Polyacrylates in aqueous solution. The dependence of protonation on molecular weight, ionic medium and ionic strength

Stefano, Concetta De; Gianguzza, Antonio; Piazzese, Daniela; Sammartano, Silvio

doi:10.1016/s1381-5148(02)00194-3

Cited by 46 publications

(71 citation statements)

References 12 publications

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“…As reported [2,15,16,18], the stability of these complexes is strictly dependent on the charges involved in the formation reaction, and when the charges are the same, similar values of formation constants were obtained. These behaviours can be observed in the formation constant values and the log K pj /ζ ratio obtained for the interaction of phytate with some biogenic amines (ethylenediamine (En), 1-4-diaminobutane (putrescine, Ptr), 1,5-diaminopentane (cadaverine, 1,5d), diethylenetriamine (Dien), N,N'-bis[3-aminopropyl]-1,4-diaminobutane (sperimine, Sper), N-[3-aminopropyl]-1,4-diaminobutane (spermidine, Spd), tetraethylenpentamine (Tetren) and pentaethylenehexamine (Penten)) [18] and of some polyammonium cations with polycarboxylate (i.e.…”

Section: Comparison With Other Similar Systemssupporting

confidence: 79%

“…To simplify the thermodynamic study of some natural organic molecules, such as humic and fulvic acids [1], often high molecular weight polyelectrolytes were chosen as model molecules in order to obtain information about the behaviour (acid-base properties and complexing ability) of natural macromolecules. The literature reports several thermodynamic data for the interaction properties of some high molecular weight polyelectrolytes [2][3][4][5][6]; in particular these data regard the acidbase properties of polycarboxylates and their interactions with alkali, alkaline earth metals [2][3][4][5] and some low molecular weight polyamines [6]. Natural and biological fluids contain also amino compounds (amines, polyammonium cations, polyaminocarboxylates, etc.)…”

Section: Introductionmentioning

confidence: 99%

“…In our previous papers, we already studied the interaction of different polyphosphates [13][14][15][16] and nucleotides [17] with biogenic amines. More recently the interaction of some polyammonium cations [ethylenediamine, 1-4-diaminobutane (putrescine), 1,5-diaminopentane (cadaverine), diethylenetriamine, N,N'-bis[3-aminopropyl]-1,4-diaminobutane (sperimine), N-[3-aminopropyl]-1,4-diaminobutane (spermidine), tetraethylenpentamine and pentaethylenehexamine] with phytate [18], some polymers, such as polyacrylate (MW = 2 kDa), polystirenesulphonates (MW = 70 and 1000 kDa) and polyvinylsulphonate (MW = 9 kDa) [2], and alginic and fulvic acids [19] were studied.…”

Section: Introductionmentioning

confidence: 99%

“…As a further contribution to the study of the acid-base properties and complexing ability of polyelectrolytes already undertaken [2][3][4][5][6], in the present paper we studied the interaction of an high molecular weight ammonium polyelectrolyte (branched polyethylenimine MW = 750 kDa) with an high charged polyphosphate, such as phytate. This high molecular weight polyamine has a monomeric unit which contains primary, secondary and tertiary amino groups in the ratio 1:2:1, as shown in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

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Sequestering ability of phytate towards protonated BPEI and other polyammonium cations in aqueous solution

Crea

Stefano

Porcino

et al. 2008

Biophysical Chemistry

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Please cite this article as: Francesco Crea, Concetta De Stefano, Nunziatina Porcino, Silvio Sammartano, Sequestering ability of phytate towards protonated BPEI and other polyammonium cations in aqueous solution, Biophysical Chemistry (2008Chemistry ( ), doi: 10.1016Chemistry ( /j.bpc.2008 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT AbstractThe interaction between protonated branched poly(ethylenimine) [BPEI] and phytate (1,2,3,4,5,6 hexakis (di-hydrogen phosphate) myo-inositol) [Phy] was studied potentiometrically. The measurements were carried out at t = 25 °C and at low ionic strength values, without addition of supporting electrolyte, to avoid interferences with other anions and cations. In order to simplify the data treatment, BPEI was considered as a simple tetramine. Different species Phy(BPEI)H j , with j = 6,7,8, and Phy(BPEI) 2 H 7 were found, having quite high stability. The ability of phytate to sequester BPEI was quantified by considering the parameter pL 50 , namely the concentration (-log [Phy] tot ) necessary to bind 50% of polyammonium cation (as trace). In our experimental conditions, for the system phytate-BPEI-proton we have pL 50 = 7.01, at pH = 7.4 and I = 0.04 mol L -1 . As for other phytate-polyammonium cation systems, the stability of the phytate-BPEI species is strictly proportional to the charges involved in the formation reactions. Therefore, it was possible to calculate the free energy contribution per bond, 0 b G Δ = 4.4±0.4 kJ mol -1 . The dependence on temperature and ionic strength of the stability of phytate-low/high molecular weight polyammonium cations species, was studied using some semiempirical equations and enthalpy data for the protonation of both components. The dependence on temperature of the stability is quite low and the variation of pL 50 in the range 15 ≤ t/°C ≤ 37 is less than 0.5 log units. On the contrary, the effect of ionic strength is highly significant, with a lowering of pL 50 of ≈ 2 log units (I = 0 to 0.15 mol L -1 ).

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Section: Comparison With Other Similar Systemssupporting

confidence: 79%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Sequestering ability of phytate towards protonated BPEI and other polyammonium cations in aqueous solution

Crea

Stefano

Porcino

et al. 2008

Biophysical Chemistry

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“…2). The different binding capacity at both pH values is explained by the dissociation constants of the PAA reported in the literature; pK a,1 =4.8-5.4, and pK a,2 =6.5-7.5 extrapolated to I=0 M at 25°C for PAA with molecular weights from 2 to 750 kDa (Katchalsky 1954;Hogfeldt et al 1989;de Stefano et al 2000de Stefano et al , 2003David et al 2008;Crea et al 2009;de Stefano et al 2010). Accordingly with these values the largest dissociation degree of the PAA, and, therefore, the largest binding capacity for Cd would be expected at pH 8.5.…”

Section: Qd-only Effect Of Phmentioning

confidence: 83%

Stability of core/shell quantum dots—role of pH and small organic ligands

Domingos¹,

Franco²,

Pinheiro

2013

Environ Sci Pollut Res

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The improvement of knowledge about the toxicity and even processability, and stability of quantum dots (QD) requires the understanding of the relationship between the QD binding head group, surface structure, and interligand interaction. The scanned stripping chronopotentiometry and absence of gradients and Nernstian equilibrium stripping techniques were used to determine the concentration of Cd dissolved from a polyacrylate-stabilized CdTe/ CdS QD. The effects of various concentrations of small organic ligands such as citric acid, glycine, and histidine and the roles of pH (4.5-8.5) and exposure time (0-48 h) were evaluated. The highest QD dissolution was obtained at the more acidic pH in absence of the ligands (52 %) a result of the CdS shell solubility. At pH 8.5 the largest PAA ability to complex the dissolved Cd leads to a further QD solubility until the equilibrium is reached (24 % of dissolved Cd vs. 4 % at pH 6.0). The citric acid presence resulted in greater QD dissolution, whereas glycine, an amino acid, acts against QD dissolution. Surprisingly, the presence of histidine, an amino acid with an imidazole functional group, leads to the formation of much strong Cd complexes over time, which may be non-labile, inducing variations in the local environment of the QD surface.

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The Protonation of Polyacrylate in Seawater. Analysis of Concentration Effects

Battaglia

Crea

et al. 2005

Annali di Chimica

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The protonation of polyacrylate (PAA, MW 2 kDa) was studied potentiometrically at 25 degrees C, in mixed electrolyte aqueous solution simulating the composition of seawater, in the salinity range 30 < or = S < or = 40. The salt composition of different solutions was varied in order to study its effect on apparent protonation constants. Results were analysed using two fairly different approaches: by simple regression analysis on a combination of concentration parameters and salinity, and by canonical correlation analysis. Unexpectedly we found that variations on protonation constants, due to the different relative component concentrations, are fairly low, revealing a sort of buffering capacity of seawater respect to protonation properties of polyacrylate (and likely for other HMW and LMW polycarboxylates). The intrinsic protonation constant of polyacrylate 2 kDa at 25 degrees C and 35 salinity is log K(H*) = log K(int) = 4.399 +/- 0.004. The use of different pH scales and standard seawater compositions is also discussed.

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Polyacrylates in aqueous solution. The dependence of protonation on molecular weight, ionic medium and ionic strength

Cited by 46 publications

References 12 publications

Sequestering ability of phytate towards protonated BPEI and other polyammonium cations in aqueous solution

Sequestering ability of phytate towards protonated BPEI and other polyammonium cations in aqueous solution

Stability of core/shell quantum dots—role of pH and small organic ligands

The Protonation of Polyacrylate in Seawater. Analysis of Concentration Effects

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