Interaction of naphthalene‐labeled poly(hydrochloride quaternized 2‐norbornene‐5‐methyleneamine) with O/W microemulsion droplets

Interaction between naphthalene‐labeled poly(hydrochloride quaternized 2‐norbornene‐5‐methyleneamine), poly(HCQNBMA)/NA (luminophore), and quencher, emulsifier or coemulsifier in the aqueous or microemulsion media was studied by using steady‐state fluorescence measurements. Fluorescence experiments were carried out with poly(HCQNBMA)/NA dissolved in the aqueous solutions of ionic and nonionic emulsifiers, emulsifier/n‐hexane/water microemulsion (A) and emulsifier/n‐hexane/1‐pentanol/water microemulsion (B), respectively. The intensity of fluorescence emission of poly(HCQNBMA)/NA was much higher in the aqueous phase than in microemulsion. Furthermore, the aqueous solution of ionic emulsifier increased the monomer emission. The increase in the monomer emission can be ascribed to the shielding of the naphthalene (NA) groups by SDS micelles. This separates NA groups from each other, which depresses the deactivation of excited states. The strong decrease in monomer emission within the microemulsion media probably results from the elongated conformation structure of the polymer molecule, and higher conformation freedom of NA groups, which increases interaction between the probe and the quencher. The formation of nonfluorescence clusters is not ruled out. The quenching of NA emission by nitromethan (NM) is much stronger in microemulsion than in the aqueous phase, and the quenching is more pronounced for the low molecular weight 2‐norbornene‐5‐methoxylnaphthalene (NBMNA) than for its polymer. The extent of penetration of reactants into the interfacial layer governs quenching of hydrophobic NA probe by hydrophilic quencher. Furthermore, the quenching events are connected with the thickness and density of the interfacial layer, as well as its charge. The addition of coemulsifier (1‐pentanol) increases the total surface area of the microdroplets, the entry rate of reactants into the microdroplets, and the interaction of hydrophobic and hydrophilic reactants. The quenching events are more pronounced in the close packed o/w interfacial layer than in the loosely packed one. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 101–114, 2001     

Partitioning of unsaturated hydrophilic monomer in microemulsion media monitored by pyrene fluorescence method

The extent of intra‐ and interchain associations of (un)charged water‐soluble monomers in the homogeneous and micellar solutions was studied with steady‐state fluorescence spectroscopy. Fluorescence spectroscopic experiments were performed on uncharged (acryl amide) and charged hydrophilic monomers [zwitterionic 3‐dimethyl(methacryloyloxyethyl)ammonium propane sulfonate (DMAPS), etc.] with pyrene as a probe. In both the homogeneous and micellar solutions, linear Stern–Volmer plots were obtained that implied that the quenching process can be considered as totally dynamic. The Stern–Volmer constant (K_SV) for DMAPS decreased with an increasing dielectric constant of solvent and the concentration of simple electrolyte. An abrupt decrease in K_SV was observed in the presence of a small amount of anionic emulsifier [below the critical micelle concentration (cmc)]. The dependence of K_SV on pH for DMAPS was described by a curve with a maximum at about pH = 7. This was interpreted in terms of segregation of DMAPS and the variation of a optimal microenvironment for the probe and quencher with pH. The quenching rate in the micellar solutions strongly increased above the cmc but was lower than that in the homogeneous solutions. In the micellar solutions (above the cmc), the microenvironment for an interaction between the probe and quencher was suggested to be the whole microdroplet. The dependence of K_SV on pH for DMAPS is described by a curve with a maximum at about pH = 9.3. The synergistic effect arises from the segregation of charged quencher molecules within the microdroplets. The complex (or strong interaction) between quencher and additive(s) is supposed to increase the dynamic nature of microdroplets that provides an optimal microenvironment for probe and quencher. A good coemulsifier, however, removes quencher from the interface and creates a barrier for entering monomer (quencher) into the core of micelles; therefore, quenching is depressed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 571–581, 2003     

Lyotropic liquid crystalline epoxide-amine addition polymers

A new type of amphiphilic polymer is described. It is built up from a hydrophilic main chain and hydrophobic n-alkyl chains directly attached to the monomer units. With this chemical constitution the formation of micelles and micellar aggregates is expected, where the hydrophobic side chains are organised on a convex surface. The polymers are synthesised by the polyaddition of tetra-, hexa- and octaethylene diglycidyl ether and n-dodecyl- and n-hexadecyl amine. Polymers are synthesised by systematic variation of the hydrophilic/lipophilic balance (HLB). Although the HLB of the polymers is varied, only a uniform polymorphism is observed in aqueous solutions. A broad miscibility gap and a hexagonal phase at polymer concentrations of 70–80 wt.% polymer exist. Due to the new head-type constitution of the polymers, the hexagonal phase is expected to be of the inverse type.     

The preparation of sterically stabilized polymer dispersions

The emulsion polymerizations of styrene (St) and butyl acrylate (BA) stabilized by nonionic polyoxyethylene type emulsifiers did not show the long stationary rate interval. This was discussed in terms of two opposing effects: 1) the decreased monomer concentration at the reaction loci due to the depletion of monomer droplets or depressed monomer droplet degradation and 2) the increased number of polymer particles with increasing conversion. The continuous particle nucleation is attributed to the continuous release of emulsifier from the emulsifier saturated monomer droplets and/or the presence of monomer swollen micelles (microdroplets). The limited particle flocculation operative at lower emulsifier concentrations increases the nonstationary-state polymerization. The particle agglomeration is accompanied by the increased reaction order x (N_p vs. [E]^x) above 0.6. The increased uniformity of monomer emulsion stabilized by Tween 20 by homogenization of monomer emulsion increased the final conversion and the polymerization rate as well. The polymerization rate vs. conversion curve of the homogenized emulsion characterized with broader stationary rate interval reminds the four rate intervals system typical for miniemulsion. The accumulation of polymer and nonionic emulsifier within the monomer phase preserves the monomer droplets up to high conversion. The decreased monomer droplet degradation rises the monomer-starved condition or the depressed transport of both monomer and emulsifier to the reaction loci.     

Sterically and electrosterically stabilized emulsion polymerization. Kinetics and preparation

The principal subject discussed in the current paper is the radical polymerization in the aqueous emulsions of unsaturated monomers (styrene, alkyl (meth)acrylates, etc.) stabilized by non-ionic and ionic/non-ionic emulsifiers. The sterically and electrosterically stabilized emulsion polymerization is a classical method which allows to prepare polymer lattices with large particles and a narrow particle size distribution. In spite of the similarities between electrostatically and sterically stabilized emulsion polymerizations, there are large differences in the polymerization rate, particle size and nucleation mode due to varying solubility of emulsifiers in oil and water phases, micelle sizes and thickness of the interfacial layer at the particle surface. The well-known Smith-Ewart theory mostly applicable for ionic emulsifier, predicts that the number of particles nucleated is proportional to the concentration of emulsifier up to 0.6. The thin interfacial layer at the particle surface, the large surface area of relatively small polymer particles and high stability of small particles lead to rapid polymerization. In the sterically stabilized emulsion polymerization the reaction order is significantly above 0.6. This was ascribed to limited flocculation of polymer particles at low concentration of emulsifier, due to preferential location of emulsifier in the monomer phase. Polymerization in the large particles deviates from the zero-one approach but the pseudo-bulk kinetics can be operative. The thick interfacial layer can act as a barrier for entering radicals due to which the radical entry efficiency and also the rate of polymerization are depressed. The high oil-solubility of non-ionic emulsifier decreases the initial micellar amount of emulsifier available for particle nucleation, which induces non-stationary state polymerization. The continuous release of emulsifier from the monomer phase and dismantling of the non-micellar aggregates maintained a high level of free emulsifier for additional nucleation. In the mixed ionic/non-ionic emulsifiers, the released non-ionic emulsifier can displace the ionic emulsifier at the particle surface, which then takes part in additional nucleation. The non-stationary state polymerization can be induced by the addition of a small amount of ionic emulsifier or the incorporation of ionic groups onto the particle surface. Considering the ionic sites as no-adsorption sites, the equilibrium adsorption layer can be thought of as consisting of a uniform coverage with holes. The de-organization of the interfacial layer can be increased by interparticle interaction via extended PEO chains--a bridging flocculation mechanism. The low overall activation energy for the sterically stabilized emulsion polymerization resulted from a decreased barrier for entering radicals at high temperature and increased particle flocculation.     

A new design for light-breakable polymer micelles

A new and general design strategy is presented for amphiphilic block copolymers whose micellar aggregates can be dissociated by light. A diblock copolymer composed of hydrophilic poly(ethylene oxide) (PEO) and a hydrophobic polymethacrylate bearing pyrene pendant groups (PPy) was synthesized using ATRP. Upon UV light irradiation of polymer micellar solutions, the photosolvolysis of pyrene moieties results in their detachment from the polymer and converts the hydrophobic PPy block into hydrophilic poly(methacrylic acid). This effect leads to complete dissociation of polymer micelles.     

Amphiphilic azopolymers capable to generate photo-sensitive micelles

Amphiphilic macromolecular micelles are advantageous for drug delivery applications due to the decrease of side-effects, ease of screening drugs against degradation, long-term stability, targeted delivery and control of the amount of the released drug. A series of amphiphilic azo-polymers having a flexible or rigid main-chain were synthesized and characterized. The presence of chlorobenzyl side-groups allowed both the easy bonding of photo-sensitive or hydrophilic groups and good control of the degree of substitution. The chemical structure was confirmed by ¹H-NMR. The critical concentration of aggregation (CCA) was calculated using the fluorescence emission spectrum of pyrene. The interest was focused on a preliminary study concerning the disaggregation capacity of micelles under UV irradiation. The presence of micellar aggregates was confirmed by DLS and SEM and different organization of the amphiphilic polymers was evidenced depending on polymers concentration and polymers structure. In low polymer concentrations in water predominantly globular aggregates were formed. The increase in concentration increased the polydispersity index due to the fusion of micelles and formation of associates of globular aggregates, inter-micellar associates (clusters) and vesicles.      

Investigation of pH-responsive properties of polymeric micelles with a core-forming block having pendant cyclic ketal groups

In this study, three kinds of amphiphilic block copolymers, termed MPEG-block-PDMMA, MPEG-block-PCPMA, and MPEG-block-PMPMA, which were composed of one hydrophilic monomethoxy poly(ethylene glycol) (MPEG) block and one hydrophobic polyacrylate block bearing pendant six-member cyclic ketal groups, were synthesized by atom transfer radical polymerization (ATRP). These polymers can disperse in aqueous media to self-assemble into micellar aggregates with a spherical core-shell structure with mean diameter below 300 nm. The stimuli-responsiveness of polymeric micelles from MPEG-block-PDMMA was detected by fluorescence-probe technique at pH 3.5 and 37 °C. The effect of chemical architecture and composition of the polymers on the pH-responsive properties of polymeric micelles was also studied. A combination of pH and temperature to trigger release behavior of these polymeric micelles was discussed by comparing the encapsulated molecule release ability under various pH and temperature conditions and analyzing chemical structural changes of the polymer before and after the triggering.     

Remarkably stable amphiphilic random copolymer assemblies: A structure–property relationship study

Synthesis of a library of amphiphilic random copolymers from a single reactive pre‐polymer and their self‐assembly is reported. Post‐polymerization modifications of the parent polymer containing pendant N‐hydroxy succinimide (NHS) ester groups with various oligooxyethylene (OE) amines produce amphiphilic random copolymers with same degree of polymerization and equal extent of randomness. ¹H‐NMR and FT‐IR data indicate quantitative substitution in all cases. The critical aggregation concentration (CAC) for all the polymers is estimated to be in the range of 10^?5 M. Stability of these nano‐aggregates is studied by photoluminescence using time dependent F—rster Resonance Energy Transfer (FRET) between co‐encapsulated lipophilic dyes namely DiO and DiI in the hydrophobic pocket of the aggregates. These studies suggest remarkably high stability for all systems. However those with shorter hydrophilic pendant chains are found to be even more robust. Morphology is examined by high resolution transmission electron microscopy (HRTEM) which reveals multi‐micellar clusters and vesicles for polymers containing short and longer OE segments, respectively. Encapsulation efficacy is tested with both hydrophobic and hydrophilic guest molecules. All of them can encapsulate hydrophobic guest pyrene while a hydrophilic dye Calcein can be sequestered only in vesicle forming polymers. Lower critical solution temperature (LCST) is exhibited by only one polymer that contains the shortest OE chains. All polymers exhibit excellent cell viability as determined by MTT assay. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4932–4943     

Photophysics of a cationic biological photosensitizer in anionic micellar environments: combined effect of polarity and rigidity

A steady-state and time-resolved photophysical study of a cationic phenazinium dye, phenosafranin (PSF), has been investigated in well-characterized biomimetic micellar nanocavities formed by anionic surfactants of varying chain lengths, namely, sodium decyl sulfate (S(10)S), sodium dodecyl sulfate (S(12)S), and sodium tetradecyl sulfate (S(14)S). In all these micellar environments, the charge transfer fluorescence of PSF shows a large hypsochromic shift along with an enhancement in the fluorescence quantum yield as compared to that in aqueous medium. A reduction in the nonradiative deactivation rate within the hydrophobic interior of micelles led to an increase in the fluorescence yield and lifetime. The present work shows the degree of accessibility of the fluorophore toward the ionic quencher in the presence of surfactants of different surfactant chain lengths. The fluorometric and fluorescence quenching studies suggest that the fluorophore resides at the micelle-water interfacial region. The enhancements in the fluorescence anisotropy and rotational relaxation time of the probe in all the micellar environments from the pure aqueous solution suggest that the fluorophore binds in motionally restricted regions introduced by the micelles. Polarity and viscosity of the microenvironments around the probe in the micellar systems have been determined. The work has paid proper attention to the hydrophobic effect of the surfactant chain length on photophysical observations.     

Research on association between multi-sticker amphiphilic polymer and water-soluble β-cyclodextrin polymer

The host cyclodextrin polymer-P(AM/A-β-CD/NaA) is prepared by redox free-radical copolymerization. Additionally, the multi-sticker amphiphilic polymer-P(AM/BHAM/NaA) as a guest polymer is synthesized using micellar polymerization. The copolymer structures are characterized by ¹H NMR. Subsequently, all the polymers and inclusion complexes are evaluated in terms of apparent viscosity, optical absorption spectra and rheological property. The results indicate that the inclusion association between the cyclodextrin group (CD) and multi-sticker hydrophobic monomer (BHAM) is in accordance with ternary interaction (CD/BHAM?=?2:1). Because of the inclusion association between the host and guest polymers, the solution of inclusion complex has much higher viscoelasticity even under the low amphiphilic polymer concentration. When the molar ratio of CD to BHAM is 1:1, the critical aggregation concentration (CAC) of the inclusion complex solution still remains. Furthermore, above the CAC, two types of associations, inclusion association and inter-molecular hydrophobic association, can occur in the complex solution and these interactions were also verified by fluorescence spectroscopy and atomic force microscopy (AFM). In this paper, the inclusion rule of cyclodextrin polymer with the multi-sticker amphiphilic polymer is discussed, and the rule of the enhanced solution viscosity is further explored.     

Photophysical and Photochemical Processes in Micellar Systems

A fascinating feature inherent to aqueous surfactant solutions is the phenomenon of self-organization: above a certain critical concentration (the critical micelle concentration, CMC) detergent molecules associate spontaneously to build up structural entities of colloidal dimensions called micelles. The architecture of these agglomerates is such that the interior contains the hydrophobic alkyl chain of the amphiphile while the hydrophilic head groups are located at the surface and are in contact with bulk water. In the case of ionic micelles the interface is charged giving rise to an electrical double layer and a potential difference of up to several hundred millivolts between the micellar pseudophase and water. Thus micellar systems are microheterogeneous in character: the electrostatic potential and polarity prevailing in the interior of the aggregate differ from those of the bulk aqueous phase. A particularly attractive aspect of photochemical studies in micellar systems is the possibility of organizing the reactants at a molecular level: by comparison of the data in micelles with similar data in homogeneous solution one can learn about the molecular details of a given reaction and establish which conditions favor one pathway or another. In simple surfactant systems differences in rate and efficiency of a reaction will often be controlled by local electrostatic potentials and the compartmentalization of the reagents within the surfactant aggregates. Through the latter effect the statistics of probe distribution over the micelles becomes important in controlling fast photochemical events. Functional micelles are distinguished by the fact that the surfactant molecule contains a group which itself participates in the photoprocess. These units are unique in that self-assembly often introduces striking cooperative effects.     

Silica nanoparticles at interfaces modulated by amphiphilic polymer and surfactant

The interfacial behavior of silica nanoparticles in the presence of an amphiphilic polymer poly( N-isopropylacrylamide) (PNIPAM) and an anionic surfactant sodium dodecyl sulfate (SDS) is studied using neutron reflectivity. While the nanoparticles do not show any attraction to hydrophilic and hydrophobic surfaces in pure water, presence of the amphiphilic polymer induces significant adsorption of the nanoparticles at the hydrophobic surface. This interfacial behavior is activated due to interaction of the nanoparticles with PNIPAM, the amphiphilic nature of which leads to strong adsorption at a hydrophobic surface but only weak interaction with a hydrophilic surface. The presence of SDS competes with nanoparticle-PNIPAM interaction and in turn modulates the interfacial properties of the nanoparticles. These adsorption results are discussed in relation to nanoparticle organization templated by dewetting of charged polymer solutions on a solid substrate. Our previous studies showed that nanoparticle assembly can be induced to form complex morphologies produced by dewetting of the polymer solutions, such as a polygonal network and long-chain structures. This approach, however, works on a hydrophilic substrate but not on a hydrophobic substrate. These observations can be explained in part by particle-substrate interactions revealed in the present study.     

共溶剂性质对双亲性无规共聚物P(St-co-DM)胶束化行为及其性能的影响

以苯乙烯(St)和甲基丙烯酸二甲氨乙酯(DMAEMA)为共聚单体, 通过普通自由基溶液聚合合成了双亲性无规共聚物P(St-co-DM). 用傅里叶变换红外(FTIR)光谱、核磁共振氢谱(¹H NMR)、凝胶渗透色谱(GPC)和差示扫描量热(DSC)仪对聚合物结构进行表征. 研究了共溶剂的性质对P(St-co-DM)自组装胶束结构及其乳化性能的影响. 用透射电镜(TEM)和动态激光光散射(DLS)表征了自组装胶体粒子的形态、粒径大小及其分布. 通过测量胶束在甲苯/水界面的接触角表征胶束表面性能. 结果表明: P(St-co-DM)以四氢呋喃(THF)为共溶剂自组装时, 胶束的临界聚集水含量较大, 胶束表面亲水性较强, 流体力学半径较大; 用二氧六环或THF为共溶剂, 水为选择性溶剂, P(St-co-DM)自组装可以得到外层松散、内层比较密实的球状胶束, 用N,N-二甲基甲酰胺(DMF)为共溶剂时, 胶束整体呈现比较密实的球状胶束; 分别用DMF、二氧六环和THF为共溶剂制备的胶束, 其接触角均值都小于90°, 可形成O/W型(水包油型)乳液. 乳化实验结果表明, 以二氧六环和THF为共溶剂制备的胶束作为颗粒乳化剂制备的乳液性能较好.     

正离子型疏水改性聚氧乙烯单成相组分双水相系统的相行为

对正离子型疏水改性聚氧乙烯(HM-EO)单成相组分双水相系统的相行为进行了考察,并分析其电荷特性.HM-EO在水溶液中呈现两亲性,可以形成胶束,进而形成带电的胶束簇集体.通过改变溶液的pH值、盐浓度及添加带相反电荷的表面活性剂SDS,可改变胶束簇集体的带电状态,从而影响系统的相行为.增大pH值,有利于系统的分相.盐的添加也可以增大双水相两相区域,正离子影响次序为K+>Na+,负离子次序为SO42->F->Cl->Br->I-.进一步考察了HM-EO和SDS之间的相互作用,结果表明SDS能与HM-EO形成混合胶束簇集体,改变HM-EO双水相系统的带电特性.     

Synthesis of Y-shaped poly(solketal acrylate)-containing block copolymers and study on the thermoresponsive behavior for micellar aggregates

One novel type of Y-shaped amphiphilic copolymers with two hydrophobic poly(solketal acrylate) (PSA) branches and one hydrophilic monomethoxy poly(ethylene glycol) (MPEG) block was synthesized by atom transfer radical polymerization (ATRP). These Y-shaped polymers can disperse in aqueous media to self-assemble into micellar aggregates with a spherical core-shell structure. The aqueous copolymer solutions exhibited transmittancy transition in the temperature range of 30-60 °C via optical transmittance measurements. An interesting thermo-dependent size of the micellar aggregates was observed by dynamic light scattering techniques and transmission electron microscopy, which showed that the micelle diameters were decreased with temperature increasing. The nile red release from the micelles at 25 °C and 37 °C under various pHs showed that temperature has great influence on release behavior. With good biocompatibility, the micellar aggregates formed from MPEG-block-(PSA)(2) may serve as one promising thermosensitive nanovehicle for targeted drug delivery.     

聚(辛二酸-四甘醇酯)的合成及其微相分离结构的研究

通过熔融缩聚合成了一种新型的两亲性聚酯——聚(辛二酸-四甘醇酯)(PTEGSub),利用GPC,NMR,FTIR,TG,DSC等手段对聚合物的结构进行了表征.研究发现,在25℃时,PTEGSub在水中可以形成胶束,粒径主要集中在20～120nm之间,其临界胶束浓度(CMC)随分子量的升高而降低.通过TEM观察了在选择性溶剂中的胶束形态.利用AFM研究了PTEGSub的微相分离,发现聚合物膜中存在有球状的相分离结构.     

Modulated photophysics of 3-pyrazolyl-2-pyrazoline derivative entrapped in micellar assembly

The photophysical behavior of 3-pyrazolyl-2-pyrazoline derivative (PZ), a newly synthesized biologically active compound has been studied in micellar solutions of anionic sodium dodecyl sulfate (SDS), cationic cetyl trimethylammonium bromide (CTAB) and nonionic p- tert-octylphenoxy polyoxyethanol (Triton X-100, TX-100) micelle using steady state and time-resolved fluorescence spectroscopy technique. Influence of the micelles on the photophysics of PZ has also been investigated using different approaches. The location of the fluorophore PZ in the micelle has been identified by cetyl pyridinium chloride (CpCl) induced fluorescence quenching and micropolarity surrounding that fluorophore in micellar solution. The effect of urea on the steady state fluorescence and relaxation dynamics of the micelle bound probe has also been observed. The results have been interpreted in terms of the model that urea displaces water molecules from the micellar interface and the consequent destabilization leads to the expulsion of the probe molecules from the interfacial region. An attempt has been made to determine probe sensing microviscosities for these micellar microenvironments in the light of average reorientation times of the probe PZ.     

On the feasibility of using sodium octyl sulfate micelles for template polymerization of a cationic monomer

Spin probe EPR spectroscopy has been employed to study the effect of a cationic monomer, trimethyl(methacryloxyethyl)ammonium methyl sulfate, on the formation, local structure, and dynamics of sodium octyl sulfate micelles in aqueous solutions. It has been established that the monomer does not affect significantly the parameters of probe rotation in micelles of this surfactant, thereby indicating a weak interaction between the studied monomer and surfactant micelles. The absence of a template effect upon monomer polymerization in micellar sodium octyl sulfate solutions, which has been confirmed by unchanged molecular-mass characteristics of obtained polymers, indicates that it is inefficient to use sodium octyl sulfate micelles as a template for radical polymerization of cationic monomers in aqueous media, in contrast to sodium dodecyl sulfate micelles studied previously.     

Polymerization of oriented monomers. V. Radiation-induced polymerization of 3n-dodecyl-1-vinylimidazolium iodide in micellar aggregates

In the present study radiation-induced polymerization of 3n-dodecyl-1-vinylimidazolium iodide (I) in micellar aggregates was investigated. For comparison, the corresponding isotropic polymerization of I was also studied. Micellization was obtained in concentrated aqueous solutions; that is, above the monomer's critical micelle concentration (CMC) polymers obtained by both modes of polymerization were treated similarly and subsequently subjected to physical characterization. The main purpose of this study was to investigate whether the degree of organization of the monomer in micelles would affect polymer properties. Attempts to determine tacticity by ¹³C-NMR spectrometry failed because of the particular structure of the polymer. Crystallization of these polymers from ethyl alcohol or acetone was not possible as indicated by x-ray powder diffraction patterns that were characteristic of amorphous polymers. On the other hand, viscosity data of polymers do not depend on the mode of polymerization. It is therefore concluded that micellar aggregates are not sufficiently organized to affect polymer properties.