, the nanofiber diameters are reduced by approximately half, and thinner nanofibers are obtained


2020 ◽  
Vol 73 (1) ◽  
pp. 87-94
Author(s):  
Satoshi FUJIWARA ◽  
Taro KOSUGE ◽  
Masanori MARUOKA ◽  
Hiromi FUJIWARA

2020 ◽  
Vol 9 (1) ◽  
pp. 9-19
Author(s):  
Ida Sriyanti ◽  
Meily P Agustini ◽  
Jaidan Jauhari ◽  
Sukemi Sukemi ◽  
Zainuddin Nawawi

The purposes of this research were to investigate the synthesized Nylon-6 nanofibers using electrospinning technique and their characteristics. The method used in this study was an experimental method with a quantitative approach. Nylon-6 nanofibers have been produced using the electrospinning method. This fiber was made with different concentrations, i.e. 20% w/w (FN1), 25% w/w (FN2), and 30% w/w (FN3). The SEM results show that the morphology of all nylon-6 nanofibers) forms perfect fibers without bead fiber. Increasing fiber concentration from 20% w/w to 30% w/w results in bigger morphology and fiber diameter. The dimensions of the FN1, FN2, and FN3 fibers are 1890 nm, 2350 nm, and 2420 nm, respectively. The results of FTIR analysis showed that the increase in the concentration of nylon-6 (b) and the electrospinning process caused a peak shift in the amide II group (CH2 bond), the carbonyl group and the CH2 stretching of the amide III group from small wave numbers to larger ones. The results of XRD characterization showed that the electrospinning process affected the changes in the XRD pattern of nylon-6 nanofiber (FN1, FN2, and FN3) in the state of semi crystal. Nylon-6 nanofibers can be used for applications in medicine, air filters, and electrode for capacitors


2020 ◽  
Author(s):  
Muhammad Nasir ◽  
Megat Azmi Megat Johari ◽  
Mohammed Maslehuddin ◽  
Moruf Olalekan Yusuf

2012 ◽  
Vol 531-532 ◽  
pp. 531-534
Author(s):  
Yun Qian Cao ◽  
Qin Fei Ke ◽  
Xiang Yu Jin ◽  
Sha Sha Guo

In this paper, regenerated silk fibroin/polybutylene terephthalate blended mats were prepared using electrospinning method with different blending ratios. The influence of regenerated silk fibroin/polybutylene terephthalate ratio on the morphology behaviors, fiber diameter and the surface wettability of the blended mats were studied. The morphology of the electrospun fibers were characterized by SEM. The average fiber diameter and its distribution can be obtained from the SEM pictures using software Image J. The average fiber diameter was 280nm to 486nm and it changed with the blending ratio. The contact angles and penetration times were used to characterize the surface wettability of the nanofiber membranes. It was found that with the increase of regenerated silk fibroin amount, the surface contact angles and penetration times decreased, which meant that the wettability was greatly improved.


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