Recent citations nonlocal effects in shear banding of polymeric flows sandra lerouge and peter d. Pdf superposition rheology of shearbanding wormlike. Giant micelles resulting from the growth of cylindrical 1d structures are equilibrium or. Rheological characterizations of wormlike micellar solutions. Transient extensional rheology of wormlike micelle solutions. Jan 21, 2016 please use one of the following formats to cite this article in your essay, paper or report. Wormlike micelles form a transient network structure in which the micelles entangle with one another. For amphiphilic block copolymers with value of f nearly 35%. Targeted worm micelles biomacromolecules acs publications. Among these, worm like micelles, cubic liquid crystals, and hexagonal liquid crystals are found to form gels with high viscosity. By imposing a shear oscillation, the interface between high and low. Worm like micelles form a transient network structure in which the micelles entangle with one another. Nonlinear rheology of surfactant wormlike micelles bridged by telechelic polymers. Rheology of wormlike micelles from nonequilibrium molecular.
Feb 01, 2011 in this work, the rheology of complex fluids, i. Particularly striking is the spherical to wormlike micelle transition, where the viscosity changes by a factor of more than 104. Aug 27, 2007 a twofluid semiphenomenological model is proposed for superposition rheology in the shear banding regime, which allows us to extract a characteristic velocity for the interface dynamics from experiments involving only a standard rheometer. Pdf nonlinear rheology of surfactant wormlike micelles. However, the imposition of very large stresses and strains on wormlike micelle solutions can result in a wealth of complex phenomena.
Rheological behavior of wormlike micelles in a mixed. A quantitative fit to the extensional rheology of each of the wormlike micelle solution tested is achieved with a fenepm model having as few as two relaxation modes. Wormlike micelles are also considered as models for polymers because of their nonlinear rheological properties. Among these, wormlike micelles, cubic liquid crystals, and hexagonal liquid crystals are found to form gels with high viscosity. A diblock copolymer made of poly1,4butadieneblockpolyethylene oxide, with a degree of polymerization of the polybutadiene and polyethylene oxide blocks of 37 and 57, respectively, selfassembles in water as wormlike micelles determined by small angle neutron scattering with an average diameter of. Sep 01, 2007 superposition rheology of shearbanding wormlike micelles ballesta, pierre 20070901 00. Wormlike micelle solutions are submitted to smallamplitude oscillatory shear superimposed to steady shear in the shear banding regime. In a semidilute aqueous solution under certain conditions, surfactant molecules will self assemble to form wormlike micelles. However, experimental results prove that the scaling law is. The terminology introduced was that of giant 5,11,12 or wormlike 6,810 micelles, instead of. Transient extensional rheology of wormlike micelle. Rheology of wormlike micelles with varying hydrophobicity.
Rheooptical study of wormlike micelles undergoing a shear. The mechanism proposed for shear thickening is that this system undergoes shearinduced micellar growth and a transition from rod like micelles to aligned worm like micelles. The leastaligned state of the plms is observed to migrate from the total strain extreme toward. Statics and dynamics of wormlake surfactant micelles 6871 for cylinders that are long compared to i, the main departure from conventional theory of polymer solutions 29,30 is that in micellar systems, the reversibility of the selfassembly process ensures that in polymer language the molecular weight distribution mwd of the wormlike polymeric species is in thermal equilibrium. Rheooptical study of wormlike micelles undergoing a. Please use one of the following formats to cite this article in your essay, paper or report. Rheooptical study of wormlike micelles undergoing a shear banding flow r. Jeanfranqois bemet, jacqueline appell, and gr6goire porte. By interpreting the peak in the scattered intensity as a correlation distance, the au. Wormlike micelles of almost the same diblock copolymer, but with a smaller. We have studied the linear and nonlinear rheology of dilute aqueous solutions of the surfactant system ctat cetyltrimethylammonium tosilate at 25 c. Microstructure and dynamics of wormlike micelles formed by mixing.
When micelles grow and become wormlike, the aggregates are much like. Yet, if aromatic additives like salts like sodium salicylate, nasal are added into the system, the cmc of the transition is lowered, so the spherical to worm like micelle transition happens at lower concentrations, as well as the viscoelastic behavior. Superposition rheology of shearbanding wormlike micelles superposition rheology of shearbanding wormlike micelles ballesta, pierre 20070901 00. Dynamic viscoelastic experiments were performed on mixtures of cetyl trimethylammonium tosylate ctat and cetyl trimethylammonium 3hydroxy naphthalene 2carboxylate ctahnc to understand the effect of hydrophobicity of the counterions on the structure of aggregates formed. Olmstedpredicting the effect of additives on wormlike micelle and liquid crystal formation and rheology with phase inversion. Due to their unusual rheological behaviour, great attention has been focused on the effect of shear on the structure of these elongated aggregates. Constituent copolymers are endbiotinylated to mediate high affinity binding of worm micelles to both avidinbearing surfaces and biotinspecific receptors on smooth muscle cells. Statics and dynamics of wormlike surfactant micelles. The rheology of wormlike micellar fluids request pdf.
Pdf we study the effect of salt content on the rheological properties of wormlike micelles formed from hexadecyltrimethylammonium bromide. Attention to these systems is given in section 3 of this chapter. Yet, if aromatic additives like salts like sodium salicylate, nasal are added into the system, the cmc of the transition is lowered, so the spherical to wormlike micelle transition happens at lower concentrations, as well as the viscoelastic behavior. The rheological properties of such phases are very interesting and have been the subject of a large number of experimental and theoretical studies in recent years. Characterization of wormlike micelles based on rheology. Wormlike micelles and vesicles in mixed surfactants. Superposition rheology of shearbanding wormlike micelles. Structure, rheology, and microrheology of wormlike. The rheology and microstructure of branched micelles under shear. Rheology of nematic wormlike micelles article pdf available in journal of rheology 394.
The rheology and microstructure of branched micelles under. R a and boek, e s, the rheology of wormlike micellar. The rheology and shearinduced structures of a series of selfassembled surfactant wormlike micelles wlms with varying levels of branching are measured using rheo and. The degree of branching in the mixed cationicanionic surfactant ctatsdbs wlms is. The rheology of solutions of wormlike micelles formed by oppositely charged surfactant mixtures cationic cetyl trimethylammonium ptoluene sulfonate, ctat, and anionic sodium dodecyl sulfate, sds, in the dilute and semidilute regimes, were studied under simple shear and porous media flows.
By imposing a shear oscillation, the interface between high and lowshear regions oscillates in time. Contrasting effects of temperature on the rheology of. Several surfactant molecules selfassemble in solution to form long, cylindrical, flexible wormlike micelles. The viscoelastic properties of the wormlike micelles can be predicted using simple theological models. Contrasting effects of temperature on the rheology of normal and reverse wormlike micelles shihhuang tung, yien huang, and srinivasa r. Other than the entangled wormlike micelles, a few branched micelles with joints. The rheology of solutions of wormlike micelles formed by oppositely charged surfactant mixtures cationic cetyl trimethylammonium ptoluene sulfonate, ctat, and anionic sodium dodecyl sulfate, sds, in the dilute and semidilute regimes, were. Surfactant mixtures will be the preferred choice than. Smallangle neutron scattering sans and rheology are used to probe the wormlike micelles formed in mixtures of a cationic cetyl trimethylammonium tosylate. Shear rheology and porous media flow of wormlike micelle. The nonlinear rheology of worm like micelles has appeared lately as a topic of interest in the field of colloidal physics. Application note micelles using rheology characterizing. Structure, rheology, and microrheology of wormlike micelles.
Equilibrium properties and shear banding transitions. Main factor governing the morphology of micelles is the hydrophilichydrophobic balance of the block copolymer defined by the hydrophilic volume fraction, f. Micellar structure changes in aqueous mixtures of nonionic. These wormlike micelles are found to overlap with each other and entangle into threedimensional network structures, which corroborate the results of the rheology measurements, i. Multiscale investigation of the nonlinear rheology of wormlike micelles by abdulrazaqabiodunadams adissertationsubmittedinpartialfulfillment. The ability of wormlike micelles in increasing the viscosity. Distinguishing between linear and branched wormlike micelle. Structure and rheology of wormlike micelles springerlink. Vane rheometry of an aqueous solution of wormlike micelles v. The micelles are dynamic in structure since they can break and reform, providing an additional mode of relaxation. Structure and rheology of wormlike micelles sciencedirect. Hassan the journal of physical chemistry b 2011 115 37, 1081710825. Rheology of wormlike micelles with varying hydrophobicity of. Rheology of branched wormlike micelles university of delaware.
These micelles can be entangled with each other leading to viscoelastic phases. Anderson and others published the rheology of wormlike micellar fluids find, read and cite all the research you need on. By a combination of light scattering, rheology and magnetic birefringence, it was rst shown that under certain conditions, cylindrical micelles could be very long, up to micrometer in contour length, and exible 410. In special situations, they can also grow in two dimensions. Above a threshold concentration, they entangle into a dynamic network, reminiscent of polymer solutions, and display remarkable viscoelastic properties, which have been exploited in numerous industrial and technological fields. The nonlinear rheology of wormlike micelles has appeared lately as a topic of interest in the field of colloidal physics. At a critical stress, nearly independent of strain rate, the wormlike micelle solutions filaments are found to fail through a dramatic rupture near the axial midplane. In particular, wormlike micelles are well known to form gels even when the surfactant concentration is low. Due to their unusual rheological behaviour, great attention has been focused on the effect of shear. Control of surfactant solution rheology using mediumchain cosurfactants z. Shearinduced transitions and instabilities in surfactant. Application note micelles using rheology characterizing the. The molecular model considers that the surfactant molecule is composed of a hydrophilic head, affine to solvent, and a hydrophobic tail made of four monomers. A twofluid semiphenomenological model is proposed for superposition rheology in the shear banding.
The total surfactant concentration is fixed at 100 mm, and the ratio of the two counterions. N2 the topology of selfassembled surfactant solutions includes varying degrees of micellar branching, ranging from linear wormlike micelles to a micellar network. The topology of selfassembled surfactant solutions includes varying degrees of micellar branching, ranging from linear wormlike micelles to a. Equilibrium properties and shear banding transition article pdf available july 2004 with 331 reads how we measure reads.
Formation of wormlike micelles in mixed nhexadecyln. Cylindrical micelles can grow into very long wormlike micelles with increasing surfactant concentration. They could also be used for drag reduction 53 in the future, and they arc model fluids for many concepts of complex fluids science. Vane rheometry of an aqueous solution of wormlike micelles. In particular, worm like micelles are well known to form gels even when the surfactant concentration is low. The rheology of wormlike micellar fluids semantic scholar. Herve tabuteau, laurence ramos, kaori nakayayaegashi, masayuki imai and christian ligoure. Lamellar structures at given concentrations form liquid crystalline phases exhibiting a complex rheological behavior. Wormlike micelles are elongated flexible selfassembly structures formed by the aggregation of amphiphiles.
Worm like micelles of almost the same diblock copolymer, but with a smaller. Globular micelles cannot only grow unidimensionally to wormlike micelles. One reason for this interest is due to their remarkable rheological properties. The mechanism proposed for shear thickening is that this system undergoes shearinduced micellar growth and a transition from rodlike micelles to aligned wormlike micelles. These observations demonstrate how sensitive the extensional rheology of wormlike micelles is to. Rheology of branched wormlike micelles university of. Multiscale investigation of the nonlinear rheology of. Here we show that worm micelles can be targeted to cells with internalization and delivery of nontoxic dyes as well as cytotoxic drugs. The rheological behavior of worm like micelles follows simple scaling laws 118, 119, also discussed later in the chapter. The rheological characteristics of these wms are comparable to polymer solutions 56. This strongly viscoelastic surfactant solution is an almost perfect maxwellian fluid in the lowfrequency range.
The effect of preshear on the extensional rheology of. Aug 25, 2003 a quantitative fit to the extensional rheology of each of the wormlike micelle solution tested is achieved with a fenepm model having as few as two relaxation modes. Wormlike micelles living polymers abrupt changes cylindrical micelles breaking and forming large shear rates most are small fragments2 25 1 3 4 0 dilute solution concentrated solution wormlike micelle log log p sunthar iit bombay polymer rheology comflu 2009 32 44. Characterization of worm like micelles based on rheology. Unusual scaling in the rheology of branched wormlike micelles formed by cetyltrimethylammonium bromide and sodium oleate prasuna koshy, v. Under these conditions, the disklike structures usually grow indefinitely large and the systems forms l.
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