Molecular-hydrodynamic study of poly(N-methyl-N-vinylacetamide) macromolecules

Okatova, O. V.; Mikhailova, A. V.; Ul’yanova, N. N.; Гаврилова, И. И.; Panarin, E. F.

doi:10.1134/s1811238210010078

Cited by 8 publications

(3 citation statements)

References 13 publications

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“…Water solution of poly(N-vinyl formamide) (PVFA) was studied with Photocor instrument (Figure 4). A 109 kDa fraction obtained according to [19] was used. PVFA is a hydrophilic nonionizable polymer that has no reason to associate in an aqueous medium.…”

Section: Processing Of Model Datamentioning

confidence: 99%

Study of Nanoparticles by Dynamic Light Scattering: Processing Challenges

Annenkov

2023

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Nanoparticles are of great importance for various scientific and technological applications, drug discovery, ecology, molecular biology, etc. Size is a basic characteristic of any particle, and dynamic light scattering is beyond competition when measuring particle size in dispersions ranging from nanometers to micrometers. Unfortunately, this method has a serious problem in processing and interpreting experimental data. Instrument noise and polydispersity of the sample lead to the situation when one initial autocorrelation function corresponds to several different particle size distributions. Sometimes these different solutions of the inverse task can be found by changing parameters in the software. Sometimes the scientist cannot be suspicious of possible other solutions, having one result from the program. In this article I demonstrate the problem on model and experimental data using three known programs: CONTIN, the Malvern Zetasizer and DynaLS. I also present my own free program Autocor, which allows to test our own hypotheses about the modality and shape of the particle size distribution by optimizing the parameters of our own models with a small number of degrees of freedom.

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Section: Processing Of Model Datamentioning

confidence: 99%

Study of Nanoparticles by Dynamic Light Scattering: Processing Challenges

Annenkov

2023

Preprint

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“…Poly( N -methyl- N -vinylacetamide) samples were synthesized by radical polymerization of MVAA in the presence of water-soluble azobis(2,2-methylpropanediamine) hydrochloride. The details of synthesis are described in refs − .…”

Section: Experimental Partmentioning

confidence: 99%

Strong Linear Polyelectrolytes in Solutions of Extreme Concentrations of One–One Valent Salt. Hydrodynamic Study

et al. 2014

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Two series of highly charged linear aliphatic polymerssodium polystyrene-4-sulfonate and random copolymer of N-methyl-N-vinylacetamide and N-methyl-N-vinylamine hydrochloridewere studied in water solution without added salts and in solutions containing up to 5 M NaCl. Intrinsic viscosity in salt-free solutions was estimated by a method proposed earlier [Pavlov et al. Russ. J. Appl. Chem. 2006, 79, 1407−1412. Molecular characteristics were obtained in 0.2 M NaCl. The polyelectrolytes were studied in more than 10-fold range of molar mass. Qualitatively, the conformational status of the polyelectrolyte chains in different ionic strength was defined with the Kuhn−Mark−Houwink−Sakurada plots normalized by the value of linear chain density. In salt-free solution both polyelectrolytes could be attributed to extra rigid chains with the statistical segment length of 650 nm for sodium polystyrene-4-sulfonate and 100 nm for copolymer chains. Such statistical segment lengths are provided by short-range electrostatic intrachain interactions and are comparable with the Debye screening length. At extremely high NaCl concentration polyelectrolyte chains became discriminated by their degree of hydrophobicity. Chains of hydrophobic nature are compacted up to preglobular state, whereas the chains of the hydrophilic nature stay in the conformation of swelling coils at the highest concentration of NaCl.

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“…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.…”

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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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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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Molecular-hydrodynamic study of poly(N-methyl-N-vinylacetamide) macromolecules

Cited by 8 publications

References 13 publications

Study of Nanoparticles by Dynamic Light Scattering: Processing Challenges

Study of Nanoparticles by Dynamic Light Scattering: Processing Challenges

Strong Linear Polyelectrolytes in Solutions of Extreme Concentrations of One–One Valent Salt. Hydrodynamic Study

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

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