Нейтронні дослідження впливу домішок NaBr на міцелоутворення в системі важка вода−тетрадецилтриметиламоній бромід

Методом малокутового розсiяння нейтронiв дослiджено формування мiцел в потрiйних рiдинних системах тетрадецилтриметиламонiй бромiд–важка вода–NaBr. Данi про малокутову дифракцiю нейтронiв на заряджених мiцелах було оброблено у наближеннi моделi перемасштабованої середньосферичної апроксимацiї Хайтер...

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Hauptverfasser: Булавін, Л.А., Горделій, В.І., Іваньков, О.І., Ісламов, А.Х., Куклін, А.І.
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Zitieren:Нейтронні дослідження впливу домішок NaBr на міцелоутворення в системі важка вода−тетрадецилтриметиламоній бромід / Л.А. Булавін, В.І. Горделій, О.І. Іваньков, А.Х. Ісламов, А.І. Куклін // Укр. фіз. журн. — 2010. — Т. 55, № 3. — С. 289-293. — Бібліогр.: 13 назв. — укр.

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spelling nasplib_isofts_kiev_ua-123456789-134122025-02-09T15:21:39Z Нейтронні дослідження впливу домішок NaBr на міцелоутворення в системі важка вода−тетрадецилтриметиламоній бромід Нейтронные исследования влияния примесей NaBr на мицеллообразование в системе тяжелая вода–тетрадецилтриметиламмоний бромид Neutron Studies of the NaBr Impurity Influence on Micelle Formation in the Heavy Water–Tetradecyltrimethylammonium Bromide System Булавін, Л.А. Горделій, В.І. Іваньков, О.І. Ісламов, А.Х. Куклін, А.І. М'яка речовина Методом малокутового розсiяння нейтронiв дослiджено формування мiцел в потрiйних рiдинних системах тетрадецилтриметиламонiй бромiд–важка вода–NaBr. Данi про малокутову дифракцiю нейтронiв на заряджених мiцелах було оброблено у наближеннi моделi перемасштабованої середньосферичної апроксимацiї Хайтера–Пенфольда. Визначено залежнiсть розмiрiв мiцел та числа агрегацiї вiд температури рiдинної системи та концентрацiї NaBr. Методом малоуглового рассеяния нейтронов изучено формирование мицелл в тройных жидкостных системах тетрадецилтриметиламмоний бромид–тяжелая вода–NaBr. Данные о малоугловой дифракции нейтронов на заряженных мицеллах были обработаны в приближении модели перемасштабированной среднесферической аппроксимации Хайтера–Пенфольда. Определена зависимость размеров мицелл и числа агрегации от температуры жидкостной системы и концентрации NaBr. Micelle formation in the triple liquid system tetradecyltrimethylammonium bromide–heavy water–NaBr has been studied by means of small-angle neutron scattering (SANS). The rescaled mean-spherical approximation by Hayter–Penfold has been used to treat the small-angle neutron diffraction data on charged micelles. The dependences of the micelle size and aggregation number on the liquid system temperature and NaBr concentration have been found. 2010 Article Нейтронні дослідження впливу домішок NaBr на міцелоутворення в системі важка вода−тетрадецилтриметиламоній бромід / Л.А. Булавін, В.І. Горделій, О.І. Іваньков, А.Х. Ісламов, А.І. Куклін // Укр. фіз. журн. — 2010. — Т. 55, № 3. — С. 289-293. — Бібліогр.: 13 назв. — укр. 2071-0194 PACS 61.05.fg https://nasplib.isofts.kiev.ua/handle/123456789/13412 538,97 uk application/pdf application/pdf Відділення фізики і астрономії НАН України
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
language Ukrainian
topic М'яка речовина
М'яка речовина
spellingShingle М'яка речовина
М'яка речовина
Булавін, Л.А.
Горделій, В.І.
Іваньков, О.І.
Ісламов, А.Х.
Куклін, А.І.
Нейтронні дослідження впливу домішок NaBr на міцелоутворення в системі важка вода−тетрадецилтриметиламоній бромід
description Методом малокутового розсiяння нейтронiв дослiджено формування мiцел в потрiйних рiдинних системах тетрадецилтриметиламонiй бромiд–важка вода–NaBr. Данi про малокутову дифракцiю нейтронiв на заряджених мiцелах було оброблено у наближеннi моделi перемасштабованої середньосферичної апроксимацiї Хайтера–Пенфольда. Визначено залежнiсть розмiрiв мiцел та числа агрегацiї вiд температури рiдинної системи та концентрацiї NaBr.
format Article
author Булавін, Л.А.
Горделій, В.І.
Іваньков, О.І.
Ісламов, А.Х.
Куклін, А.І.
author_facet Булавін, Л.А.
Горделій, В.І.
Іваньков, О.І.
Ісламов, А.Х.
Куклін, А.І.
author_sort Булавін, Л.А.
title Нейтронні дослідження впливу домішок NaBr на міцелоутворення в системі важка вода−тетрадецилтриметиламоній бромід
title_short Нейтронні дослідження впливу домішок NaBr на міцелоутворення в системі важка вода−тетрадецилтриметиламоній бромід
title_full Нейтронні дослідження впливу домішок NaBr на міцелоутворення в системі важка вода−тетрадецилтриметиламоній бромід
title_fullStr Нейтронні дослідження впливу домішок NaBr на міцелоутворення в системі важка вода−тетрадецилтриметиламоній бромід
title_full_unstemmed Нейтронні дослідження впливу домішок NaBr на міцелоутворення в системі важка вода−тетрадецилтриметиламоній бромід
title_sort нейтронні дослідження впливу домішок nabr на міцелоутворення в системі важка вода−тетрадецилтриметиламоній бромід
publisher Відділення фізики і астрономії НАН України
publishDate 2010
topic_facet М'яка речовина
url https://nasplib.isofts.kiev.ua/handle/123456789/13412
citation_txt Нейтронні дослідження впливу домішок NaBr на міцелоутворення в системі важка вода−тетрадецилтриметиламоній бромід / Л.А. Булавін, В.І. Горделій, О.І. Іваньков, А.Х. Ісламов, А.І. Куклін // Укр. фіз. журн. — 2010. — Т. 55, № 3. — С. 289-293. — Бібліогр.: 13 назв. — укр.
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fulltext L.A. BULAVIN, V.I. GORDELIY, O.I. IVANKOV et al. NEUTRON STUDIES OF THE NaBr IMPURITY INFLUENCE ON MICELLE FORMATION IN THE HEAVY WATER–TETRADECYLTRIMETHYLAMMONIUM BROMIDE SYSTEM L.A. BULAVIN,1 V.I. GORDELIY,2, 3 O.I. IVANKOV,1, 2 A.KH. ISLAMOV,2 A.I. KUKLIN2 1Taras Shevchenko National University of Kyiv, Faculty of Physics (1, Bld., 2, Academician Glushkov Ave., Kyiv 03022, Ukraine) 2I.M. Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research (6, Joliot-Curie Str., Dubna 141980, Russia) 3Institut de Biologie Structurale J.P. Ebel (41, Jules Horowitz Str., Grenoble F-38027, France) PACS 61.05.fg c©2010 Micelle formation in the triple liquid system tetradecyltrimethy- lammonium bromide–heavy water–NaBr has been studied by means of small-angle neutron scattering (SANS). The rescaled mean- spherical approximation by Hayter–Penfold has been used to treat the small-angle neutron diffraction data on charged micelles. The dependences of the micelle size and aggregation number on the liq- uid system temperature and NaBr concentration have been found. 1. Introduction One of the properties of surfactants in a solution is their ability to self-organize, the mechanisms of which have not been studied in full till now. Challenging are the researches of the influence of the temperature and elec- trolyte concentration in such a liquid system on the micelle structure [1]. In work [2], the light scattering method was used to study the dependence of a varia- tion of micelle dimensions and shapes on the concentra- tion of salt added to the liquid system. The authors showed that, provided the electrolyte concentration was high, micelles became prolate ellipsoids. The next step in studying the behavior of such micellar systems was their research using small-angle neutron scattering [3]. In that work, a possibility for bromine ions to arrange on the micelle surface or for the micelle head group to dehydrate under the electrolyte action, which changes the micelle size, was studied. Our work continues the researches of the micellar systems of cation surfactant tetradecyltrimethylammonium bromide (TTABr). The work aimed at determining the influence of the concen- tration of an electrolyte added to the liquid system on the micelle parameters within the temperature interval 25–60 ◦C using the small-angle scattering of thermal neutrons. 2. Experimental Technique To find the micelle sizes and the aggregation number [1], we used the method of SANS. The corresponding experi- ments were carried out on a YuMO installation [4] in the two-detector regime [5, 6]. The installation was located at an IBR-2 pulsed reactor of I.M. Frank Laboratory of Neutron Physics (the Joint Institute for Nuclear Re- search, Dubna, Russia). It allowed the researches to be carried on in the range of transferred wave vectors with absolute values |q| = (0.07 ÷ 5) nm−1 (or in the range of neutron wavelengths λ = (0.05 ÷ 0.8) nm). It made possible the density heterogeneities in the liquid system under investigation to be measured in the range from 1 to 100 nm. The diagram of YuMO installation for small- angle neutron scattering is presented in Fig. 1. The basic installation components are two-reflector system (1), a reactor zone with moderator (2), chopper (3), first (4) and second (6) collimators, vacuum pipe (5), thermo- stat (7), a cartridge with specimens in thermostatting box (8), a table for specimens (9), vanadium standards (10), ring detectors with central holes (11 and 12), and direct beam detector (14). In the YuMO installation, the absolute value of q- vector was changed by varying both the wavelength λ and the angle θ. The main change of q occurred due to a variation of the neutron wavelength. The angle was changed by means of two ring He detectors of scattered neutrons. The neutron wavelength was determined by the time-of-flight method [7]. The specimens to study were arranged at a distance of about 18 m from the 288 ISSN 2071-0194. Ukr. J. Phys. 2010. Vol. 55, No. 3 NEUTRON STUDIES OF THE NaBr IMPURITY INFLUENCE Fig. 1. Diagram of the YuMO installation for small-angle neutron scattering at the IBR-2 reactor of JINR (Dubna, Russia) moderator surface, being imbedded into a special con- tainer. A computer-assisted thermostat allowed the tem- perature in the container to be maintained within the researched temperature interval of 25–60 ◦C to an ac- curacy of ±0.01 ◦C. During measurements, specimens in the neutron beam were changed automatically. The peculiarities of the YuMO installation were central aper- tures in the scattered-neutron detectors, as well as a vanadium scatterer that was automatically inserted into and removed from the neutron beam and served to cali- brate the scattered radiation. The former allowed unde- sirable effects produced by long-periodic oscillations of reactor power to be avoided, the latter made it possible to obtain the scattering cross-section in absolute units [4]. A direct beam detector was used to measure the transmission of objects under investigation. A neutron diffraction pattern recorded in such a man- ner is a dependence of the pulse number produced by reg- istered neutrons in every analyzer channel on the chan- nel number, which corresponds to either the transit time or the wavelength of neutrons. Therefore, the neutron diffraction pattern recorded at the YuMO installation represents a time scan of the diffraction pattern of ther- mal neutrons scattered by a specimen. 3. Specimen Fabrication We fabricated a micellar liquid system, namely, a TTABr solution in heavy water with a concentration of 9.2 × 10−4 m.f. (molecular fraction, m.f. = N2/(N1 + N2), where N1 and N2 are the numbers of water and sur- factant molecules, respectively). NaBr admixtures were Fig. 2. SANS dependences for the micellar liquid system TTABr– heavy water at a temperature of 40 ◦C, the TTABr concentration 9.4 × 10−4 m.f., and various NaBr concentrations: 0 (�), 4.6 × 10−4 (�), 9.3 × 10−4 (•), 1.9 × 10−3 (◦), 3.7 × 10−3 (+), and 7.6× 10−3 m.f. (N) added to the studied micellar system to obtain ternary liquid systems heavy water–TTABr–NaBr with concen- trations of 4.6×10−4, 9.3×10−4, 1.9×10−3, 3.7×10−3, 7.6× 10−3, and 1.6× 10−2 m.f. To prepare micellar liq- uid systems of the surfactant, we used dry TTABr pro- duced by Sigma-Aldrich Co. (a TTABr content of 99%) and D2O produced by Isotope (Moscow) (a D2O con- tent of 99.8%). The specimens fabricated were placed in a Hellma quartz cuvette across a beam of neutrons with a neutron path length of 1 or 2 mm. 4. Experimental Part In Fig. 2, we present the SANS curves obtained for the micellar liquid system TTABr–heavy water with a TTABr concentration of 9.2× 10−4 m.f. at the temper- ature t = 40 ◦C and with addition of certain NaBr con- centrations. The analysis of the curves testifies that the SANS curves in the liquid systems TTABr–heavy water demonstrate a peak which corresponds to the intermi- celle interaction or the presence of a certain short-range order in the micelle arrangement in the given liquid sys- tem. An addition of NaBr impurities to the TTABr– heavy water system changes the character of the inten- sity curve substantially, namely, the peak gradually dis- appears. This testifies to the disappearance of the elec- trostatic interaction between micelles [3]. Figure 2 shows that, at NaBr concentrations higher than 1.9×10−3 m.f., the peak is absent. The subsequent addition of NaBr is accompanied by a growth of the scattering intensity in ISSN 2071-0194. Ukr. J. Phys. 2010. Vol. 55, No. 3 289 L.A. BULAVIN, V.I. GORDELIY, O.I. IVANKOV et al. the range of small q, which evidences the growth of the size of micellar formations. 5. Experimental Results The neutron scattering intensity in the liquid system un- der study can be written down as follows: I = n〈F 2(q)〉S(q), (1) where n is the particle concentration, and F (q) is a form- factor that describes the intensity of neutron scattering by a single micelle: F 2(q) = [∫ (ρ− ρs) exp(iqr)d3r ]2 . (2) Here, ρ and ρs are the densities of scattering length for a micelle and the solution, respectively. In formula (1), S(q) describes the interaction between micelles and cor- responds to a certain distribution of micelle centers of masses in space. For the structure factor S(q), we have [8] S(q) = 1 + V −1 [∫ (g(r)− 1) exp(iqr)d3r ] , (3) where g(r) is the pair correlation function, and V is the volume per one micelle. In our case, this volume is ap- proximately equal to 550 Å3 [9]. In the absence of interaction between micelles, S(q) = 1, so that experimental data can be approximated taking only the formfactor into account. Provided that micelles formed in the liquid system can be approximated as ellipsoids of rotation with semiaxes a, a, and νa, the expression for the formfactor reads [10] P (q) = 1∫ 0 Φ2[qa √ 1 + x2(v2 − 1)]dx, (4) where Φ(t) = 3(sin(t)− t cos(t))/t3. If a micelle is a cylinder of radius R and height H, the formfactor looks like P (q) = 4 1∫ 0 J2 1 (qR √ 1− x2) (qR √ 1− x2)2 Z2( qHx 2 )dx, (5) where Z(t) = sin(t)/t. The interaction between micelles makes it necessary to consider the structure factor. To find it, it is nec- essary to solve the Ornstein–Zernike equation. In work [13], the authors proposed a method for determining the structure factor, the rescaled mean-spherical approxima- tion (RMSA). Let us write down the Ornstein–Zernike equation: h(r) = c(r) + nd3 ∫ h(|r− r′|)c(r)d3r, (6) where, according to the RMSA, the boundary conditions are given by the system of equations{ c(r) = −βVc(r), r > d, g(r) = 0, r < d, (7) In this formula, Vc(r) is the Coulomb repulsion potential between two charged spherical particles which is given by the expression Vc(r) = πεε0d 2ψ2 0 exp[−κ(r − d)]/r, r > d, (8) where d is the micelle diameter, r the distance between ions, ε0 the dielectric permittivity of vacuum, ε the di- electric constant of the medium, κ the inverse Debye screening length, and ψ0 = z εε0〈d〉(2 + κ〈d〉) (9) is the surface potential of a micelle with charge z. To approximate the SANS data obtained by us for ternary micellar systems TTABr–heavy water–NaBr, we used two computer programs: the Fitter program [11] which does not make allowance for the interaction be- tween micelles (Fig. 3), and the FISH program [12] (Fig. 4) which takes such an interaction into account using the RMSA. Those programs were applied to ob- tain information on micelle parameters in the following way: we used the FISH program for concentrations lower that 1.9 × 10−3 m.f. and the Fitter program for higher ones. Figures 3 and 4 demonstrate that the model curve describes the experimental data well. The micelle pa- rameters obtained by treating the experimental data are quoted in Table, where a = b and c are the semiaxes of the ellipsoid of rotation, and Nagg is the number of surfactant monomers in a micelle, i.e. the aggregation number. The analysis of the tabulated data shows that the mi- celle dimensions and the aggregation number decrease, as the temperature of the liquid system heavy water– TTABr grows. At the same time, the addition of salt brings about the growth of micelle dimensions and an increase of the aggregation number. 290 ISSN 2071-0194. Ukr. J. Phys. 2010. Vol. 55, No. 3 NEUTRON STUDIES OF THE NaBr IMPURITY INFLUENCE Fig. 3. Approximation of SANS data for the ternary liquid system TTABr–heavy water–NaBr using the FISH computer code (taking the interaction between micelles into account). The TTABr con- centration is 9.4 × 10−4 m.f., the NaBr concentration is 0 m.f.: experiment (circles), resulting theoretical curve (solid curve), the- oretical formfactor (dotted curve), theoretical structure factor (dashed curve) Micelle parameters for the ternary liquid system TTABr– heavy water–NaBr. The TTABr concentration is 9.4 × 10−4 m.f XNaBr, 25 ◦C 10−4 m.f. a = b,Å c,Å Nagg χ2 0 19.9 30.22 95 2.115 4.6 20.45 34.24 113 2.33 9.3 20.58 36.4 120 2.52 19 21.16 37.82 133 2.38 37 18.92 79.50 324 2.95 76 19.21 152.8 642 3.45 40◦C 0 19.34 27.67 83 2.09 4.6 19.88 30.69 96 2.07 9.3 20.00 31.84 101 2.07 19 20.2 32.14 103 4.95 37 20.4 41.74 137 3.35 76 18.62 90.55 370 2.04 60◦C 0 18.57 25.42 70 2.132 4.6 19.05 27.99 81 2.11 9.3 19.26 28.57 85 2.37 19 19.54 31.15 92 1.77 37 19.5 32.18 95 2.05 76 19.52 45.48 134 5.05 Fig. 4. Approximation of SANS data for the ternary liquid system TTABr–heavy water–NaBr taking no interaction between micelles into account. The TTABr concentration is 9.4 × 10−4 m.f., the NaBr concentration is 0.016 m.f.: experiment (circles), resulting theoretical curve (solid curve) 6. Conclusions The method of small-angle neutron scattering was applied to study the influence of salt on the mi- celle formation in the liquid system heavy water– tetradecyltrimethylammonium bromide–NaBr in the temperature interval 25–60 ◦C. The addition of salt to the liquid system heavy water–TTABr has been shown to result in the growth of micelle dimensions and the aggregation number. 1. I.I. Adamenko and L.A. Bulavin, Physics of Liquids and Liquid Systems (ASMI, Kyiv, 2006) (in Ukrainian). 2. T. Imae and S. Ikeda, J. Phys. Chem. 90, 5216 (1986). 3. G. Eckold and N. Gorski, Colloids Surf. A 183, 361 (2001). 4. Yu.M. Ostanevich, Makromol. Chem. Macromol. Symp. 15, 91 (1988). 5. A.I. Kuklin et al., Poverkhnost 6, 74 (2006). 6. A.I. Kuklin et al., Neutron News 16, 16 (2005). 7. L.A. Bulavin, T.V. Karmazina, V.V. Klepko et al., Neu- tron Spectroscopy of Condensed Matters (Akademperi- odyka, Kyiv, 2005) (in Ukrainian). 8. J. Teixeira, in Structure and Dynamics of Strongly Inter- acting Colloids and Supramolecular Aggregates in Solu- ISSN 2071-0194. Ukr. J. Phys. 2010. Vol. 55, No. 3 291 L.A. BULAVIN, V.I. GORDELIY, O.I. IVANKOV et al. tion, edited by S.H. Chen, J.S. Huang, and P. Tartaglia (Kluwer, Dordrecht, 1992), p. 635. 9. R. Zana, C. Picot, and R. Duplessix, J. Colloid Interface Sci. 93, 43 (1983). 10. D.I. Svergun and L.A. Feigin, X-ray and Neutron Small- Angle Scattering (Nauka, Moscow, 1986) (in Russian). 11. A.G. Soloviev et al., http://wwwinfo.jinr.ru/ pro- grams/jinrlib/fitter/index.html. 12. R. Heenan, http://www.isis.rl.ac.uk/largescale/loq/ canSAS/FISH_manual.pdf. 13. J. Hansen and J. Hayter, Mol. Phys. 46, 651 (1982). Received 18.11.09. Translated from Ukrainian by O.I. Voitenko НЕЙТРОННI ДОСЛIДЖЕННЯ ВПЛИВУ ДОМIШОК NaBr НА МIЦЕЛОУТВОРЕННЯ В СИСТЕМI ВАЖКА ВОДА–ТЕТРАДЕЦИЛТРИМЕТИЛАМОНIЙ БРОМIД Л.А. Булавiн, В.I. Горделiй, О.I. Iваньков, А.Х. Iсламов, А.I. Куклiн Р е з ю м е Методом малокутового розсiяння нейтронiв дослiджено фор- мування мiцел в потрiйних рiдинних системах тетрадецилтри- метиламонiй бромiд–важка вода–NaBr. Данi про малокутову дифракцiю нейтронiв на заряджених мiцелах було обробле- но у наближеннi моделi перемасштабованої середньосферичної апроксимацiї Хайтера–Пенфольда. Визначено залежнiсть роз- мiрiв мiцел та числа агрегацiї вiд температури рiдинної систе- ми та концентрацiї NaBr. 292 ISSN 2071-0194. Ukr. J. Phys. 2010. Vol. 55, No. 3