improve of direct dye (direct orange 46) sorption on ...on the dye. the advantages of direct dyes...
Post on 02-Oct-2020
4 Views
Preview:
TRANSCRIPT
Journal of Applied Chemical Research, 18, 7-14 (2011)
Journal of App l ied Chemical Research
www.jacr.k iau.ac. i r
Improve of Direct Dye (Direct Orange 46) Sorption on Pretreated Cotton Fabric by Cationic Agent
Y. Khanjani1, K. Farizadeh2*, S.Ahmadi2 1Young Researchers Club, Islamic Azad University, Shahr-e-Rey Branch, Tehran, Iran.
2Islamic Azad University, Shahr-e-Rey Branch, Tehran, Iran. (Received 27 April 2011; Final version received 12 May 2011)
AbstractThe sorption properties of direct dye on bleached cotton and cationized cotton (treated with Cibafix WFF) was studied. Cationization of cotton fabric at different conditions (time and cationic agent concentration) wasinvestigated. Nitrogen content of cotton samples pretreated with cationic agent were determined by Kjeldahl method. The results showed that at higher cationizing treatment time and initial cationic agent concentration lead to higher nitrogen content on cotton fabric. The adsorption isotherm of Direct Orange 46 (DO46) on cationized cotton was tested by fitting the adsorption data with Langmuir and Frendlich. Standard adsorption affinity of direct dyes on cationized cotton was measured. The results showed that standard affinity value is negative. This indicated that the adsorption of DO46 on cationized cotton is an exothermic process. According to results, the adsorption of direct dye on cationized cotton is more than bleached cotton. It is clear that the present of cationic group on cationized cotton fabric causes more attractionf or sorption of inionic dyes.Keywords: Cationized Cotton, Direct dyes, Adsorption isotherm, Standard affinity, Langmuir, Frendlich.
Introduction
Cotton is an abundant natural fiber which
consist of practically pure cellulose (about
88- 96 % )[1]. Cotton fibers due to hydroxyl
groups in its structure faces problem of fiber-
dye attraction. Many attempts have aimed
to improve dye bonding and dye adsorption
on materials through chemical modification
[2]. Cellulose fiber when comes in contact
with water produce slightly negative charge
(ξ=-11 Mv) that due to presence of hydroxyl
and carboxyl groups.Whereas common dyes
appropriate for cotton dyeing are anionic
(such as reactive and direct dyes) in dyeing
bath[3.4]. The slightly negative charge on the
fibers repels anionic dyestuff and hence the
efficiency of dye exhaustion and fixation on
cellulosic fiber is generally low[5].
The surface modification of textile fibers is
considered as the best process to obtain modern * Corresponding author: Dr. K. Farizadeh, Assistant Prof., Shahr-Rey branch, Islamic Azad University, Tehran, Iran. Email: khosrofarizad@yahoo.com. Cell: 09121543906, Fax: 02122251140.
Y. Khanjani et al., J. Appl. Chem. Res., 18, 7-14 (2011)8
textile treatment [6]. In order to enhance the
dyeing capacity of the cotton fibers, inclusion of
an extensive functional compounds; for example
polyepichlorohydrin dimethyl amine (PECH-
amine), poly (4-vinylpridine) quaternary
ammonium compound, polyamidoamine
(PAMAM) and chitosan bio polymer on cotton
fibers has been reported.It was found that such
pretreatment increased the color strength of
the dyed cotton and improved wash fastness
properties [6]. Many substrates containing
quaternary ammonium groups or amino groups
have been used following this application [6].
Chemical modifications of cotton by reaction
with the functional groups (hydroxyl groups)
already present in the fiber are also investigated.
Etherification, esterification, grafting and
crosslinking reaction defined for chemical
modification of cotton have been extensively
studied [5]. By introduction of amino groups,
the cellulosic fiber will be cationized giving
high substantivity for anionic dyes due to the
columbic attraction between the positive charge
groups (NH2+) on the fiber and the negative
charge on the anionic dyes that is shown in
Figure 1.
Cell
Cell
OH + CH2CHCH2 CH2CHCH2
CH2CHCH2
Na2CO3N N
N
R2 R2
OH PA PA
PAOH
Fixation
O
O
Cl R1+ +
+
R1
R1
R2
Figure1. Chemical structure of Cibafix WFF compound and its reaction with cellulose.
On the other hand, the exhaustion of anionic
dyes (reactive, direct and acid dyes) on cationic
modified cotton can be improved greatly [5].
Direct dyes are used on cellulose fibers such
as cotton, rayon, and linen. The name “direct
dye” alludes to the fact that these dyes do not
require any form of “fixing”. They are almost
always azo dyes. They also have sulphonate
functionality, but in this case, it is only to
improve solubility and the negative charges
on the dye. The advantages of direct dyes are
resistance to faiding in the light and easy to
handle. The chemical structure of DO46 is
shown in Figure 2.
N N NH2SO3Na
Figure 2. C.I.Direct orange 46 (DO46).
The dyeing of cotton fabrics with anionic dyes
such as direct and reactive dyes require the
presence of large concentration of electrolyte
such as Glauber̕ s salt or sodium chloride and
alkaline to increase dye uptake, resulting in
critical environmental problems. The best
solution to avoid this problem is to cationized
the cotton fiber with cationic agent that promote
the colour strength of the dyed samples and
improve wash fastness properties [7-8]. In this
paper, we compared the adsorption isotherm of
DO46 and standard affinity of direct dyeing of
cotton pretreated with cationic agent (Cibafix
WFF) with untreated cotton.
Y. Khanjani et al., J. Appl. Chem. Res., 18, 7-14 (2011) 9
Experimental
Materials
Woven cotton fabric was provided free of
charge by a local producer in Iran. Direct
Orange 46 (DO46)(Sirius Orange K-CFN)
was from Dystar representative in Iran. The
purification of DO46 was by re-crystallization
with acetone. The Cibafix WFF (a Polyamino
Chlorohydrin Quaternary Ammonium
Compound), as a cationic agent, was obtained
from Ciba representative in Iran.
Instrumentation
A Unico 4802 UV-Visible spectrophotometer
was used for absorbance measurements using
quartz cell of 1 cm path length. A Shimadzu
1601 PC UV-Visible spectrophotometer was
employed for measuring of L*a*b* values. A
shaker bath equipped with thermostat, Shirley
(SDL–D403/1-3), operated at 75 rpm, was used to
study the adsorption of DO46 onto cotton samples.
Methods
Preparation of Fabric
Desizing
Before being used, the grey cotton fabric was
desized in solution containing 2% amylase
enzyme under slightly acidic pH at 60oC for
1 hour in laboratory mill. The enzyme was
deactivated with boiling of suspension at 90oC
for 15 min and the degraded starch products
was tested with potassium iodide and then
thoroughly washed out.
Scouring
The desized cotton fabric was scoured
in solution containing 1 g/lit Non- ionic
detergent, 5% Na2 CO3 at 100°C for 1 hr. Then
the samples were washed by cold water.
Bleaching
The desized and scoured fabric was bleached
with 5% hydrogen peroxide, 3% sodium
hydroxide and 1% sodium silicateat 100°C.
After that samples were rinsed with cold water
and neutralized with 1% acetic acid and then
it was washed thoroughly and dried in 50°C.
Cationizing of Cotton Fabric
The pretreatment of cotton fabric was carried
out by exhaust method in solution containing
20% o.w.f (% on weight of fabric) Polyamino
Chlorohydrin Quaternary Ammonium
Compound (Cibafix WFF), 15 g/l soda ash
(pH=9) for well- prepapred cotton, in L:G
20:1 for 60 min at 70°C.Then the fabric was
neutralized and washed thoroughly and dried
at ambient temperature.
Nitrogen Percentage
The nitrogen content was determined by the
Cole and Parks modification of the semimicro
Kjeldahl method [3].
UV-Visible Spectrometric
The UV-visible spectra of visible region (400-
800 nm) of DO 46 is shown in Figure 3.
Y. Khanjani et al., J. Appl. Chem. Res., 18, 7-14 (2011)10
Figure 3. UV- visible spectrum of DO46.
The wavelength of maximum absorbance (λmax)
of DO 46 was measured using Shimadzu 1601
PC UV-Visible spectrophotometer. In order
to determine λmax, the diluted dye solution
(0.05 g/lit) was prepared and absorption of
dye solution at visible region was measured.
According to the graph, the λmax of direct
orange 46 (DO46) is 558 nm.
Kinetic Studies
One gram of cotton samples (bleached
andcationized cotton) were dyed with DO46
at 40°C at different times, keeping the L.R. of
100:1 and an initial dye concentration of 1 %.
The quantity of dye adsorbed on cotton samples
were estimated using the following equation (1):
qt = (C0 – Ct)V/W Equation (1)
whereqt is the quantity of dye adsorbed on
cotton sample (mg/g cotton) at any time,
C0 and Ct are the initial and concentrations
(mg/L) after dyeing time t, respectively. V
is the volume of dye bath (mL) and W is the
weight of cotton sample (g).
The DO46 concentrations graph for standard
solution versus absorbance at 558 nm
wavelength, (maximum absorbance), was
plotted and used to determine the concentration
of an unknown solution. For each dyeing, the
absorbance of dye solution was monitored.
Then, the concentrations of dye in the residual
bath and the dye uptake were calculated using
the standard graph. Subsequently, the dyeing
rate of DO46 on cotton sample was plotted.
Equilibrium Studies
One gram of cotton sample (bleached
andcationized cotton) was dyed with different
dye concentrations (0.5- 4%) at 40˚C for 120
min. The quantity of dye adsorbed on cotton
samples at equilibrium were estimated using
the following equation (2):
qe= (C0 – Ce)V/W Equation (2)
where qe is the quantity of dye adsorbed on
cotton sample (mg/g cotton) at equilibrium,
C0 and Ce are the initial and equilibrium dye
concentrations (mg/l), respectively. V is the
volume of dye bath (mL) and W is the weight
of cotton sample (g).
Results and Discussion
Effect of Different Concentrations of Cibafix
WFFThe content of nitrogen in pretreated
cotton with different concentrations of Cibafix
WFF (10, 20 and 25% o.w.f) is summurized
in Table1.The results show that increase in
concentration of cationic agent leads to higher
nitrogen content in cationized cotton fabric.
Although nitrogen of cotton sample increase
Y. Khanjani et al., J. Appl. Chem. Res., 18, 7-14 (2011) 11
at higher Cibafix WFF concentration and also
25% o.w.f Cibafix WFF shows better result
(Table 1).
Effect of Cationizing TreatmentTimeThe content of nitrogen in cotton pretreated at different times with Cibafix WFF are listed in Table 1. The results show that increase in thecationizing treatment leads to increase in nitrogen content. Although nitrogen content increase with increase of the time and 60 min shows better result (Table 1).
Table 1. The effect of treatment time and cationic agent concentration on nitrogen content in cotton pretreated with Cibafix WFF.
Parameters Nitrogen percent(%)Time(min)
15 0.0530 0.0860 0.12
Cationic agent (%)15 0.0920 0.1225 0.14
Rate of Dyeing
Determining of equilibrium time is one of the
most important characteristics which represent
the adsorption of DO46 on cotton samples
(either bleached cottonor cationized cotton).
The adsorption of dye on cationized cotton
is more than bleached cotton (Figure 4). It is
clear that presence of cationic group on cotton
fabric leads to more attractive site of sorption
for anionic dye.
Time (min)Figure 4. Effect of dyeing time of cotton samples (bleachedandcationizedcotton) dyeid with Direct Orange 46 (DO46). Dyeing conditions: initial dye concentration 1%, 40 °C andL.R.100:1.
The adsorption of dye increased at 120 min,
of dyeing and then reached the equilibrium
gradually. The L*a*b* values of cotton
samples are listed in Table 2.
Table2. The CIE Lab values of cotton samples (bleached andcationized cotton) dyed with Direct Orange 46 (DO46) at different times. Dyeing conditions: initial dye concentration 1%, 40 °C and L.R. 100:1.
Cationized cottonBleached cottonParametersb*a*L*b*a*L*Time (min)
54.5520.5667.2650.3714.9470.081556.2720.5666.1052.8316.1769.193057.3221.4865.6953.0117.9868.566057.5921.7664.9053.7518.2167.679058.1122.0063.3254.5819.6267.2712058.6022.1263.1055.1719.8366.5215058.8122.5863.2155.6220.1566.4118059.1022.9863.0755.4720.5566.53210
Y. Khanjani et al., J. Appl. Chem. Res., 18, 7-14 (2011)12
The results reveal that, L* values decreases and
a*, b* values increases as the time increases to
120 min and then the L*a*b* remains almost
constant. Therefore, time of dyeing was set at
120 min.
Adsorption Isotherms
Several models have been published to describe
the adsorption isotherms. The Langmuir and
Freundlich models are the most frequently
employed models [9]. In this research, to
describe the relation between the amount of dye
adsorbed on cotton samples and the amount of
dye in residual dyeing bath at 40°C, Langmuir
and Freundlich models were used. The most
widely used equation describing the adsorption
process is Langmuir equation, which has the
linear form (equation 3) [10]:
Where Q is the maximum amount of the dye
adsorbed on cotton samples to form a complete
monolayer coverage bond to the surface at
high equilibrium dye concentration Ce, qe is
the amount of dye adsorbed on cotton samples
at equilibrium, and b is Langmuir constant
related to the affinity of the binding sites.
The value of Q represents practical limit of
adsorption capacity when the surface is fully
covered with dye molecules and provides
the comparison for adsorption performance.
The values of Q and b can be calculated from
intercepts and slops of the straight lines of plot
of 1/q against 1/Ce [11]. The values of Q and b
are calculated and listed in Table 3.
Table 3. Langmuir and Freundlich values of adsorption of Direct Orange 46 (DO46) on cotton samples (bleached and cationized cotton).
Isotherm modelsParametersBleached cottonCationized cotton
LangmuirQ( mg\g fiber)26.3231.28
B9.513.30R20.9330.978
FreundlichQf( mg\g fiber)42.7364.32
N1.651.73R20.9570.912
Correlation coefficients of Langmuir and
Freundlich models are also listed in Table 3.
The results show that experimental data for
adsorption of DO46 on bleached cotton does
not fit the Langmuir model but experimental
data for adsorption of DO46 on cationized
cotton fit the Langmuir model. The Freundlich
equation is another model which is often used to describe adsorption data. The linear form of the Freundlich isotherm can be represented in equation 4:
where Qf is roughly an indicator of the
Y. Khanjani et al., J. Appl. Chem. Res., 18, 7-14 (2011) 13
adsorption capacity and 1/n is the adsorption
intensity. Therefore, Qf and 1/n can be
determined from the linear plot of lnqe against
lnCe. The Qf and n values are listed in Table 3.
Correlation coefficients show that experimental
data for adsorption of DO46 on bleached
cotton fitted by this model. The magnitude
of the exponent 1/n gives an indication of the
favorability of adsorption. Values of n > 1
represent favorable adsorption conditions [11].
Standard Affinity
The standard affinity (-∆µ˚) was determined
using equation 5 [12]:
-∆µ˚= RT lnK (5)
Where R is the gas constant, T is the absolute
temperature (K) and K is the partition ratio.
The values of partition ratio (K) and standard
affinity (-∆µ˚) are presented in Table 4.
Table 4. Standard affinity (∆µ˚) and partition ratio (K) for the adsorption of Direct Orange 46 by cotton samples (bleached and cationized cotton).
-∆µ˚(kj/mol)KSample12.1957.83Bleached cotton12.5196.58Cationized cotton
It can be observed from Table 4 that the
standard affinity are negative which means
that the adsorption of DO46 on cotton samples
(bleached and cationized cotton) are an
exothermic process.
Conclusion
The adsorption of Direct Orange 46(DO46)
on cotton samples (bleached and cationized
cotton) was studied. The results indicated that
the adsorption of DO46 on cationized cotton
is more than bleached cotton. It is clear that
presence of cationic group on cotton fabric
leads to more attractive sites for sorption
of dye. The adsorption isotherm of DO46
oncationized cotton and bleached cotton are
Langmuir and Freundlich types, respectively.
The partition ratio (K), the standard affinity
(∆µ˚) was determined. It was noted that the
adsorption of DO46 on cotton samples is
exothermic process.
References
[1] S. Rattanaphani,M. Chairat, J.Bremner,
V. Rattanaphani, Dyes and pigments, 88, 46
(2007).
[2] S. Janhom, R.Watanesk,S. Watanesk, P.
Griffiths, O.A.Arquero, and W. Naksata, Dyes
and Pigments, 71, 188 (2006).
[3] A.I.Vogeld, “Elementery practical organic
chemistry, 2nd ed, Longman, London (1975).
[4] S. Janhom, P. Griffiths , R.Watanesk
S.Watanesk, Dyes and pigments, 159, 217
(2002).
[5] H.Wang , D.M. Lewis , JSDC , 1, 59 (2002).
[6] M.A.Wei, Z. Shufen, Y.Jin-zong, The
Proceedings of the 3rd International
Conference on Functional Molecules, 69
(2004).
[7] F.Zhang,Y.Chen, H.Lin, H.Wang Bing zhao,
Carbohydrate Polymers, 74, 250 (2008).
Y. Khanjani et al., J. Appl. Chem. Res., 18, 7-14 (2011)14
[8] M.S.Kannan, M.G.Krishnan, S.kumararel,
R.Nithyanadan, K.J.Rajashankar and T.
Rtadicherala, J.Tex. App. Tech. Manag., 1, 44
(2006 ).
[9] M.Chairat, S.Rattanaphani, J.B.Bremner,
andV.Rattanaphanti, Dyes and pigments, 64,
231 (2005).
[10] G.C.H. Derksen, G.P. Lelyveld, T.A.V
Beek, A. Capelle, E.D.Groot, Phytochem.
Anal., 15, 397 (2004).
[11] G.C.H. Derksen, M. Naayer, M., Beek,
T.A.V., A. Capelle, I.K. Haaksman, H.A.V.
Doren, and E.D. Groot, Phytochem. Anal., 14,
137 (2003).
[12] S. Paul, E. Grover, A. Sharma,
International Dye, 55, 22 (2003).
top related