HTML / Full Text View Download Manuscript
Chemical Science & Engineering Research
Research Article
Temperature Dependence on the Molecular Interaction of Amaranth Dye with Cetyltrimethylammonium bromide in the Premicelle Region: A Spectroscopy Study
Olaseni Segun Esan
Department of Chemical Sciences, Adekunle Ajasin University, Akungba-Akoko, Nigeria
*Corresponding author E-mail address: lincolnolaseni@yahoo.com
Abstract: Interactions of amaranth dye [Amr] with cetyltrimethylammonium ammonium bromide [CTABr] have been investigated using UV-spectrophotometric technique. Finding from the variation absorption spectral shows that absorbance values at the highest peak changes on addition of CTABr indicating that interaction exist between Amr and CTABr. The binding constant [Kb] between the micellar/water phases has been obtained using appropriate model from which the thermodynamic parameters have been calculated at different temperatures. The binding decreases with increasing temperatures. The free energy [∆G0], entropy [∆S0] and enthalpy [∆H0] changes regarding binding process are spontaneous, exothermic and enthalpy driven.
Keywords: Amaranth; Pre-micelle; Reso-Drago; Binding constant; Spectroscopy
Publication details: Received: 26th February 2020; Revised: 16th March 2020; Accepted: 16th March 2020; Published: 06th April 2020
1. Introduction
Dye-surfactant interaction has recorded so many applications in recent years in the following area of industrial applications (i) pharmaceutical[1] (ii) photography printing,[2] (iii) photosensitization[3] etc. On this note, more attention has drawn to the study of dye-surfactant interaction.[4-11] Investigation on dye-surfactant interactions has shown that it help in understanding chemical equilibria mechanisms and kinetics of surfactants-sensitized color and fluorescence reaction.[12] Several factors influenced dye-surfactant interaction among which chemical structures played a prominent role. Irrespective of either of these factors, dye-surfactant complexes, ion-pairs, self-aggregate of dye; pre-micellar aggregate and pure micelles of surfactant with solubilized dye are formed in course of this interaction.
Amaranth (Amr) commonly referred to as Red No. 2, Food Red 9, Acid Red 27, and Azorubin S, belong the group of Azo dyes which are broadly used in the textile, color solvent, ink, paint, varnish, plastic, food, drug and cosmetic industries.[13] It is a water-soluble dye, with sharp absorption peak in the visible region (λmax = 520 nm) with no shift due to pH change.[14]
Cetyltrimethyl ammonium bromide (CTABr) is widely used in industrial application most especially as auxiliary in textile finishing process.[15] Undertaken this study is very important and interesting for improving dyeing process from theoretically point of view, which account for its valuable exploring the interaction between dye and surfactant.[16]
When surfactant is found in solution it changes from pre-micelle to micelle. At low concentration, it arranges itself on the surface of the aqueous solution in such a way that the hydrophobic part is facing outward and hydrophilic part is towards an aqueous solution. Micelle formation is a cooperative process that occurs over a narrow range of concentration, where the transition from monomeric solution to a solution containing both monomers and micelle take place. The single concentration within this narrow range is called critical micelle concentration (CMC) with hydrophobic part within the core of the cluster and hydrophilic part facing the aqueous solution. Each kind of formation (assembly) has its own peculiar characteristic and performance, while its effect on reaction has always been a matter of study.
Interaction of dye- surfactant in pre-micellar region results in the formation of ion association complex while in post – micelle region dye molecule are localized at the micelle surface. Considering the above, Sidract et al.,[17] monitored the change in electrical conductivity and spectra behavior before and after micelle formation in the dye-surfactant system. Likewise, catalytic effect of CTABr reverse micellar systems on the alkaline fading of malachite green has been reported by Somnath et al.,[18] to taking place at a much faster rate than in normal micelles or in a continuous aqueous medium. Observation from there study shows that both the electrostatic interaction between dye and surfactant and the dissolution of dye-surfactant aggregate depends on the concentration of surfactant.
There are different methods for the study of the dye-surfactant system which has been reported by various researchers such as spectrophotometric,[19,20,21,22] conductometric,[23,24,25] tensiometric,- [26,27] and potentiometric[28] etc. Result has shown that these methods reveal that the oppositely charge dye (+/-) and surfactant (-/+) have strongest interaction and same charge dye (+/-) and surfactant (+/-) have almost zero interaction.[29] Summarily, it was also believed that shifting in λmax and increase or decrease in intensity also attributed to complexation or dye-surfactant interaction.
Surfactant in any of its formation either at pre or post micellar stage influence absorption spectral of many dyes.[19] Hence, spectrophotometric method is widely adopted in monitoring dye-surfactant interaction.[29] In literature, study on the interaction of food colourant dye with either cationic, anionic and non-ionic surfactant using spectrophotometric has not been comprehensively monitor. Herein, study was made on the interaction of Amaranth dye (Amr) with cetyltrimethylammonium bromide (CTABr) in order to explore the nature and the stability of the interaction as a function of temperature within the premicellar range.
The aim of the presence study is to investigate the interaction between Amr and CTABr at the temperatures 298.15K, 303.15K, 308.15K, 313.15K, and 318.15K using spectrophotometric method and to determine the values of binding constant viz a viz thermodynamic parameter.
2. Materials and method
2.1. Materials
Amaranth dye (Amr) Cetyltrimethyl ammonium bromides (CTABr) were purchased from Sigma Aldrich Chemical Company. The reagents were of analytical grade (AR) and used without further purification. The chemical structures of Amr dye and CTABr surfactant are shown in scheme 1 and 2 respectively.
Scheme 1. Molecular structure of Amaranth (Amr)
Scheme 2. Molecular structure of Cetyltrimethylammonium Bromide (CTABr)
2.2. Solution preparation
Aqueous stock solution of dye Amaranth (Amr) (1.0 x 10-4 M) and Cetyltrimethyl ammonium bromide (CTABr) (2.0 x 10-2 M), were prepared by dissolving their known amounts in doubly distilled deionized water and expressed in molar concentration. The subsequent dilutions were made by using doubly distilled deionized water. The dye concentration was fixed at 2.7 x 10-5 M during the measurements so as to have absorbance of the solutions in the reasonable range.
2.3. Experimental techniques
A series of dye solution was prepared from stock solution of Amr (1.0 x 10-4 M) to determine the molar extinction coefficient (ꜪAmr). For the spectrophotometric measurement, an exact volume of dye was added to a known volume of doubly distilled deionized water and the absorption spectrum of dye was recorded. The reaction mixture was prepared by taking an exact volume of dye and surfactant in a cell containing a known volume of deionized water. The variation of absorbance of the dye solution was recorded as a function of increase in surfactant concentration at the wavelength of maximum absorbance at varying temperature.
2.4. Calculations Binding Constant
The binding constant (Kb) between Amr and CTABr were determined in the pre-micellar region of CTABr and it can be expressed as:
Where Cx is the concentration of reaction product, and , are the initial concentration of surfactant and dye respectively. When , the CTABr concentration may be assume constant. On this note, the experimental data can be analyzed using Reso-Drago equation.[30,31] The equation can be expressed as;
According to Beer-Lambert law, the absorbance of a unit thickness absorbing layer can be expressed as:
Where A is the absorbance of Amr and is the molar absorptivity of Amr. At equilibrium, absorbance value can be expressed as:
Addition of equation (3) and (4) yields
Assuming the molar absorption coefficient for CTABr is ignored at wavelength of 520nm, equation (5) can be re-written as:
Where , K and are obtained from the slope and intercept of the plot of .
2.5. Thermodynamic Parameters
The free energy changes, ∆G0, the enthalpy changes, ∆H0, and entropy changes, ∆S0, belonging to the association equilibrium constant Kb for the interaction of Amr with CTABr at different temperature can be calculate from the equation below;[32]
3. Results and Discussions
3.1. Behavior of Amr in the absence and presence of CTABr at pre-micellar region
The visible absorption spectrum of Amr (2.7 x 10-5 mol dm-3) in aqueous solution exhibit an absorption maximum at 520nm with a molar extinction coefficient (ꜪAmr) of 1.554 x 104 L mol-1 cm-1 obtained by plotting series of absorbance against different concentrations of Amr as shown in Fig. 1.
Spectra of Amr in the absence and presence of CTABr were presented in fig. 2. On addition of CTABr, the absorbance decreases without any significant change in the λmax. The decrease in the absorbance with increasing CTABr concentration in the pre micelle region can be explained in terms of dye–surfactant ion pair complex formation due to long-range electrostatic interaction between the positive charges of CTABr molecules and anionic sulfonate group of the Amr and short range hydrophobic forces which are strong enough for the formation of a stable ion pair complex of Amr-CTABr.[33]
This is further established by the fact that there is also no perturbation in the spectrum of the Amr and CTABr which has also been observed for other different dye– surfactant systems.[34-38] The dye interacted with the polar and non-polar part of the surfactant depending on the substituents.[33]
3.2. Effect of temperature on the behavior of Amr in the presence of CTABr at pre-micellar region
In order to analyze the influence of temperature on 2.7 x 105 moldm-3 spectra of Amr in the presence of 0.2mmoldm-3 CTABr, UV-Vis spectra were recorded. Fig. 3 shows variation in the UV-Vis spectra of Amr at different temperatures. The characteristic peak at 520nm did not change with increasing temperature. Observation shows there is significant decrease in absorbance value of Amr as temperature increases. This may be attributed to the interaction between anionic dye (Amr) and cationic surfactant (CTABr).
Adoption of Reso – Drago equation for the interaction of Amr and CTABr at different temperature accounts for the parameter obtained in Table 1. Indication from the Table 1 shows that as temperature increases, both the binding constant Kb and the molar absorption coefficient Ꜫx for the interaction of Amr and CTABr decreases. This means that high temperature causes a reduction in the interaction between Amr and CTABr molecule. In other word, the strength of interaction between Amr and CTABr at 318.15K is weaker than at 298.15K.
T/K
|
Kb M-1
|
Ꜫx/M-1cm-1
|
298.15
|
28571
|
18873
|
303.15
|
11125
|
18814
|
308.15
|
10011
|
18465
|
313.15
|
7500
|
18214
|
318.15
|
6000
|
18005
|
Effect of temperature on the trend of monomers absorbance of Amr in the presence CTABr were calculated from the data obtained in fig. 3 and depicted in fig. 4. As seen in Fig. 4, monomers of CTABr are available rather than the micellar aggregate.
Hence the monomer is interacting with the Amr molecules. The profile can be divided into two regions. In region I, the absorbance of Amr increases with increasing CTABr concentration. In this region, ion pair between Amr and CTABr and aggregate of ion pair are formed with CTABr concentration. Upon this, Amr-CTABr complex dissociate and the concentration of free Amr increases which allow Amr molecule to be accommodated into the pre-micelle monomeric molecule. In region II, there is decrease in absorbance value of Amr. This is due to the fact that there is less dissociation of Amr- CTABr complex. Consequently, the number of free Amr molecule decreases hence decrease in absorbance
To evaluate the thermodynamic aspects of the binding of Amr to CTABr pre-micelle, the thermodynamic parameters were calculated and are summarized in Table 2. The values of the Gibbs free energy of interaction (ΔG0), the standard enthalpy (ΔH0) and the standard entropy (ΔS0) changes were calculated from the values obtained for Kb at different temperatures from the spectral studies using equations (7) – (9) respectively.[32] As seen in Table 2, all ∆G0 values are negative indicating that the binding process of Amr molecule to the CTABr monomeric molecule occur spontaneously. The ΔG0 values become less negative with the increase in temperature for binding of Amr to CTABr pre-micelle. This means that binding process is preferred at lower temperatures.
The negative values of ΔH0 indicate that binding process is exothermic in nature. The net ΔH0 is the sum of the change in enthalpies resulting from hydrophobic interactions, electrostatic interactions, hydration of polar head groups, and counter ion binding to micelles.[39-41] Negative values of ΔH0 may occur when electrostatic interactions and hydration of polar head groups become more effective. In these cases, hydration of water molecules around the hydrophilic head group become more important than that of the decrease of hydration around the hydrophobic alkyl chains of surfactant monomers.[39-40,42] Positive values of ΔH0 may arise when the hydrophobic interactions are stronger and due to the transfer of hydrophilic head groups from the aqueous environment into micelle core.[43] For Amr – CTABr system, significant negative value of ΔH0 for binding process indicate that the electrostatic interactions play a major role. The binding process is also accompanied with negative entropy (∆S0) as the temperature increases. The values of ΔH0 and ΔS0 indicate that binding process of Amr to CTABr pre-micelles are enthalpy controlled over the range of studied temperatures.
Process
|
T/K
|
∆G0/KJmol
|
∆H0/KJmol
|
∆S0/JmolK-1
|
Binding
|
298.15
|
-25420.3
|
-62595
|
-124.75
|
|
303.15
|
-23470.7
|
|
-129.12
|
|
308.15
|
-23587.8
|
|
-126.64
|
|
313.15
|
-23219.3
|
|
-125.80
|
|
318.15
|
-23000.2
|
|
-124.51
|
4. Conclusions
The addition of CTABr does not change the characteristic absorption peaks of Amr but decrease in intensity, indicating interactions between Amr and CTABr molecule and formation of ion pair complex. By measuring the absorbance of Amr in different solutions as a function of temperature and using the appropriate association models to analyze the experimental data, the association binding constant Kb and thermodynamic parameters were obtained. The results show that the absorbance value of dye increases with the addition of CTABr within the pre-micelle region. The increase in the temperature of solution causes a reduction in the binding constant values of Amar – CTABr system due to the weakening of interactions between dye and surfactant molecules at high temperatures. The negative values for the thermodynamic parameters ∆G0, ∆S0 and ∆H0 pointed out that the binding of Amar to CTABr are spontaneous in nature and enthalpy driven.
Conflicts of Interest
The authors declare no conflict of interest
References
- Berthois Y.; Katzenellenbogen J.A.; Katzenellenbogen B.S. Phenol Red in Tissue Culture Media is a Weak Estrogen: Implications Concerning the Study of Estrogen-Responsive Cells in Culture. Proc. Natl. Acad. Sci., 1986, 83, 2496-2500. [CrossRef]
- Shapiro B.I. Aggregates of Cyanine Dyes: Photographic Problems. Russ. Chem. Rev., 1994, 63, 231. [CrossRef]
- Dutta R.K.; Bhat S.N. Interaction of Phenazinium Dyes and Methyl Orange with Micelles of Various Charge Types. Colloids Surf. A, 1996, 106, 127-134. [CrossRef]
- Halide A.; Cigdem K. Conductometric Studies of the Interaction of C.I. Reactive Orange 16 with Cationic Alkyltrimethylammonium Bromide Surfactants. Dyes Pigm., 2007, 72, 383-386. [CrossRef]
- Halide A.; Cigdem K. C.I. Reactive Orange 16-Dodecylpyridinium Chloride Interactions in Electrolytic Solutions. Spectrochim. Acta A., 2006, 65, 95-99. [CrossRef]
- Shen T.; Xiao R.; Wang Q.; Yang, L.; Wang N. Study of interactions and association thermodynamics between Sudan Red and sodium dodecyl sulfate in microemulsions. J. Dispersion Sci. Technol., 2014, 35, 435-440. [CrossRef]
- Dutta R.K.; Bhat S.N. Interaction of methyl orange with submicellar cationic surfactants. Bull. Chem. Soc. Jpn., 1993, 66, 2457-2460. [CrossRef]
- Forte-Tavcer P. Interactions between some anionic dyes and cationic surfactants with different alkyl chain length studied by the method of continuous variations. Dyes Pigm., 2004, 63, 181-189. [CrossRef]
- Ghoreishi S.M.; Behpour M.; Farsani A.G. Study of interaction between a cationic surfactant and two anionic azo dyes by ion-selective electrode technique and spectrophotometry. Dyes Pigm., 2007, 74, 585-589. [CrossRef]
- Wang N.; Zhao M. Study on Thermodynamics and Kinetics of Association Interactions between Malachite Green and OP-10 in Aqueous Solutions. J. Dispersion Sci. Technol., 2016, 37, 190-195. [CrossRef]
- Buwalda R.T.; Engberts J.B. Aggregation of dicationic surfactants with methyl orange in aqueous solution. Langmuir, 2001, 17, 1054-1059. [CrossRef]
- Gokturk S.; Tuncay M. Spectral studies of safranin-O in different surfactant solutions. Spectrochim. Acta A, 2003, 59, 1857-1866. [CrossRef]
- Shu H.Y.; Huang C.R. Degradation of commercial azo dyes in water using ozonation and UV enhanced ozonation process. Chemosphere, 1995, 31, 3813-3825. [CrossRef]
- Nadupalli S.; Koorbanally N.; Jonnalagadda S.B. Kinetics and mechanism of the oxidation of amaranth with hypochlorite. J. Phys. Chem. A, 2011, 115, 7948-7954. [CrossRef]
- Wang N.; Su C.; Xiao S. Interaction of Phenol Red with cetyltrimethylammonium bromide in aqueous solution. Color. Technol., 2015, 131, 434-438. [CrossRef]
- Lin H.; Zhu H.; Guo, J.; Wang, N. Interactions between bromophenol blue and cetyl-trimethylammonium bromide in aqueous solutions and microemulsions. J. Disper. Sci. Technol., 2017, 38, 1410-1414.[CrossRef]
- Samiey B.; Golestan S. Adsorption of Triton X-100 on silica gel: effects of temperature and alcohols. Open Chem., 2010, 8, 361-369. [CrossRef]
- Dasmandal S.; Mandal H.K.; Kundu A.; Mahapatra A. Kinetic investigations on alkaline fading of malachite green in the presence of micelles and reverse micelles. J. Mol. Liq., 2014, 193, 123-131. [CrossRef]
- Hosseinzadeh R.; Maleki R.; Matin A.A.; Nikkhahi Y. Spectrophotometric study of anionic azo-dye light yellow (X6G) interaction with surfactants and its micellar solubilization in cationic surfactant micelles. Spectrochim. Acta A, 2008, 69, 1183-1187. [CrossRef]
- Arıkan B.; Tuncay M. The effect of SDS micelles on reduction of toluidine blue by ascorbic acid in acid medium. Colloids Surf. A, 2006, 273, 202-207. [CrossRef]
- Edbey K.; Bader N.; Eltaboni F.B.; Imragaa, A.; Albaba, S.; Ahmed, M. Conductometric and spectrophotometric study of the interaction of methyl violet with sodium dodecyl sulfate. International Research. Pure. Appl. Chem., 2015, 9, 1-7. [CrossRef]
- Berlett B.S.; Levine R.L.; Stadtman E.R. Use of isosbestic point wavelength shifts to estimate the fraction of a precursor that is converted to a given product. Anal. Biochem., 2000, 287, 329-333. [CrossRef]
- Edbey K.; Bader N.; Eltaboni F.B.; Imragaa A.; Albaba, S.; Ahmed M. Conductometric and spectrophotometric study of the interaction of methyl violet with sodium dodecyl sulfate. Int. Res. J. Pure Appl. Chem., 2015, 9, 1-7. [CrossRef]
- Bracko S.; Span J. Conductometric investigation of dye–surfactant ion pair formation in aqueous solution. Dyes Pigm., 2000, 45, 97-102. [CrossRef]
- Benito I.; Garcia M.A.; Monge C.; Saz J.M.; Marina M.L. Spectrophotometric and conductimetric determination of the critical micellar concentration of sodium dodecyl sulfate and cetyltrimethylammonium bromide micellar systems modified by alcohols and salts. Colloids Surf. A, 1997, 125, 221-224. [CrossRef]
- N.A. Al-Omair, Sci. J. King Faisal Univ. Sci 16(2015) 27.
- Chandravanshi S.; Upadhyay S.K. Natural dye–surfactant interactions: thermodynamic and surface parameters. Color. Technol., 2012, 128, 300-305. [CrossRef]
- Simoncic B.; Kovac F. A study of dye–surfactant interactions. Part 2. The effect of purity of a commercial cationic azo dye on dye–surfactant complex formation. Dyes Pigm., 1999, 40, 1-9. [CrossRef]
- Mall C.; Solanki P.P. Spectrophotometric and conductometric studies of molecular interaction of brilliant cresyl blue with cationic, anionic and non-ionic surfactant in aqueous medium for application in photogalvanic cells for solar energy conversion and storage. Energy Rep., 2018, 4, 23-30. [CrossRef]
- Tunc S.; Duman O.; Kancı B. Spectrophotometric investigation of the interactions between cationic dye (CI Basic Yellow 2) and anionic surfactant (sodium dioctylsulfosuccinate) in the premicellar and micellar region. Dyes Pigm., 2012, 94, 233-238. [CrossRef]
- Rose N.J.; Drago R.S. Molecular addition compounds of iodine. I. An absolute method for the spectroscopic determination of equilibrium constants. J. Am. Chem. Soc., 1959, 81, 6138-6141. [CrossRef]
- Ikushima Y.; Saito N.; Hatakeda K.; Arai M. Water/AOT/ethane microemulsion under supercritical conditions as a reaction medium. J. Supercrit. Fluids, 1998, 13, 217-224. [CrossRef]
- Castellan GW. Physical chemistry. California: The Benjamin/Cummings Publishing Company, Inc.; 1983.
- Muhammad M.T.; Khan M.N. Oppositely charged dye surfactant interactions: Extent and selectivity of ion pair formation. J. Mol. Liq., 2018, 266, 591-596. [CrossRef]
- Duman O.; Tunc S.; Kancı B. Spectrophotometric studies on the interactions of CI Basic Red 9 and CI Acid Blue 25 with hexadecyltrimethylammonium bromide in cationic surfactant micelles. Fluid Phase Equilib., 2011, 301, 56-61. [CrossRef]
- Erdainc N.; Gokturk S.; Tuncay M. Interaction of epirubicin HCl with surfactants: Effect of NaCl and glucose. J. Pharm. Sci., 2004, 93, 1566-1576. [CrossRef]
- Enache M.; Volanschi, E. Spectral studies on the molecular interaction of anticancer drug mitoxantrone with CTAB micelles. J. Pharm. Sci., 2011, 100, 558-565. [CrossRef]
- Joshi S.; Pant D.D. Steady state and time-resolved fluorescence spectroscopy of quinine sulfate dication bound to sodium dodecylsulfate micelles: fluorescent complex formation. J. Lumin., 2014, 145, 224-231. [CrossRef]
- Gujar, V.B. and Ottoor, D., 2017. Medium dependent dual turn on/turn off fluorescence sensing for Cu2+ ions using AMI/SDS assemblies. Spectrochim Acta A, 173, 666-674.[CrossRef]
- Akhtar F.; Hoque M.A.; Khan M.A. Interaction of cefadroxyl monohydrate with hexadecyltrimethyl ammonium bromide and sodium dodecyl sulfate. J. Chem. Thermodyn., 2008, 40, 1082-1086. [CrossRef]
- Hoque M.A.; Khan M.A.; Hossain M.D. Interaction of cefalexin monohydrate with cetyldimethylethylammonium bromide. J. Chem. Thermodyn., 2013, 60, 71-75. [CrossRef]
- Usman M.; Siddiq M. Surface and micellar properties of chloroquine diphosphate and its interactions with surfactants and human serum albumin. J. Chem. Thermodyn., 2013, 58, 359-366. [CrossRef]
- Robins D.C.; Thomas I.L. The effect of counterions on micellar properties of 2-dodecylaminoethanol salts: I. Surface tension and electrical conductance studies. J. Colloid Interface Sci., 1968, 26, 407-414. [CrossRef]
- Shimizu S.; Pires P.A.R.; Loh W.; El Seoud O.A. Thermodynamics of micellization of cationic surfactants in aqueous solutions: consequences of the presence of the 2-acylaminoethyl moiety in the surfactant head group. Colloid. Polym. Sci., 2004, 282, 1026-1032. [CrossRef]
© 2020, by the authors. Licensee Ariviyal Publishing, India. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).