Conformation of carboxymethylcellulose in cadoxen-water solutions

Lavrenko, P. N.; Okatova, O. V.; Tsvetkov, V.N.; Dautzenberg, H.; Philipp, B.

doi:10.1016/0032-3861(90)90131-h

Cited by 43 publications

(4 citation statements)

References 13 publications

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“…L p was calculated from the intrinsic viscosity according to Yamakawa et al The same value is obtained by Kamide et al who applied various theoretical models (Benoit−Doty and Yamakawa 4 ) to published viscosity data. A value of 8.5 nm was obtained by Lavrenko et al from viscosity measurements of CMC solutions in mixtures of water and cadoxen (Cd 2+ −ethylenediamine complex).…”

Section: Introductionmentioning

confidence: 98%

Persistence Length of Carboxymethyl Cellulose As Evaluated from Size Exclusion Chromatography and Potentiometric Titrations

Hoogendam¹,

Keizer²,

Stuart³

et al. 1998

Macromolecules

145

132

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The intrinsic persistence length of carboxymethyl cellulose (CMC) is determined by size exclusion chromatography in combination with multiangle laser light scattering (SEC−MALLS) as well as from potentiometric titrations. Samples with degree of substitution (ds) ranging from 0.75 to 1.25 were investigated. The relation between molar mass M and radius of gyration R g as obtained by SEC−MALLS is determined in 0.02, 0.1, and 0.2 mol L-1 NaNO3. Using the electrostatic wormlike chain theory a bare (intrinsic) persistence length L p0 of CMC is assessed at 16 nm, irrespective of the degree of substitution. A somewhat lower value (12 nm) is obtained when Odijk's theory for the description of polyelectrolyte dimensions is applied. The difference between L p0 assessed from both models is discussed briefly. Potentiometric titrations were carried out in NaCl solutions (ranging from 0.01 to 1 mol L-1). From the titrations the radius of the CMC backbone was obtained by application of the model of a uniformly charged cylinder. The radius amounts to 0.95 nm for CMC ds = 0.75, and increases to 1.15 nm for CMC with ds = 1.25. The pK for the intrinsic dissociation constant of the carboxyl groups (i.e., at zero degree of dissociation) amounted to 3.2. L p0 was also deduced from potentiometric titrations. A model developed by Katchalsky and Lifson, which relates the dissociation behavior of a polyelectrolyte to the stiffness of its chain, was applied to CMC. From analyses of the potentiometric titrations an intrinsic persistence length of 6 nm was deduced. The difference between L p0 assessed from SEC−MALLS and potentiometric titrations is discussed briefly.

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Section: Introductionmentioning

confidence: 98%

Persistence Length of Carboxymethyl Cellulose As Evaluated from Size Exclusion Chromatography and Potentiometric Titrations

Hoogendam¹,

Keizer²,

Stuart³

et al. 1998

Macromolecules

145

132

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“…In this work, we have used sodium carboxymethylcellulose (carboxyMC), an anionic polysaccharide with an intermediate backbone rigidity ( l p int = 5−16 nm − ). CarboxyMC is a useful component of many food systems and is widely used as a thickener and binding agent in pharmaceutical applications.…”

Section: Introductionmentioning

confidence: 99%

Surfactant-Induced Collapse of Polymer Chains and Monodisperse Growth of Aggregates near the Precipitation Boundary in Carboxymethylcellulose−DTAB Aqueous Solutions

et al. 2002

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We have studied aqueous solutions of a polyelectrolyte, carboxymethylcellulose, which is an anionic cellulose derivative, and a cationic surfactant, dodecyltrimethylammonium bromide (DTAB). We have investigated the interactions between the two species, both at the air/water interface and in the bulk, for increasing DTAB concentrations. Mixed surfactant/polymer aggregates are formed at the air/water surface at extremely low surfactant concentrations, whereas bulk aggregates are formed later, above a critical aggregation concentration (cac). A small viscosity maximum at the cac reveals a small degree of bridging of the polymer chains by the surfactant. Above the cac, the viscosity drops, indicating that the polymer chains undergo a rapid collapse. At higher surfactant concentrations, light scattering shows the existence of larger structures, which are surprisingly monodisperse and whose size increases with surfactant concentration. At still higher surfactant concentrations, a classical strong associative phase separation takes place. During the evolution of bulk properties, the surface tension remains constant, suggesting that the surface aggregates remain unchanged.

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“…Sodium carboxyMC is a water-soluble, anionic, linear random multiblock copolymer. , This polymer has an intermediate intrinsic persistence length l p int = 5−16 nm. − We used here sodium carboxyMC12, denoting Blanose 12M31P (Aqualon Hercules) having a substitution degree DS of 1.23 (0 < DS ≤ 3 and corresponding to the average number of hydroxyl groups substituted by carboxymethyl groups per monomer). This highly purified polymer is used in food, cosmetic, and pharmaceutical applications (minimum purity of 99.5%) and was used as supplied.…”

Section: Methodsmentioning

confidence: 99%

Ordered Structures in Carboxymethylcellulose−Cationic Surfactants−Copper Ions Precipitated Phases: in Situ Formation of Copper Nanoparticles

et al. 2008

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Small-angle X-ray scattering has been used to investigate the nanostructures in precipitated phases of carboxymethylcellulose/oppositely charged C(n)TAB surfactants mixtures in interaction with bivalent copper ions. In copper-free precipitates, a transition from a 2D hexagonal phase H(I) to a micellar cubic surfactant structure Pm3n was found on increasing the polymer concentration (n = 14, 16). By addition of small amounts of copper ions, the internal structure also changes from H(I) to Pm3n cubic and finally turns into a less-ordered phase. The concentration at which this transition occurs strongly depends on the surfactant tail length. The presence of copper ions in the precipitated phase leads at the same time to a disorganization of the surfactant micelles' order and to the formation of a lamellar ordering, revealed by the presence of additional diffraction peaks above 10 mM copper. We used the polymer/surfactant networks as template systems, controlled by the copper ion content, for preparing embedded copper nanoparticles via in situ reduction of copper sulfate by sodium borohydride. The zerovalent copper particles formed in the cubic lattice are well-defined in size (less than 10 nm) and have a homogeneous distribution, whereas they are very polydisperse when the reduction is performed in the unorganized phase because the lack of order in the matrix does not protect them from aggregation.

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Conformation of carboxymethylcellulose in cadoxen-water solutions

Cited by 43 publications

References 13 publications

Persistence Length of Carboxymethyl Cellulose As Evaluated from Size Exclusion Chromatography and Potentiometric Titrations

Persistence Length of Carboxymethyl Cellulose As Evaluated from Size Exclusion Chromatography and Potentiometric Titrations

Surfactant-Induced Collapse of Polymer Chains and Monodisperse Growth of Aggregates near the Precipitation Boundary in Carboxymethylcellulose−DTAB Aqueous Solutions

Ordered Structures in Carboxymethylcellulose−Cationic Surfactants−Copper Ions Precipitated Phases: in Situ Formation of Copper Nanoparticles

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