scholarly journals Chain dynamics and intermolecular association in dilute aqueous solutions of isotactic and atactic Poly(Methacrylic acid): Effect of NaCl concentration

Polymer ◽  
2019 ◽  
Vol 174 ◽  
pp. 1-10
Author(s):  
Simona Sitar ◽  
Vladimir Aseyev ◽  
Ema Žagar ◽  
Ksenija Kogej
Keyword(s):  
Aqueous Solutions ◽  
Methacrylic Acid ◽  
Chain Dynamics ◽  
Acid Effect ◽  
Nacl Concentration ◽  
Intermolecular Association ◽  
Dilute Aqueous Solutions

Study of polymer chain dynamics in solution by time-resolved spectrofluorometry

1989 ◽  
Vol 54 (11) ◽  
pp. 3011-3024 ◽  
Author(s):  
Vlastimil Fidler ◽  
Stefan Vajda ◽  
Zuzana Limpouchová ◽  
Jiří Dvořák ◽  
Karel Procházka ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Conformational Changes ◽  
Methacrylic Acid ◽  
Correlation Time ◽  
General Level ◽  
Polymeric Chain ◽  
Relative Molecular Mass ◽  
Chain Dynamics ◽  
Time Resolved ◽  
Covalently Bonded

The methodology of polarization time-resolved fluorometry and interpretation of its results are outlined at a general level, and the measurement on and use of facilities of the Edinburgh Instruments Model 299T apparatus are discussed in detail. The dynamics of conformational changes in chains of poly(methacrylic acid) containing covalently bonded dansyl labels are studied in aqueous solutions at various pH. It is shown that at pH > 6, the shorter effective rational correlation time τr < 2 ns corresponds to the rotation of the free dansyl label about bonds by which it is attached to the polymeric chain; at pH < 4 the longer effective rational correlation time τr = 20-26 ns corresponds to the rotation of the compact spherical formation constituted by a part of the collapsed polymeric chain in which the label is fixed and whose relative molecular mass is approx. 15 000-20 000.

scholarly journals Effect of Multivalent Cations on Intermolecular Association of Isotactic and Atactic Poly(Methacrylic Acid) Chains in Aqueous Solutions

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 605 ◽  
Author(s):  
Patricija Hriberšek ◽  
Ksenija Kogej
Keyword(s):  
Aqueous Solutions ◽  
Methacrylic Acid ◽  
Shape Parameter ◽  
The Other ◽  
Carboxyl Groups ◽  
Carboxylate Groups ◽  
Intermolecular Association ◽  
Core Shell Structure ◽  
Cooperative Hydrogen Bonding ◽  
Aggregate Structures

The formation of nanoparticles of two poly(methacrylic acid) (PMA) isomers, atactic (aPMA) and isotactic (iPMA), was investigated in aqueous solutions in the presence of mono- (Na+) and multivalent cations (Mg2+ and La3+). Using dynamic (DLS) and static light scattering (SLS), we show that PMA nanoparticles have characteristics of microgel-like particles with a denser core and a swollen corona. iPMA aggregates are stable at a much higher degree of neutralization (αN) than the aPMA ones, indicating a much stronger association between iPMA chains. This is explained by proposing segregation of ionized and unionized carboxyl groups within the iPMA aggregates and subsequent cooperative hydrogen-bonding between COOH groups. The calculated shape parameter (ρ) suggests different behavior of both isomers in the presence of Mg2+ ions on one hand and Na+ and La3+ on the other. The microgel-like particles formed in the presence of Mg2+ ions have a more even mass distribution (possibly a no core-shell structure) in comparison with those in the presence of Na+ and La3+ ions. Differences between the aggregate structures in the presence of different ions are reflected also in calorimetric experiments and supported by pH and fluorimetric measurements. Reasons for different behavior in the presence of Mg2+ ions lie in specific properties of this cation, in particular in its strong hydration and preference towards monodentate binding to carboxylate groups.

The reactions of oligoalcohols with arsenic, arsenous, boric and germanic acids

1980 ◽  
Vol 45 (10) ◽  
pp. 2645-2655 ◽  
Author(s):  
Antonín Mikan ◽  
Miloš Bartušek
Keyword(s):  
Aqueous Solutions ◽  
Equilibrium Constants ◽  
Dilute Aqueous Solutions

The reactions of sorbitol, mannitol, adonitol, dulcitol, glucose and glycerol with H3AsO4, H3AsO3, H3BO3 and GeO2 acids in dilute aqueous solutions were studied by potentiometric neutralization titrations. The formation of the following chelates was demonstrated: As(V)L3-, As(III)L(OH)2-, HAs(III)L(OH)2, BL2-, GeL2(OH)- and GeL32- and the equilibrium constants for their formation were found. Conditions for formation of these chelates of organic oligohydroxy compounds are discussed.

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