JOURNAL OF APPLIED SCIENCES RESEARCH

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JOURNAL OF APPLIED SCIENCES RESEARCH
JOURNAL home page: http://www.aensiweb.com/jasr.html
2014 March; 10(3): pages 218-229.
Published Online: 15 January 2014.
Research Article
Functional Finishes of Acrylic Fibers Using Different Technologies
L.K. El-Gabry, A. Abou El-Kheir, M. Salama, S. Mowafi and H. El-Sayed
Textile Research Division, National Research Centre, Dokki, Cairo, Egypt
Received: 12 November 2013; Revised: 14 December, 2013; Accepted: 20 December 2013.
© 2014
AENSI PUBLISHER All rights reserved
ABSTRACT
The current article aims to focus on conventional and the recent technologies used in functionalization of acrylic fibers. Different
technologies such chemical, grafting, thermal, irradiation, plasma, biofinishing, microwave and nanotechnology have been highlighted in
this review. The functional finishing properties imparted to acrylic fibers were flame retardation, ion-exchange, improved wettability and
dyeability, antistatic resistance, UV-protection, thermal stability, carbonization and antibacterial resistance.
Key words:
Introduction
Acrylic fibre in which the fiber-forming substance is
any long chain synthetic polymer composed of at
least 85% by weight of acrylonitrile units [-CH2CH(CN)-]. Acrylic fibers are produced by two basic
methods of spinning (extrusion), dry and wet. In wet
spinning, the spinning solution is extruded into a
liquid coagulating bath to form filaments, which are
drawn, dried, and processed [1]. Acrylic fibers are
synthetic
fibers
made
from
a
polymer
(polyacrylonitrile) with an average molecular weight
of ~100,000, about 1900 monomer units. The Dupont
Corporation created the first acrylic fibers in 1941
and trademarked them under the name "Orlon".
Acrylic has a warm and dry hand like wool. Its
density is 1.17 g/cm3 as compared to 1.32 g/cm3of
wool. Acrylic has a moisture regain of 1.5-2% at
65% relative humidity (RH) and 25oC. It has a
tenacity of 5 gm/denier in dry state and 4-8
gm/denier in wet state. Breaking elongation is 15%
on (both states). It has a good thermal stability.
Acrylic shrinks by about 1.5% when treated with
boiling water for 30 min. It has a good resistance to
mineral acids. The resistance to weak alkalis is good,
while hot strong alkalis rapidly attack acrylic. It has
an outstanding stability towards commonly bleaching
agents [2, 3]. Acrylic fibers used as knit Jersey,
Sweater, blankets, wrinkle resistant fabrics, pile and
Fleece fabrics, carpets and rugs [1]. Various
modifications of the acrylic fibers are targeted to
attain better properties.
Functional finishing with traditional methods:
Various chemical modifications are used to
impart certain desired properties to acrylic fibers. It
was carried out to improve dyeability, hydrophilicity,
conductivity, antimicrobial, fire resistance, tensile
strength, and performance properties (smoother
surface and antipilling properties).
Antimicrobial acrylic fibers:
Antimicrobial property is generally important
for textiles. The bactericidal textiles prepared are
lethal not only to pathogenic bacteria but to fungi as
well [4, 5]. The polyurethane prepolymer was
extended with chitosan of two different molecular
weight used as finishing agent for acrylic fabrics.
Pretreatment of acrylic fabrics with hydrazine
hydrate was found to improve the uptake of the
polymer by the fabric. The antibacterial activity of
the acrylic fabric treated with the polyurethanechitosan solution was improved even after 15
washing times [6]. Acrylic fabrics are treated with
different
concentrations
of
chitosan
and
chitosan/copper sulphate. The treatment with
chitosan/copper sulphate gave the highest
antimicrobial activity than treatment with chitosan
only [7]. The antibacterial fibers were prepared by
heat-treating acrylic fibers containing antibacterial
metallic compounds at pH 1 –6 [8, 9].
The antimicrobial cationic dyes were employed
in dyeing acrylic fabrics. It was found that these
functional dyes could be effectively introduced to
acrylic fibers to achieve simultaneous coloration and
functional finishing effects. All the dyed fabrics
exhibited antimicrobial efficacy against Escherichia
coli and Staphylococcus aureus. The washing
durability of antimicrobial functions on the treated
fabrics was further studied [10].
The fabrics with silver content 0.5-100 ppm,
useful for towels, handkerchiefs, and sheets, contain
Corresponding Author: Lamiaa El- Gabry, Textile Research Division, National Research Centre, Dokki, Cairo, Egypt.
E-mil: [email protected]
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Lamiaa El- Gabry et al, 2014 /Journal Of Applied Sciences Research 10(3), March, Pages: 218-229
20-80% hydrophobic fibers, 80-20% hydrophilic
fibers, and N-C10-20-acylamino acid silver salts. Thus,
acrylonitrile-methacrylate-sodium methallylsulfonate
copolymer fiber was immersed in an aqueous
solution of silver N-stearyl-L-glutamic acid, dried,
spun with cotton, dyed, and woven into a pile fabric
showing good water absorption and antibacterial
activity against Escherichia Coli [11]. Silver-loading
polyacrylonitrile hollow fiber was spun via the dry
jet-wet spinning technique from a dope containing
0.5% silver nitrate. After flushing with water for 60
days, the silver content in the hollow fibers decreased
to 0.1%, and still showing antibacterial activity
against Escherichia coli and Staphylococcus aureus.
On the other hand, by permeating water through the
hollow fibers, silver content was decreased faster and
may require periodical replenish [12]. The acrylic
fibers containing silver and ̸ or zinc exchanged
titanium silicate particles that act as slow- release
antibacterial agents. The antibacterial agents is
insoluble water, detergent, organic solvents and is
thermally stable, so its activity is permanent [11, 13].
Ionic interactions can be used in antimicrobial
finishing of acrylic fabrics with quaternary
ammonium salts. The adsorption of cetylpyridinium
chloride (cpc) on acrylics is higher and quicker than
that of benzyl dimethyl hexadedyl ammonium
chloride (BDHAC), possibly due to the size
difference. Varying finishing pH conditions in a
slightly acidic range and addition of sodium sulfate
appear to be less important in affecting uptakes of the
salts
[14].
Polyacrylonitrile-co-3-allyl-5,5dimethylhydantoin (Cop7-1) was prepared by a free
radical polymerization process. The copolymer was
blended with polyacrylonitrile (PAN) in a NaSCN
aqueous solution, and the mixture was employed as a
spinning solution. The blend fibers showed good
antibacterial ability [15].
The antimicrobial functions assigned to acetyl
pyridine chloride embedded on fabrics and their
durability formed through ionic bonds among the
anionic groups on fiber and cationic acetyl pyridine
chloride, which depend on the quantity of the agent
embedded during the finishing treatment. The
aggressive alkaline conditions of the treatment may
cause negative impacts both on mechanical
properties and chromaticity of the textile material,
due to a potential alkaline reaction induced by the
acrylic polymers, resulting in C=N conjugated
systems [16, 17].
UV- protection:
Titanium dioxide is widely used UV blocking of
acrylic fibers. Titanium dioxide is a photocatalyst;
once it is illuminated by light with energy higher
than its band gaps, the electrons in TiO2 will jump
from the valence band to the conduction band, the
electron (e-) and electric whole (h+) pairs will form
on the surface of the photocatalyst. The negative
electrons and oxygen will combine into O2-; the
positive electric holes and water will generate
hydroxyl radicals. Since both are unstable chemical
substances, when the organic compound falls on the
surface of the photocatalyst, it will combine with O2and OH- respectively and turn into carbon dioxide
(CO2) and water (H2O) [18].
Fire- resistance acrylic fibers:
Acrylic fibers were treated with sodium
hydroxide at 90ºC, washed and then treated with an
aqueous calcium hydroxide solution to give modified
acrylic fibers. Poly(ethylene terephthalate) staple
fibers with a degree of hollowness (35 %) were
sprayed coated with a composition mainly containing
di-Me polysiloxane and heated to give coated fibers,
A carded web comprising 70 % of the above coated
fibers and 30 % modified acrylic fibers was made
into nonwoven fire resistance fabric that can be used
for bending, stuffing and bed pads. The staple fibers
containing synthetic fibers, heat-bondable and
modified acrylic fibers or fibers having a crosslinked
structure with carboxyl groups in the form of metal
salts were coated with silicones [19, 20].
The fibers were manufactured by treating a
sample of saturated acrylic fibre, with intermediate
rinsing steps, in an autoclave with: (1) a hydrazine
solution at 100º-120ºC preferably at 105ºC for
crosslinking, (2) a sodium hydroxide solution for
hydrolysis, (3) a neutralization solution such as
sulphuric acid, and (4) a salt solution of, e.g., zinc
acetate. The treated fibers have a denier with at least
of 1.5 times, preferably 1.8-2.6 times that of the
untreated fibers, a tenacity of >15 cN/tex and an
elongation about 30%, this fibers has fire resistant
property[21].
The polyacrylonitrile (PAN) fibers was treated
with metal acetate ((M (II) CH3COO)2, M(II)
=Cu(II), Zn(II), Mn(II) and Ni(II) to improve
flammability. Thermal properties of the modified
polyacrylonitrile (PAN) fibers were studied by DTA,
TG, GC and cone calorimetry. The apparent
activation energies for the decomposition of the
unmodified and modified PAN fibers were
determined using Kissinger equation and Broido
equation [22].
Thermal treatment:
PAN fibers were stabilized in a continuous
oxidizing furnace with 3.4 m/min speed in air. The
oxidized PAN fibers of different colours were cut
down as testing samples. The oxidized PAN fibers
were mounted on a scanning electron microscope
(SEM) holder, and their cross-sections were etched
using dimethyl sulphoxide (DMSO) at room
temperature for 2 min. The results, the cyclization
propagation path involves four steps: (i) cyclization
in the amorphous region on the surface of the fiber,
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(ii) cyclization in the amorphous region in the center
of the fiber, (iii) cyclization in the crystal region on
the surface of the fiber and (iv) cyclization in the
crystal region in the center of the fiber. The
aromatization index (AI) value was calculated from
AI = la/ (Ip + Ia) 1448 where Ia is the diffraction
intensity of the aromatic structure at 20 -26°C and Ip
is the diffraction intensity of the PAN crystal at 20 17°C.
Aromatization Index (AI) = la/ (Ip + Ia) [23].
PAN fabrics are treated with chemical/ thermal
treatments (potassium dichromate or hydroxylamine
then heat treated in air) under various conditions.
Thermal treatment of PAN fabrics in air led to an
increase in the tensile strength as compared to the
untreated one, accompanied by a decrease in the
elongation property. The results of both
dichromate/thermally and hydroxylamine/thermally
treated PAN fabrics showed an increase in the tensile
strength than the untreated fabric, but the elongation
has decreased. All treatments gave some changes in
infrared spectra, these show some decrease in the
nitrile group. It was found that the AI increased with
increasing
the
temperature
and
with
hydroxylamine/thermal
treatment.
The
hydroxylamine/thermal treatment led to a decrease in
melting temperature than untreated one [24].
According to the distribution coefficients the
order of decreasing selectivity of the cation
exchanger for the various metal ions was Cu 2+ >
Zn2+ > Cr 3+ > Hg 2+ > Cd 2+ > Pb 2+ > Ni 2+ > Co 2+.
The product could be reused after regeneration with
diluted nitric acid. A modified synthesis method has
been developed. A modified synthesis method has
been developed. The carboxyl group containing
hydrazine modified polyacrylonitrile fiber is an
amphoteric ion exchange. The kinetics of the
modified PAN fiber metal ions interaction have been
found to be sufficiently rapid in most cases for the
extraction of trace metals. The application of the new
fiber for the construction of moving belt ion
exchangers would offer some advantages.
Channelling of ions cannot occur due to the
structural properties, because no bead is needed,
bead-related problems cannot occur [25].
The competitive binding of ions Cu2 +, Pb2+,
2+
Cd , Ni2+, Zn2+ on the ion-exchange resins and
chelate ion-exchange fibrous material Akvalit-2 has
been investigated. Selectivity rows were obtained for
examined samples. Competitive binding constants as
well as rate constant of adsorption were calculated.
Akvalit-2 was established to have the best sorption
kinetics and affinity to Pb2+and Cd2+ ions in
comparison
with conventional
ion-exchange
materials. Material TP207 showed a high affinity to
Cu2+ ions [26]. Many methods (such as adsorption,
electroplating, ion exchange, membrane separation,
precipitation, and so forth) are being used to remove
the ions of the metals such as chromium, copper,
iron, lead, silver, and zinc, from aqueous effluents
[27, 28].
Polyacrylonitrile fibers were chemically
modified by conversion of their nitrile groups into
other effective adsorbent groups under a two-step
process. At first, the modification process was
initiated through hydrolysis of the fibers in an
alkaline solution. In the next step, functionalization
of the fibers was carried forward by thiourea. The
modified polymer-metal complexes were obtained in
aqueous solutions at different pH media of 2 to 8.
The adsorption capacities of the samples towards
Cr3+, Hg2+ and Pb2+ were in the given order of 0.73,
0.09, and 0.14 mmol/g (at pH 4). These results may
be considered as an indication of higher selectivity of
the modified fibers towards Cr3+ ions compared to
Hg2+ and Pb2+ ions. The study on these modified ion
exchange fibers (HTPANFs) for industrial effluents
revealed that the maximum capacities of the
modified PAN fibers towards Cr3+, Hg2+ and Pb2+ are
0.41, 0.05, and 0.11 mmol/g (at pH 4), in the given
order. The thermogravimetric data indicated that the
initial thermal stability of the modified fibers is
lower than those of raw fibers due to conversion of
nitrile groups into amine and thioamide
functionalities [29].
Functional finishing by grafting:
Methyl methacrylate (MMA) was grafted onto
commercial acrylic fibers (PAN) using azobis
(isobutyro)- nitrile (AIBN) as an initiator. The
optimum conditions for this grafting reaction were
obtained with an MMA concentration of 0.7 M, an
AIBN concentration of 0.0073 M, a reaction
temperature of T 5 85oC and with a 60 min reaction
time. Grafting yield, have occurred in fibers samples
up to 13.5%. Grafting also slightly affected the fiber
morphology. Grafting of poly MMA improved water
absorption. The maximum grafting yield was 94%
[30].
Polyacrylonitrile (PAN) fiber was grafted with
casein after alkaline hydrolysis and chlorination
reactions of the original fiber. Moisture absorption,
specific electric resistance, water retention value, and
mechanical properties were enhanced. The grafted
PAN fiber has better hygroscopicity compared with
the untreated one. With proper tensile strength, the
modified fiber could still meet the requirement for
wearing. A mechanism was proposed to explain the
deposit of casein on the synthetic acrylic fiber,
Figure 1. Casein-grafted acrylic fiber exhibits better
hygroscopicity, anti-static property and spinnablity,
which gives the proof that the surface properties of
the original acrylic fiber have been improved [31,
32].
A novel method of modifying polyacrylonitrile
(PAN) fibers grafted with soybean protein (SP). The
reactant of PAN-g-SP fiber was prepared based on
chlorination of the hydrolyzed PAN fiber. The
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grafting efficiency first increases with the increase of
the addition of thionyl chloride (SOCl2), chlorination
time and temperature and then levels off. In grafting
reaction, grafting efficiency increases at first and
then declines significantly with increasing addition
of sodium hydroxide (NaOH), grafting temperature
and time. PAN-g-SP also exhibits good
hygroscopicity and proper mechanical properties
[33].
Fig. 1: Proposed mechanism of Grafting modification of PAN fiber.
As one of the major techniques developed to
achieve surface modification of polymeric materials,
UV-induced surface graft polymerization has been
widely applied as a simple, useful and versatile
approach to improve the surface properties of
polymers. UV-induced surface graft polymerization
carried with (1) various initiating methods,
controlled/living grafting, self-initiated grafting
(grafting without the addition of photo initiators),
graft polymerizations with monomer pairs able to
form charge transfer (CT) complexes, grafting in
liquid, vapor and bulk phase, and the substrates used
for grafting; (2) the topography of grafted surface
layers, including granular structure, crosslinked
structure, and well-defined structure; and (3) the
application of techniques to prepare functionalized
polymer surfaces with designed performances, e.g.,
to obtain polymer materials suitable for biomedical
applications, membranes or microfluidics % [34].
Recent Technologies in Functionalization acrylic:
Carbonization:
Some commercial PAN precursor fibers
displayed double separated peaks and these fibers
were of high quality because of their process stability
during their conversion to carbon fibers of high
performance. Some fabrication processes, such as
spinning, drawing, could not apparently change the
DSC features of a PAN precursor fibre. It was
concluded that the thermal properties of a PAN
precursor fiber was mainly determined from its comonomer content type and compositions [35].
Acrylic fabric wastes were reused to produce an
activated carbon fabric. The precursor fabric was
stabilized in the condition of as obtained at 250oC for
5 h to get the degree of stabilization of 79%. The
stabilized fabric was subsequently carbonized with
stepwise sequential heat treatment, denoted as the
sequential multistage carbonization technique,
followed by activation with steam. The specific
surface area and the total pore volume changed little
through stabilization and sequential multistage
carbonization while the total weight loss increased
almost linearly with the increase of heat treatment
temperature. When the carbonized fabric was
activated at 900oC for 5 min, both the specific
surface area and the total pore volume increased
abruptly to 2400 m/g and 31.15 cm/g, respectively
[36]. The observed changes suggest a change in the
mechanism of activation from one involving
principally gasification of amorphous or more
reactive carbon at low burn-off to one involving
principally attack of individual crystallites and their
re-organization at higher burn-off [37].
To find out the high quality polyacrylonitrile
(PAN) fibers, some differences are sought by
comparison domestic PAN fibers with the foreign
ones are used. The high- quality PAN fiber have high
density, lower titer, higher or adequate tension
strength, and they also have better conglomeration
structure, smaller crystal dimension with dispersive
distribution, lessmicrovids and flaws [38]. Carbon
fibers are a significant volume fraction of modern
structural airframes. Embedded into polymer
matrices, they provide significant strength and
stiffness gains by unit weight compared with
competing structural materials. Our data highlight the
predominance of the in-plane graphene properties in
all graphitic structures examined [39]. The proper
pre-oxidation time, pre-oxidation temperature, and
pre-oxidation stretching ratio are the base of
preparing high-quality CF. During pre-carbonization,
the enhancement of the pre-carbonization
temperature and the application of the precarbonization stretching are helpful to increase the
tensile strength of CF, but the stretching ratio should
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be controlled carefully by on-line tension values. The
tensile strength of carbon fibers CF increases quickly
below 1200°C and then slowly above 1200°C as the
carbonization temperature raises. Even though during
carbonization, a proper relaxation should also be
explored in order to prepare optimal CF [40].
PAN-based 3000 filament batch and the
shrinkage of PAN fibers were monitored by the
displacement of weight. Stabilization was carried out
between the temperatures of 180°C – 220°C, air flow
of 0.3 m3/hr. The carbonization furnace was heated in
high-purity nitrogen from room temperature to
1000◦C at a rate of 5°C/min, and heating ceased when
the temperature was reached. During stabilization in
air, moisture acts as a plasticizer to reduce the Van
de var force between molecular chains. Figures 2 and
3 show carbon fibers structure prepared from acrylic
fibers [41].
Fig. 2: Carbon fibers structure.
Fig. 3: Carbon fibers structure.
Polyacrylonitrile (PAN) polymers are used as
precursors for carbon fibers production. The obtained
results showed that the addition of itaconic acid and
methyl acrylate MA as co-monomers resulted a
lower heat flow during the process comparing to the
PAN homo-polymer. The cyclization temperature
decreases when MA is incorporated into the
terpolymer compared to the MMA terpolymer and
increases when MAA is the acidic monomer. The
acid co-monomer plays an important role in the
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thermal behavior of the terpolymer. Among
terpolymers, the one that acrylic acid (AA) is
incorporated into the polymer (AN/MA/AA),
exhibited one of the best thermal properties
compared to other terpolymers: low cyclization
temperature together with low heat effect. The
itaconic acid, which incorporated into the terpolymer
decreases the heat effect of the PAN terpolymer and
the initial and peak temperatures, leading to a
formation of carbon fiber with better mechanical
properties [42].
Modification of polyacrylonitrile (PAN) fibers
with cobaltous chloride has increased crystal size,
crystallinity, and density, and also improved tensile
strength and modulus of the resulting carbon fibers.
The modification process improved the tensile
strength, the tensile modulus as well as electrical
conductivity by about 15% of the resulting carbon
fibers at carbonization temperature of 1300°C. A
higher stacking size (Lc), or a greater carbon basal
plane in crystalline, is one of the reasons to improve
the modulus and conductivity of the final carbon
fibers [43]. The surface chemistry of porous carbons
could be modified by various methods, such as, acid
treatment, oxidization, ammonization, plasma,
microwave treatment, and i.e. [44].
Functional finishing with gamma irradiation:
Gamma irradiation was used by many workers
to improve some properties of acrylic fibers. The
effect of irradiation dose on the dye affinity of
acrylic fabric was monitored. Irradiated acrylic fabric
showed a higher dye affinity for the used dyes
compared to the un-irradiated fabrics. Fabrics
irradiated to a radiation dose of 1 Mrad showed the
highest dye affinity with high leveling of dyeing. The
pH of the dyeing bath at which the highest color
strength obtained was 3. A mechanism was proposed
for the dyeing of acrylic fabrics with direct dyes in
the presence of copper ions, Figure 4 [45].
Fig. 4: Proposed mechanism of effect of gamma irradiation on dyeing of acrylic fiber.
Acrylic fibers containing alumina-zinc silicate
were irradiated by electron beams at doses of 3-24
kGy. This study showed that the fibers irradiated
attained greater antibacterial activity than nonirradiated fibers and also clarified the optimum
irradiation dose range for fiber products [46].
Functional finishing with plasma technology:
Plasma treatment, as a clean, dry and
environmental friendly physical technique, opens up
a new possibility in this field. Plasma usually induce
the following processes: dehydrogenation and
consequent unsaturated bond formation, rapped
stable free radicals formation, generation of polar
groups through post-plasma reaction, and generation
of increased surface roughness through referential
amorphous structure ablation processes. In fact,
plasma treatments allow modification of the textile
surface behavior with a flexible process, which can
impart particular properties to the fabrics, such as
waterproofing, oil repellence, antistatic behavior, etc.
In addition, plasma processes are characterized by
the very small quantity of chemicals involved and by
the absence of solvent or water, which are usually
employed in traditional finishing processes. Figure 5
shows the Atmospheric plasma unit at North
Carolina State College of Textiles [47].
The effect of different plasma treatments on the
properties of acrylic fabrics for outdoor applications
was explored. In particular, the possibility of
substituting plasma processes for the traditional
cleaning and waterproofing processes of outdoor
acrylic fabrics was evaluated. The properties of the
plasma treated acrylic fabrics have been compared
with the characteristics of the fabrics traditionally
treated. The resistance of plasma treatments to wear,
UV and weather exposure has been also evaluated.
Figure 6 shows plasma processes [48].
Acrylic fibers are treated by nitrogen glowdischarge plasma to promote surface antistatic
properties. The treated surfaces are characterized by
scanning electron microscopy (SEM), specific
surface area analysis (BET) and X-ray photoelectron
spectroscopy (XPS). Plasma treatment is found to
increase the surface roughness, to modify the nature
and density of surface functionalities, and to
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drastically improve the wettability and antistatic
ability of acrylic fibers [49].
Usually three different types of plasma processes
are referred to: One is the modification of surface
structure of the material itself under the influence of
the glow discharge mostly performed with non
polymer is precursors such as noble gases, nitrogen,
oxygen, hydrogen, ammonia or water vapor. The
second is plasma polymerization i.e. the deposition
of thin polymer film on the surface by using organic,
organ silicone or organ metallic vapors. The third is
the plasma grafting after activation of the surface by
means of plasma treatment [50]. Acrylic fabrics were
treated in low temperature plasma to increase the
hydrophilicity to increase soil resistance, and
improve dyeability. Three different modifications
were applied. Fabrics were directly treated in acrylic
acid, water, and argon plasma. Wettability, soil
resistance, and dyeability of Polyacrylonitrile fabrics
were significantly improved by these methods and
more hydrophilic surfaces were created [51, 52].
Fig. 5: Atmospheric plasma unit at NC State College of Textiles.
Fig. 6: Plasma processes.
Acrylic fabrics were processed with atmospheric
pressure plasma generator and afterwards a
fluorocarbon finish was applied through a traditional
pad-dry-cure method. Two gas mixtures were tested
(helium and helium/oxygen) with different plasma
treatment times. The ageing of the finishing was
simulated through repeated accelerated laundry
cycles. The water and oil repellencies were measured
through standard test methods. While the initial
water and oil repellency did not change, the plasma
treatment improved the durability of the finish after
artificial ageing [53].
Biofinishing:
The surface of fibers has been modified by
enzyme treatment. The newly formed amide groups
were then able to react with the acid dyes typically
used to stain natural fibers, conferring the coloring
properties to the otherwise inert polymer surface
[54]. Nitrile groups on the surface of acrylic fibers
were selectively hydrolyzed to the corresponding
amidic groups by nitrile hydratase from Arthrobacter.
The dyeability with acid dyes on the enzymatically
modified acrylic fiber was enhanced [55]. Hydrolysis
of nitrile groups of acrylic fibers with enzymes from
R. rhodochrous was studied. Surfacial nitrile groups
of acrylic fiber were hydrolyzed by the enzyme
preparation to a maximum of only 16%. The dyeing
efficiency was increased by enzyme treatment for
both acid and cationic dyestuffs [56].
The enzyme used was a nitrile hydratase, a
member of the class of nitrile converting enzymes.
The pendant nitrile groups were selectively
converted into the corresponding amides as assessed
by x-ray photoelectron spectroscopic analysis. The
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modified acrylic fibers became more hydrophilic [57,
58]. The major advantages of enzymes in polymer
modification compared with chemical methods are
milder reaction conditions and highly specific
nondestructive transformations targeted to surfaces.
Polyacrylonitrile
Using
X-ray
photoelectron
spectroscopy,
enzyme
preparations
from
Rhodococcus rhodochrous [56], Brevibacterium
imperiale and Corynebacterium nitrilophilus were
shown to hydrolyze PAN. Interestingly, nitrile
groups of granular PANs were converted into the
corresponding acids by the sequential action of nitrile
hydratase and amidase from R. rhodochrous, while
16% of surface nitrile groups of PAN fibers were
converted to the corresponding amides by the nitrile
hydratase. Owing to the enzymatic modification, the
acrylic fibers became more hydrophilic and the
adsorption of dyes was enhanced [54].
The hydrolysis of nitrile groups to carboxylic
groups is the most common pathway for the
microbial degradation of nitrile compounds. This
reaction can proceed through two distinct pathways:
the direct conversion catalyzed by nitrilase (EC
3.5.5.1) and the two-step conversion catalyzed by
nitrile hydratase (EC 4.2.1.84) and amidase (EC
3.5.1.4). The nitrilase action on the acrylic fabric was
improved by the combined addition of 1 M sorbitol
and 4% N,N-dimethylacetamide. The color levels for
samples treated with nitrilase increased 156 %
comparing to the control samples. When the
additives were introduced in the treatment media, the
color levels increased 199%. The enzymatic
conversion of nitrile groups into the corresponding
carboxylic groups, on the fiber surface, was followed
by the release of ammonia and polyacrylic acid. The
application of the nitrilase for the acrylic treatment is
intimately dependent on reaction media parameters,
such as time, enzyme activity and formulation [59].
Review attempts to describe in detail the three major
classes of nitrile-converting enzymes, namely
nitrilases, nitrile hydratases and amidases. Various
aspects of these enzymes including their occurrence,
mechanism
of
action,
characteristics
and
applicability in different sectors have been
elaborately elucidated [60].
Functional finishing with Microwave irradiation:
Microwave dyeing was carried out under a
variety of conditions in terms of the power and time
of a microwave. The dyeability of acrylic fibers was
significantly improved under microwave irradiation
caused by the increased adsorption of the dye into
fibers due to the local overheating and an amplified
reaction probability between the dye and fiber. Dye
adsorption at low concentrations using the
microwave-based procedure is higher and much
faster than conventional methods, but K/S is the
same around the saturation point. The surfaces of
microwave-irradiated acrylic fibers are rougher than
conventionally dyed fibers, allowing the dye
molecules to permeate and adsorb into the acrylic
fibers. A power of 720 W and microwave irradiation
time of 14 minutes have been found to be an
optimum dying condition for acrylic fibers, although
5 minutes using 720 W microwave irradiation is
enough to obtain the same dyeability as conventional
methods [61].
Functional finishing with nanotechnology:
Nanotechnology is defined as the utilization of
structures with at least one dimension of nanometer
size for the construction of materials, devices or
systems with novel or significantly improved
properties due to their nano-size. Nanotechnology
can be described as activities at the level of atoms
and molecules that have applications in the real
world. Nano-particles commonly used in commercial
products are in the range of 1 to 100 nm.
Nanotechnology also has real commercial potential
for the textile industry.
Nanotechnology can provide high durability for
fabrics, because nano-particles have a large surface
area-to-volume ratio and high surface energy, thus
presenting better affinity for fabrics and leading to an
increase in durability of the function. In addition, a
coating of nano-particles on fabrics will not affect
their breathability or hand feel. The use of
nanotechnology in the textile industry has increased
rapidly due to its unique and valuable properties [62].
Polyacryloamidoxime fibers were successfully
formed on the surface of polyacrylonitrile fibers
using a hydroxylamine solution. Silver nano-clusters
are identified by X-ray diffraction (XRD) and SEM
microscopy. SEM observations reveal that the Ag
nanoparticles were loosely arranged with a larger
size distribution of 24.9 nm at pH=5, and a narrower
size distribution of 23.5 nm at pH=7 at a reaction
temperature of 30oC. Additionally, the size of the Ag
nanoparticles increased to 29.8 nm as the reaction
temperature increased to 60oC, indicating that
temperature can accelerate the reduction of Ag+ into
Ag faster than changing pH. The use of silver
nanoparticles is also important, as several pathogenic
bacteria have developed resistance against various
antibiotics. Hence, silver nanoparticles have emerged
up with diverse medical applications. The silver
nanoparticles with their unique chemical and
physical properties are proving as an alternative for
the development of new antibacterial agents. The
silver nanoparticles have also found diverse
applications in the form of wound dressing, coating
for medical devices, silver nanoparticles impregnated
textile fabrics, Figure 7. The advantage of using
silver nanoparticles is that there is continuous release
of silver ions and the devices can be coated by both
the outer and inner side thereby, enhancing its
antimicrobial efficacy [63, 64].
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Lamiaa El- Gabry et al, 2014 /Journal Of Applied Sciences Research 10(3), March, Pages: 218-229
Coating is a common technique used to apply
nano-particles
onto
textiles.
The
coating
compositions that can modify the surface of textiles
are usually composed of nano-particles, a surfactant,
ingredients and a carrier medium. The nano-particles
are attached to the fabrics with the use of a padder
adjusted to suitable pressure and speed, followed by
drying and curing. The properties imparted to textiles
using nanotechnology include water repellence, soil
resistance, wrinkle resistance, anti-bacteria, antistatic and UV-protection, flame retardation,
improvement of dyeability and i.e. Figure 8
illustrates silver nano particles [65].
Fig. 7: The reaction of silver ions with bacteria.
Fig. 8: Nano-particles of silver.
Rayleigh’s scattering theory stated that the
scattering was strongly dependent upon the
wavelength, where the scattering was inversely
proportional to the wavelength to the fourth power.
This theory predicts that in order to scatter UV
radiation between 200 and 400 nm, the optimum
particle size will be between 20 and 40 nm. TiO2
nanoparticles have the potential to improve UV
resistance, antistatic, as well as impart self-cleaning
by photo-catalysis and thereby de-odor and
antimicrobial effects [66].
Thermal properties of precursor polyacrylonitrile
fibers containing nanoparticles of additives such as
SiO2, hydroxyapatite and montmorillonite have been
examined. Based on the thermogravimetric curves,
the coefficients of thermal stability of the fibers were
found. It has been found that the thermal stability of
PAN fibers is affected by the type of nano-additives
and the value of the as-spun draw out ratio used
during fiber spinning [67]. Polyacrylonitrile (PAN)
nano-fiber mats were prepared by electro spinning
and they were further modified to contain amidino
diethylenediamine chelating groups on their surface
via heterogeneous reaction with diethylenetriamine
(DETA). The aminated PAN (APAN) nano-fiber
mats were evaluated for their chelating property with
four types of metal ions, namely Cu(II), Ag(I),
Fe(II), and Pb(II) ions. The amounts of the metal ions
adsorbed onto the APAN nano-fiber mats were
influenced by the initial pH and the initial
concentration of the metal ion solutions. Increasing
the contact time also resulted in a monotonous
increase in the adsorbed amounts of the metal ions,
which finally reached equilibrium at about 10 h for
Cu(II) ions and about 5 h for Ag(I), Fe(II), and Pb(II)
ions. The maximal adsorption capacities of the metal
ions on the APAN nano-fiber mats, as calculated
from the Langmuir model, were 150.6, 155.5, 116.5,
and 60.6 mg g-1, respectively. Lastly, the spent
APAN nano-fiber mats could be facilely regenerated
with a hydrochloric acid (HCl) aqueous solution
[68].
Future outlook for functional finishing:
The new technologies such as nanotechnology,
nano-fibre formation using electrospinning technique
are promising approaches in the future for improving
all textiles properties. Nanotechnology can provide
high durability for fabrics, because nano-particles
have a large surface area-to-volume ratio and high
surface energy, thus presenting better affinity for
fabrics and leading to an increase in durability of the
function. In addition, a coating of nano-particles on
fabrics will not affect their breathability or hand feel.
It is expected that nanometal (silver, titanium and
zinc e.g.) as well as its colloidal solution will be
useful to give excellent antibacterial, anti-static antiUV, water repellency, conductivity, fire-resistance
and deodorant finish of acrylic fibers.
Plasma processes are characterized by the very
small quantity of chemicals involved and by the
227
Lamiaa El- Gabry et al, 2014 /Journal Of Applied Sciences Research 10(3), March, Pages: 218-229
absence of solvent or water, which are usually
employed in traditional finishing processes. Nonthermal plasma has been used extensively in
biomedical applications; plasma technology seems to
be good tool to alter the surface property, wettability,
surface adhesiveness, electrical conductivity,
antibacterial and dyeability, and printability of the
treated acrylic fibers.
The enzymatic modification of synthetic
materials has immense potential both in the
functionalization of bulk materials, such as
polyacrylonitrile, polyamide or polyester, and in the
production of polymers for specialty applications
(e.g. for the production of medical devices and
electronics). The major advantages of enzymes in
polymer modification compared with chemical
methods are milder reaction conditions and highly
specific nondestructive transformations targeted to
surfaces. The demand of applying this treatment in
industrial sector can avoid hazardous chemical and
save the environment.
Today's textile industry makes use of
microencapsulated materials to enhance the
properties of finished goods. One application
increasingly utilized is the incorporation of
microencapsulated phase change materials (PCMs).
Phase change materials absorb and release heat in
response to changes in environmental temperatures.
The property of microencapsulated phase change
materials can be harnessed to increase the comfort
level for users of sports equipment, military gear,
bedding, clothing, building materials, and many other
consumer products.
Many different active materials like drugs,
enzymes, vitamins, pesticides, flavors and catalysts
have been successfully encapsulated inside microballoons or microcapsules made from a variety of
polymeric and non-polymeric materials including
poly(ethylene
glycol)s,
poly(methacrylate)s,
poly(styrene)s, cellulose, poly(lactide)s, poly(lactideco-glycolide)s, gelatin and acacia, etc. These
microcapsules release their contents at appropriate
time by using different release mechanisms,
depending on the end use of encapsulated products.
This technology has been used in several fields
including pharmaceutical, agriculture, food, printing,
cosmetic, textile and defiance.
Acrylic fibers are considered the most suitable
precursor for making high performance carbon
fibers. A study is aimed to understand the role played
by acrylic fibre modification treatment in order to
improve the carbon fibers properties. Porous carbons
had been widely used as adsorbents, catalyst/catalyst
supports, electronic material and energy storage
material due to its higher surface area and larger pore
volume.
Future studies can be boosted on some
treatments on acrylic fibers waste to prepare carbon
fibers and to obtain new composites as well as ion
exchange for metal removal. Also, it is possible to
recycle acrylic fibers in two stages as production
waste and in the form of blends with natural polymer
such as keratin outerwear and can be used for carpets
and blanket.
References
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Kroschwitz, J.I., 1990. Polymers: fibers and
textiles: a compendium: Wiley.
Vigo, T.L., 1994. Textile processing and
properties: preparation, dyeing, finishing, and
performance: Elsevier Science Publishers BV.
Kirk, R.E. and D.F. Othmer, 1972. Kirk-Othmer
encyclopedia
of
chemical
technology.
Interscience.
Parthasarathi, K. and S. Borkar, 2007.
Antibacterial and UV protection finishes of
textiles by metal and metal oxide nano particles:
A review. Colourage, 54(7): 43-45.
Lin, J., et al., 2003. Mechanism of bactericidal
and fungicidal activities of textiles covalently
modified with alkylated polyethylenimine.
Biotechnology and Bioengineering, 83(2): 168172.
El-Sayed, A.A., L. El Gabry and O. Allam,
2010. Application of prepared waterborne
polyurethane extended with chitosan to impart
antibacterial properties to acrylic fabrics.
Journal of Materials Science: Materials in
Medicine, 21(2): 507-514.
El Gabry, L.K., B.A. and M. Abo Hamr, T2010.
reatment of Acrylic Fabric and Its Wool Blend
with Chitosan to Impart Antimicrobial Activity,
in 7th International Conference of Textile
Research Division: NRC, Cairo, Egypt, p. 905913.
Hiroki, K. and N. Hideo, 2001. Photocatalytic
Active Antibacterial Acrylonitrile Polymer
Fibres
Manufactured
by
Heat-Treating
Acrylonitrile Polymer Fibres Containing AntiBacterial Metal Compounds at pH 1-6. Kokai
Tokkyo Koho JP, 89968.
Hideo,
N.
and
N.
Tetsuo,
2005.
Trichlorophyton-Inhibiting
Silver-Containing
Acrylonitrile Fibre Structures. Kokai Tokkyo
Koho JP, 45.
Ma, M. and G. Sun, 2005. Antimicrobial
cationic dyes. Part 3: simultaneous dyeing and
antimicrobial finishing of acrylic fabrics. Dyes
and pigments, 66(1): 33-41.
Shah, M.S.A.S., et al., 2008. Silver on PEG-PUTiO2 polymer nanocomposite films: An excellent
system for antibacterial applications. Chemistry
of Materials, 20(7): 2455-2460.
Yu, D.G., et al., 2003. Characterization and
inhibitory effect of antibacterial PAN-based
hollow fiber loaded with silver nitrate. Journal
of membrane science, 225(1): 115-123.
Yeo, S.Y. and S.H. Jeong, 2003. Preparation
and characterization of polypropylene/silver
228
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
Lamiaa El- Gabry et al, 2014 /Journal Of Applied Sciences Research 10(3), March, Pages: 218-229
nanocomposite fibers. Polymer International,
52(7): 1053-1057.
Kim, Y.H. and G. Sun, 2002. Functional
finishing of acrylic and Cationic dyeable
fabrics: intermolecular interactions. Textile
research journal, 72(12): 1052-1056.
Wang, L., et al., 2006. Preparation of
antimicrobial polyacrylonitrile fibers: Blending
with
polyacrylonitrile-co-3-allyl-5,
5dimethylhydantoin. Polymer Bulletin, 56(2-3):
247-256.
Cai, Z. and G. Sun, 2005. Antimicrobial
finishing of acrilan fabrics with cetylpyridinium
chloride: affected properties and structures.
Journal of applied polymer science, 97(3): 12271236.
Sun, G., 2001. Bioactive Fibers and Polymers.
in JV Edwards, TL, Editors, American Chemical
Society, Symposium Series.
Yang, H., S. Zhu and N. Pan, 2004. Studying the
mechanisms
of
titanium
dioxide
as
ultraviolet‐blocking additive for films and
fabrics by an improved scheme. Journal of
Applied Polymer Science, 92(5): 3201-3210.
Weil, E.D. and S.V. Levchik, 2008. Flame
retardants in commercial use or development for
textiles. Journal of Fire Sciences, 26(3): 243281.
Masson, F., et al., 2004. UV-curable
formulations for UV-transparent optical fiber
coatings: I. Acrylic resins. Progress in organic
coatings, 49(1): 1-12.
Ko, T.H., 1994. Preparation of flame resistant
fibers from polyacrylonitrile fibers. Materials
chemistry and physics, 38(3): 289-296.
Xu, J., et al., 2000. Study on the thermal
behaviour and flammability of the modified
polyacrylonitrile fibers. Journal of thermal
analysis and calorimetry, 63(2): 501-506.
Tsai, J.S., 1994. Cyclization propagation path
during oxidation of polyacrylonitrile fibre.
Journal of materials science letters, 13(20):
1448-1450.
Bendak, A., L.K. El-Gabry and O.G. Allam,
2009. Chemical/Thermal Modifications of
Acrylic Fabric as a Precursor of Quasi-Carbon
Fibres, in 10th International Conference of
Textile Research Division: NRC, Cairo, Egypt.
Zhang, B., et al., 1994. Synthesis of carboxyl
group
containing
hydrazine-modified
polyacrylonitrile fibres and application for the
removal of heavy metals. Reactive Polymers,
24(1): 49-58.
Shunkevich, A., et al., 2005. Acid–base
properties of ion exchangers. III. Anion
exchangers on the basis of polyacrylonitrile
fiber. Reactive and Functional Polymers, 63(1):
27-34.
Navarro, R.R., S. Wada and K. Tatsumi, 2005.
Heavy metal precipitation by polycation-
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
polyanion
complex
of
PEI
and
its
phosphonomethylated derivative. Journal of
hazardous materials, 123(1): 203-209.
Panayotova, T., M. Dimova-Todorova and I.
Dobrevsky, 2007 urification and reuse of heavy
metals
containing
wastewaters
from
electroplating plants. Desalination, 206(1): 135140.
Bagheri, B., et al., 2010. Efficient Removal of
Cr3+, Pb2+ and Hg2+ Ions from Industrial
Effluents
by
Hydrolyzed/Thioamidated
Polyacrylonitrile Fibres. Iran Polym J., 19: 911925.
Celik, M., 2004. Graft copolymerization of
methacrylamide onto acrylic fibers initiated by
benzoyl peroxide. Journal of applied polymer
science, 94(4): 1519-1525.
Jia, Z. and S. Du, 2006. Grafting of casein onto
polyacrylonitrile fiber for surface modification.
Fibers and Polymers, 7(3): 235-240.
Jia, Z., S. Du and G. Tian, 2007. Surface
modification of acrylic fiber by grafting of
casein. Journal of Macromolecular Science, Part
A: Pure and Applied Chemistry, 44(3): 299-304.
Jia, Z. and Y. Yang, 2007. Surface modification
of polyacrylonitrile (PAN) fibers by grafting of
natural polymer-soybean protein (SP). Polymer
Bulletin, 59(1): 13-23.
Deng, J., et al., 2009. Developments and new
applications of UV-induced surface graft
polymerizations. Progress in Polymer Science,
34(2): 156-193.
Zhang, W. and M. Li, 2005. DSC study on the
polyacrylonitrile precursors for carbon fibers.
Journal of materials science and technologyshenyang, 21(4): 581.
You, S.Y., Y.H. Park and C.R. Park, 2000.
Preparation and properties of activated carbon
fabric from acrylic fabric waste. Carbon, 38(10):
1453-1460.
Carrott, P., et al., 2001. Preparation of activated
carbon fibres from acrylic textile fibres. Carbon,
39(10): 1543-1555.
He, D., et al., 2005. Comparison of structure
and properties among various PAN fibers for
carbon fibers. Cailiao Kexue Yu Jishu(Journal
of Materials Science & Technology), 21(3): 376380.
Frank, O., et al., 2011. Development of a
universal stress sensor for graphene and carbon
fibres. Nature Communications, 2: 255.
Jing, M., et al., 2008. Effects of preoxidation and
carbonization technologies on tensile strength of
PAN‐based carbon fiber. Journal of Applied
Polymer Science, 108(2): 1259-1264.
Wu, G., et al., 2004. Effect of moisture on
stabilization of polyacrylonitrile fibers. Journal
of materials science, 39(8): 2959-2960.
Catta Preta, I.F., et al., 2007. Thermal behavior
of polyacrylonitrile polymers synthesized under
229
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
Lamiaa El- Gabry et al, 2014 /Journal Of Applied Sciences Research 10(3), March, Pages: 218-229
different
conditions
and
comonomer
compositions. Journal of Thermal Analysis and
Calorimetry, 87(3): 657-659.
Ko, T.H. and L.C. Huang, 1998. The influence of
cobaltous chloride modification on physical
properties and microstructure of modified PAN
fiber during carbonization. Journal of applied
polymer science. 70(12): 2409-2415.
Shen, W., Z. Li and Y. Liu, 2008. Surface
chemical functional groups modification of
porous carbon. Recent Patents on Chemical
Engineering, 1(1): 27-40.
Zohdy, M., A. El-Naggar and M. Marie, 1999.
Effect of copper treatment on the dyeability of
gamma irradiated acrylic fabrics with different
dyestuffs. Materials chemistry and physics,
61(3): 237-243.
Takekawa, T., et al., 2006. Enhancement of the
Antibacterial Activity of Acrylic Fibers
Containing Alumina-Zinc Silicate. BOKIN
BOBAI. 34(2): 73.
Oktem, T., et al., 2000. Modification of
polyester and polyamide fabrics by different in
situ plasma polymerization methods. Turkish
Journal of Chemistry, 24(3): 275-286.
Pane, S., R. Tedesco and R. Greger, 2001.
Acrylic fabrics treated with plasma for outdoor
applications. Journal of Industrial Textiles,
31(2): 135-145.
Liu, Y.C., Y. Xiong and D.N. Lu, 2006. Surface
characteristics and antistatic mechanism of
plasma-treated acrylic fibers. Applied surface
science, 252(8): 2960-2966.
Bai, G. and Y. Liu, 2010. Antistatic Property of
Polyacrylonitrile Fiber by Plasma-grafting
Treatment. Textile Research Journal, 80(16):
1658-1664.
Oktem, T., et al., 2001. Modification of PAN
fabrics by in situ-plasma polymerisation
methods. Melliand Textilberichte International
Textile Reports, 82(3): E51-E52.
Kang, J.Y. and M. Sarmadi, 2004. Textile
plasma treatment review: natural polymer-based
textiles. AATCC review, 4(10): 28-32.
Ceria, A. and P.J. Hauser, 2010. Atmospheric
plasma treatment to improve durability of a
water and oil repellent finishing for acrylic
fabrics. Surface and Coatings Technology,
204(9): 1535-1541.
Battistel, E., M. Morra and M. Marinetti, 2001.
Enzymatic surface modification of acrylonitrile
fibers. Applied Surface Science, 177(1): 32-41.
Wang, N., et al., 2004. Enzymatic surface
modification of acrylic fiber. AATCC review,
4(9): 37-41.
Tauber, M., et al., 2000. Nitrile Hydratase and
Amidase
fromRhodococcus
rhodochrous
Hydrolyze Acrylic Fibers and Granular
Polyacrylonitriles. Applied and environmental
microbiology, 66(4): 1634-1638.
57. Colbrie, G.F., S. Heuman and G. Gubitz, 2005.
Biotechnology in the Textile Industry: Enzymatic
Modification of Synthetic fibres, in 2nd
International Conference of Textile Research
Division: NRC, Cairo, Egypt.
58. Gübitz, G.M. and A.C. Paulo, 2003. New
substrates for reliable enzymes: enzymatic
modification of polymers. Current opinion in
biotechnology, 14(6): 577-582.
59. Matamá, T., et al., 2007. Using a nitrilase for
the surface modification of acrylic fibres.
Biotechnology journal, 2(3): 353-360.
60. Banerjee, A., R. Sharma and U. Banerjee, 2002.
The nitrile-degrading enzymes: current status
and future prospects. Applied Microbiology and
Biotechnology, 60(1-2): 33-44.
61. Nourmohammadian, F. and M.D. Gholami,
2008. An Investigation of the Dyeability of
Acrylic Fiber Via Microwave Irradiation. textile
industries, 3: 5.
62. Wong, Y., et al., 2006. Selected applications of
nanotechnology in textiles. AUTEX Research
Journal, 6(1): pp: 1-8.
63. Chu, Y.C., et al., 2005. Surface modification of
polyacrylonitrile fibers and their application in
the preparation of silver nanoparticles. Journal
of Inorganic and Organometallic Polymers and
Materials, 15(3): 309-317.
64. Landage, S. and A. Wasif, 2012. Nanosilver-an
effective antimicrobial agent for finishing of
textiles. International Journal of Engineering
Sciences & Emerging Technologies, 4(1): 66-78.
65. Samal, S.S., P. Jeyaraman and V. Vishwakarma,
2010. Sonochemical coating of Ag-TiO2
nanoparticles on textile fabrics for stain
repellency
and
self-cleaning-the
Indian
scenario: a review. J. Min. Mater. Char. Eng.,
9(6): 519-525.
66. Burniston, N., C. Bygott and J. Stratton, 2007.
Nano technoology meets titanium dioxide.
Surface coatings international. Part A, Coatings
journal, 87(4): 179-184.
67. Janowska, G., T. Mikołajczyk and M. Boguń,
2007. Effect of the type of nanoaddition on the
thermal properties of polyacrylonitrile fibres.
Journal of thermal analysis and calorimetry,
89(2): 613-618.
68. Kampalanonwat, P. and P. Supaphol, 2010.
Preparation and adsorption behavior of
aminated
electrospun
polyacrylonitrile
nanofiber mats for heavy metal ion removal.
ACS Applied Materials & Interfaces, 2(12):
3619-3627.