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Mandal HK, Patel BK, Saha S, Saha S, Mahapatra A. Effect of cyclodextrins’ cavity on the kinetics of alkaline hydrolysis of tris(1,10-Phenanthroline)Fe(II) in presence of surfactant. J DISPER SCI TECHNOL 2021. [DOI: 10.1080/01932691.2021.1993891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
| | - Biman Kumar Patel
- Department of Chemistry, Jadavpur University, Kolkata, West Bengal, India
| | - Suman Saha
- Department of Chemistry, Jadavpur University, Kolkata, West Bengal, India
| | - Sushanta Saha
- Department of Chemistry, Sree Chaitanya College, Habra, West Bengal, India
| | - Ambikesh Mahapatra
- Department of Chemistry, Jadavpur University, Kolkata, West Bengal, India
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2
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Kaur K, Jindal R, Jindal D. Synthesis, characterization and studies on host-guest interactions of inclusion complexes of metformin hydrochloride with β–cyclodextrin. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.02.127] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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3
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Rodríguez M, Silva L, Parajó M, Rodríguez-Dafonte P, García-Río L. Use of dye complexation dynamics to determine α-cyclodextrin host:guest stability constants. J PHYS ORG CHEM 2019. [DOI: 10.1002/poc.3820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- María Rodríguez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), Departamento de Química Física; Universidade de Santiago de Compostela; 15782 Santiago Spain
| | - Lara Silva
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), Departamento de Química Física; Universidade de Santiago de Compostela; 15782 Santiago Spain
| | - Mercedes Parajó
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), Departamento de Química Física; Universidade de Santiago de Compostela; 15782 Santiago Spain
| | - Pedro Rodríguez-Dafonte
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), Departamento de Química Física; Universidade de Santiago de Compostela; 15782 Santiago Spain
| | - Luis García-Río
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), Departamento de Química Física; Universidade de Santiago de Compostela; 15782 Santiago Spain
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4
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Seweryn A. Interactions between surfactants and the skin - Theory and practice. Adv Colloid Interface Sci 2018; 256:242-255. [PMID: 29685575 DOI: 10.1016/j.cis.2018.04.002] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/03/2018] [Accepted: 04/04/2018] [Indexed: 01/14/2023]
Abstract
One of the primary causes of skin irritation is the use of body wash cosmetics and household chemicals, since they are in direct contact with the skin, and they are widely available and frequently used. The main ingredients of products of this type are surfactants, which may have diverse effects on the skin. The skin irritation potential of surfactants is determined by their chemical and physical properties resulting from their structure, and specific interactions with the skin. Surfactants are capable of interacting both with proteins and lipids in the stratum corneum. By penetrating through this layer, surfactants are also able to affect living cells in deeper regions of the skin. Further skin penetration may result in damage to cell membranes and structural components of keratinocytes, releasing proinflammatory mediators. By causing irreversible changes in cell structure, surfactants can often lead to their death. The paper presents a critical review of literature on the effects of surfactants on the skin. Aspects discussed in the paper include the skin irritation potential of surfactants, mechanisms underlying interactions between compounds of this type and the skin which have been proposed over the years, and verified methods of reducing the skin irritation potential of surfactant compounds. Basic research conducted in this field over many years translate into practical applications of surfactants in the cosmetic and household chemical industries. This aspect is also emphasized in the present study.
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Vargas C, Schönbeck C, Heimann I, Keller S. Extracavity Effect in Cyclodextrin/Surfactant Complexation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:5781-5787. [PMID: 29683671 DOI: 10.1021/acs.langmuir.8b00682] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cyclodextrin (CD) complexation is a convenient method to sequester surfactants in a controllable way, for example, during membrane-protein reconstitution. Interestingly, the equilibrium stability of CD/surfactant inclusion complexes increases with the length of the nonpolar surfactant chain even beyond the point where all hydrophobic contacts within the canonical CD cavity are saturated. To rationalize this observation, we have dissected the inclusion complexation equilibria of a structurally well-defined CD, that is, heptakis(2,6-di- O-methyl)-β-CD (DIMEB), and a homologous series of surfactants, namely, n-alkyl- N, N-dimethyl-3-ammonio-1-propanesulfonates (SB3- x) with chain lengths ranging from x = 8 to 14. Thermodynamic parameters obtained by isothermal titration calorimetry and structural insights derived from nuclear magnetic resonance spectroscopy and molecular dynamics simulations revealed that, upon inclusion, long-chain surfactants with x = ≥10 extend beyond the canonical CD cavity. This enables the formation of hydrophobic contacts between long surfactant chains and the extracavity parts of DIMEB, which make additional favorable contributions to the stability of the inclusion complex. These results explain the finding that the stability of CD/surfactant inclusion complexes monotonously increases with the surfactant chain length even for long chains that completely fill the canonical CD cavity.
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Affiliation(s)
- Carolyn Vargas
- Molecular Biophysics , Technische Universität Kaiserslautern (TUK) , Erwin-Schrödinger-Str. 13 , 67663 Kaiserslautern , Germany
| | - Christian Schönbeck
- Department of Science and Environment , Roskilde University , Universitetsvej 1 , 4000 Roskilde , Denmark
| | - Ina Heimann
- Molecular Biophysics , Technische Universität Kaiserslautern (TUK) , Erwin-Schrödinger-Str. 13 , 67663 Kaiserslautern , Germany
| | - Sandro Keller
- Molecular Biophysics , Technische Universität Kaiserslautern (TUK) , Erwin-Schrödinger-Str. 13 , 67663 Kaiserslautern , Germany
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6
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Adsorption and electrokinetic properties in the system: Beta-cyclodextrin/alumina in the presence of ionic and non-ionic surfactants. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2015.05.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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7
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Mixed aggregates based on tetronic-fluorinated surfactants for selective oils capture. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2015.02.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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8
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Tsianou M, Fajalia AI. Cyclodextrins and surfactants in aqueous solution above the critical micelle concentration: where are the cyclodextrins located? LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:13754-64. [PMID: 25126838 DOI: 10.1021/la5013999] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Cyclodextrins (CDs) are known to bind surfactant molecules below the surfactant critical micelle concentration (CMC); however, interactions of CDs with surfactant micelles (above the CMC) are not well understood. In particular, direct structural evidence of the location of CDs in the different subphases found in micellar solutions is lacking. We have utilized small-angle neutron scattering (SANS) with contrast matching to probe the localization of α-cyclodextrin (α-CD) and 2-hydroxypropyl-β-cyclodextrin (HPβ-CD) in sodium dodecyl sulfate (SDS) micelles in aqueous (D2O) solutions. SANS data from solutions containing either hydrogenated or deuterated surfactants were analyzed by considering three different scenarios pertaining to the localization of cyclodextrin, either all in solution or some in the micelle shell or some in the micelle core, and were simultaneously fitted using the core-shell prolate ellipsoid form factor and the Hansen-Hayter-based structure factor. The scenario that considered a fraction of CD to localize in the micelle core well described the SANS data from both hydrogenated and deuterated SDS-CD-D2O solutions, while the other two scenarios did not. Among the various structural and interaction parameters obtained from this analysis, it emerged that the micelle core consisted of up to ∼10% HPβ-CD or ∼16% α-CD with respect to the total number of molecules (surfactants and CDs) present in the micelle at 25 mM SDS, and up to 14% HPβ-CD or 28% α-CD at 50 mM SDS. This is the first study that provides direct evidence on the location of cyclodextrin in the core of surfactant micelles. An improved understanding of CD interactions with surfactants and lipids would enable better strategies for drug encapsulation and delivery with CDs.
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Affiliation(s)
- Marina Tsianou
- Department of Chemical & Biological Engineering, University at Buffalo, The State University of New York (SUNY) , Buffalo, New York 14260-4200, United States
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9
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Bagheri A, Rafati AA. Thermodynamic investigation of inclusion complex formation between cetyltrimethyl ammonium bromide (CTAB) and β-cyclodextrin at various temperatures. J Mol Liq 2014. [DOI: 10.1016/j.molliq.2014.02.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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10
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Jiang L, Yan Y, Huang J. Versatility of cyclodextrins in self-assembly systems of amphiphiles. Adv Colloid Interface Sci 2011; 169:13-25. [PMID: 21839422 DOI: 10.1016/j.cis.2011.07.002] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 07/14/2011] [Accepted: 07/16/2011] [Indexed: 11/25/2022]
Abstract
Recently, cyclodextrins (CDs) were found to play important yet complicated (or even apparently opposite sometimes) roles in self-assembly systems of amphiphiles or surfactants. Herein, we try to review and clarify the versatility of CDs in surfactant assembly systems by 1) classifying the roles played by CDs into two groups (modulator and building unit) and four subgroups (destructive and constructive modulators, amphiphilic and unamphiphilic building units), 2) comparing these subgroups, and 3) analyzing mechanisms. As a modulator, although CDs by themselves do not participate into the final surfactant aggregates, they can greatly affect the aggregates in two ways. In most cases CDs will destroy the aggregates by depleting surfactant molecules from the aggregates (destructive), or in certain cases CDs can promote the aggregates to grow by selectively removing the less-aggregatable surfactant molecules from the aggregates (constructive). As an amphiphilic building unit, CDs can be chemically (by chemical bonds) or physically (by host-guest interaction) attached to a hydrophobic moiety, and the resultant compounds act as classic amphiphiles. As an unamphiphilic building unit, CD/surfactant complexes or even CDs on their own can assemble into aggregates in an unconventional, unamphiphilic manner driven by CD-CD H-bonds. Moreover, special emphasis is put on two recently appeared aspects: the constructive modulator and unamphiphilic building unit.
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11
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Yang C, Castelvetro V, Scalarone D, Bianchi S, Zhang Y. Three different β-cyclodextrins direct the emulsion copolymerization of a highly fluorinated methacrylate toward distinctive nanostructured particle morphologies. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/pola.24921] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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12
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Dou Z, Xing H, Xiao J. Hydrogenated and Fluorinated Host–Guest Surfactants: Complexes of Cyclodextrins with Alkanes and Fluoroalkyl‐Grafted Alkanes. Chemistry 2011; 17:5373-80. [DOI: 10.1002/chem.201003443] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Indexed: 11/09/2022]
Affiliation(s)
- Zeng‐Pei Dou
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (P.R. China), Fax: (+86) 10‐62561871
| | - Hang Xing
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (P.R. China), Fax: (+86) 10‐62561871
- Beijing FLUOBON Surfactant Institute, Beijing 100080 (P.R. China)
| | - Jin‐Xin Xiao
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (P.R. China), Fax: (+86) 10‐62561871
- Beijing FLUOBON Surfactant Institute, Beijing 100080 (P.R. China)
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Beiginejad H, Bagheri A, Yekta LS, Nojini ZB. Thermodynamic studies of inclusion complex formation between alkylpyridinium chlorides and β-cyclodextrin using conductometric method. J INCL PHENOM MACRO 2009. [DOI: 10.1007/s10847-009-9704-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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14
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Zhou H, Yang Z, Zhao P, Li X. Effect of β-Cyclodextrin on the Micellization of Cetyltrimethylammonium in Aqueous Solution at High Temperature. J DISPER SCI TECHNOL 2009. [DOI: 10.1080/01932690902735645] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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15
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García-Río L, Godoy A. Use of Spectra Resolution Methodology to Investigate Surfactant/β-Cyclodextrin Mixed Systems. J Phys Chem B 2007; 111:6400-9. [PMID: 17511497 DOI: 10.1021/jp070780z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A study of the spectral behavior of crystal violet in mixed systems formed by hexadecyltrimethylammonium chloride (CTACl) and beta-cyclodextrin (beta-CD) has been carried out. The spectra resolution methodology was used to decompose the absorption spectra of crystal violet in the sum of constituent sub-bands centered at 17,953, 16,807, and 16,474 cm(-1). The sub-bands centered at upsilon = 17,953 and 16,807 cm(-1) correspond to planar and pyramidal isomers of the dye in water and the same isomers associated with the cyclodextrin and micelle. The sub-band centered at upsilon = 16,474 cm(-1) is due to the formation of an inclusion complex between the dye and the cyclodextrin, where solvation of the carbocation takes place through the hydroxyl groups of the cyclodextrin and the association of the crystal violet to micelles of CTACl through the formation of ion pairs in the Stern layer. The results obtained in the mixed systems are compatible with the results obtained in the previously studied simple systems, thus supporting the situation where interactions do not exist between cyclodextrins and micelles once these have formed.
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Affiliation(s)
- Luis García-Río
- Departamento de Química Física, Facultad de Química, Universidad de Santiago, 15782 Santiago, Spain.
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16
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Liao D, Dai S, Tam KC. Interaction between Fluorocarbon End-Capped Poly(ethylene oxide) and Cyclodextrins. Macromolecules 2007. [DOI: 10.1021/ma0622884] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dongsheng Liao
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Sheng Dai
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Kam Chiu Tam
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
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17
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Xie J, Zhang Y, Du J, Zeng X, Liu Y, Shunzo Y, Yoshimi S. Micelle Catalyzed Hydrolysis of Carboxylic Acid Esters in Water–β‐Cyclodextrin–Cetyltrimethylammonium Bromide Systems. J DISPER SCI TECHNOL 2007. [DOI: 10.1081/dis-120017948] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Jiaqing Xie
- a Faculty of Chemistry , Sichuan University , Chengdu , 610064 , P. R. China
| | - Yi Zhang
- b Chongqing Academy of Environmental Science , Chongqing , P. R. China
| | - Juan Du
- a Faculty of Chemistry , Sichuan University , Chengdu , 610064 , P. R. China
| | - Xian‐cheng Zeng
- a Faculty of Chemistry , Sichuan University , Chengdu , 610064 , P. R. China
| | - Ying‐jin Liu
- c Department of Chemistry, Faculty of Science , Okayama University , Okayama , Japan
| | - Yamamoto Shunzo
- c Department of Chemistry, Faculty of Science , Okayama University , Okayama , Japan
| | - Sueishi Yoshimi
- c Department of Chemistry, Faculty of Science , Okayama University , Okayama , Japan
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18
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Yang Z, Wang J, Gao L, Zhang N, Zhao Y, Yue Y, Zhuo K. Effect of β-Cyclodextrin on the Micellar Behavior of Cetyltrimethylammonium Chloride in Aqueous Solution. Z PHYS CHEM 2007. [DOI: 10.1524/zpch.2007.221.2.215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Molar volume and conductivity measurements have been carried out at 298.15 K for cetyltrimethylammonium chloride (CTAC) + H2O and CTAC + β-cyclodextrin (β-CD) + H2O systems. The apparent critical micelle concentrations (cmc), the dissociation degree of the micelle (β), the transfer free energy for the hydrocarbon chain of CTAC (ΔG
0
HP), the standard partial molar volumes of CTAC (V
0
Φ,S), the stoichoimetry and the association constants for the inclusion complex of CTAC with β-CD have been determined. The influence of β-CD and its complex on the micellization processes of CTAC is analyzed. It is shown that β-CD partly screened the hydrophobic hydrocarbon chain of CTAC molecules from contact with the surrounding medium, and retarded the formation of CTAC micelles in a certain extent. The thermodynamic activity of CTAC is decreased due to the formation of complex. The β-CD and its complexes do not participate the formation of micelles of CTAC, and the complex have no effect on the micelle properties once the micelles are formed. Based on a simple model, the number of CH2 groups entered the cavity of β-CD was calculated. The result suggests that, β-CD forms strong complex with CTAC; the stoichoimetry is found to be 1:1 complexes coexist at very low concentration of β-CD and 2:1 at higher concentrations of β-CD.
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Cabaleiro-Lago C, García-Río L, Hervés P, Mejuto JC, Pérez-Juste J. In Search of Fully Uncomplexed Cyclodextrin in the Presence of Micellar Aggregates. J Phys Chem B 2006; 110:15831-8. [PMID: 16898733 DOI: 10.1021/jp0626871] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The chemical behavior of beta-cyclodextrin/nonionic surfactant mixed systems has been investigated using the basic hydrolysis of N-methyl-N-nitroso-p-toluenesulfonamide as a chemical probe. The experimental results prove that at the cmc, there are significant quantities of uncomplexed beta-CD in equilibrium with the micellar aggregates. In contrast to the expected situation, the percentage of uncomplexed beta-CD in equilibrium with the micellar system increases on increasing the hydrophobicity of the surfactant molecule. This behavior is due to the existence of two simultaneous processes: complexation of surfactant monomers by cyclodextrin and the process of self-assembly to form micellar aggregates. The autoaggregation of surfactant monomers is expected to be more important than the complexation process in this mixed system. Varying the hydrophobicity of the surfactant monomer enabled us to determine that the percentages of uncomplexed cyclodextrin in equilibrium with the micellar system were in the range of 5-95%.
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Affiliation(s)
- C Cabaleiro-Lago
- Departamento de Química Física, Facultad de Química, Universidad de Vigo, 36310 Vigo, Spain
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20
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Manabe M, Ochi T, Kawamura H, Katsu-ura H, Shiomi M, Bakshi MS. Volumetric study on the inclusion complex formation of ?- and ?-cyclodextrin with 1-alkanols at different temperatures. Colloid Polym Sci 2004. [DOI: 10.1007/s00396-004-1216-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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21
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De Lisi R, Lazzara G, Milioto S, Muratore N. Characterization of the Cyclodextrin−Surfactant Interactions by Volume and Enthalpy. J Phys Chem B 2003. [DOI: 10.1021/jp034105a] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- R. De Lisi
- Dipartimento di Chimica Fisica “F. Accascina”, Università di Palermo, Viale delle Scienze, Parco D'Orleans II, 90128 Palermo, Italy
| | - G. Lazzara
- Dipartimento di Chimica Fisica “F. Accascina”, Università di Palermo, Viale delle Scienze, Parco D'Orleans II, 90128 Palermo, Italy
| | - S. Milioto
- Dipartimento di Chimica Fisica “F. Accascina”, Università di Palermo, Viale delle Scienze, Parco D'Orleans II, 90128 Palermo, Italy
| | - N. Muratore
- Dipartimento di Chimica Fisica “F. Accascina”, Università di Palermo, Viale delle Scienze, Parco D'Orleans II, 90128 Palermo, Italy
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Fernández MA, de Rossi RH. Changing mechanisms in the beta-cyclodextrin-mediated hydrolysis of phenyl esters of perfluoroalkanoic acids. J Org Chem 2003; 68:6887-93. [PMID: 12946127 DOI: 10.1021/jo034402b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The rate of hydrolysis of esters CF(3)(CF(2))(n)COOPh (1 (n = 1), 2 (n = 2), and 3 (n = 6)) was measured at pH 6.00 and at pH higher than 9.00 in the presence of beta-cyclodextrin (beta-CD). For compounds 1 and 2 the reaction rate decreases as the beta-CD concentration increases, and they show saturation effects at all pH. It is suggested that the substrate forms an inclusion complex with cyclodextrin. Analysis of the rate data allows calculation of the association equilibrium constant, K(CD), the rate constant for the reaction of the included compound, k(c), and K(TS) which is the hypothetical association equilibrium constant for the transition state of the cyclodextrin-mediated reaction. The dependence of log K(CD) and log K(TS) with the number of atoms in the chain is different. We suggest that the reactions of 1 and 2 take place with the perfluorinated alkyl chain included in the cavity, whereas the transition state for the reaction of phenyl trifluoroacetate involves a complex with the aryl ring inside the cavity. At low pH the inhibition comes from the protection of the carbonyl group toward nucleophilic attack by water. In basic pH the reaction of HO(-) as an external nucleophile is also inhibited. The cyclodextrin-mediated reaction involves the ionized OH group at the rim of the cyclodextrin cavity with poor efficiency due to an unfavorable orientation of the substrate in the complex. On the other hand, the reaction of compound 3 is strongly accelerated by cyclodextrin because the association of the substrate with cyclodextrin competes with the monomer-aggregate equilibrium and at high enough cyclodextrin concentration the main species present in solution is the complex between 3 and cyclodextrin.
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Affiliation(s)
- Mariana A Fernández
- Instituto de Investigaciones en Físico-Química de Córdoba, Facultad de Ciencias Químicas, Departamento de Química Orgánica, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000, Córdoba, Argentina
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23
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Lo Nostro P, Fratoni L, Ninham BW, Baglioni P. Water absorbency by wool fibers: Hofmeister effect. Biomacromolecules 2002; 3:1217-24. [PMID: 12425658 DOI: 10.1021/bm0255692] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Wool is a complex material, composed of cuticle and epicuticle cells, surrounded by a cell membrane complex. Wool fibers absorb moisture from air, and, once immersed in water, they take up considerable amounts of liquid. The water absorbency parameter can be determined from weight gain, according to a standard method, and used to quantify this phenomenon. In this paper we report a study on the water absorbency (or retention) of untreated wool fibers in the presence of aqueous 1 M salt solutions at 29 degrees C and a relative humidity of either 33% or 56%. The effect of anions was determined by selecting a wide range of different sodium salts, while the effect of cations was checked through some chlorides and nitrates. Our results show a significant specific ion and ion pair "Hofmeister" effects, that change the amount of water absorbed by the fibers. To understand this phenomenon, the water absorbency parameter (A(w)) is compared to different physicochemical parameters such as the lyotropic number, free energy of hydration of ions, molar surface tension increment, polarizability, refractive index increment, and molar refractivity. The data indicate that this Hofmeister phenomenon is controlled by dispersion forces that depend on the polarizability of ionic species, their adsorption frequencies, the solvent, and the substrate. These dispersion forces dominate the behavior in concentrated solutions. They are in accord with new developing theories of solutions and molecular interactions in colloidal systems that account for Hofmeister effects.
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Affiliation(s)
- Pierandrea Lo Nostro
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3-Sesto Fiorentino, 50019 Florence, Italy
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24
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De Lisi R, Milioto S, Muratore N. Thermodynamic Evidence of Cyclodextrin−Micelle Interactions. J Phys Chem B 2002. [DOI: 10.1021/jp013648m] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R. De Lisi
- Dipartimento di Chimica Fisica, Università di Palermo, Viale delle Scienze, Parco D'Orleans II, 90128 Palermo, Italy
| | - S. Milioto
- Dipartimento di Chimica Fisica, Università di Palermo, Viale delle Scienze, Parco D'Orleans II, 90128 Palermo, Italy
| | - N. Muratore
- Dipartimento di Chimica Fisica, Università di Palermo, Viale delle Scienze, Parco D'Orleans II, 90128 Palermo, Italy
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25
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Lo Nostro P, Lopes JR, Ninham BW, Baglioni P. Effect of Cations and Anions on the Formation of Polypseudorotaxanes. J Phys Chem B 2002. [DOI: 10.1021/jp012915l] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Pierandrea Lo Nostro
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3 Sesto Fiorentino 50019 Florence, Italy, Instituto de Quìmica, Universidade Estadual de Campinas, Caixa Postal 6154, 13083−970 Campinas (Brasil), and Department of Applied Mathematics, Research School of Physical Sciences, Australian National University, Canberra, A. C. T., Australia 0200
| | - Josias R. Lopes
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3 Sesto Fiorentino 50019 Florence, Italy, Instituto de Quìmica, Universidade Estadual de Campinas, Caixa Postal 6154, 13083−970 Campinas (Brasil), and Department of Applied Mathematics, Research School of Physical Sciences, Australian National University, Canberra, A. C. T., Australia 0200
| | - Barry W. Ninham
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3 Sesto Fiorentino 50019 Florence, Italy, Instituto de Quìmica, Universidade Estadual de Campinas, Caixa Postal 6154, 13083−970 Campinas (Brasil), and Department of Applied Mathematics, Research School of Physical Sciences, Australian National University, Canberra, A. C. T., Australia 0200
| | - Piero Baglioni
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3 Sesto Fiorentino 50019 Florence, Italy, Instituto de Quìmica, Universidade Estadual de Campinas, Caixa Postal 6154, 13083−970 Campinas (Brasil), and Department of Applied Mathematics, Research School of Physical Sciences, Australian National University, Canberra, A. C. T., Australia 0200
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26
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Yang JZ, Wang J, Yue Y, Zhuo K. Effect of β-Cyclodextrin on the Micellar Behavior of Cetylpydinium Chloride in Aqueous Solution. ACTA ACUST UNITED AC 2002. [DOI: 10.1524/zpch.2002.216.9.1085] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Molar volume and conductivity measurements have been carried out at 298.15 K for cetylpydinium chloride (CPC) + H
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27
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Mehta S, Sharma S, Joshi I. Thermodynamic investigation of surfactant aggregation in 2-pyrrolidinone. Colloids Surf A Physicochem Eng Asp 2002. [DOI: 10.1016/s0927-7757(01)01035-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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28
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Bakshi MS. Cationic Mixed Micelles in the Presence of beta-Cyclodextrin: A Host-Guest Study. J Colloid Interface Sci 2000; 227:78-83. [PMID: 10860597 DOI: 10.1006/jcis.2000.6866] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The conductances of trimethyltetradecylammonium bromide (TTAB)+triphenyltetradecylphosphonium bromide (TTPB) and TTAB+trimethylhexadecylammonium bromide (HTAB) over the entire mole fraction range of TTAB (alpha(TTAB)) were measured in water and in beta-cyclodextrin+water (CD+W) mixtures at fixed 4 and 8 mM of CD at 30 degrees C. The conductivity plots for both binary mixtures show a single break from which the mixed critical micelle concentration (cmc) and degree of micelle ionization (chi) were computed. From the slopes of the conductivity curves, the equivalent ionic conductivities of the monomeric (Lambda(m)), associated (Lambda(ass)), and the micelle (Lambda(mic)) states were calculated and discussed with respect to the surfactant-CD complexation in the whole mole fraction range of both surfactant binary mixtures. The association constant (K) between the respective monomeric surfactant and CD cavity of fixed 4 mM CD was computed by considering 1:1 association from the surface tension measurements. A comparison among the K values for HTAB-CD, TTAB-CD, and TTPB-CD shows that the former complexation is significantly stronger in comparison to the other ones due to the longer hydrophobic tail. The nonideality in mixed micelle formation in pure water was evaluated by using the regular solution theory, and it was observed that both binary mixtures exhibit close to ideal behavior. Copyright 2000 Academic Press.
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Affiliation(s)
- MS Bakshi
- Department of Chemistry, Guru Nanak Dev University, Amritsar, Punjab, 143005, India
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29
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Wilson LD, Verrall RE. A Volumetric Study of Cyclodextrin-α,ω-Alkyl Dicarboxylate Anion Complexes in Aqueous Solutions. J Phys Chem B 2000. [DOI: 10.1021/jp993406a] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lee D. Wilson
- National Research Council, Steacie Institute for Molecular Sciences, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada, and Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - Ronald E. Verrall
- National Research Council, Steacie Institute for Molecular Sciences, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada, and Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
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30
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González-Gaitano G, Crespo A, Tardajos G. Thermodynamic Investigation (Volume and Compressibility) of the Systems β-Cyclodextrin + n-Alkyltrimethylammonium Bromides + Water. J Phys Chem B 2000. [DOI: 10.1021/jp9926995] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- G. González-Gaitano
- Departamento de Química y Edafología (sección de Química Física), Facultad de Ciencias, Universidad de Navarra, 31080 Pamplona, Spain and Departamento de Química-Física I, Facultad de Químicas, Universidad Complutense, 28040 Madrid, Spain
| | - A. Crespo
- Departamento de Química y Edafología (sección de Química Física), Facultad de Ciencias, Universidad de Navarra, 31080 Pamplona, Spain and Departamento de Química-Física I, Facultad de Químicas, Universidad Complutense, 28040 Madrid, Spain
| | - G. Tardajos
- Departamento de Química y Edafología (sección de Química Física), Facultad de Ciencias, Universidad de Navarra, 31080 Pamplona, Spain and Departamento de Química-Física I, Facultad de Químicas, Universidad Complutense, 28040 Madrid, Spain
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