Polyacrylonitrile Composite Hollow Fibers Prepared by Wet

Subscriber access provided by ORTA DOGU TEKNIK UNIVERSITESI KUTUPHANESI

Article

Novel lignin/polyacrylonitrile composite hollow fibers prepared by wet-spinning method Zhen Jia, Chunxiang Lu, Yaodong Liu, Pucha Zhou, and Lu Wang ACS Sustainable Chem. Eng., Just Accepted Manuscript • DOI: 10.1021/ acssuschemeng.6b00351 • Publication Date (Web): 22 Mar 2016 Downloaded from http://pubs.acs.org on March 24, 2016

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

ACS Sustainable Chemistry & Engineering is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Sustainable Chemistry & Engineering

Novel lignin/polyacrylonitrile composite hollow fibers prepared by wet-spinning method Zhen Jia1, 2, Chunxiang Lu1, *, Yaodong Liu1, *, Pucha Zhou1, Lu Wang1, 2 1

National Engineering Laboratory for Carbon Fiber Technology, Institute of Coal

Chemistry, Chinese Academy of Sciences, 27 Taoyuan South Road, Taiyuan 030001, China 2

University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China

E-mails:

[email protected] (Chunxiang Lu) [email protected] (Yaodong Liu)

1

ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ABSTRACT: Lignin is the second most abundant and inexpensive natural biopolymers on earth. In this work, lignin/polyacrylonitrile composite fibers were prepared by wet-spinning method. A transition from solid fiber to hollow fiber was observed when the volume fraction of water in a mixed dimethyl sulfoxide/water coagulation bath was increased. The rheological measurements results showed that the spinning solution had no chemical reactions and was stable at the spinning conditions. Lots of interconnected macro and medium pores (50 ~ 90 nm) were formed inside the wall section of these hollow fibers. The change of coagulation solvent had little influence on the outer diameters of the fibers. The formations of the hollow structure and the pores are ascribed to a diffusion controlled procedure. The reaction between formaldehyde and hydroxyl groups (–OH) in lignin molecule was found to slightly improve fiber modulus and thermal stability. This study provides a facial way to prepare lignin-based hollow fibers for many applications.

KEYWORDS: High boiling solvent (HBS) lignin, Polyacrylonitrile, Hollow fiber, Wet-spinning, Coagulation

2


Page 2 of 20

Page 3 of 20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


INTRODUCTION Hollow fibers have numerous applications in many commercial fields, such as

medicine, micro-reactor, wastewater treatment, gas/azeotropic/hydrocarbon separation, and biochemistry1. The hollow fibers are commonly made by materials with excellent mechanical, physical and chemical properties, for example polysulfone, polyether sulfone, and polyvinylidene fluorid2. The manufactures of these fossil-based materials are costly, and also produce environmental hazards. Therefore, bio-based alternatives of these chemical compounds are highly desired to reduce manufacturing cost and avoid environmental pollutions. Lignin is the second most abundant natural materials on earth3. It is sustainable and relatively inexpensive. Therefore, lignin is gaining more and more interests from academic researchers and industrial developers. One of the most promising applications of lignin is that it is able to be converted to carbon fibers with a possible high carbon yield and very short thermal conversion duration4. Various forms of lignin are available in the market according to its isolation procedures and sources5. One of the difficulties for lignin to be used as carbon fiber precursor is that most lignin contains lots of inorganic impurities such as ashes and salts, which lead to poor performance of the resultant carbon fibers6. In order to obtain lignin with high purity, high boiling solvent (HBS) is used for lignin extraction. The HBS lignin has high purity (>99%) and is sulfur-free (a low ash and carbohydrate content). The HBS used for the extraction procedure can be recycled by distillation without losing its extraction efficiency which will significantly reduce the extraction cost7. Also, 3



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

cellulose, which has been widely used in many industries, is the major by-product of HBS lignin manufacture. The poor mechanical properties of lignin fibers are the major barrier for their manufacturing and applications. As reported in the previous literature8, either cross-linking lignin or adding polymers as enhancer, such as poly (ethylene oxide) (PEO)9,

10

, poly (vinyl alcohol) (PVA)11,

12

, polyacrylonitrile (PAN)13-15, could

effectively improve the mechanical properties of lignin fibers. Among these polymers, PAN is known as one of the most proper materials to produce both polymer fibers and carbon fibers with excellent mechanical strength.16 Even though the researchers have reported the lignin/PAN fibers through electron spinning8 and gel spinning15 in the former literatures, the lignin/PAN fibers prepared through wet spinning can be continues and hollow or solid fibers which are advantages comparing with fibers obtained through electron spinning and gel spinning methods. Additionally, the lignin molecules could be cross-linked by the reaction between hydroxyl groups on lignin molecule with formaldehyde (HCHO) which could possibly improve the tensile property of the fibers. The objective of this study was to fabricate HBS lignin/PAN fibers through wet spinning, and a structure transition from solid to hollow was observed when the water content in a mixed water/DMSO coagulation solvent was increased. Even though there were reports about blending with PAN with lignin14, 17, 18 and introducing phenol reaction between lignin and the HCHO19, to our best knowledge, such wet-spun lignin/PAN hollow fiber has not been reported previously13, 20, 21

. Hollow fibers were usually fabricated by sheath-core geometry bi-component 4


Page 4 of 20

Page 5 of 20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


spinning with a sacrifice material as core component22-24. For example, Xie et al23 fabricated carbon nanotube (CNT) hollow fibers by using CNT/polyvinyl butyral/N, N-Dimethylformamide solution as sheath component and water as core component. Bi-component

spinning

requires

much

more

complicated equipments

and

experimental parameters than the conventional single component spinning used in this study.

EXPERIMENTAL

Materials The lignin was extracted from spruce in our laboratory following the previous report25. 1, 4-butanediol (HBS) was obtained from Tianjin Fuchen Chemical Reagent Factory. Dimethyl sulfoxide (DMSO), HCHO and hydrochloric acid (HCl) were from Shanghai Civi Chemicla Technology Co, China. The atactic PAN (Mw ~150000 g/mol)/DMSO solution has a solid content of 20 wt%. All chemicals used in the experiments were reagent grade, and were used without further purification. Fiber spinning Lignin and PAN with a total concentration of 20 wt% was dissolved in DMSO by the following procedures. (1) 1 g PAN was firstly dissolved in DMSO (4.13 ml) under constant stirring for 2 h until a clear and homogeneous solution was obtained. (2) 1 g lignin powder was dissolved in DMSO (3.52 ml) with constant stirring. (3) The two solutions were mixed together, and the mixture was stirred for 12 h at 50 °C. This spinning solution was transferred into a preheated spinning tank (50 °C) and degassed. 5



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

During wet-spinning (Figure S1), the spinning solution was extracted through a single hole spinneret (0.08 mm/hole, hole aspect ratio=1.5) into a coagulation bath maintained at 50 °C. The coagulation solvent contained water, DMSO, and HCHO at various concentrations as listed in Table 1. The as-spun fibers were post-treated in the coagulation bath at 80 °C for 18 h, followed by washing with distilled water. Finally, the lignin based fibers were dried at 60 °C for 2 hours under vacuum before further characterizations.

Table 1 Coagulation bath ingredients and sample abbreviations. Sample abbreviation

Coagulation bath

Fiber_1

water

Fiber_2

water with HCHO (1mol/L)

Fiber_3

Water/DMSO 83/17 v/v with HCHO (1 mol/L)

Fiber_4

Water/DMSO 61/39 v/v with HCHO (1 mol/L)

Characterizations The dynamic rheological measurements were conducted using an Advanced Solution and Melt Rotation Rheometer (Anton Paar China Com.) equipped with two parallel plates (plate diameter: 25 mm, solution thickness: 1mm). A thin layer of paraffin oil was applied on solution surface to minimize solvent evaporation. The surface and cross-section of the fibers were observed under scanning electron microscopy (SEM) (JSM-7001F, Japanese electron) after gold sputter coating. Fourier 6


Page 6 of 20

Page 7 of 20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


transform infrared (FTIR) spectra of HBS lignin and hollow fibers was recorded with a Magna-IR 750 Fourier transform infrared spectrophotometer (Nicolet Company, USA). The spectra were recorded in the range from 4000 to 400 cm-1 at 2 cm-1 resolution. The thermal degradation of the fibers was tested by a thermogravimetric analyzer (TGA, Q600, TA Instrument) from room temperature (25 °C) to 600 °C at a heating rate of 10 °C /min in nitrogen environment. The tensile properties of fibers (20 for each sample) were tested on a tensile tester (XQ-1C, Shanghai New Fiber Instrument Co.) at a gauge length of 20 mm and a crosshead speed of 2 mm/min-1, while the fineness of each fiber was measured on a vibrating fineness meter (XD-1, Shanghai New Fiber Instrument Co.). The porosity was calculated using a weighting method based on eq. (1) p=

(m1 m2 )/ρw m2 /ρh (m1 m2 )/ρw

× 100%

(1)

where p is the porosity (%), m1 and m2 are the weight of the hollow fiber in water and air, respectively, and ρh and ρw are the density of the fiber and water, respectively. And the ρh was calculated according to the Archimedes drainage method.

RESULTS AND DISCUSSION

Stability of the spinning solution The stability of the spinning solution during the spinning process was checked by rheological measurements. During temperature ramping (Figure S2.a), the decrease of storage modulus G′ and loss modulus (G′) along with the increase of temperature is attributed to the decrease of solution viscosity (6.45 Pa⋅s-1 at 50 °C). With the 7



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

increasing of shear rate, viscosity of the spinning solution decrease. (Figure S3) The time dependent measurement of the spinning solution is shown in Figure S2.b. The G′ and G″ during the long time scanning slowly increased along with measuring time. After the measurement, gel structure was observed to be formed at the edge of the parallel plates, which was caused by the volatilization of solvent. This suggested that the increase of modulus was caused by the slow solvent evaporation during the measurement. Overall, these results suggested that the spinning solution had no chemical reactions and was stable at the spinning conditions.

Fiber morphologies

Figure 1 SEM photos of the surface and cross-section of lignin/PAN fibers. All scale bar: 50 µm.

8


Page 8 of 20

Page 9 of 20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Table 2 Sizes of the hollow fibers as measured from SEM images. Samples

Outer diameter (µm)

Wall thickness (µm)

Porosity (p, %)

Fiber_1

64.0 ± 0.8

7.8 ± 0.7

71.6

Fiber_2

63.0 ± 1.0

8.2 ± 0.5

55.8

Fiber_3

68.0 ± 1.1

11.0 ± 1.0

58.0

Fiber_4

67.0 ± 0.9

NA

60.0

As shown in Figure 1 (surface) and Table 2, the outer diameters of the fibers were in the range of 60 to 70 µm. By comparing the outer diameters of Fiber _1, 2, and 3, DMSO weight fractions in the coagulation solvent showed no visible effect on the outer diameters of the fibers. By comparing Fiber_1 and 2, the addition of HCHO in the coagulation bath didn’t affect the wall thickness of the hollow fibers. From the results of FTIR (Figure S4), the functional groups on the four fibers was similar while that was different with that of HBS lignin, and this indicated that reaction between OH in lignin molecule and HCHO in coagulation was lunched. Moreover, the peaks in lignin-based hollow fiber around 2244 cm-1 was indicative of –C≡N bond in PAN.21 Additionally, the wall thickness of Fiber_3 was larger than that of Fiber_2, and Fiber_4 had no core-shell structure but large finger-like pores. This was attributed to the diffusion controlled process in the coagulation bath. While the volume fraction of DMSO in the coagulation bath increased, the solvent diffusions of DMSO from fiber to coagulation bath and water from bath to fiber (Figure S5) became slower, which resulted in a slower solidification. The hollow structure and wall thickness of the 9



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

lignin/PAN fibers are ascribed to diffusion controlled coagulation conditions. While the extraction of DMSO from fibers is fast, the surface of fibers quickly solidifies, and forms a solid shell, and the inner portion of the fibers becomes hollow. In contrast, a slower phase separation will result in a denser fiber structure. It was also observed that the wall thickness of the fibers increased while the outer diameter of the fibers had little change. Beside coagulation bath, another parameter which will possibly affect the wall thickness of the hollow fibers is the solid content of spinning dope. The porosity of hollow fibers is showed in Table 2. The porosity of Fiber_1 was the highest among all fibers.

Figure 2 SEM images of the surface and cross-section of Fber_3.

The surface and cross-section morphology of Fiber_3 (as sample for illustrating the morphology of the hollow fibers) are showed in Figure 2. The fiber surface is smooth, even though some grooves along fiber directions can be observed. There 10


Page 10 of 20

Page 11 of 20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


were many pores (50~90 nm) in the wall section, which were formed during coagulation. The pore size is mainly affected by non-solvent diffusion during coagulation process. Thus, we can optimize the pore size by adjusting the non-solvent component fraction and/or temperature of the coagulation bath or adopting multiple-step coagulation.

Thermal properties of the hollow fibers

Figure 3 TGA (a) and DTG (b) curves of the HBS lignin-based fibers.

The TGA and DTG curves of these HBS lignin-based fibers are shown in Figure 3. The weight losses of all hollow fibers were mainly caused by the loss of the physically absorbed water at below 100 °C, and by the dehydration between hydroxyl groups in alkyl groups and heterolysis/homolysis dissociate of β-aryl ether bonds between 100 to 260 °C.26 After heating to 266 °C, the weight loss of Fiber_1 was higher than other fibers that reacted with HCHO. And this phenomenon might be attributed to the reaction between HCHO and –OH in the HBS lignin molecule that could consume a large number of oxygen. The fibers reacted with HCHO (Fiber_2, 3, 11



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

and 4) had higher residue content than non-reacted fibers (Fiber_1) after heated up to 600 °C, which suggests that the cross-linking reaction could improve the thermal stability of lignin and possibly lead to a higher carbon yield. Additionally, the residue contents of all fibers are higher than 60% after heated to 600 °C, which makes lignin based hollow fiber a promising precursor for making hollow carbon fibers.

Tensile properties

Figure 4 Tensile strength and modulus of HBS lignin-based fibers produced under various coagulation conditions.

Figure 4 shows modulus, strength of lignin-based fibers. Fiber_2, 3 and 4 have higher modulus than Fiber_1. This is due to the reaction between HCHO and –OH in the HBS lignin molecule which cross-links lignin molecules and leads to a stiffer structure. On the other hand, while the volume fraction of DMSO in the coagulation bath increases, the coagulation process becomes slower and results in a less porous structure. The number of surface defects in a certain length of fibers will be lower if 12


Page 12 of 20

Page 13 of 20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


fibers become less porous, since fibers have less area of outer and inner surfaces. Thus, the higher DMSO volume fraction in the coagulation bath could benefit the strength of the resultant fibers as shown in the tensile strength curve in Figure 4. Overall, varying coagulation ingredients doesn’t change the tensile strength and modulus of the resultant fibers much, while it significantly affects the fiber morphologies.

CONCLUSIONS In conclusion, we have fabricated a facile lignin/PAN hollow fiber through

wet-spinning. The outer diameter of the obtained fibers was in the range from 60 to 70 µm and a wall thickness of 6 to 11 µm. It was observed that many interconnected pores (diameter: 50~90 nm) were formed inside the wall. The reaction between HCHO and –OH in lignin molecule was found to slightly improve fiber modulus and thermal stability. The hollow fiber is a promising precursor for making hollow carbon fibers. These hollow fibers could serve as adsorbent, micro reactor, and channel for gas or liquid transfer.

ASSOCIATED CONTENT

Supporting Information The Supporting Information is available free of charge on the ACS Publication website. Schematic diagram of wet-spinning system and diffusions in coagulation bath, the 13



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

rheological properties of the spinning solution and FTIR spectra of hollow fibers, (PDF).

AUTHOR INFORMATION

Corresponding Authors *Phone: +86-0351-4250093. Fax: +86-0351-4166215 E-mail: [email protected] (Chunxiang Lu) *E-mail: [email protected] (Yaodong Liu) Funding This research was supported by the National Natural Science Foundation of China (No. 51303199). Notes The authors declare no competing financial interest.

ACKNOWLEDGEMENTS This research was financially supported by National Natural Science Foundation

of China (No. 51303199) and National Engineering Laboratory for Carbon Fiber Technology, Institute of Coal Chemistry, Chinese Academy of Sciences, China.

REFERENCES

(1) Feng, C. Y.; Khulbe, K. C.; Matsuura, T.; Ismail, A. F., Recent progresses in polymeric hollow fiber membrane preparation, characterization and applications. Sep. 14


Page 14 of 20

Page 15 of 20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Purif. Technol. 2013, 111, 43-71. (2) Vilakati, G. D.; Hoek, E. M. V.; Mamba, B. B., Investigating the structure and water permeation of membranes modified with natural and synthetic additives using tensile, porosity, and glass transition temperature studies. J. Appl. Polym. Sci. 2014, 131 (16). (3) Mahmood, N.; Yuan, Z.; Schmidt, J.; Charles Xu, C., Production of polyols via direct hydrolysis of kraft lignin: effect of process parameters. Bioresour. Technol. 2013, 139, 13-20. (4) Baker, D. A.; Rials, T. G., Recent Advances in Low-Cost Carbon Fiber Manufacture from Lignin. J. Appl. Polym. Sci. 2013, 130 (2), 713-728. (5) Azadi, P.; Inderwildi, O. R.; Farnood, R.; King, D. A., Liquid fuels, hydrogen and chemicals from lignin: A critical review. Renew. Sus. Enger. Rev. 2013, 21, 506-523. (6) Zhang, M.; Ogale, A. A., Carbon fibers from dry-spinning of acetylated softwood kraft lignin. Carbon 2014, 69, 626-629. (7) Kishimoto, T.; Sano, Y., Delignification mechanism during high boiling solvent pulping Part 2 Homolysis of guaiacylglycerol beta guaiacyl ether. Holzforschung 2002, 56, 623-631. (8) Oroumei, A.; Fox, B.; Naebe, M., Thermal and Rheological Characteristics of Biobased Carbon Fiber Precursor Derived from Low Molecular Weight Organosolv Lignin. ACS Sustain. Chem. Eng. 2015, 3 (4), 758-769. (9) Schreiber, M.; Vivekanandhan, S.; Mohanty, A. K.; Misra, M., A study on the electrospinning behaviour and nanofibre morphology of anionically charged lignin. 15



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Adv. Mater. Lett. 2012, 3 (6), 476-480. (10) Vida, P.; Mohanty, A. K.; Misra, M., Electrospinning of aqueous lignin_poly(ethylene oxide) complexes. J. Appl. Polym. Sci. 2015, 132 (2), 41260. (11) Ago, M.; Okajima, K.; Jakes, J. E.; Park, S.; Rojas, O. J., Lignin-based electrospun nanofibers reinforced with cellulose nanocrystals. Biomacromolecules 2012, 13 (3), 918-26. (12) Lai, C.; Zhou, Z.; Zhang, L.; Wang, X.; Zhou, Q.; Zhao, Y.; Wang, Y.; Wu, X.-F.; Zhu, Z.; Fong, H., Free-standing and mechanically flexible mats consisting of electrospun carbon nanofibers made from a natural product of alkali lignin as binder-free electrodes for high-performance supercapacitors. J. Power Sources 2014, 247, 134-141. (13) Xu, X.; Zhou, J.; Jiang, L.; Lubineau, G.; Payne, S. A.; Gutschmidt, D., Lignin-based carbon fibers: Carbon nanotube decoration and superior thermal stability.

Carbon 2014, 80, 91-102. (14) Choi, D. I.; Lee, J.-N.; Song, J.; Kang, P.-H.; Park, J.-K.; Lee, Y. M., Fabrication of polyacrylonitrile/lignin-based carbon nanofibers for high-power lithium ion battery anodes. J. Solid State Electr. 2013, 17 (9), 2471-2475. (15) Liu, H. C.; Chien, A.-T.; Newcomb, B. A.; Liu, Y.; Kumar, S., Processing, Structure, and Properties of Lignin- and CNT-Incorporated Polyacrylonitrile-Based Carbon Fibers. ACS Sustain. Chem. Eng. 2015, 3 (9), 1943-1954. (16) Sudo, K.; Shimizu, K., A new carbon-fiber from lignin. J. Appl. Polym. Sci. 1992, 44 (1), 127-134. 16


Page 16 of 20

Page 17 of 20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(17) Seo, D. K.; Jeun, J. P.; Kim, H. B.; Kang, P. H., Preparation and characterization of the carbon nanofiber mat produced from electrospun PAN_lignin precursors by electron beam irradiation. Rev. Adv. Mater. Sci. 2011, 28, 31-34. (18) Dong, X.; Lu, C.; Zhou, P.; Zhang, S.; Wang, L.; Li, D., Polyacrylonitrile/lignin sulfonate blend fiber for low-cost carbon fiber. Rsc Adv. 2015, 5 (53), 42259-42265. (19) Shen, Q.; Zhang, T.; Zhang, W.-X.; Chen, S.; Mezgebe, M., Lignin-based activated carbon fibers and controllable pore size and properties. J. Appl. Polym. Sci. 2011, 121 (2), 989-994. (20) Sun, N.; Li, W.; Stoner, B.; Jiang, X.; Lu, X.; Rogers, R. D., Composite fibers spun directly from solutions of raw lignocellulosic biomass dissolved in ionic liquids.

Green Chem. 2011, 13 (5), 1158. (21) Maradur, S. P.; Kim, C. H.; Kim, S. Y.; Kim, B.-H.; Kim, W. C.; Yang, K. S., Preparation of carbon fibers from a lignin copolymer with polyacrylonitrile. Synthetic

Met. 2012, 162 (5-6), 453-459. (22) Xu, J.; Xu, Z.-L., Poly(vinyl chloride) (PVC) hollow fiber ultrafiltration membranes prepared from PVC_additives_solvent. J. Membrane Sci. 2002, 208, 203-212. (23) Wei, G.; Chen, S.; Fan, X.; Quan, X.; Yu, H., Carbon nanotube hollow fiber membranes: High-throughput fabrication, structural control and electrochemically improved selectivity. J. Membrane Sci. 2015, 493, 97-105. (24) Zhang, X.; Lang, W.-Z.; Yan, X.; Lou, Z.-Y.; Chen, X.-F., Influences of the structure

parameters

of

multi-walled

carbon

nanotubes(MWNTs)

17


on


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

PVDF_PFSA_O-MWNTs hollow fiber ultrafiltration membranes. J. Membrane Sci. 2016, 499, 179-190. (25) Jia, Z.; Lu, C.; Zhou, P.; Wang, L., Preparation and characterization of high boiling solvent lignin-based polyurethane film with lignin as the only hydroxyl group provider. Rsc Adv. 2015, 5 (66), 53949-53955. (26) Hirose, S.; Kobashigawa, K.; Izuta, Y.; Hatakeyama, H., Thermal degradation of polyurethanes containing lignin studied by TG-FTIR. Polym. Int. 1998, 47, 247-256.

18


Page 18 of 20

Page 19 of 20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Table of Contents Graphic

Novel lignin/polyacrylonitrile composite hollow fibers prepared by wet-spinning method Zhen Jia, Chunxiang Lu, Yaodong Liu, Pucha Zhou, Lu Wang

A facial

way

is

provided

to

convert

bio-renewable

lignin/polyacrylonitrile composite hollow fibers.

19


lignin

into

novel


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

31x11mm (600 x 600 DPI)


Page 20 of 20

Polyacrylonitrile Composite Hollow Fibers Prepared by Wet

Recommend Documents