Sorption behavior of iodine vapor into pitches and its stabilizing mechanism below the melting temperature of the pitches

Tanabe, Yasuhiro; Tanaka, Fumio; Takahashi, Miwa; Iiyama, Taku; Miyajima, Naoya; Fujisawa, Shoji; Yasuda, Eiichi

doi:10.1016/j.carbon.2004.02.002

Cited by 16 publications

(9 citation statements)

References 18 publications

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“…Figure 5b shows a fiber mat after its fiber structure has been completely destroyed due to an extended iodine treatment. A similar effect was observed by Tanabe et al for coal tar pitches 36 in which they found that when the amount of iodine absorbed exceeded a certain threshold of iodine to absorbate molecule, the absorbate melted. This melting was caused by the CTCs acting as permanent dipoles (with the iodine as the anion and aromatic as the cation), which developed electrostatic repulsions strong enough to overcome the energy barrier to viscous flow.…”

Section: ■ Results and Discussionsupporting

confidence: 80%

Iodine Treatment of Lignin–Cellulose Acetate Electrospun Fibers: Enhancement of Green Fiber Carbonization

Schreiber

Vivekanandhan

Mohanty

et al. 2014

ACS Sustainable Chem. Eng.

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Pure biopolymer-based electrospun precursor carbon fibers are fabricated using an abundant and inexpensive biopolymer lignin blended with renewable resource-based cellulose acetate (CA). Iodine treatment on the fabricated green fiber was successfully performed in order to enhance the carbonization process as well as the retention of fiber morphology. The absorption mechanism of iodine by lignin and cellulose acetate and their derived electrospun green fibers has been investigated by means of thermal behavior and morphological retention. It was found that iodine treatment plays a vital role in altering the graphitization behavior as well as morphology retention during the carbonization process. With the help of iodine treatment, the green precursor fibers were successfully converted into thin carbon fibers, and scanning electron microscopy analysis confirmed the retention of fibrous structures with diameters around 250 nm. Raman spectroscopy revealed that although the overall level of graphitization was lower compared to polyacrylonitrile-based fibers, the graphitic crystallite size was larger in the produced carbon fibers. The produced pure biopolymer fibers and iodine treatments show promise for the production of green and costreduced carbon fibers.

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Section: ■ Results and Discussionsupporting

confidence: 80%

Iodine Treatment of Lignin–Cellulose Acetate Electrospun Fibers: Enhancement of Green Fiber Carbonization

Schreiber

Vivekanandhan

Mohanty

et al. 2014

ACS Sustainable Chem. Eng.

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“…This complexforming phenomenon has been exploited in different ways. For example, the iodine was used to fractionate the coal tar pitch [26], to modify its rheology and carbonization behaviors [27][28][29][30], and to enhance the electrical property of asphaltenes [31]. Also, the iodine complexing propensity towards cyclodex trin in a hostguest chemistry led to the application of the latter molecule in nuclear waste management [32].…”

Section: Molecular Iodine In Polymer Complexationmentioning

confidence: 99%

Molecular iodine/polymer complexes

Moulay

2013

Journal of Polymer Engineering

163

127

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A unique feature of molecular iodine by far, is its ability to bind to polymeric materials. A plethora of natural and synthetic polymers develop complexes when treated with molecular iodine, or with a mixture of mole cular iodine and potassium iodide. Many unexpected findings have been encountered upon complexation of iodine and the polymer skeleton, including the color formation, the polymer morphology changes, the compl exation sites or regions, the biological activity, and the electrical conductivity enhancement of the complexes, with poly iodides (I n¯) , mainly I 3¯ and I 5¯, as the actual binding species. Natural polymers that afford such complexes with iodine species are starch (amylose and amylopectin), chitosan, glycogen, silk, wool, albumin, cellulose, xylan, and natural rubber; iodinestarch being the oldest iodinenatural polymer complex. By contrast, numerous synthetic polymers are prone to make com plexes, including poly(vinyl alcohol) (PVA), poly(vinyl pyrrolidone) (PVP), nylons, poly(Schiff base)s, poly aniline, unsaturated polyhydrocarbons (carbon nano tubes, fullerenes C 60 /C 70 , polyacetylene; iodinePVA being the oldest iodinesynthetic polymer complex.

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“…This is a consequence of the iodine, as an oxidizing agent, affecting electron withdrawal from electron-rich molecules, especially aromatic rings, to form polyiodides [ 43 ]. Through the heating process, the iodine and adsorbent can form the charge transfer complexes (CTCs) [ 30 ], subsequently producing HI and leaving behind a free radical. Thanks to the free radicals, this dehydrogenation approach promotes cross-linking reactions to improve and speed up the thermostabilization process and generates more orderly fiber morphology [ 43 ].…”

Section: Resultsmentioning

confidence: 99%

“…In addition, their chemical composition is reflected in Table 1. (20,30,40, and 50% (wt/v)) embedded under magnetic stirring in water bath sonication for 24 h to eliminate particle agglomeration. All of the above-mentioned solutions have been subjected to the process of electrospinning.…”

Section: Chemical Analysis Of Extracted Ligninmentioning

confidence: 99%

“…Iodine has been investigated as a treatment to improve the stabilization process of various materials [ 29 ]. Iodine is well known to make charge transfer complexes (CTCs) with electron-rich particles such as those with lone pairs and aromatic rings within the form of polyiodides [ 30 ]. Consequently, this promotes improvements of dehydrogenation and speeds up the thermostabilization process.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fabrication, Modification, and Characterization of Lignin-Based Electrospun Fibers Derived from Distinctive Biomass Sources

Attia¹,

Abas²,

Nada

et al. 2021

Polymers

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From the environmental point of view, there is high demand for the preparation of polymeric materials for various applications from renewable and/or waste sources. New lignin-based spun fibers were produced, characterized, and probed for use in methylene blue (MB) dye removal in this study. The lignin was extracted from palm fronds (PF) and banana bunch (BB) feedstock using catalytic organosolv treatment. Different polymer concentrations of either a plasticized blend of renewable polymers such as polylactic acid/polyhydroxybutyrate blend (PLA-PHB-ATBC) or polyethylene terephthalate (PET) as a potential waste material were used as matrices to generate lignin-based fibers by the electrospinning technique. The samples with the best fiber morphologies were further modified after iodine handling to ameliorate and expedite the thermostabilization process. To investigate the adsorption of MB dye from aqueous solution, two approaches of fiber modification were utilized. First, electrospun fibers were carbonized at 500 °C with aim of generating lignin-based carbon fibers with a smooth appearance. The second method used an in situ oxidative chemical polymerization of m-toluidine monomer to modify electrospun fibers, which were then nominated by hybrid composites. SEM, TGA, FT-IR, BET, elemental analysis, and tensile measurements were employed to evaluate the composition, morphology, and characteristics of manufactured fibers. The hybrid composite formed from an OBBL/PET fiber mat has been shown to be a promising adsorbent material with a capacity of 9 mg/g for MB dye removal.

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Sorption behavior of iodine vapor into pitches and its stabilizing mechanism below the melting temperature of the pitches

Cited by 16 publications

References 18 publications

Iodine Treatment of Lignin–Cellulose Acetate Electrospun Fibers: Enhancement of Green Fiber Carbonization

Iodine Treatment of Lignin–Cellulose Acetate Electrospun Fibers: Enhancement of Green Fiber Carbonization

Molecular iodine/polymer complexes

Fabrication, Modification, and Characterization of Lignin-Based Electrospun Fibers Derived from Distinctive Biomass Sources

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