Translational friction and the characteristic visocity of polyamide benzimidazole molecules in solution

Selyunin, S.G; Shil'dyayeva, N.A.; Yakopson, S. M.; Efros, L. S.; Usova, S. V.

doi:10.1016/0032-3950(85)90200-x

Cited by 8 publications

(1 citation statement)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In all cases, the sedimentation boundaries preserved their unimodal nature throughout the experiment (~90 min). The primary experimental data were processed using well-known procedures [20,22,23]. The experiments on the Beckman XLI analytical ultracentrifuge were carried out at the rotor rotation rate n = 55 000 rpm using both interference and absorption optical devices (at the light wavelength l = 250 nm) at the concentration c = 0.03 0 10 32 g cm 33 .…”

Section: Methodsmentioning

confidence: 99%

Molecular Characteristics of Star-Like Polyvinylpyrrolidone with Fullerene C60 as the Branching Site in Dilute Solutions

et al. 2005

View full text Add to dashboard Cite

Star-like water-soluble macromolecules with fullerene as the branching site were synthesized by the reaction of fullerene C 60 with polyvinylpyrrolidone whose molecules contain one terminal primary amino group. The initial and C 60 -containing polymers were studied by UV spectroscopy, thin-layer chromatography, centrifugal sedimentation, translation diffusion, and viscometry in aqueous buffer solutions. Diffusion3sedimentation and sedimentation two-detector analyses of the initial and fullerene-containing samples were performed. The molecular weights of the polymers were estimated by the Svedberg equation. The proportion of the fullerene-containing segment in the samples synthesized was determined, and the number of the branches in the fullerene-containing macromolecules was estimated.Fullerenes have recently become a subject of active studies in macromolecular chemistry. The specific features of the chemistry of fullerenes are determined by their aromatic nature and a high symmetry. Both fullerene-containing polymers with covalently bound fullerenes and fullerene-based noncovalent complexes were synthesized [133]. Fullerenes and their derivatives exhibit a spectrum of biological properties. They are capable of penetrating lipid membranes and exhibit antioxidative, antimicrobial, and antiviral activities and immunomodulating properties [4 37].The biological properties of fullerenes should be studied with their water-soluble derivatives. There are published data on water-soluble derivatives of fullerene based on hydrophilic polymers such as poly(ethylene oxide) and polyvinylpyrrolidone (PVP), prepared by radical or anionic polymerization of the corresponding monomers in the presence of fullerene [83 10], as well as on noncovalent complexes of fullerene with PVP [11,12]. Water-soluble compounds of fullerene based on polyalkylenimines and polyoxyethylene were synthesized by polymer-analogous transformations [13,14]. Reactions of amine-containing polymers with fullerenes represent a convenient method of synthesis of their polymeric derivatives, since primary aliphatic amino groups under mild conditions easily react with fullerenes. This procedure was used for synthesizing compounds based on polyalkylenimines, polyallylamine, and allylamine copolymers with styrene, methyl methacrylate, and hydroxypropyl methacrylate [15,16]. The reactions of fullerenes with polymers containing one terminal amino group should yield star-like derivatives, as revealed for polystyrene, polyoxyethylene, and polyoxypropylene [17,18].In this work, we studied reactions of fullerene C 60 with a water-soluble polymer, poly-N-vinylpyrrolidone containing a terminal amino group (PVP-NH 2 ). We studied the fullerene-containing and initial PVP samples by molecular hydrodynamics methods (centrifugal sedimentation, translational diffusion, and viscometry) in aqueous buffer solutions. EXPERIMENTALThe initial polymers PVP-NH 2 (PVP-1 and PVP-2) were synthesized as described previously in [19]. We took advantage of the capability for chain propagation in...

show abstract

Section: Methodsmentioning

confidence: 99%