Determination of intrinsic viscosity of polyelectrolytes in salt-free solutions

Gubarev, A. S.; Zaitseva, I. I.; Sibileva, M. A.

doi:10.1134/s1070427206090035

Cited by 29 publications

(17 citation statements)

References 10 publications

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“…The same table lists The intrinsic viscosities in aqueous solutions were calculated as the initial slopes of the lnη r = f(c) depen dences for c → 0: [η]* = dlnη r /dc, where η r is the rela tive viscosity of the solution at concentration с. It was shown that the [η]* value determined in this way nearly coincides with the intrinsic viscosities deter mined by the classical isoionic dilution method [10]. From analysis of the data presented in Table 1, it fol lows that on passing from solutions with the lowest ionic strength to solutions with the highest ionic strength, the intrinsic viscosities of MVAA-MVAH copolymer fractions change by more than an order of magnitude over the whole range of molecular mass.…”

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confidence: 63%

Characteristic features of the behavior of charged hydrophilic and hydrophobic macromolecules in solutions of different ionic strength

et al. 2013

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16Polyelectrolytes attract considerable attention of researchers due to their ability to form interpolymer complexes with synthetic polymers and biopolymers. They are used as carriers for biologically active com pounds, as transporting agents in gene therapy for the delivery of genetic material (DNA) to the cells [1-3]. Some of them exhibit various types of biological activ ity: immunostimulating, membrane, antimicrobial, antiviral, and other types of activity [4]. In recent years, studies have concerned issues related to the role of hydrophobic hydrophilic interactions in the poly electrolyte chains under electrostatic interactions caused by the formation of complexes involving poly electrolytes or by the formation of surface films [5]. A large number of works are devoted to computer mod eling of polyelectrolytes and polyelectrolyte systems [6]. This study demonstrates for the fist time the dif ferences in the behaviors of strong polyelectrolytes having hydrophilic or hydrophobic backbones, which are revealed in the studies of polyelectrolyte solutions over a broad range of ionic strength.The conformation and the size of the linear charged macromolecules in aqueous solutions are determined, in addition to the contour length, by the linear electric charge density in the polymer chain and ionic strength of the solution. In addition, features of the chemical structure of the macromolecule, in par ticular, its hydrophobic or hydrophilic nature, can play a certain role in the formation of one or another con formation of the linear polyelectrolyte chain. To clar ify these issues, the random copolymer of N methyl N vinylacetamide and N methyl N vinylamine hydrochloride (MVAA-MVAH) was synthesized, hydrodynamic studies of its fractions were performed, and the results were compared with earlier data con cerning the hydrodynamic characteristic of sodium polystyrene 4 sulfonate (PSSNa) [7,8]. The non charged analogue of the MVAA-MVAH copolymer is water soluble poly N methyl N vinylacetamide (PMVAA), while hydrophobic polystyrene is the non charged analogue of PSSNa.The random copolymer MVAA-MVAH was pre pared by partial acid hydrolysis of the MVAA homopolymer. The details of synthesis and studies of the molecular characteristics of MVAA-MVAH copolymer fractions were reported earlier [9]. The degree of hydrolysis (copolymer composition) was determined by argentometric titration. The copolymer composition differs little for different fractions, the average content of MVAH being (43.6 ± 0.6)%. The molecular masses of the fractions determined from sedimentation diffusion analysis of the MVAA-MVAH copolymers in a 0.2 M solution of NaCl are presented in Table 1. The same table lists the intrinsic viscosities determined in H 2 O and in 0.2 and 5.0 M solutions of NaCl.The intrinsic viscosities in aqueous solutions were calculated as the initial slopes of the lnη r = f(c) depen dences for c → 0: [η]* = dlnη r /dc, where η r is the rela tive viscosity of the solution at concentration с. It was shown that the [η]* value determined in...

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Characteristic features of the behavior of charged hydrophilic and hydrophobic macromolecules in solutions of different ionic strength

et al. 2013

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“…Among all the extrapolation methods describe above, the Fedors equation has been reported within the past few years to be applicable for many polymers and to a much wider range of concentration with good linearity compared to other equations (Rotureau et al 2006;Maia et al 2011;Pavlov et al 2006;Durand 2007b).…”

Section: Empirical Methods For Intrinsic Viscosity Determinationmentioning

confidence: 99%

Aqueous solutions of HEC and hmHEC: effects of molecular mass versus hydrophobic associations on hydrodynamic and thermodynamic parameters

Vadodaria

English

2016

Cellulose

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Aqueous solutions of amphiphilic polymers usually comprise of inter-and intramolecular associations of hydrophobic groups often leading to a formation of a rheologically significant reversible network at low concentrations that can be identified using techniques such as static light scattering and rheometry. However, in most studies published till date comparing water soluble polymers with their respective amphiphilic derivatives, it has been very difficult to distinguish between the effects of molecular mass versus hydrophobic associations on hydrodynamic (intrinsic viscosity [g]) and thermodynamic parameters (second virial coefficient A 2 ), owing to the differences between their degrees of polymerization. This study focuses on the dilute and semi-dilute solutions of hydroxyethyl cellulose (HEC) and its amphiphilic derivatives (hmHEC) of the same molecular mass, along with other samples having a different molecular mass using capillary viscometry, rheometry and static light scattering. The weight average molecular masses (M W ) and their distributions for the nonassociative HEC were determined using size exclusion chromatography. Various empirical approaches developed by past authors to determine [g] from dilute solution viscometry data have been discussed. hmHEC with a sufficiently high degree of hydrophobic modification was found to be forming a rheologically significant network in dilute solutions at very low concentrations as opposed to the hmHEC with a much lower degree of hydrophobic modification which also enveloped the hydrophobic groups inside the supramolecular cluster as shown by their [g] and A 2 . The ratio A 2 M W /[g], which takes into account hydrodynamic as well as thermodynamic parameters, was observed to be less for associative polymers compared to that of the non-associative polymers.

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“…Since standard viscosity measurements require a large amount of materials, we have calculated the dynamic viscosity of each polymer solution using the Staudinger equation for the intrinsic viscosity h ¼ K h M a , where a and K h are the parameters tabulated for a variety of polymer/solvent systems. [39,40] Here, values of 0.69 and 0.017 cm 3 Á g À1 were taken for a and K h , respectively. The solution properties are summarized in Table 1.…”

Section: Molar Mass Influence On the Droplet Spreadingmentioning

confidence: 99%

The Spreading of Inkjet‐Printed Droplets with Varying Polymer Molar Mass on a Dry Solid Substrate

Perelaer

Smith

Bosch

et al. 2009

Macro Chemistry & Physics

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An experimental study on the spreading of inkjet printed droplets of a polystyrene/toluene solution with varied molar masses on solid dry surfaces is presented. The polymer's number‐averaged molar mass was varied between 1.5 and 545 kDa, which also caused a variation in the viscosity from 0.6 to 1.7 mPa · s. The results were compared with theoretical models for droplet spreading and were found to fit with an error between 2 and 20% with the predictions. Furthermore, the in‐flight evaporation of the free‐falling droplet was investigated for polystyrene/toluene solutions that have a constant vapor pressure by printing from a systematically increased height.

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Determination of intrinsic viscosity of polyelectrolytes in salt-free solutions

Cited by 29 publications

References 10 publications

Characteristic features of the behavior of charged hydrophilic and hydrophobic macromolecules in solutions of different ionic strength

Characteristic features of the behavior of charged hydrophilic and hydrophobic macromolecules in solutions of different ionic strength

Aqueous solutions of HEC and hmHEC: effects of molecular mass versus hydrophobic associations on hydrodynamic and thermodynamic parameters

The Spreading of Inkjet‐Printed Droplets with Varying Polymer Molar Mass on a Dry Solid Substrate

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