scholarly journals The Preparation and Characterization of Polyacrylonitrile-Polyaniline (PAN/PANI) Fibers

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 664 ◽  
Author(s):  
Iwona Karbownik ◽  
Olga Rac-Rumijowska ◽  
Marta Fiedot-Toboła ◽  
Tomasz Rybicki ◽  
Helena Teterycz
Keyword(s):  
Specific Resistance ◽  
Strong Interactions ◽  
Mechanical Parameters ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Strength Tests ◽  
Pan Fibers

The paper presents a method of modifying polyacrylonitrile (PAN) fibers using polyaniline (PANI). The PAN fibers were doped with polyaniline that was obtained in two different ways. The first consisted of doping a spinning solution with polyaniline that was synthesized in an aqueous solution (PAN/PANI blended), and the second involved the synthesis of polyaniline directly in the spinning solution (PAN/PANI in situ). The obtained fibers were characterized by the methods: X-ray powder diffraction (XRD), scanning electron microscope (SEM), fourier-transform infrared spectroscopy (FTIR), thermogravimetry (TG) and differential scanning calorimetry (DSC). Analysis of the results showed strong interactions between the nitrile groups of polyacrylonitrile and polyaniline in the PAN/PANI in situ fibers. The results of mechanical strength tests indicated that the performance of the PAN/PANI mixture significantly improved the mechanical parameters of polyaniline, although these fibers had a weaker strength than the unmodified PAN fibers. The fibers obtained as a result of the addition of PANI to PAN were dielectric, whereas the PANI-synthesized in situ were characterized by a mass-specific resistance of 5.47 kΩg/cm2.

scholarly journals Characterization of the Interface Between the Bulk Glass Forming Alloy Zr41Ti14Cu12Ni10Be23 with Pure Metals and Ceramics

2000 ◽  
Vol 15 (7) ◽  
pp. 1617-1621 ◽  
Author(s):  
Jan Schroers ◽  
Konrad Samwer ◽  
Frigyes Szuecs ◽  
William L. Johnson
Keyword(s):  
Sessile Drop ◽  
Bulk Glass ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Glass Forming ◽  
Processing Times ◽  
Thermal Stability Of

The reaction of the bulk glass forming alloy Zr41Ti14Cu12Ni10Be23 (Vit 1) with W, Ta, Mo, AlN, Al2O3, Si, graphite, and amorphous carbon was investigated. Vit 1 samples were melted and subsequently solidified after different processing times on discs of the different materials. Sessile drop examinations of the macroscopic wetting of Vit 1 on the discs as a function of temperature were carried out in situ with a digital optical camera. The reactions at the interfaces between the Vit 1 sample and the different disc materials were investigated with an electron microprobe. The structure and thermal stability of the processed Vit 1 samples were examined by x-ray diffraction and differential scanning calorimetry. The results are discussed in terms of possible applications for composite materials.

scholarly journals Effects of Chlorinated Polypropylene on the Conformation of Polypropylene in Polypropylene/Chlorinated Polypropylene/Polyaniline Composites

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jianjun Chen ◽  
Yueyue Jia ◽  
Zhiye Zhang ◽  
Xinlong Wang ◽  
Lin Yang
Keyword(s):  
Intensity Ratio ◽  
Maximum Level ◽  
In Situ Ftir ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Infrared Band ◽  
X Ray ◽  
Polyaniline Composites

We investigated the changes in the conformation and crystalline structure of polypropylene (PP) using a combination of Fourier transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WAXD), and differential scanning calorimetry (DSC) based on PP/chlorinated PP (CPP)/polyaniline (PANI) composites. The DSC heating thermograms and WAXD patterns of the PP/CPP/PANI composites showed that theβ-crystal was affected greatly by the CPP content. Characterization of the specific regularity in the infrared band variation showed that the conformational orders of the helical sequences in PP exhibited major changes that depended on the CPP content. Initially, the intensity ratio ofA840/A810increased with the CPP concentration and reached its maximum level when the CPP content was <13.22% before decreasing as the CPP content increased further. The effect of increased temperature on the conformation of PP was studied by in situ FTIR. Initially, the intensity ratio ofA999/A973decreased slowly with increasing the temperature up to 105°C before decreasing sharply with further increases in temperature and then decreasing slowly again when the temperature was higher than 128°C.

Characterization of Lauric Acid Precipitated from Biocompatible Solvents

2019 ◽  
Vol 819 ◽  
pp. 209-214
Author(s):  
Napaphol Puyathorn ◽  
Takorn Chantadee ◽  
Setthapong Senarat ◽  
Thawatchai Phaechamud
Keyword(s):  
Lauric Acid ◽  
Phase Inversion ◽  
Water Resistance ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Degradation Temperature ◽  
Lower Melting Point ◽  
Methyl Pyrrolidone

Water resistance of lauric acid (L) dissolved in biocompatible solvents mainly depended on the water affinity of solvent. L in DMSO (DL) was most sensitive to water and higher than L in N-methyl pyrrolidone (NL) and L in 2-pyrolidone (PL), respectively. From scanning electron microscope, differential scanning calorimetry, thermogravimetric analysis, powder x-ray diffractometry and hot stage microscope tests revealed the alteration of L crystal owing to the interference by solvent during precipitation. All L precipitates had lower melting point and degradation temperature than intact L in which L precipitated from 2-pyrrolidone exhibited the lowest melting temperature. These characteristics will be useful for modifying L in phase inversion in situ forming gel.

Syntheses and Characterization of Chitosan Oligosaccharide-Graft-Polycaprolactone Copolymer I Thermal and Spherulite Morphology Studies

2011 ◽  
Vol 183-185 ◽  
pp. 155-160 ◽  
Author(s):  
Feng Hong Li ◽  
San Xi Li ◽  
Tao Jiang ◽  
Yong Sun
Keyword(s):  
Ring Opening ◽  
Optical Microscope ◽  
Chitosan Oligosaccharide ◽  
Dsc Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Spherulite Morphology ◽  
Thermal Stable

The thermoplastic graft copolymers of chitosan oligosaccharide (PHCSO-g-PCL) were successfully synthesized via ring-opening polymerization (ROP) of ε-caprolactone (CL) through an amino group protection route using phthaloyl chitosan oligosaccharide (PHCSO) as intermediate. The graft reaction was carried out in Pyridine at 120 °C with a chitosan oligosaccharide (CSO) initiator and a tin 2-ethylhexanoate (Sn (Oct)2) catalyst. The prepared copolymer was characterized by FTIR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide-angle X-ray diffraction (WAXD). DSC analysis of PHCSO-g-PCL showed higher melting point at 54.8 °C than linear PCL. The TGA analysis showed that PHCSO-g-PCL was more thermal stable than original CSO. The banded spherulite structure of PHCSO-g-PCL and the growth of spherulite were observed by polarized optical microscope (POM); this was further proven by WAXD results.

Preparation and Characterization of Polysulfone Membranes Containing Ag Nanoparticles by a Convenient Ultraviolet Irradiation Technique

2009 ◽  
Vol 151 ◽  
pp. 145-149 ◽  
Author(s):  
Viorica Gaina ◽  
Constantin Gaina ◽  
Mihaela Olaru
Keyword(s):  
Ultraviolet Irradiation ◽  
Silver Salt ◽  
In Situ Reduction ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Aggregation Phenomena

A novel silver/polysulfone nanocomposite membrane was prepared by a convenient ultraviolet irradiation technique, through in situ reduction of silver salt (AgNO3) added to a solution of commercial UDEL polyethersulfone dissolved in N-methyl-2-pyrrolidinone (NMP). The UV-reduction of Ag+ to Ag0 nanoparticles was confirmed by means of UV-vis spectroscopy, from aggregation phenomena. The effects of dispersion of silver nanoparticles within polysulfone matrix were investigated by means of ATR-FTIR, dynamic mechanical thermal analysis and differential scanning calorimetry. Using X-ray diffraction, it was shown that annealing produced silver crystallites of 70-90 nm across, which are partially textured in “sheetlike” {110} planes.

scholarly journals Study on reaction mechanisms of iron matrix compositesreinforced with in situ Al2O3 particles reacted byAl-Fe2O3-Fe system

2018 ◽  
Vol 238 ◽  
pp. 02006
Author(s):  
Chengyan Zhu ◽  
Jie Jiang ◽  
Heguo Zhu
Keyword(s):  
Heating Rate ◽  
Reaction Mechanisms ◽  
Reaction Times ◽  
Matrix Composites ◽  
Dsc Analysis ◽  
Iron Matrix ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Higher Temperature

Iron matrix composites reinforced with Al2O3 particles were fabricated in situ through exothermic dispersive (XD) reaction from a powder mix of pure elements Fe, Al and Fe2O3. The fabrication and reaction mechanisms were investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS) and differential scanning calorimetry (DSC) analysis. The reaction between Al and Fe2O3 was found to occur in three steps. Their activation energies are 203.8 kJ/mol, 1100.9 kJ/mol and 380 kJ/mol, respectively. DSC analysis shows that the reaction peak shifts to a higher temperature with an increase in the heating rate. When the heating rate is 10 K/min, the rates of the three reactions exhibit a similar trend, i.e., the reaction rate is very slow at the start, and then it increases rapidly, finally it becomes slow again. Their reaction times are 456, 672 and 650 s, respectively.

Study of Cellulose-Dibutyl Sebacate Copolymer Synthesis and Characterization of Crosslinked Cellulose-Dibutyl Sebacate Copolymers for Oil Absorbency

2011 ◽  
Vol 311-313 ◽  
pp. 2075-2083
Author(s):  
Halidan Mamat
Keyword(s):  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
X Ray ◽  
Oil Absorbency ◽  
Dibutyl Sebacate ◽  
Oil Absorbent

A novel cellulose-based oil absorbent crosslinked cellulose-dibutyl sebacate copolymers was prepared by the graft crosslinking polymerization of in situ synthesized dibutyl sebacate and cotton cellulose using potassium persulfate as an initiator. The copolymers were characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetry, differential scanning calorimetry, etc. The effects of reaction conditions, such as, ratio of reaction regents, reaction temperature, reaction time, etc, on the efficiency of oil absorbency were examined. The optimized reaction conditions for the synthesis of crosslinked cellulose-dibutyl sebacate copolymers were: m(cotton pulp):m(K2S2O8 initiator):m(dibutyl sebacate) = 1 0.025 2.0(W/W)，75°C，and 5-6 h. The resulting crosslinked cellulose-dibutyl sebacate copolymers were floppy and exhibited excellent oil absorbency efficiency.

Synthesis of an In Situ Aluminum Matrix Composite Fabricated by Al-Cr2O3 System

2014 ◽  
Vol 905 ◽  
pp. 119-122
Author(s):  
He Guo Zhu ◽  
Hao Sun ◽  
Bo Hua ◽  
Guan Hong Guo ◽  
Jie Wen Huang ◽  
...  
Keyword(s):  
Aluminum Matrix ◽  
Aluminum Matrix Composite ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Dsc Analysis ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Higher Temperature

In situ aluminum matrix composites were fabricated through exothermic dispersive (XD) reaction from a powder mixture of Al and Cr2O3. The reaction mechanism was investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS) and differential scanning calorimetry (DSC) analysis. When the temperature increases to around 1050K, Al can react with Cr2O3to form the reinforcments Al2O3particles and CrAl4blocks. With the increase of heating rate, DSC analysis shows that the reaction peak shifts to a higher temperature and the corresponding ignition temperature also increases. Based on DSC curves with different heating rates, the activation energy can be calculated and its value is 191.8 kJ/mol.

Preparation and characterization of conducting nylon 6 fibers

2009 ◽  
Vol 24 (8) ◽  
pp. 2728-2735 ◽  
Author(s):  
A. Saritha Chandran ◽  
Sunil K. Narayanankutty
Keyword(s):  
Photoelectron Spectroscopy ◽  
In Situ Polymerization ◽  
Fiber Surface ◽  
Nylon 6 ◽  
Etching Time ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

Conducting nylon 6 fibers were prepared by in situ polymerization of aniline on to the fiber surface, after providing a chemical etching treatment to the fibers using chromic acid. The properties of the etched and polyaniline (PANI) coated fibers were evaluated using scanning electron microscopy, x-ray photoelectron spectroscopy, infrared spectroscopy, x-ray diffraction, thermogravimetry, and differential scanning calorimetry. Though the etching process caused a marginal decline in the mechanical properties of the fiber, it provided a reasonably rough surface for PANI adhesion and enhanced the conductivity of the fiber. The conductivity increased from 4.22 × 10−2 to 3.72 × 10−1 S/cm at an etching time of 4 h.

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