1
|
Singh P, Sharma VK, Singha S, García Sakai V, Mukhopadhyay R, Das R, Pal SK. Unraveling the Role of Monoolein in Fluidity and Dynamical Response of a Mixed Cationic Lipid Bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:4682-4692. [PMID: 30807692 DOI: 10.1021/acs.langmuir.9b00043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The maintenance of cell membrane fluidity is of critical importance for various cellular functions. At lower temperatures when membrane fluidity decreases, plants and cyanobacteria react by introducing unsaturation in the lipids, so that the membranes return to a more fluidic state. To probe how introduction of unsaturation leads to reduced membrane fluidity, a model cationic lipid dioctadecyldimethylammonium bromide (DODAB) has been chosen, and the effects of an unsaturated lipid monoolein (MO) on the structural dynamics and phase behavior of DODAB have been monitored by quasielastic neutron scattering and time-resolved fluorescence measurements. In the coagel phase, fluidity of the lipid bilayer increases significantly in the presence of MO relative to pure DODAB vesicles and becomes manifest in significantly enhanced dynamics of the constituent lipids along with faster hydration and orientational relaxation dynamics of a fluorophore. On the contrary, MO restricts both lateral and internal motions of the lipid molecules in the fluid phase (>330 K), which is consistent with relatively slow hydration and orientational relaxation dynamics of the fluorophore embedded in the mixed lipid bilayer. The present study illustrates how incorporation of an unsaturated lipid at lower temperatures (below the phase transition) assists the model lipid (DODAB) in regulating fluidity via enhancement of dynamics of the constituent lipids.
Collapse
Affiliation(s)
- Priya Singh
- Department of Chemical, Biological & Macromolecular Sciences , S. N. Bose National Centre for Basic Sciences , Block JD, Sector III , Salt Lake, Kolkata 700106 , India
| | | | - Subhankar Singha
- Department of Chemistry , Pohang University of Science and Technology (POSTECH) , 77 Cheongam-Ro , Nam-Gu, Pohang , Gyungbuk 37673 , Republic of Korea
| | - Victoria García Sakai
- ISIS Pulsed Neutron and Muon Facility, Rutherford Appleton Laboratory , Science and Technology Facilities Council , Didcot OX11 0DE , U.K
| | | | - Ranjan Das
- Department of Chemistry , West Bengal State University , Barasat, Kolkata 700126 , India
| | - Samir Kumar Pal
- Department of Chemical, Biological & Macromolecular Sciences , S. N. Bose National Centre for Basic Sciences , Block JD, Sector III , Salt Lake, Kolkata 700106 , India
| |
Collapse
|
2
|
Lone MS, Chat OA, Vashishtha M, Dar AA. Transition from Competitive to Non-Competitive Solubilization with the Decrease in Number of Oxyethylene (OE) Units of Non-Ionic Surfactants towards Polycyclic Aromatic Hydrocarbons. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2019. [DOI: 10.1246/bcsj.20180215] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Mohd Sajid Lone
- Physical Chemistry Division, Department of Chemistry, University of Kashmir, Srinagar-190006, J&K, India
| | - Oyais Ahmad Chat
- Physical Chemistry Division, Department of Chemistry, University of Kashmir, Srinagar-190006, J&K, India
- Department of Chemistry, Government Degree College, Pulwama-192301, J & K, India
| | - Manu Vashishtha
- Department of Chemical Engineering, Indian Institute of Technology, Bombay, Powai 400076, India
| | - Aijaz Ahmad Dar
- Physical Chemistry Division, Department of Chemistry, University of Kashmir, Srinagar-190006, J&K, India
| |
Collapse
|
3
|
Dutta R, Ghosh M, Pyne A, Sarkar N. Insight into the Dynamics of Different Fluorophores in the Interior of Aerosol OT Lamellar Structures in the Presence of Sugars: From Picosecond-to-Femtosecond Study. J Phys Chem B 2018; 123:117-129. [DOI: 10.1021/acs.jpcb.8b10609] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rupam Dutta
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India
| | - Meghna Ghosh
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India
| | - Arghajit Pyne
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India
| | - Nilmoni Sarkar
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India
| |
Collapse
|
4
|
Singh P, Choudhury S, Sharma VK, Mitra S, Mukhopadhyay R, Das R, Pal SK. Modulation of Solvation and Molecular Recognition of a Lipid Bilayer under Dynamical Phase Transition. Chemphyschem 2018; 19:2709-2716. [PMID: 30030893 DOI: 10.1002/cphc.201800522] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Indexed: 11/09/2022]
Abstract
It is well accepted in contemporary biology that an ∼30 Å thick lipid bilayer film around living cells is a matter of life and death as the film typically delimits the environments that serve as a crucial margin. The dynamic organization of lipid molecules both across the lipid bilayer and in the lateral dimension are known to be crucial for cellular transport and molecular recognition by important biological macromolecules. Here, we study dilute (20 mM) Dioctadecyldimethylammonium bromide (DODAB) vesicles at different temperatures in aqueous dispersion with well-defined phases namely liquid crystalline, gel and subgel. The spectroscopic studies on two fluorescent probes 8-anilino-1-naphthalene sulfonic acid ammonium salt (ANS) and Coumarin 500 (C500), former in the head group region of the lipid-water interface and later located deeper in the lipid bilayer follow dynamics (solvation and fluidity) of their local environments in the vesicles. Binding of an anti-tuberculosis drug rifampicin has also been studied employing Förster resonance energy transfer (FRET) technique. The molecular insight concerning the effect of dynamical organization of the lipid molecules on the local dynamics of aqueous environments in different phases leading to molecular recognition becomes evident in our study.
Collapse
Affiliation(s)
- Priya Singh
- Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, SaltLake, Kolkata, 700 106, India
| | - Susobhan Choudhury
- Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, SaltLake, Kolkata, 700 106, India
| | - V K Sharma
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - S Mitra
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - R Mukhopadhyay
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Ranjan Das
- Department of Chemistry, West Bengal State University, Barasat, Kolkata, 700126
| | - Samir Kumar Pal
- Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, SaltLake, Kolkata, 700 106, India
| |
Collapse
|
5
|
Dutta R, Pyne A, Sarkar N. Effect of sugars on the dynamics of hydrophilic fluorophores confined inside the water pool of anionic reverse micelle: A spectroscopic approach. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2017.12.137] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
6
|
Roy N, Nath S, Paul PC, Singh TS. Fluorescence Behavior of Schiff Base-N, N'-bis(salicylidene) Trans 1, 2-Diaminocyclohexane in Proteinous and Micellar Environments. J Fluoresc 2017; 27:2295-2311. [PMID: 28831629 DOI: 10.1007/s10895-017-2171-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/10/2017] [Indexed: 11/28/2022]
Abstract
Fluorescence properties of N, N'-bis(salicylidene) trans 1, 2-diaminocyclohexane (H 2 L) is used to probe the anionic (SDS), cationic (CTAB) and nonionic (TX-100) micelles as well as in serum albumins (BSA and HSA) and chicken egg white lysozyme (LYZ) by steady state and picosecond time-resolved fluorescence spectroscopy. The fluorescence band intensity was found to increase with concomitant blue-shift with gradual addition of different surfactants. All the experimental results suggest that the probe molecule resides in the micelle-water interface rather than going into the micellar core. However, the penetration is more towards the micellar hydrocarbon core in nonionic surfactant (TX-100) while comparing with ionic surfactants (SDS and CTAB). Several mean microscopic properties such as critical micelle concentration, polarity parameters and binding constant were calculated in presence of different surfactants. The decrease in nonradiative decay rate constants in micellar environments indicates restricted motion of the probe inside the micellar nanocages with increasing fluorescence emission intensity and quantum yields. Further in this work, we also investigated the interaction behavior of the probe with different proteins at low concentrations under physiological conditions (pH = 7.4). Stern-Volmer analysis of the tryptophan (Trp) fluorescence quenching data in presence of probe reveals Stern-Volmer constant (Ksv) as well as bimolecular quenching rate constant (Kq). The binding constant as well as the number of binding sites of the probe with proteins were also monitored and found to be 1:1 stoichiometry ratio.
Collapse
Affiliation(s)
- Nayan Roy
- Department of Chemistry, Assam University, Silchar, Assam, 788 011, India
| | - Surjatapa Nath
- Department of Chemistry, Assam University, Silchar, Assam, 788 011, India
| | - Pradip C Paul
- Department of Chemistry, Assam University, Silchar, Assam, 788 011, India
| | - T Sanjoy Singh
- Department of Chemistry, Assam University, Silchar, Assam, 788 011, India.
| |
Collapse
|
7
|
Rakshit S, Sarkar A, Bhattacharya SC. A differential approach towards understanding the enhanced emission induced superior bio-imaging and cytotoxicity within block copolymeric nanomicelles. Colloids Surf B Biointerfaces 2017; 155:390-398. [DOI: 10.1016/j.colsurfb.2017.04.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 04/16/2017] [Accepted: 04/17/2017] [Indexed: 10/19/2022]
|
8
|
Roy A, Kundu S, Dutta R, Sarkar N. Influence of bile salt on vitamin E derived vesicles involving a surface active ionic liquid and conventional cationic micelle. J Colloid Interface Sci 2017; 501:202-214. [PMID: 28456104 DOI: 10.1016/j.jcis.2017.04.051] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/17/2017] [Accepted: 04/18/2017] [Indexed: 11/30/2022]
Abstract
This study has been actually performed with the aim to develop vitamin E derived vesicles individually from a surface active ionic liquid (1-Hexadecyl-3-Methylimidazolium chloride ([C16mim]Cl)) and a common cationic amphiphile (benzyldimethylhexadecylammonium chloride (BHDC)) and also to investigate their consequent breakdown in presence of bile salt molecule. From this study, it is revealed that the rotational motion of coumarin 153 (C153) molecule is hindered as the vitamin E content is increased in the individual micellar solution of [C16mim]Cl and BHDC. The extent of enhancement in rotational relaxation time is more pronounced in case of [C16mim]Cl-vitamin E solutions than in the BHDC-vitamin E vesicular aggregates which confirms the greater rigidity of the former vesicular system than the later one. Moreover, the effect of bile salt in the vitamin E forming vesicular assemblies have also been unravelled. It is found that the large area occupancy by the steroidal backbone of the bile salt plays a crucial role towards the enlargement of the average surfactant head group area. This results in disintegration of the vesicles composed of vitamin E and consequently, vesicles are transformed into mixed micellar aggregates. From the anisotropy measurement it is found that the rotational motion of C153 is more hindered in the [C16mim]Cl/BHDC-NaCh mixed micelles compared to that inside the individual vesicles. The fluorescence correlation spectroscopic (FCS) study also confirms that the mixed micelles have a more compact structure than that of the [C16mim]Cl-vitamin E and BHDC-vitamin E vesicles. Altogether, the micelle to vesicle transition involving any vitamin and their disruption by bile salt would be an interesting investigation both from the view point of basic colloidal chemistry and towards the generation of new drug delivery vehicle due to their unique microenvironment. Therefore, in future, these systems can be utilised as vehicle for the transport and as well as delivery of drugs and as probable reactor in nanomaterial synthesis.
Collapse
Affiliation(s)
- Arpita Roy
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India
| | - Sangita Kundu
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India
| | - Rupam Dutta
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India
| | - Nilmoni Sarkar
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India.
| |
Collapse
|
9
|
Roy A, Banerjee P, Dutta R, Kundu S, Sarkar N. Probing the Interaction between a DNA Nucleotide (Adenosine-5'-Monophosphate Disodium) and Surface Active Ionic Liquids by Rotational Relaxation Measurement and Fluorescence Correlation Spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10946-10956. [PMID: 27690468 DOI: 10.1021/acs.langmuir.6b02794] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This article demonstrates the interaction of a deoxyribonucleic acid (DNA) nucleotide, adenosine-5'-monophosphate disodium (AMP) with a cationic surface active ionic liquid (SAIL) 1-dodecyl-3-methylimidazoium chloride (C12mimCl), and an anionic SAIL, 1-butyl-3-methylimidazolium n-octylsulfate ([C4mim][C8SO4]). Dynamic light scattering (DLS) measurements and 1H NMR (nuclear magnetic resonance) studies indicate that substantial interaction is taking place among the DNA nucleotide (AMP) and the SAILs. Moreover, cryogenic transmission electron microscopy (cryo-TEM) suggests that SAILs containing micellar assemblies are transformed into larger micellar assemblies in the presence of DNA nucleotides. Additionally, the rotational motion of two oppositely charged molecules, rhodamine 6G perchlorate (R6G) and fluorescein sodium salt (Fl-Na), have been monitored in these aggregates. The rotational motion of R6G and Fl-Na differs significantly between SAILs micelles and SAILs-AMP containing larger micellar aggregates. The effect of negatively charged DNA nucleotide (AMP) addition into the cationic and anionic SAILs is more prominent for the cationic charged molecule R6G than that of anionic probe Fl-Na due to the favorable electrostatic interaction between the AMP and cationic R6G. Moreover, the influence of the anionic DNA nucleotide on the cationic and anionic SAIL micelles is monitored through the variation of the lateral diffusion motion of oppositely charged probe molecules (R6G and Fl-Na) inside these aggregates. This variation in diffusion coefficient values also suggests that the interaction pattern of these oppositely charged probes are different within the SAILs-nucleotide containing aggregates. Therefore, both rotational and translational diffusion measurements confirm that the DNA nucleotide (AMP) renders more rigid microenvironment within the micellar solution of SAILs.
Collapse
Affiliation(s)
- Arpita Roy
- Department of Chemistry, Indian Institute of Technology , Kharagpur 721302, WB India
| | - Pavel Banerjee
- Department of Chemistry, Indian Institute of Technology , Kharagpur 721302, WB India
| | - Rupam Dutta
- Department of Chemistry, Indian Institute of Technology , Kharagpur 721302, WB India
| | - Sangita Kundu
- Department of Chemistry, Indian Institute of Technology , Kharagpur 721302, WB India
| | - Nilmoni Sarkar
- Department of Chemistry, Indian Institute of Technology , Kharagpur 721302, WB India
| |
Collapse
|
10
|
Ruiz CC, Hierrezuelo JM, Molina-Bolivar JA. Analysis of the Photophysical Behavior and Rotational-Relaxation Dynamics of Coumarin 6 in Nonionic Micellar Environments: The Effect of Temperature. Molecules 2015; 20:19343-60. [PMID: 26512635 PMCID: PMC6332106 DOI: 10.3390/molecules201019343] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 10/08/2015] [Accepted: 10/16/2015] [Indexed: 12/25/2022] Open
Abstract
The photodynamics of Coumarin 6 have been investigated in three nonionic micellar assemblies, i.e., n-dodecyl-β-D-maltoside (β-C12G₂), p-tert-octyl-phenoxy polyethylene (9.5) ether (Triton X-100 or TX100) and n-dodecyl-hexaethylene-glycol (C12E₆), to assess their potential use as encapsulation vehicles for hydrophobic drugs. To evaluate the effect of the micellar size and hydration, the study used a broad temperature range (293.15-323.15 K). The data presented here include steady-state absorption and emission spectra of the probe, dynamic light scattering, together with fluorescence lifetimes and both steady-state, as well as time-resolved fluorescence anisotropies. The time-resolved fluorescence anisotropy data were analyzed on the basis of the well-established two-step model. Our data reveal that the molecular probe in all of the cases is solubilized in the hydration layer of micelles, where it would sense a relatively polar environment. However, the probe was found to undergo a slower rotational reorientation when solubilized in the alkylpolyglycoside surfactant, as a result of a more compact microenvironment around the probe. The behavior of the parameters of the reorientation dynamics with temperature was analyzed on the basis of both micellar hydration and the head-group flexibility of the surfactants.
Collapse
Affiliation(s)
- Cristóbal Carnero Ruiz
- Department of Applied Physics II, Engineering School, University of Malaga, Malaga 29071, Spain.
| | - José Manuel Hierrezuelo
- Department of Applied Physics II, Engineering School, University of Malaga, Malaga 29071, Spain.
| | | |
Collapse
|
11
|
Ghosh S, Kuchlyan J, Roychowdhury S, Banik D, Kundu N, Roy A, Sarkar N. Unique Influence of Cholesterol on Modifying the Aggregation Behavior of Surfactant Assemblies: Investigation of Photophysical and Dynamical Properties of 2,2′-Bipyridine-3,3′-diol, BP(OH)2 in Surfactant Micelles, and Surfactant/Cholesterol Forming Vesicles. J Phys Chem B 2014; 118:9329-40. [PMID: 25036947 DOI: 10.1021/jp503938b] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Surajit Ghosh
- Department
of Chemistry, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Jagannath Kuchlyan
- Department
of Chemistry, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Subhajit Roychowdhury
- Department
of Chemistry, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Debasis Banik
- Department
of Chemistry, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Niloy Kundu
- Department
of Chemistry, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Arpita Roy
- Department
of Chemistry, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Nilmoni Sarkar
- Department
of Chemistry, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| |
Collapse
|
12
|
Bairu S, Ramakrishna G. Two-Photon Absorption Properties of Chromophores in Micelles: Electrostatic Interactions. J Phys Chem B 2013; 117:10484-91. [DOI: 10.1021/jp405416d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Semere Bairu
- Department of Chemistry, Western Michigan University, Kalamazoo, Michigan 49008, United States
| | - Guda Ramakrishna
- Department of Chemistry, Western Michigan University, Kalamazoo, Michigan 49008, United States
| |
Collapse
|
13
|
Pan A, Mati SS, Naskar B, Bhattacharya SC, Moulik SP. Self-Aggregation of MEGA-9 (N-Nonanoyl-N-methyl-d-glucamine) in Aqueous Medium: Physicochemistry of Interfacial and Solution Behaviors with Special Reference to Formation Energetics and Micelle Microenvironment. J Phys Chem B 2013; 117:7578-92. [DOI: 10.1021/jp400139d] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Animesh Pan
- Centre for Surface
Science, Department of Chemistry, Jadavpur University, Kolkata 700032, India
| | - Soumya Sundar Mati
- Centre for Surface
Science, Department of Chemistry, Jadavpur University, Kolkata 700032, India
| | - Bappaditya Naskar
- Centre for Surface
Science, Department of Chemistry, Jadavpur University, Kolkata 700032, India
| | | | - Satya Priya Moulik
- Centre for Surface
Science, Department of Chemistry, Jadavpur University, Kolkata 700032, India
| |
Collapse
|
14
|
Ruiz CC, Molina-Bolívar JA, Hierrezuelo JM, Liger E. Self-assembly, surface activity and structure of n-octyl-β-D-thioglucopyranoside in ethylene glycol-water mixtures. Int J Mol Sci 2013; 14:3228-53. [PMID: 23385232 PMCID: PMC3588041 DOI: 10.3390/ijms14023228] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 01/25/2013] [Accepted: 01/28/2013] [Indexed: 11/21/2022] Open
Abstract
The effect of the addition of ethylene glycol (EG) on the interfacial adsorption and micellar properties of the alkylglucoside surfactant n-octyl-β-d-thioglucopyranoside (OTG) has been investigated. Critical micelle concentrations (cmc) upon EG addition were obtained by both surface tension measurements and the pyrene 1:3 ratio method. A systematic increase in the cmc induced by the presence of the co-solvent was observed. This behavior was attributed to a reduction in the cohesive energy of the mixed solvent with respect to pure water, which favors an increase in the solubility of the surfactant with EG content. Static light scattering measurements revealed a decrease in the mean aggregation number of the OTG micelles with EG addition. Moreover, dynamic light scattering data showed that the effect of the surfactant concentration on micellar size is also controlled by the content of the co-solvent in the system. Finally, the effect of EG addition on the microstructure of OTG micelles was investigated using the hydrophobic probe Coumarin 153 (C153). Time-resolved fluorescence anisotropy decay curves of the probe solubilized in micelles were analyzed using the two-step model. The results indicate a slight reduction of the average reorientation time of the probe molecule with increasing EG in the mixed solvent system, thereby suggesting a lesser compactness induced by the presence of the co-solvent.
Collapse
Affiliation(s)
- Cristóbal Carnero Ruiz
- Department of Applied Physics II, Engineering School, University of Málaga, Málaga 29071, Spain.
| | | | | | | |
Collapse
|
15
|
Hierrezuelo JM, Ruiz CC. Rotational diffusion of coumarin 153 in nanoscopic micellar environments of n-dodecyl-β-D-maltoside and n-dodecyl-hexaethylene-glycol mixtures. J Phys Chem A 2012; 116:12476-85. [PMID: 23214482 DOI: 10.1021/jp308379j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The microstructure of mixed micelles containing n-dodecyl-β-D-maltoside and n-dodecyl-hexaethylene-glycol, two nonionic surfactants belonging to the alkyl polyglucoside and polyoxyethyelene alkyl ether families, respectively, has been investigated. With the aim of understanding how the micellar composition affects the microenvironmental properties of micelles, we have examined the photophysics and dynamics of the neutral probe coumarin 153 in the binary mixtures of the surfactants across the entire composition range. We present data on the steady-state absorption and emission spectra of the probe, as well as fluorescence lifetimes and both steady-state and time-resolved fluorescence anisotropies. These data indicate that the participation of the ethoxylated surfactant in the mixed micelle induces an increasing hydration in the palisade layer of the micelle, which forces the probe to migrate toward the inner micellar region, where it senses a slightly less polar environment. The time-resolved fluorescence anisotropy data were analyzed on the basis of the two-step and wobbling-in-cone model. The average reorientation time of the probe molecule was found to decrease with the presence of the ethoxylated surfactant, in good agreement with steady-state fluorescence anisotropy data, suggesting a reduction of the microviscosity in the solubilization site of the probe. The behavior of all diffusion reorientation parameters was analyzed on the basis of two factors: the micellar hydration and the headgroup flexibility of both surfactants. It was concluded that the increasing participation of the ethoxylated surfactant induces a greater hydration in the micellar palisade layer, producing the formation of a less compact microenvironment where the probe experiences a faster rotational reorientation.
Collapse
Affiliation(s)
- J M Hierrezuelo
- Departamento de Física Aplicada II, Escuela de Ingenierías, Universidad de Málaga, Málaga, Spain
| | | |
Collapse
|
16
|
Naous M, Aguiar J, Ruiz CC. Synergism in mixtures of n-octyl-β-d-thioglucoside and different n-alkyltrimethylammonium bromides: effect of the alkyl chain length. Colloid Polym Sci 2012. [DOI: 10.1007/s00396-012-2617-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
17
|
Carnero Ruiz C. Rotational dynamics of coumarin 153 in non-ionic mixed micelles of n-octyl-β-d-thioglucoside and Triton X-100. Photochem Photobiol Sci 2012; 11:1331-8. [DOI: 10.1039/c2pp25049g] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
18
|
Structural and dynamical characterization of unilamellar AOT vesicles in aqueous solutions and their efficacy as potential drug delivery vehicle. Colloids Surf B Biointerfaces 2011; 88:345-53. [DOI: 10.1016/j.colsurfb.2011.07.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 06/17/2011] [Accepted: 07/05/2011] [Indexed: 11/24/2022]
|
19
|
Paul BK, Guchhait N. Spectroscopic probing of location and dynamics of an environment-sensitive intramolecular charge transfer probe within liposome membranes. J Colloid Interface Sci 2011; 363:529-39. [DOI: 10.1016/j.jcis.2011.07.074] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 07/20/2011] [Accepted: 07/21/2011] [Indexed: 01/08/2023]
|
20
|
Characterization of mixed non-ionic surfactants n-octyl-β-d-thioglucoside and octaethylene–glycol monododecyl ether: Micellization and microstructure. J Colloid Interface Sci 2011; 361:178-85. [DOI: 10.1016/j.jcis.2011.05.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 05/06/2011] [Accepted: 05/06/2011] [Indexed: 11/22/2022]
|
21
|
Zhu R, Lu R, Yu A. Photophysics and locations of IR125 and C152 in AOT reverse micelles. Phys Chem Chem Phys 2011; 13:20844-54. [DOI: 10.1039/c1cp21946d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
22
|
Khan MN. A new semi-empirical kinetic method for the determination of ion exchange constants for the counterions of cationic micelles. Adv Colloid Interface Sci 2010; 159:160-79. [PMID: 20673861 DOI: 10.1016/j.cis.2010.06.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 06/17/2010] [Accepted: 06/19/2010] [Indexed: 11/25/2022]
Abstract
A new method, based upon semi-empirical kinetic approach, for the determination of ion exchange constant for ion exchange processes occurring between counterions at the cationic micellar surface is described in this review article. Basically, the method involves a reaction kinetic probe which gives observed pseudo-first-order rate constants (k(obs)) for a nucleophilic substitution reaction between the nonionic and anionic reactants (R and S) in the presence of a constant concentration of both reactants as well as cationic micelles and varying concentrations of an inert inorganic or organic salt (MX). The observed data (k(obs), versus [MX]) fit satisfactorily (in terms of residual errors) to an empirical equation which could be derived from an equation explaining the mechanism of the reaction of the kinetic probe in terms of pseudophase micellar (PM) model coupled with another empirical equation. This (another) empirical equation explains the effect of [MX] on cationic micellar binding constant (K(S)) of the anionic reactant (say S) and gives an empirical constant, K(X/S). The magnitude of K(X/S) is the measure of the ability of X(-) to expel S(-) from a cationic micellar pseudophase to the bulk aqueous phase through ion exchange X(-)/S(-). The values of K(X/S) and K(Y/S) (where Y(-) is another inert counterion) give the ion exchange constant, K(X)(Y) (=K(X)/K(Y) where K(X) and K(Y) represent cationic micellar binding constants of X(-) and Y(-), respectively). The suitability of this method is demonstrated by the use of three different reaction kinetic probes and various MX.
Collapse
|
23
|
Paul BK, Guchhait N. Modulated Photophysics of an ESIPT Probe 1-Hydroxy-2-naphthaldehyde within Motionally Restricted Environments of Liposome Membranes Having Varying Surface Charges. J Phys Chem B 2010; 114:12528-40. [DOI: 10.1021/jp1048138] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Bijan Kumar Paul
- Department of Chemistry, University of Calcutta, 92 A. P. C. Road, Calcutta-700009, India
| | - Nikhil Guchhait
- Department of Chemistry, University of Calcutta, 92 A. P. C. Road, Calcutta-700009, India
| |
Collapse
|
24
|
Molina-Bolívar J, Ruiz CC. Light scattering and fluorescence studies of non-ionic surfactant binary mixtures formed by MEGA-10 and C12E8. J Mol Liq 2010. [DOI: 10.1016/j.molliq.2010.05.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
25
|
Mahata A, Sarkar D, Bose D, Ghosh D, Girigoswami A, Das P, Chattopadhyay N. Photophysics and Rotational Dynamics of a β-Carboline Analogue in Nonionic Micelles: Effect of Variation of Length of the Headgroup and the Tail of the Surfactant. J Phys Chem B 2009; 113:7517-26. [DOI: 10.1021/jp900575e] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Atanu Mahata
- Department of Chemistry, Jadavpur University, Kolkata 700032, India
| | - Deboleena Sarkar
- Department of Chemistry, Jadavpur University, Kolkata 700032, India
| | - Debosreeta Bose
- Department of Chemistry, Jadavpur University, Kolkata 700032, India
| | - Debanjana Ghosh
- Department of Chemistry, Jadavpur University, Kolkata 700032, India
| | | | - Paramita Das
- Department of Chemistry, Jadavpur University, Kolkata 700032, India
| | | |
Collapse
|
26
|
The use of coumarins as environmentally-sensitive fluorescent probes of heterogeneous inclusion systems. Molecules 2009; 14:210-37. [PMID: 19127249 PMCID: PMC6253935 DOI: 10.3390/molecules14010210] [Citation(s) in RCA: 310] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Revised: 12/23/2008] [Accepted: 01/04/2009] [Indexed: 11/16/2022] Open
Abstract
Coumarins, as a family of molecules, exhibit a wide range of fluorescence emission properties. In many cases, this fluorescence is extremely sensitive to the local environment of the molecule, especially the local polarity and microviscosity. In addition, coumarins show a wide range of size, shape, and hydrophobicity. These properties make them especially useful as fluorescent probes of heterogeneous environments, such as supramolecular host cavities, micelles, polymers and solids. This article will review the use of coumarins to probe such heterogeneous systems using fluorescence spectroscopy.
Collapse
|
27
|
Banerjee P, Pramanik S, Sarkar A, Bhattacharya SC. Modulated Photophysics of 3-Pyrazolyl-2-pyrazoline Derivative Entrapped in Micellar Assembly. J Phys Chem B 2008; 112:7211-9. [DOI: 10.1021/jp800200v] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Paltu Banerjee
- Department of Chemistry, Jadavpur University, Kolkata 700032, India
| | | | - Arindam Sarkar
- Department of Chemistry, Jadavpur University, Kolkata 700032, India
| | | |
Collapse
|
28
|
Khatua D, Ghosh S, Dey J, Ghosh G, Aswal VK. Physicochemical Properties and Microstructure Formation of the Surfactant Mixtures of Sodium N-(2-(n-Dodecylamino)ethanoyl)-l-alaninate and SDS in Aqueous Solutions. J Phys Chem B 2008; 112:5374-80. [DOI: 10.1021/jp7096636] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dibyendu Khatua
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India, and UGC-DAE Consortium for Scientific Research and Solid State Physics Division, BARC, Trombay, Mumbai 400 085, India
| | - Sampad Ghosh
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India, and UGC-DAE Consortium for Scientific Research and Solid State Physics Division, BARC, Trombay, Mumbai 400 085, India
| | - Joykrishna Dey
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India, and UGC-DAE Consortium for Scientific Research and Solid State Physics Division, BARC, Trombay, Mumbai 400 085, India
| | - Goutam Ghosh
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India, and UGC-DAE Consortium for Scientific Research and Solid State Physics Division, BARC, Trombay, Mumbai 400 085, India
| | - V. K. Aswal
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India, and UGC-DAE Consortium for Scientific Research and Solid State Physics Division, BARC, Trombay, Mumbai 400 085, India
| |
Collapse
|
29
|
Chakrabarty A, Das P, Mallick A, Chattopadhyay N. Effect of Surfactant Chain Length on the Binding Interaction of a Biological Photosensitizer with Cationic Micelles. J Phys Chem B 2008; 112:3684-92. [DOI: 10.1021/jp709818d] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alok Chakrabarty
- Department of Chemistry, Jadavpur University, Calcutta 700 032, India, and Division of Frontier Material Science, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
| | - Paramita Das
- Department of Chemistry, Jadavpur University, Calcutta 700 032, India, and Division of Frontier Material Science, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
| | - Arabinda Mallick
- Department of Chemistry, Jadavpur University, Calcutta 700 032, India, and Division of Frontier Material Science, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
| | - Nitin Chattopadhyay
- Department of Chemistry, Jadavpur University, Calcutta 700 032, India, and Division of Frontier Material Science, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
| |
Collapse
|
30
|
Singh TS, Mitra S. Fluorescence behavior of intramolecular charge transfer probe in anionic, cationic, and nonionic micelles. J Colloid Interface Sci 2007; 311:128-34. [PMID: 17362973 DOI: 10.1016/j.jcis.2007.02.046] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Revised: 02/08/2007] [Accepted: 02/15/2007] [Indexed: 11/19/2022]
Abstract
The intramolecular charge transfer (ICT) property of trans-ethyl p-(dimethylamino) cinnamate is used to probe the anionic, cationic, and nonionic micelles by steady-state and picosecond time-resolved fluorescence spectroscopy. The ICT fluorescence band intensity was found to increase with concomitant blue shift with addition of surfactants. All the experimental results suggest that the probe molecule resides in the micelle-water interface rather than going into the core. However, the penetration is more toward the micellar core in nonionic surfactants when compared with ionic micelles. The decrease in nonradiative decay constants in micellar environments indicate restricted motion of the probe toward the formation of ICT state. Critical micelle concentrations were determined from the sharp change in fluorescence intensity and effective dielectric constants of the micelle-water interface were calculated from the correlation diagram of 0,0 transition energy with polarity of the medium.
Collapse
Affiliation(s)
- T Sanjoy Singh
- Department of Chemistry, North-Eastern Hill University, NEHU Permanent Campus, Umshing, Shillong 793 022, India
| | | |
Collapse
|
31
|
A concise review of dynamical processes in polymorphic environments of a block copolymer: Rotational diffusion and photoisomerization. J CHEM SCI 2007. [DOI: 10.1007/s12039-007-0022-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
32
|
Mali KS, Dutt GB, Mukherjee T. Rotational Diffusion of Organic Solutes in Surfactant−Block Copolymer Micelles: Role of Electrostatic Interactions and Micellar Hydration. J Phys Chem B 2007; 111:5878-84. [PMID: 17489625 DOI: 10.1021/jp068490q] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rotational diffusion of a cationic solute rhodamine 110 and a neutral solute 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole, DMDPP has been examined in the surfactant-block copolymer system of sodium dodecyl sulfate (SDS) and poly(ethylene oxide)20-poly(propylene oxide)70-poly(ethylene oxide)20 (P123). In this study, the mole ratio of SDS to P123 was varied from 0 to 5 in steps of one unit, to investigate the role of electrostatic interactions and micellar hydration on solute rotation. It has been noticed that there is a significant enhancement in the average reorientation time of rhodamine 110, when [SDS]/[P123] increased from 0 to 1. This has been rationalized on the basis of migration of rhodamine 110 from the interfacial region of P123 micelles to the palisade layer (corona region) due to the electrostatic interaction with negatively charged head groups of SDS, whose tails are embedded in the polypropylene oxide core. Further increase in the mole ratio of SDS to P123 has resulted in only a marginal decrease in the average reorientation time of rhodamine 110, which is probably due to the solute molecule experiencing a microenvironment similar to the interfacial region of SDS micelles. In contrast, a gradual decrease has been observed in the average reorientation time of DMDPP with [SDS]/[P123], which is due to the increase in hydration levels in the palisade layer (corona region) of the micelle. These explanations are consistent with the structure of the SDS-P123 micellar system that has been deduced from neutron scattering and viscosity measurements recently.
Collapse
Affiliation(s)
- K S Mali
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India
| | | | | |
Collapse
|
33
|
Lebedeva N, Ranganathan R, Bales BL. Location of Spectroscopic Probes in Self-Aggregating Assemblies. II. The Location of Pyrene and Other Probes in Sodium Dodecyl Sulfate Micelles. J Phys Chem B 2007; 111:5781-93. [PMID: 17488113 DOI: 10.1021/jp070540j] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The location of pyrene in sodium dodecyl sulfate (SDS) micelles is determined as a function of the aggregation number, N, by exploiting the fact that spin probes 5- and 16-doxyl stearic acid methyl esters (5DSE and 16DSE, respectively) are effective quenchers of pyrene fluorescence. The locations of the two spin probes are known from Part 1 of this series (J. Phys. Chem. B 2006, 110, 9791) and the distance between the probes and pyrene is determined by using a hydrodynamic theory to predict the quenching rate constant. The hydrodynamic theory requires the microviscosity of the regions through which the probe and pyrene diffuse. The same spin probe that serves as quencher provides a measure of the microviscosity; thus, all the information needed to locate pyrene is available from each spin probe. Employing 5DSE, at N = 53, pyrene is found to diffuse through a zone 67% of which lies within the Stern layer and 33% in the core. As the micelle grows, due to increasing either the surfactant or added-salt concentration, this diffusion zone moves outward such that, at N = 130, near the sphere-rod transition, it lies approximately 75% within the Stern layer and 25% in the core. Employing 16DSE, the location of pyrene is within 0.4 A of that found from 5DSE at low values of N and within 0.8 A at high values. Full information required to locate pyrene by using the currently developed method is not yet available for other spin probes and other commonly employed quenchers; nevertheless, using a variety of strategies and reasonable assumptions leads to the same location of pyrene within the uncertainties of the method. All of the spectroscopic probes employed in this study are largely located within the polar shell of the micelles, the largest departure being about 4% of the diameter of the micelle.
Collapse
Affiliation(s)
- Nataly Lebedeva
- Department of Physics and Astronomy and the Center for Supramolecular Studies, California State University at Northridge, Northridge, California 91330-8268, USA
| | | | | |
Collapse
|
34
|
Yamamoto S, Hyodo SA. Mesoscopic simulation of the crossing dynamics at an entanglement point of surfactant threadlike micelles. J Chem Phys 2007; 122:204907. [PMID: 15945777 DOI: 10.1063/1.1914767] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The crossing dynamics at an entanglement point of surfactant threadlike micelles in an aqueous solution was studied using a mesoscopic simulation method, dissipative particle dynamics, with a coarse-grained surfactant model. The possibility of a phantom crossing, which is the relaxation mechanism for the pronounced viscoelastic behavior of surfactant threadlike micellar solution, was investigated. When two threadlike micelles were encountered at an entanglement point under the condition close to thermal equilibrium, they fused to form a four-armed branch point. Then, a phantom crossing reaction occurred occasionally, or one micelle was cut down at the branch point. Increasing the repulsive forces between hydrophilic parts of the surfactants, fusion occurred less and the threadlike micelle was frequently broken down at an entanglement point. In these three schemes (a phantom crossing cut down at the branch point, and break down at the entanglement point), the breakage occurs at somewhere along the threadlike micelle. The breakage is considered as an essential process in the relaxation mechanism, and a phantom crossing can be seen as a special case of these processes. To explain the experimental evidence that a terminal of threadlike micelles is scarcely observed, a mechanism was also proposed where the generated terminal merges into the connected micelle part between two entanglement points due to the thermal motion.
Collapse
Affiliation(s)
- Satoru Yamamoto
- Toyota Central Research and Development Laboratories, Inc., Nagakute, Aichi 480-1192, Japan.
| | | |
Collapse
|
35
|
Mali KS, Dutt GB, Mukherjee T. Rotational diffusion of an ionic solute in polymorphic environments of a block copolymer: influence of interfacial friction on solute rotation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:1041-6. [PMID: 17241011 DOI: 10.1021/la062682v] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In an attempt to understand the role of interfacial friction on solute rotation, fluorescence anisotropy decays of a cationic solute, rhodamine 110, have been measured in polymorphic environments of a triblock copolymer, (PEO)20-(PPO)70-(PEO)20 (P123) (PEO = poly(ethylene oxide), PPO = poly(propylene oxide)). It has been noticed that even though rhodamine 110 is located in the interfacial region of the micelles, sol-gel transition does not significantly influence its rotation. Micelle-micelle entanglement, which is responsible for gelation, persists even in the micellar solution phase, perhaps to a lesser degree, and this entanglement is responsible for the observed behavior. This hypothesis has been substantiated by undertaking concentration-dependent studies in which it is shown that the reorientation time of the solute increases with an increase in the micellar concentration. In the case of reverse micelles, it has been observed that an enhancement in the water content facilitates solute rotation, which has been rationalized on the basis of solute migration from the hydrated poly(ethylene oxide) region to the poly(ethylene oxide)-water interface within the core.
Collapse
Affiliation(s)
- K S Mali
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | | | | |
Collapse
|
36
|
|
37
|
Das P, Mallick A, Chakrabarty A, Haldar B, Chattopadhyay N. Effect of nanocavity confinement on the rotational relaxation dynamics: 3-acetyl-4-oxo-6,7-dihydro-12H indolo-[2,3-a] quinolizine in micelles. J Chem Phys 2006; 125:44516. [PMID: 16942165 DOI: 10.1063/1.2219751] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In continuation of our recent study on the steady state photophysics of a biologically active beta-carboline derivative, 3-acetyl-4-oxo-6,7-dihydro-12H indolo-[2,3-a] quinolizine (AODIQ), in the present article we have investigated the effect of nanocavity confinement on the excited state dynamics and rotational relaxation of the probe using picosecond time resolved fluorescence and fluorescence anisotropy techniques. The polarity dependent intramolecular charge transfer process is responsible for the remarkable sensitivity of this biological fluorophore in micellar environments. The fluorescence anisotropy decay of AODIQ incorporated inside the micelle is biexponential. The rotational motion of the probe was interpreted on the basis of a two step model consisting of a fast restricted rotation of the probe and a slow lateral diffusion of the probe in the micelle; both coupled to the overall rotation of the micelle. Experimental results reveal that micellar environment causes significant retardation of both the wobbling as well as the translational motion of the probe.
Collapse
Affiliation(s)
- Paramita Das
- Department of Chemistry, Jadavpur University, Calcutta 700032, India
| | | | | | | | | |
Collapse
|
38
|
Roy S, Khatua D, Dey J. Giant vesicles of a single-tailed chiral cationic surfactant, (1R,2S)-(–)-N-dodecyl-N-methylephedrinium bromide, in water. J Colloid Interface Sci 2005; 292:255-64. [PMID: 16024030 DOI: 10.1016/j.jcis.2005.05.054] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2005] [Revised: 05/18/2005] [Accepted: 05/18/2005] [Indexed: 11/26/2022]
Abstract
Self-assembly properties of a single-tailed chiral cationic surfactant, (1R,2S)-(-)-N-dodecyl-N-methylephedrinium bromide (DMEB), have been studied in water. The molecular self-assemblies of the amphiphile have been characterized by surface tension, fluorescence probes, light scattering, and microscopic techniques. The results have been compared with those of dodecyltrimethylammonium bromide (DTAB) surfactant. The critical aggregation concentration of DMEB was found to be much less than that of DTAB. Surface tension and fluorescence probe studies have suggested formation of micellar structures at low temperature (<28 degrees C) and spontaneous formation of giant vesicles in water above 28 degrees C. The mean size of the aggregates has been measured by a dynamic light scattering method. The micropolarity and microviscosity of the self-assemblies were determined by fluorescence probe technique. The (1)H NMR and FTIR spectra were recorded to elucidate the role of the hydrophobic head group towards the formation of bilayer structures. The phase transition temperatures of the vesicular aggregates were determined by measurement of fluorescence anisotropy at various temperatures.
Collapse
Affiliation(s)
- Sumita Roy
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India
| | | | | |
Collapse
|
39
|
Dutt GB. Comparison of microenvironments of aqueous sodium dodecyl sulfate micelles in the presence of inorganic and organic salts: a time-resolved fluorescence anisotropy approach. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:10391-7. [PMID: 16262297 DOI: 10.1021/la051444h] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Microenvironments of aqueous sodium dodecyl sulfate (SDS) micelles was examined in the presence of additives such as sodium chloride and p-toluidine hydrochloride (PTHC) by monitoring the fluorescence anisotropy decays of two hydrophobic probes, 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DMDPP) and coumarin 6 (C6). It has been well-established that SDS micelles undergo a sphere-to-rod transition and that their mean hydrodynamic radius increases from 19 to 100 A upon the addition of 0.0-0.7 M NaCl at 298 K. A similar size and shape transition is induced by PTHC at concentrations that are 20 times lower compared to that of NaCl. This study was undertaken to find out how the microviscosity of the micelles is influenced under these circumstances. It was noticed that the microviscosity of the SDS/NaCl system increased by approximately 45%, whereas there was a less than 10% variation in the microviscosity of the SDS/PTHC system. The large increase in the microviscosity of the former system with salt concentration has been rationalized on the basis of the high concentration of sodium ions in the headgroup region of the micelles and their ability to strongly coordinate with the water present in this region, which decreases the mobility of the probe molecules.
Collapse
Affiliation(s)
- G B Dutt
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India.
| |
Collapse
|
40
|
Mali KS, Dutt GB, Ganguly R, Mukherjee T. Effect of “inverse melting transition” of aqueous triblock copolymer solutions on solute rotational dynamics. J Chem Phys 2005; 123:144913. [PMID: 16238430 DOI: 10.1063/1.2056550] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Rotational dynamics of two structurally similar hydrophobic solutes, 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DMDPP) and 1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DPP), has been investigated in 30% wv aqueous solution of triblock copolymer, poly(ethylene oxide)(20)-poly(propylene oxide)(70)-poly(ethylene oxide)(20) as a function of temperature. This study has been undertaken in an attempt to explore how the dynamics of a solute molecule solubilized in a copolymer solution is influenced when it undergoes sol-to-gel transition. It has been observed that the anisotropy decays of both DMDPP and DPP can be described by biexponential functions in the sol as well as in the gel phase. This observation has been rationalized on the basis of the probe molecule undergoing two different kinds of motion rather than being located in two different regions of the micelle. Even in the gel phase, which results as a consequence of micelle-micelle entanglement due to an increase in their volume fraction, the rotational relaxation of the solutes is similar to that observed in the micellar solution. The outcome of this work indicates that even though these gels have very high macroscopic viscosities and hence do not flow, the microenvironments experienced by the solutes are akin to that of a micellar solution.
Collapse
Affiliation(s)
- K S Mali
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | | | | | | |
Collapse
|
41
|
Roy S, Mohanty A, Dey J. Microviscosity of bilayer membranes of some N-acylamino acid surfactants determined by fluorescence probe method. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.07.046] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
42
|
Dutt GB. How Critical Micelle Temperature Influences Rotational Diffusion of Hydrophobic Probes Solubilized in Aqueous Triblock Copolymer Solutions. J Phys Chem B 2005; 109:4923-8. [PMID: 16863148 DOI: 10.1021/jp0453459] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Rotational diffusion of two structurally similar hydrophobic probes, 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DMDPP) and 1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DPP), has been examined in aqueous solutions of poly(ethylene oxide)20-poly(propylene oxide)70-poly(ethylene oxide)20 triblock copolymer as a function of temperature. These studies have been carried out to explore the influence of critical micelle temperature (cmt) on probe dynamics. It has been observed that, below cmt, the anisotropy decays can be adequately described by single-exponential functions with one time constant each for DMDPP and DPP. However, above cmt, biexponential functions with two time constants are needed to satisfactorily fit the anisotropy decays. Another important observation is that both the probes rotate more rapidly below the critical micelle temperature. The dynamics of the probe molecules are akin to that in a homogeneous solution below cmt, whereas above cmt, the rotational diffusion of the probes has been accounted by the two-step model, which is usually employed to explain the results in micelles. A comparison between the microviscosities of these micelles with other nonionic micelles such as Triton X-100 and Brij-35 reveals that the internal environment of the micelles formed with the triblock copolymer is less fluid.
Collapse
Affiliation(s)
- G B Dutt
- Radiation Chemistry & Chemical Dynamics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
| |
Collapse
|
43
|
Dutt GB. Does the Onset of Water Droplet Formation Alter the Microenvironment of the Hydrophobic Probes Solubilized in Nonionic Reverse Micelles? J Phys Chem B 2004. [DOI: 10.1021/jp049160d] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- G. B. Dutt
- Radiation Chemistry and Chemical Dynamics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| |
Collapse
|