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The effect of surfactant micelles and the second ligand on the efficiency of energy transfer in the [Tb.sup.3+]--flumxin complex was studied. The fluorescence intensity of the [Tb.sup.3+]--flumxin complex was shown to 100-fold increase in the presence of Tween 80 micelles and the second trioctylphosphine oxide ligand. A procedure for the fluorimetric determination of flunixin in the Flunex drug product (NITA-FARM, Saratov, Russia) was developed. The linearity range of the calibration curve was from 1 x [10.sup.-7] to 1 x [10.sup.-4] M, [r.sup.2] = 0.991, and the limit of detection was 4 x [10.sup.-8] M (3[sigma]). Keywords: flunixin, terbium, sensitized fluorescence, second ligand, surfactants, micelles, Flunixin (2-[[2-methyl-3-(trifluoromethyl)-phenyl]amino]pyridine-3 carboxylic acid) belongs to nonsteroid anti-inflammatory, anesthetic, and febrifuge agents, widely used in veterinary. This substance should be determined in both biological objects and drugs. In biological objects [...]

It was established that the micellar extracts of spices are electrochemically active on a glassy carbon electrode modified with cerium dioxide nanoparticles in a 0.02 M Brij[R] 35 in the presence of a phosphate buffer solution (pH 7.4) under the conditions of differential pulse voltammetry. The number of oxidation steps and their potentials vary over a wide range depending on the type of spice. A number of the oxidation peaks of the micellar extracts of spices were identified based on the oxidation potentials of the following individual antioxidants: gallic acid, ferulic acid, p-coumaric acid, caffeic acid, rosmarinic acid, thymol, eugenol, vanillin, syringaldehyde, capsaicin, rutin, quercetin, catechin, tannin, and curcumin. The contribution of the main antioxidants to the amperometric response of the extracts was confirmed by the standard addition method. A procedure for the voltammetric determination of the antioxidant capacity of the extracts of spices based on the oxidation of their antioxidants was developed. The antioxidant capacity of spices was evaluated from the total area of the oxidation steps in units of gallic acid, whose analytical range, detection limit, and determination limit were 50-2490, 11.9, and 39.6 [micro]M, respectively. Twenty types of spices were analyzed. Positive correlations of the antioxidant capacity with the ferric reducing power and the antioxidant activity (r = 0.8971 and 0.9127, respectively at [r.sub.crit] = 0.497) were found. Keywords: voltammetry, micellar media, Brij[R] 35, antioxidant capacity, spice, food analysis, Food products are the main exogenous sources of biologically active substances that enter into the human body. Among the wide variety of these substances, antioxidants, which are capable of preventing [...]

In this work, a zwitterlonic molecular micelle, poly-[epsilon]-sodium-undecanoyl lysinate (poly-[epsilon]-SUK), was synthesized and employed as a coating in open tubular capillary electrochromatography (OT-CEC) for protein separation. The zwitterionic poly-[epsilon]-SUK containing both carboxylic acid and amine groups can be either protonated or deprotonated depending on the pH of the background electrolyte; therefore, either an overall positively or negatively charged coating can be achieved. This zwitterionic coating allows protein separations in either normal or reverse polarity mode depending on the pH of the background electrolyte. The protein mixtures contained four basic proteins (lysozyme, cytochrome c, [alpha]-chymotrypsinogen A, and ribonuclease A) and six acidic proteins (myogiobin, deoxyribonuclease I, [beta]-lactoglobulin A, [beta]-lactoglobulin B, [alpha]-lactalbumin, and albumin). Protein separations were optimized specifically for acidic (reverse mode) and basic (normal mode) pH values. Varying the polymer thickness by changing the polymer and salt concentration had a great influence on protein resolution, while nearly all peaks were also baseline resolved in both modes using the optimized poly-[epsilon]-SUK coating concentration of 0.4% (w/v). Proteins in human sera were separated under optimized acidic and basic conditions in order to demonstrate the general utility of this coating. Nanoseale characterizations of the poly-[epsilon]-SUK micellar coatings on silicon surfaces were accomplished using atomic force microscopy (AFM) to gain insight into the morphology and thickness of the zwitterionic coating. The thickness of the polymer coating ranged from 0.9 to 2.4 nm based on local measurements using nanoshaving, an AFM-based method of nanolithography. 10.1021/ac902723n

Amphiphilic block copolymers poly(N-vinylcarbazole)-b-poly(N-vinylpyrrolidone) (PNVK-b-PNVP) were prepared by xanthaie-medialed reversible addition-fragmentation chain transfer (RAFT) polymerizalion. Both the PNVK and PNVP macroinitiators and the resulting block copolymers had molecular weights close to theoretical values, predicted for efficient initiation, in the range of [M.sub.n] = 30 000 to 90 000. The block copolymers dissolved in several organic solvents but, depending on their composition, in methanol formed either micelles or large aggregates, as confirmed by dynamic light scattering. The presence of globular aggregates was confirmed by tapping mode atomic force microscopy. Key words: amphiphilic block copolymer, RAFT, living radical polymerization, micelle. On a prepare des copolymeres a bloc amphiphiles poly(N-vinylcarbazolel-b-poly(N-vinylpyrrolidone) (PNVK-b-PNVP) par une reaction de polymerisation de transfert de chaine avec addition-fragmentation reversible (TCAR) catalysee par le xanthate. Les valeurs des poids moleculaires des deux macroinitiateurs PNVK et PNVP ainsi que des copolymeres a bloc qui en ont resulte etaient proches des valeurs theoriques prevues pour une initiation efficace, de l'ordre de [M.sub.n] = 30,000 a 90,000. Les copolymeres a bloc se dissolvent dans plusieurs solvants organiques; toutefois, dans le methanol, suivant leur composition, il y a formation de micelles ou de gros agregats deceles par la diffusion dynamique de la lumiere. La presence d'agregals globulaires a aussi ete confirmee par la spectroscopie en mode de forces atomiques. Mots-cles: copolymere a bloc amphiphile, transfert de chaine avec addition-fragmentation reversible (TCAR), polymerisation radicalaire vivante, micelle., [Traduit par la Redaction] Introduction The preparation and properties of amphiphilic block copolymers, with hydrophilic and hydrophobic blocks, is currently an area of active study. Amphiphilic block copolymers form various [...]

The micelles of poly(styrene-6-3-(methacryloylamino)propyltrimethylammonium chloride-b-ethylene oxide) (PS-b-PMAPTAC-b-PEO) have been successfully prepared in aqueous solutions. The micelles have a PS core, cationic PMAPTAC shell, and PEO corona. Due to the short PS chain (degree of polymerization = 8), the formation of micelles is difficult at a low concentration, and the micelles are detected only at concentrations higher than 1 g [L.sup.-1]. The addition of anionic amphiphiles, such as sodium dodecyl sulfate (SDS) and poly(methacrylie acid) (PMAA), induces the formation of mixed micelles at a low concentration level of the polymer (~0.005 g [L.sup.-1]). This can be ascribed to insolubilization of the cationic PMAPTAC block due to charge neutralization by the anionic amphiphiles. The binding of SDS or PMAA to the PMAPTAC block is confirmed by zeta-potential measurements. The mixed micelles are characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), and fluorescence measurements. Based on DLS measurements, it is revealed that the hydrodynamic diameter of the mixed micelles falls in the range of 120-130 nm. SEM measurements provided clear pictures of mixed micelles with a spherical morphology. The kinetics of exchange of organic dyes between the micelle particles was investigated by fluorescence techniques. The result indicates that the exchange of the dyes between the micelle particles takes places within a lime scale of seconds. Key words: polymeric micelles, amphiphilic ABC triblock copolymer, mixed micelles, sodium dodecyl sulfate (SDS), poly(methacrylic acid) (PMAA). Operant en solutions aqueuses, on a prepare avec succes des micelles de poly(styrene chlorure de b-3-(methacryloylamino) propyltrimethylammonium-b-oxyde d'ethylene) (PS-b-CPMAPTA-b-POE). Les micelles comportent un squelette de polyethylene (PS), une coquille cationique de chlorure de polymethacryloylaminopropyltrimethylammonium (CPMAPTA) et une couronne de polyoxyde d'ethylene (POE). En raison de la courte longueur de la chaise de polystyrene (degre de polymerisation = 8), la formation de micelles est difficile a faible concentration et les micelles ne peuvent etre detectees qu'a des concentrations superieures a l g [L.sup.-1]. L'addition d'amphiphiles anioniques, tel le dodecylsulfate de sodium (DSS) et l'acide poly(methacrylique) (APMA), induisent la formation de micelles mixtes a des niveaux de concentration faible de polymere (environ 0.005 g [L.sup.-1]). Ce comportement peut etre attribue a l'insolubilization du bloc cationique de chlorure de polymethacryloylaminopropyltrimethylammonium (CPMAPTA) provoquee par la neutralisation de la charge par les amphiphiles anioniques. La fixation du DSS on de l'acide poly(methacrylique) sur le bloc CPMAPTA est confirmee par des mesures de potentiel zeta. Les micelles mixtes ont ete caracterisees par des mesures de diffraction dynamique de la lumiere (DDL), de microscopie electronique a balayage (MEB) et de fluorescence. Sur la base de mesure de diffraction dynamique de la lumiere, on a pu etablir que le diametre hydrodynamique des micelles mixtes se situe entre 120 et 130 nm. Les mesures de microscopie electronique a balayage permettent d'etablir clairement que les micelles mixtes possedent une morphologie spherique. On a etudie les cinetiques d'echange de colorants organiques entre les particules de micelles par les techniques de fluorescence. Les resultats indiquent que l'echange des colorants entre les particules de micelles se fait sur une echelle de temps de secondes. Mots-cles: micelles polymeres, copolymere amphiphile a trois blocs ABC, micelles mixtes, dodecylsulfate de sodium (DSS), acide poly(methacrylique) (APMA)., [Traduit par la Redaction] Introduction The synthesis of nanoparticles with a unique size and shape finds potential applications in areas such as optics, electronics, catalysis, and storage devices. For their [...]

The stability of colloidal-surfactant mixture in terms of Fuchs stability ratio, W and surfactant adsorption is studied using small-angle light scattering technique. The adsorption of surfactant influences the stability of the dispersion at a lower surfactant concentration than saturation point and at higher concentrations, the formation of surfactant micelles results in depletion-induced destabilization effects.

The aqueous solution properties of polyglycidol-based analogues are examined by rhealogy in relation to pluronic block polymers. Shear thinning is observed at concentrations above the critical micellization concentration. Zero shear viscosities are maximum at polyglycidol content of 50% wt, and decreased with increase in temperature.

Coacervates made up of alkanoic ([C.sub.8]-[C.sub.16]) and alkenoic ([C.sub.18]) acid reverse micelles were described for the first time, and their potential for the extraction of organic compounds prior to liquid chromatography was examined. The coacervation process occurred in miscible binary mixtures of water and a variety of protic and aprotic solvents. The phase behavior of alkyl carboxylic acids was found to be a function of both the Hildebrand solubility parameter, [delta], and the hydrogen-bonding capability of the solvent. The best solvents for analytical extractions were those featuring the lowest [delta] values. The phase behavior of alkyl carboxylic acid/water/tetrahydrofuran (THF) ternary systems as a function of component concentration, pH, ionic strength, and temperature was investigated. The efficiency and the time required for phase separation depended on the experimental procedure used (i.e., standing, centrifugation, stirring, and sonication). The formation of alkyl carboxylic acid reverse micelles in THF was proven using both hydrophilic fluorescent probes and scattered light measurements. The structure of the coacervates consisted of spherical droplets dispersed in a continuous phase. Phase volume ratios were a function of both alkyl carboxylic acid and THF concentration. The low volume obtained (e.g., 1.5 [micro]L per mg of decanoic) compared to that obtained by other coacervates (e.g., 5.1 [micro]L per mg of dodecane sulfonic acid and 11.3 [micro]L per mg of Triton X-114) greatly improved the concentration factors reached by coacervation-based extractions. Parameters affecting the extraction efficiency were assessed. Analytes in a wide range of polarity were efficiently extracted on the basis of the hydrophobic (e.g., PAHs) and hydrogen bond (e.g., chlorophenols, bisphenols, pesticides, phthalates, nonionic surfactants, dyes, and photographic developers) interactions that reverse micelles can establish. The coacervates were compatible with the chromatographic determination of analytes following UV or MS detection. They were successfully applied to the extraction of alkylphenol ethoxylates (octyl and nonyl) and alcohol ethoxylates ([C.sub.12]-[C.sub.16]) from influent and effluent wastewater and river water samples. Nonionic surfactants in the coacervate were directly separated and quantified by liquid chromatography--ion trap mass spectrometry. Concentration factors were around 160. The recovery of nonionics in the environmental water samples ranged from 90 to 104%.

The interactions of a biological photosensitizer, phenosafranin (PSF), with anionic micelles with varying surfactant chain lengths are demonstrated. The reaction processes are strongly influenced by both polarity and rigidity of the micellar environment.

The microenvironment within the reverse micelle of the nonionic surfactant Triton X-100 (TX-100) in cyclohexane is analyzed by studying the magnetic field effect (MFE) on pyrene-dimethylaniline exciplex luminescence. Results reveal that the nature of exciplex fluorescence and its behavior in the presence of a magnetic field vary significantly with the water content of the medium.

The study report on the micellization of a diblock copolymer in dilute solution explored by dissipative particle dynamics is presented. Results reveal that weight-average aggregation number of micelles reduces with increasing the soluble-block length.

The studies about the extent of micellization, micellar composition, structure and rheological behavior for two of the styrene oxide/ethylene oxide block copolymers, [PSO.sub.10][PEO.sub.135] and [PEO.sub.69][PSO.sub.8][PEO.sub.69] are presented.

Spatially resolved small-angle neutron scattering [SANS] was used to investigate the flow-induced effects in mixed surfactant mesophases. It was found that the two different surfactant mixtures have different relative amounts of lamellar and micellar components which results in some differences in the flow-induced response.

Static (SLS) and dynamic light scattering (DLS) experiments were conducted to examine effects of uptake of n-octanol on the micellar characteristics of the surfactant pentaoxyethylene decyl [C.sub.10][E.sub.5] and hexaoxyethylene tetradecyl [C.sub.14][E.sub.6] ethers. It was found that the micellar length increases with increasing surfactant weight fraction and increasing n-octanol content in the micelles or with increasing temperature.

In order to understand the role of stacked micelles in sample preconcentration, it is necessary to understand the factors that contribute to the micelle stacking phenomenon. Various MEKC background electrolyte (BGE) solutions were prepared in the presence of Sudan III in order to monitor the micelle stacking phenomenon in the anionic sodium dodecyl sulfate and sodium cholate micelle systems. The data show that micelle stacking is a dynamic process that is strongly dependent upon the relative conductivities of the sample matrix and BGE, the relative column length of the sample plug, and the mobilities of the ions involved in the stacking process regardless of electric field conditions (i.e., field-amplified stacking, sweeping, or high-salt stacking). Conditions under which micelle stacking can be expected to occur are presented, and the extent of micelle stacking is quantified. The micelle stacking phenomenon is correlated to the separation performance of a series of neutral alkaloids. It is shown that neutral analytes migrate rapidly through the evolving stacked micelle region in the initial moments of the separation. As a consequence of this transient interaction, analytes with small retention factors spend less time in the stacked micelle region and experience lower stacked micelle concentrations than analytes with large retention factors that spend more time in the growing stacked micelle region. It is also demonstrated that the extent of analyte enrichment generally increases with injection length, by facilitating greater interaction time with stacked micelles; however, enrichment will eventually plateau with increasing injection length as a function of an analyte's affinity for the micelle. Finally, it is shown that, in contrast to conventional wisdom, a range of long injection plugs exist where separation efficiency can be dramatically improved due to analyte interaction with an actively growing stacked micelle region.

The characterization of mixed micelles of solubilized dimyristoyl phosphatidylcholine (DMPC) and the zwitterionic detergent dodecyldimethylammoniopropane sulfonate is reported.

The investigation of whether block polyelectrolyte micelles can form soluble complexes upon interaction with oppositely charged linear polyelectrolytes is presented. Complex solubility and molecular characteristics have depended on the chemical nature of the linear polyelectrolyte and the linear polyelectrolytes have formed soluble complexes with micelles if soluble complexes are formed with the corresponding linear analogues of the block polyelectrolyte.

A coarse-grained model is used to perform molecular dynamics simulations of the electrostatically driven self-assembly of strongly charged polyelectrodes and diblock copolymers of oppositely charged and neutral blocks. It is shown that stable ionic micelles are formed in the form of extended cylindrical brushes due to electrostatic interaction and the orientational ordering of anisotropic ionic micelles has taken place at a sufficiently high concentration.

The synthesis and characterization of a novel mesoporous material with a face centered cubic (fcc) symmetry and intrinsic bimodal pores is reported. A hard-sphere packing mechanism is proposed for the formation of mesoporous materials by assuming preformed robust surfactant/silicate composite micelles hard spheres.

The three dimensional structure of FXYD1 is determined in micelles by NMR spectroscopy. This helps to obtain the relative orientations of the helical segments and information about the protein dynamics.

Atomic force microscopy is used to show in situ the presence of true nanoscale micelles structure within alternating layers of a self assembled cationic and anionic diblock copolymer micelle-micelle multilayer film. The morphologies of all the layers were found to be alike and the [T.sub.g] diblock polymer films possess three-dimensional order with mechanical resilience and strong hydrated nature.

A detailed structural study of the hexagonal close packed micellar phase, observed in the binary mixtures of nonionic surfactant [C.sub.12]E[O.sub.8] and water, is presented. The analysis has indicated that the reconstructed electron density map of the phase shows perfectly spherical micelles.

The dynamics of the light-induced conformational changes of the ppR/pHtrII(I-159) complex formed in the presence of 0.1% n-dodecyl [beta]-D-maltoside (DDM) is investigated by using a fluorescence resonance energy transfer-based method. It is concluded that the light-induced conformational change of pHtrII occurs before, at the formation or during the M state and its relaxation is coupled tightly with the decay of the O state of ppR in the 1:1 complex formed in the DDM micelle.

The structural variety and chemical heterogeneity of self-assembled, hexagonal polystyrene-b-poly(vinylpyridine) micelles are successfully exploited as templates for easy and rapid fabrication of functional protein arrays over a large scale. Spontaneous formation of such polymeric template-guided protein molecules yields high-density protein arrays that exhibit repeat spacings in a nanoscopic dimension.

The creation and properties of colloidally stable shell-cross-linked cylindrical organometallic block copolymer micelles with adjustable length and swellability is reported. The findings showed that shell cross-linking is a prerequisite for generating ceramic replicas through the pyrolysis of polyisoprene-b-polyferrocenylsilane aggregates.

The fluorescence relaxation dynamics of acridine orange (AO) in reverse micelles (RM), micelles and DNA is studied using fluorescence spectroscopy. Two types of AOs are located in the nonpolar oil phase and at the interface.

The UV-vis -NIR photoluminesccence and FT-IR techniques are implemented to study the physicochemical properties of 5-aza[5]helicene (H5) in solutions of ytterbium bis(2-ethlhexyl) sulfosuccinate reversed micelles. The insertion of dissolved H5 in the micelles leads to a one-dimensional growth of reversed micelles

A new solution state NMR method is described for obtaining the orientation of helical peptides in a membrane-mimetic environment without any chemical perturbation of the peptide-micelle system. This approach has helped in the determination of [alpha]-helical membrane-proteins without the need for a complete NOE-based structure determination.

The effects of electrolyte on the hydration behavior F127 triblock copolymer micelles are investigated by using dynamic Stokes' shift and fluorescence anisotropy measurements of coumarin 153 (C153) and coumarin 151 (C151) as fluorescence probes. The results have shown that [Na.sup.+] ions reside deep in the corona region in comparison to [Li.sup.+] ions and larger clusters of F127 micelles are formed above 2M LiCl.

Numerical results from self-consistent field calculations on the micellization of telechelic associate polymers and their non-functional analogues are presented. The results are confronted with simple scaling concepts and it is found that there is a good agreement between the numerical dependence of the aggregation number upon both backbone and terminal hydrophobe length.

A combination of fluorescence spectroscopy and quantum chemical calculations is used to study the extent of fluorescence enhancement of an epicocconone in different surfactant assemblies, which are found to be very different from each other. The analysis reveals that the depth-dependent microviscosity highly affects the fluorescence quantum that further proves the involvement of fluorophore as a dual emitting marker for fluorescence microscopy.

Several studies are conducted to analyze the nonlinear response of the Belousov-Zhabotinsy (BZ) oscillator to the addition of the increasing amounts of the anionic surfactant sodium dodecyl sulfate (SDS) in various stirred batch conditions. The research is proved to be extremely significant, as it corroborates the existence of two kinds of micelles and also reveals that the bromine species show a different affinity towards the spherical, as well as the rod-like micelles.

The small-angle neutron scattering method is used to investigate the aqueous mixed micellar solutions of perflouropolyether carboxylic salts with ammonium counterions, as their shapes and dimensions are highly affected by the presence of the n3 surfactant. The analysis reveals that a close packing of the tails leads to a decrease in the micellar curvature and repulsions between the polar heads, which ultimately leads to a micellar growth in the ellipsoids with greater axial ratios.

The micelles formed with the binary mixtures of surfactant polyoxyethylene alkyl ethers are characterized by static (SLS) and dynamic light scattering (DLS) experiments. It is found that the micellar length increases with increasing concentration or with raising temperature irrespective of the composition of the surfactant mixtures.

Nuclear magnetic resonance (NMR) spectroscopy is used to determine the structural features of nonphosphorylated thylakoid soluble phosphoprotein of 9 kDa (TSP9) both in aqueous solution and in membrane mimetic micelles. A structural model of TSP9 is described that presents a novel role for the unstructured segments and their phosporylation in regulating the biological function of the proteins.

The formation of hybrid threadlike micelles consisting of an anionic surfactant and relatively common, commercially available cationic polyelectrolytes in an aqueous solution is reported. Sodium tetradecylsulfate as an anionic surfactant and poly(N.N-diallyl-N-methylamine-ran-N.N-diallyl-N-ethyl-N-methylammonium bromide) as a polyelectrolyte are employed for the anionic hybrid threadlike micellar formation in the study.

Tapping mode atomic force microscopy (TM-AFM) experiments are conducted in air for imaging cylindrical micelles deposited randomly on gold surfaces in the presence of parachlorobenzoate counterion. The result showed the ability of the ionic surfactant-based micellar structures to maintain their morphological characteristics after the complete evaporation of water.

Neutron Spin-Echo (NSE) spectroscopy is employed to study the interfacial properties of reverse micelles formed with the common surfactant sodium bis-2-ethylhexyl-sulfosuccinate (AOT) in liquid alkane solvents and compressed propane. A constant translational diffusion of the reverse micelles through the bulk phase is observed, conforming to the Stokes-Einstein relationship with isopycnic conditions.

The effect of confinement on the dynamical properties of liquid water was studied by mid-infrared ultrafast pump-probe spectroscopy on HDO:[D.sub.2]O in reverse micelles. By preparing water-containing reverse micelles of different well defined sizes, we varied the degree of geometric confinement in water nanodroplets with radii ranging from 0.2 to 4.5 nm. We find that water molecules located near the interface confining the droplet exhibit slower vibrational energy relaxation and have a different spectral absorption than those located in the droplet core. As a result, we can measure the orientational dynamics of these different types of water with high selectivity. We observe that the water molecules in the core show similar orientational dynamics as bulk water and that the water layer solvating the interface is highly immobile. AOT | confinement | infrared | mid-infrared pump-probe spectroscopy | reverse micelle

The anisotropic adsorption of molecular assemblies on crystalline surfaces is analyzed. Torque aligns both micelles and protein fibrils and the interaction energy is minimized when the assembly lies perpendicular to a symmetry axis of a crystalline substrate.

Ion transfer voltammetric measurements at microinterfaces between notrobenzene and aqueous tetraethyleneglycol solution, which acts as a model for the palisade layer of the micelles, are performed to determine the solvation energies of single ions in the hydrophilic layer of the micelles. The results allow determining the Gibbs free energy of transfer of a single ion without an extrathermodynamic assumption.

Physicochemical principles can be used to explain continuous movements in the activity of washing machines, the use of bath sponges and washing dirty dishes immersed in water previously. Most of the commercial cleaning products have at least one or various components showing surface activity, called surfactants, and their main function is to ensure that the process of detergency, consisting of the removal of unwanted material from solid surfaces, is achieved.

The interaction of the phenothiazine cationic compounds trifluoperazine (TFP) and chloropromazine (CPZ) with micelles of the zwitterionic surfactant L-alpha-lysophosphatidylcholine (LPC), at pHs 4.0 and 7.0, are studied by using small-angle X-ray scattering (SAXS). The dipole moment in LPC is almost perpendicular to the methylene chain, while a significant contribution along the methylene occurs for HPS, and evidence is presented for extensive delocalization of the charges in the headgroups, which might be relevant for the binding of the drugs.

The dynamics of a chromophore sequestered within the nonplanar regions of micelles and unilamellar vesicles comprised of decanoic acid/sodium decanoate are reported. The results have shown that these structures do produce different local environments, with the unilamellar vesicle being of slightly lower effective viscosity than the micelle.

The behavior of C343, a common molecular probe used in solvation dynamics experiments, is studied in homogeneous media and in aqueous and nonaqueous reverse micelles (RMs). It is shown that C343 forms stable H-bond complexes with solvents with high ability as H-bond acceptors and ability as H-bond donors and inside RMs, the C343 behavior has depended on the polar solvent encapsulated, revealing the different types of interactions between the solvents and sodium 1,4-bis(2-ethylhexy) sulfosuccinate (AOT).

The helix--coil transition of a series of alanine-based peptides in water pool of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelles using CD spectroscopy was studied. The results show that dehydration of the peptide backbone increases the stability of helical conformation and the thermal unfolding transition of these peptides can either be very noncooperative or very cooperative depending on water content and peptide chain length.

The effect of sodium chloride (NaCl) on the micellization, surface activity, and the evolution in the shape and size of n-octyl-[beta]-D-thioglucopyranoside (OTG) aggregates is investigated. The cmc values of OTG decreases as the NaCl concentration decreases and the adsorption data in the air-liquid interface showed that the adsorption of the surfactant occurs spontaneously and becomes more favorable in the presence of increasing NaCl concentrations.