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1.
Xiao Wang Soo Young Park Kwan Han Yoon Won Seok Lyoo Byung Gil Min 《Fibers and Polymers》2006,7(4):323-327
Poly(vinyl alcohol) (PVA)/multi-walled carbon nanotube (MWNT) composite films were prepared by casting a DMSO solution of
PVA and MWNTs, whereby the MWNTs were dispersed by sonication. A significant improvement in the mechanical properties of the
PVA drawn films was achieved by the addition of a small amount of MWNTs. The initial modulus and the tensile strength of the
PVA drawn film increased by 30% and 45% respectively, with the addition of 1 wt% MWNTs, which are close to those calculated
from the rule of mixtures, and were strongly dependent upon the orientation of the PVA matrix. The mechanical properties,
however, were not improved with a further increase in the MWNT content. The orientation of MWNTs in the composite was not
well developed compared to that of the PVA matrix. This result suggests that the improvement of the molecular orientation
of the PVA matrix plays a major role in the increase of the mechanical properties of the drawn PVA/MWNT composite films. 相似文献
2.
Textile industry generate significant amount of waste fibres in form of short lengths during mechanical processing. However these short fibres possess excellent properties suitable for many other applications. The objective of this work was to use them for the preparation of nanoparticles/nanofibres as fillers in biodegradable composite applications such as food packaging, agriculture mulch films, automotive plastics, etc. The present paper concerns with jute fibres as a source of nanocellulose for reinforcement of PVA mulch films. Jute fibres were first refined to micro/nanoscale particles in form of nanofibrillar cellulose (NFC) by high energy planetary ball milling process in dry and wet condition. Wet milling was observed more efficient than dry milling in terms of unimodality of size distribution with reduction in size below 500 nm after milling for 3 hours. Later the obtained particles were used as fillers in Poly vinyl alcohol (PVA) films and their reinforcement evaluated based on thermal properties. It was observed that glass transition temperature (Tg) of PVA films improved from 84.36 °C to 95.22 °C after addition of 5 % jute particles without affecting % crystallinity and melting temperature (T m) of PVA. Dynamic mechanical analysis of composite films with 5 % jute particles showed higher value of 14×108 Pa for storage modulus in comparison to 9×108 Pa of neat composite film. The percolation effect was observed more above glass transition temperature which consequently resulted in improved transfer of stiffness from jute particles to PVA matrix above 50 °C. The percolation phenomena also explained the improvement in thermal stability by 10 °C for every increased loading of jute particles due to formation of hydrogen bonds with PVA matrix. 相似文献
3.
Poly(vinyl alcohol) (PVA)/Ag-zeolite nanofiber webs were prepared with different concentrations of Ag-zeolite nanoparticles
by the electrospinning technique. Scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), transmission
electron microscopy (TEM), Fourier transform-infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), differential
scanning calorimetry (DSC), Instron, and antibacterial activities analysis were utilized to characterize the morphology and
properties of the PVA/Ag-zeolite nanofiber webs. The study results showed that the polymer concentration, applied voltages
and tip-to-collector distances were the main factors influencing the morphology of the electrospun nanofiber webs. The introduction
of Ag-zeolite nanoparticles improved the mechanical properties and thermal stability of the PVA nanofiber webs. TEM data demonstrated
that the Ag-zeolite nanoparticles were well distributed within the nanofiber. FTIR revealed a possible interaction between
the PVA matrix and the Ag-zeolite nanoparticles. These fibers showed an antibacterial efficacy of 99.8 % and over against
Staphylococcus aureus and Klebsiella pneumoniae at Ag-zeolite concentrations of 1 % and over, because of the presence of the
silver nanoparticles in the zeolite. 相似文献
4.
Nanocellulose reinforced PVA composite films: Effects of acid treatment and filler loading 总被引：1，自引：0，他引：1
Sun-Young Lee D. Jagan Mohan In-Aeh Kang Geum-Hyun Doh Soo Lee Seong Ok Han 《Fibers and Polymers》2009,10(1):77-82
Nanocellulose was prepared by acid hydrolysis of microcrystalline cellulose (MCC) at different hydrobromic acid (HBr) concentrations.
Polyvinyl alcohol (PVA) composite films were prepared by the reinforcement of nanocellulose into a PVA matrix at different
filler loading levels and subsequent film casting. Chemical characterization of nanocelluloses was performed for the analysis
of crystallinity (Xc), degree of polymerization (DP), and molecular weight (Mw). The mechanical and thermal properties of the nanocellulose reinforced PVA films were also measured for tensile strength
and thermogravimetric analysis (TGA). The acid hydrolysis decreased steadily the DP and Mw of MCC. The crystallinity of MCC with 1.5 M and 2.5 M HBr showed a significant increase due to the degradation of amorphous
domains in cellulose. Higher crystalline cellulose showed the higher thermal stability than MCC. From X-ray diffraction (XRD)
analysis, nanocellulose samples showed the higher peak intensity than MCC cases. Reduction of MCC particle by acid hydrolysis
was clearly observed from scanning electron microscope (SEM) images. The tensile and thermal properties of PVA composite films
were significantly improved with the increase of the nanocellulose loading. 相似文献
5.
Weiwei Zhang Wenli Li Jianjun Wang Chuanxiang Qin Lixing Dai 《Fibers and Polymers》2010,11(8):1132-1136
A simple method to decorate carbon nanotubes (CNTs) with silver nanoparticles was developed to enhance the electrical conductivity
of CNTs. The acid-treated CNTs were suspended in the silver acetate solution, ammonia solution was then added, and the CNTs
decorated with silver nanoparticles (Ag@CNTs) were produced. The Ag@CNTs were dispersed in polyvinyl alcohol (PVA) to fabricate
electrically conducting polymer composites. The electrical, thermal and mechanical properties of the composites were measured.
The electrical conductivity of the composites containing 0.8 % (o.w.f.) Ag@CNTs was more than four orders of magnitude higher
than those of pristine and functionalized CNTs respectively, which confirmed the effectiveness of the Ag@CNTs as conducting
filler. However, the improved electrical conductivity led to somewhat decrease of mechanical properties of PVA/Ag@CNTs composites. 相似文献
6.
Liang Yang Chenfei Wang Liping Chen Xuemei Wang Ping Cui Tianyun Zhang 《Fibers and Polymers》2017,18(1):33-40
The effects of the aldehydes crosslinkers on properties of the BC/PVA nanocomposite hydrogels were investigated. BC as the reinforcement and PVA as the matrix materials of the BC/PVA nanocomposite hydrogels, the hydrogels were prepared in coagulating bath of sodium sulfate and cross-linked with kinds of aldehydes. The hydrogels were characterized by Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), Equilibrium swelling ratio (ESR) tests, mechanical properties tests, thermo-gravimetric analysis (TGA) and X-ray diffraction (XRD) analysis. It was found that the dialdehyde (glyoxal, glutaraldehyde) crosslinkers were more efficient than monoaldehyde (formaldehyde, acetaldehyde) crosslinkers. The ESR, mechanical properties of the BC/PVA nanocomposite hydrogels were obviously influenced by aldehydes crosslinkers. However, their thermo stability and crystallinity were scarcely influenced. The nanocomposite hydrogels described in this study provides information for further development and optimization of a variety of nanofiber-polymer matrix composite hydrogels. 相似文献
7.
Mingbo Gu Kaitao Wang Wenli Li Chuanxiang Qin Jian-Jun Wang Lixing Dai 《Fibers and Polymers》2011,12(1):65-72
A series of blend nanofiber mats comprising poly(vinyl alcohol) (PVA) and polyurethane (PU) were prepared by dual-jet electrospinning
in various parameters. Orthogonal experimental design was used to investigate how those parameters affected on fiber diameters
and fiber diameter distribution. Altogether three parameters having three levels each were chosen for this study. The chosen
parameters were tip-to-collector distance (TCD), voltage and tip-to-tip distance (TTD). Fiber diameters, thermal properties,
mechanical properties and hydrophilicity of the blend nanofiber mats were examined by scanning electron microscopy (SEM),
thermogravimetric analysis (TGA), tensile test, contact angle and water absorption test, respectively. The results showed
that the optimum conditions for PVA/PU blend nanofiber mats fabricated by dual-jet electrospinning were TCD of 20 cm, voltage
of 18 kV and TTD of 4 cm. Besides, the thermal stability of PVA/PU blend nanofiber mats had been improved compared with pure
nanofibers. Furthermore, the elongation and tensile strength of the blend nanofiber mats were significantly increased compared
with pure PVA and pure PU, respectively. And the blend nanofiber mats exhibited well hydrophilicity. 相似文献
8.
Dense membranes of Chitosan (CS)/Poly(vinyl alcohol) (PVA)/Poly(lactic acid) (PLA) blend were successfully fabricated using casting technique. The mechanical properties, moisture regain and water vapor permeability of polymer blend membranes were estimated by tensile test, moisture regain rate and dish method test respectively. The microstructures, morphology, chemical composition and thermal properties were also characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) respectively. Results indicated that there were interactions and good compatibility among CS, PLA and PVA. And the blend membranes have good breaking elongation and slightly decreased breaking strength, and show best moisture regain at the case of CS60 (the content of CS in the blends is 60 %). They also have excellent porous structure, which is beneficial to their air permeability and may also contribute to cell regeneration. With the adding of PVA content, the melting peaks of blend membranes reduce and gradually close to that of PVA, demonstrating that the regularity of CS molecular chain may be destroyed and hydrogen bonds of macromolecules in polymers were newly formed. As a result, solution blending of the three polymers could complement their disadvantages and significantly improve the membrane performance of a single polymer, thus promote the mechanical and biological properties of blend membrane. 相似文献
9.
Lots of studies have been carried out to improve the strength of polyvinyl alcohol (PVA) fibers. One of these studies is crosslinking spinning for a good quality fiber. As a crosslinking agent, boric acid (BA, H3BO3) was used. PVA can crosslink with BA without adding cation in using dimethyl sulfoxide (DMSO). The effects of BA addition and molecular weight (MW) on the formation of the physical structure in PVA/DMSO solutions were investigated. The results showed that the time dependence of the rheological responses was greatly influenced by the BA addition to the PVA/DMSO solutions. The results also showed that the BA addition to the PVA/DMSO solutions increased the dynamic viscosity (η′), the storage modulus (G′), and the loss modulus (G″) of the PVA/DMSO solutions. Increasing MW of PVA also decreased the time dependence. In addition, the BA addition to the PVA/DMSO solutions decreased the gelation time of the PVA/DMSO solutions. These overall results suggested that the structure formation through specific interactions between PVA molecules and BA resulted in the time dependent changes of the rheological properties of the PVA/DMSO solutions. 相似文献
10.
Faheem A. Sheikh Nasser A. M. Barakat Muzafar A. Kanjwal S. J. Park Hern Kim Hak Yong Kim 《Fibers and Polymers》2010,11(3):384-390
Gallium arsenide (GaAs) does have superior electronic properties compared with silicon. For instant, it has a higher saturated
electron velocity and higher electron mobility. Weak mechanical properties and high production cost are the main drawbacks
of this interesting semiconductor. In this study, we are introducing production of GaAs nanofibers by electrospinning methodology
as a very low cost and yielding distinct product technique. In general, nano-fibrous shape is strongly improving the physical
properties due to the high surface area to volume ratio of this nanostructure. The mechanical and environmental properties
of the GaAs compound have been modified since GaAs nanofibers have been produced as a core inside a poly(vinyl alcohol) (PVA)
shell. GaAs/PVA nanofibers were prepared by electrospinning of gallium nitrate/PVA solution in presence of arsenic vapor.
The whole process was carried out in a closed hood equipped with nitrogen environment. FT-IR, XPS, TGA and UV-Vis spectroscopy
analyses were utilized to confirm formation of GaAs compound. Transmission electron microscope (TEM) analysis has revealed
that the synthesized GaAs compound is crystalline and does have nano-fibrous shape as a core inside PVA nanofibers. To precisely
recommend the prepared GaAs nanofiber mats to be utilized in different applications, we have measured the electric conductivity
and the band gap energies of the prepared nanofiber mats. Overall, the obtained results affirmed that the proposed strategy
successfully remedied the drawbacks of the reported GaAs structures and did not affect the main physical properties of this
important semiconductor. 相似文献
11.
Bayram Poyraz Ayhan Tozluoğlu Zeki Candan Ahmet Demir Mustafa Yavuz Ümit Büyuksarı H. İbrahim Ünal Hakan Fidan Rasim Cem Saka 《Fibers and Polymers》2018,19(1):195-204
This study examined the effects of matrix (PVA and Si) on the properties of TEMPO-treated nanocomposites preparing from different pulp sources (Kraft and NaBH4 treated Kraft). Chemical characterization and crystallization were determined via FT-IR, thermal stability via TGA and morphological alterations via SEM. UTM and DTMA were used to measure the Young’s and storage moduli. The real and imaginary parts of permittivity and electric modulus were evaluated using an impedance analyzer. After interaction, prominent vibrations and alteration of crystallinity were seen. Storage and Young’s moduli decreased after Si and PVA interaction. The Si-TOCN films showed higher permittivity properties and all of the films followed a similar trend of significantly dropping ε' and ε'' values at high frequency. The PVA-TOCN films had mechanical advantages at room temperature compared to the Si-TOCN films. However, the Si-TOCN films had better thermomechanical properties at high temperatures. NaBH4 revealed favorable effects on mechanical properties of the films. 相似文献
12.
Lignin is the second most abundant renewable biomass-derived natural resource that has been used to replace traditional petrochemical-based materials. However, fabricating the lignin component into the various forms required for practical application is still challenging. In this work, we fabricated water-resistant lignin/poly(vinyl alcohol) (PVA) blend fibers by wet spinning and glutaraldehyde crosslinking methods. The effect of the lignin/PVA blend ratio and glutaraldehyde crosslinking process on the physicochemical properties of wet-spun lignin/PVA blend fibers were studied using maximum draw ratios, hydrolytic degradation profiles, and mechanical properties. Furthermore, the hexavalent chromium [Cr(VI)] removal behavior of lignin/PVA blend fibers was investigated according to the effect of pH, initial Cr(VI) concentration, and contact time. The wet-spun lignin/PVA blend fiber achieved excellent water stability through glutaraldehyde crosslinking and exhibited notable Cr(VI) adsorption capacity (350.87 mg/g) and good regeneration ability. These findings demonstrate that glutaraldehyde-crosslinked lignin/PVA blend fibers could be promising adsorbents for the remediation of heavy metal species containing textile wastewater. 相似文献
13.
The present paper studies the effect of chitosan, cationic starch and polyvinyl alcohol (PVA) as sizing agents to enhance
surface properties of kenaf paper. The polymers were incorporated into the sheets by spray application. The results clearly
showed that the addition of chitosan to a sheet formed from beaten fibers had excellent improvement in surface properties,
compared to the effect of other additives. Sizing quality of cationic starch fairly matched with the sizing quality of chitosan,
however, it was able to reduce the water absorption potential of paper more than chitosan at a same concentration. In most
other properties, particularly the most important property for printing papers, surface smoothness, chitosan-sized papers
are superior to the paper sized with cationic starch or PVA. 相似文献
14.
In this study, various concentrations of polyethylene terephthalate (PET) polymeric solution were investigated to produce hollow nanofiber yarn. First, the electrospining apparatus was designed in a way that to put PVA multifilament in the core and to twist PET nanofibers onto multifilament yarn as a sheath simultaneously, followed by dissolving PVA yarn in hot water, PET hollow nanofiber yarn was produced. In this survey, it has been observed that the average thickness of sheath increased by increasing concentrations of PET polymeric solution. Results showed that maximum efficiency of extracting the PVA multifilament from the hollow yarn under certain conditions (concentration of 18 % (w/v) of PET, applied voltage of 10 kV, and flow rate of 0.0526 ml/h) was more than 85 %. The mechanical and physical properties of PET hollow yarns were investigated and indicated that the hollow nanofiber yarns at concentration of 30 % and 18 % polymeric solution had the lowest strength and the highest regain moisture, respectively. 相似文献
15.
Min Ho Jee Sung Ho Park Jin Uk Choi Young Gyu Jeong Doo Hyun Baik 《Fibers and Polymers》2012,13(4):443-449
A series of composite fibers composed of multi-walled carbon nanotube (MWCNT) and poly(vinyl alcohol) (PVA) are prepared by
varying co-flowing wet-spinning conditions such as spinning geometry and PVA concentration, which affect aligning shear stress
for MWCNTs during the wet-spinning. Then, structural features, mechanical and electrical performances of MWCNT/PVA composite
fibers are investigated as a function of the aligning shear stress of the wet-spinning process. SEM images of the composite
fibers exhibit that MWCNTs are wetted effectively with PVA chains. Polarized Raman spectra confirm that the alignment of MWCNTs
is enhanced along the composite fiber axis with increasing the aligning shear stress of the spinning process. Accordingly,
initial moduli and tensile strengths of the composite fibers are significantly increased with the increment of the aligning
shear stress. In addition, it is found that electrical conductivities of MWCNT/PVA composite fibers increase slightly with
the aligning shear stress, which is associated with the formation of efficient electrical conduction paths caused by well-aligned
MWCNTs along the composite fiber axis. 相似文献
16.
Jong Shin Park Yong-Chan Chung Sang Do Lee Jae Whan Cho Byoung Chul Chun 《Fibers and Polymers》2008,9(6):661-666
The shape memory polyurethane (PU) copolymers cross-linked by celite, a porous inorganic material with enormous surface area
and hydroxyl groups on the surface, were prepared to see if the shape memory effect and the mechanical properties were improved.
The PU copolymers with different celite contents were compared and characterized by IR, DSC, DMA, and UTM. The melting temperatures
of PU soft segment were around 20 oC independent of celite content. The shape memory effect and mechanical properties were
dependent on the celite content, and the celite addition into the reaction mixture should be made in the middle of polymerization
to get the best shape memory and mechanical properties. The best mechanical properties were found at 0.2 wt% celite content
and its shape retention rate went up to 98 %. The inclusion of celite as a cross-linker increased both shape memory effect
and mechanical properties. The reasons underlining the improvements by adopting celite as a cross-linker are discussed in
this paper. 相似文献
17.
In this study, Sericin/Poly Vinyl Alcohol (PVA)/Clay (Cloisite 30B) nanofibrous mats are prepared by electrospinning technique for antimicrobial air filtration mask. The process parameters of electro-spinning machine such as acceleration voltage, nozzle flow rate and nozzle & collector distance are optimised on the basis of morphology of fibre observed through scanning electron microscopy (SEM). The optimum conditions for producing nanofibrous mat without bead are acceleration voltage 27.5 kV, nozzle collector distance 8 cm and flow rate 0.8 ml/hr using 10 % (w/v) solution of Sericin/PVA (1:1 wt/wt). The process parameters of electro-spinning machine for the processing of Sericin/PVA/Clay nanofibrous mats with varied clay concentrations ranging from 0.1-0.75 % are also optimized. The spun fibre diameter varied from 300-400 nm at different specified conditions. These nanofibrous mats are characterized for its structural, mechanical and antimicrobial properties. Respirable Suspended Particulate Matter (RSPM) test was conducted to check the particulate matter (PM 2.5) absorption capacity of nanofibrous mats. Results shows that sericin/PVA/clay nanofibrous mat would be a promising material for making protecting clothing based air filtration mask. 相似文献
18.
Min Jae Kim Tae Hwan Oh Sung Soo Han Sang Woo Joo Han Yong Jeon Dong Wook Chang 《Fibers and Polymers》2014,15(1):101-107
Poly(vinyl alcohol) (PVA)/Ag-zeolite nanocomposite hydrogels were prepared by UV irradiation using PVA solution mixed with Ag-zeolite nanoparticles. Physical properties and changes in morphology of the PVA/Ag-zeolite hydrogels were investigated. The PVA/Ag-zeolite hydrogels were prepared at a PVA concentration of 9 wt% with a UV irradiation distance of 15 cm, where gel fraction and swelling ratio were optimized. Hardness of the PVA/Ag-zeolite hydrogels decreased with increasing amounts of Ag-zeolite, reaching that of soft elastomer when the amount of Ag-zeolite was 5 % by weight. The PVA/Ag-zeolite hydrogels showed strong antimicrobial activities against Staphylococcus aureus and Klebsiella pneumoniae, inducing a reduction of bacteria of over 99.9 % at a Ag-zeolite content of 3 wt%. 相似文献
19.
The effect of casting solvent on the structural characteristics and miscibility of regenerated silk fibroin/Poly(vinyl alcohol) blends 总被引：1，自引：0，他引：1
Regenerated silk fibroin(SF)/Poly(vinyl alcohol)[PVA] blend films were prepared using different casting solvents, water and
formic acid, to elucidate the effect of casting solvent on the structure and miscibility of SF/PVA blends. FTIR and XRD measurement
suggested thatβ-sheet conformation of SF was not changed by addition of PVA in case of formic acid casting and the casting solvent determined
the crystallized component of SF/PVA, leading to a different trend in the overall crystallinity between the two blends. The
casting solvent had a dominant role in deciding phase behavior and molecular miscibility of blend films. SEM observation and
DMTA measurement elucidated that water solvent produced phase-separated blend films while formic acid yielded one phase blend
films with partial miscibility in molecular level indicating that the miscibility of SF blend can be improved by choosing
a proper co-solvent. 相似文献
20.
Jianbo Zhou Qingqing Wang Hangyi Lu Quan Zhang Pengfei Lv Qufu Wei 《Fibers and Polymers》2016,17(11):1835-1841
Biocompatible polyvinyl alcohol (PVA)-styrylpyridinium (SbQ)/β-cyclodextrin (β-CD) composite nanofibers were obtained by electrospinning in this study. PVA-SbQ was used as the foundation polymer as well as crosslinking agent, β-CD was incorporated to achieve expected properties such as improved mechanical properties and thermal stability. The Fourier transform infrared spectroscopy (FTIR) spectra confirmed the existence of β-CD, and the morphologies and average fiber diameters of the electrospun composite nanofibers were also analyzed by SEM. X-ray diffraction patterns (XRD) of PVA-SbQ/β-CD composite nanofibers revealed that the inclusion of β-CD in the nanofibers affected the ordered phase of PVA. Besides, the thermal analyses revealed the improvement in the thermal properties for PVA-SbQ/β-CD composite nanofibers. It was found that the crosslinked composite nanofibers showed a clear higher tensile strength (TS) as well as a greater elongation at break (EB). Eventually, antifungal drug griseofulvin (GSV) has been loaded into the composite nanofibers by formation of its inclusion complex with β-CD in aqueous solution, ultraviolet light (UV-Vis) spectral analysis showed that the drug-loading nanofibers had certain sustained release effect. 相似文献