Structure of polyelectrolyte layers on colloidal particles at different ionic strengths

Radeva, Ts.; Milkova, Viktoria; Петканчин, Ивана

doi:10.1016/s0927-7757(02)00185-1

Cited by 15 publications

(13 citation statements)

References 20 publications

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“…At this stage the adsorption was only determined by interactions between polyelectrolyte molecules. Some investigators have already suggested that a transition of this kind may explain the change of growth rate in successive steps [40]. Experimentally, in the case of PAH/PSS polymer films made on colloidal silica, we have seen from the pH drop consecutive to the adsorption of the polycation PAH that the silica surface was still active in adsorption up to the third bilayer (i.e.…”

Section: Charge Balance and Discussionmentioning

confidence: 70%

Early steps in layer-by-layer construction of polyelectrolyte films: The transition from surface/polymer to polymer/polymer determining interactions

Buron

Filiâtre

Membrey

et al. 2007

Journal of Colloid and Interface Science

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The layer-by-layer deposition of two polyelectrolytes, quaternized poly(dimethylaminoethyl methacrylate chloride) (MADQUAT) and poly(acrylic acid) (PAA) on a silica substrate was investigated using optical reflectometry, as a function of pH (pH 4, 5.5 and 9), ionic strength (10(-3) to 10(-1) M) and type of salt. Attention was given to the successive deposited weights and to the corresponding deposited charge densities within the ten first deposited layers. Results show a change of growth regime between an early stage where the substrate had a dominating influence in the build-up and a second stage where the polymer uptake was ruled essentially by polymer-polymer interactions. The pH was seen to influence the growth via the charge densities of silica (first stage) and PAA (first and second stages). The increase of NaCl concentration induced an increase of the film weight between 10(-3) and 10(-2) M, but the trend was more sophisticated between 10(-2) and 10(-1) M where the polymer uptake increased in the first stage of the growth and decreased in subsequent layers. The film weight increased in accordance with the rank of ions in the Hofmeister series. AFM images revealed a heterogeneous film morphology with bumps and valleys, which was explained by a growth mechanism made of the successive formation and growth of polymer complexes.

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Section: Charge Balance and Discussionmentioning

confidence: 70%

Early steps in layer-by-layer construction of polyelectrolyte films: The transition from surface/polymer to polymer/polymer determining interactions

Buron

Filiâtre

Membrey

et al. 2007

Journal of Colloid and Interface Science

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“…Specifically concerning the preparation of polyelectrolyte brushes with a soft polymeric core and their properties the work by Haryharan et al [26] and Ballauf et al [27] should be A. Bakandritsos, S. Couris, et al / Optically Active Polyelectrolyte Brushes referenced, where macromolecules are adsorbed or grown in situ (''grafting to'' and ''grafting-from'' technique [28] ) on polystyrene latex nanoparticles of 100 nm diameter. On the other hand, work on hybrid organic-inorganic polyelectrolyte brushes is limited [29] or refer to non-aqueous and nonpolyelectrolyte systems. [30] In the present case, the polyelectrolyte of NaPSS was selected and the reaction progress was initially monitored with dynamic light scattering (DLS).…”

Section: Comments and Results On The Synthesismentioning

confidence: 99%

Optically Active Spherical Polyelectrolyte Brushes with a Nanocrystalline Magnetic Core

Bakandritsos

Bouropoulos

Zbořil

et al. 2008

Adv Funct Materials

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The unique properties of magnetic nanocrystals have triggered intensive research towards their effective functionalization and application in many technological fields. Although synthesis of magnetic colloids is being thoroughly studied, there is limited knowledge on the synthesis, characterization, and properties of magnetic polyelectrolyte spherical brushes. In the present work, the preparation of such hybrids and the subsequent formation of stable aqueous colloids are described. The core of the spherical brush consists of a magnetic γ‐Fe2O3 nanocrystallite (faceted but mostly spherical‐like) with a mean diameter of 17 nm. The bioadhesive polyelectrolyte poly(sodium 4‐styrene sulfonate), forming the surrounding brush layer, was proven to be an effective covalently modifying macromolecule for the iron oxide surface, as Fourier transform IR spectroscopy revealed. Several observations on colloidal aspects are discussed and are successfully explained by models and experiments describing polyelectrolyte brushes with a soft polymeric core. Finally, the hybrids exhibit their multifunctional character and their technological importance by combining in a single and soluble product with magnetic and nonlinear optical properties.

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“…Thickness of adsorption layers of PAA was determined using the viscosity method (Radeva et al 2002) using a rotation remoter of CVO 50 type produced by Bohlin Instruments. In order to prepare a calibration curve there were prepared a few suspensions differing in volumetric fractions of aluminum oxide (φ 0 ).…”

Section: Methodsmentioning

confidence: 99%

Influence of solution pH on stability of aluminum oxide suspension in presence of polyacrylic acid

2010

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The effect of solution pH and molecular weight of polyacrylic acid (PAA) on its adsorption as well as on stabilization-floculation properties of the colloidal Al 2 O 3 and electrolyte solution systems was studied.The measurements showed that at pH = 6, the presence of the polymer of molecular weight 2 000 and 240 000 does not change stability of Al 2 O 3 suspension. However at pH = 3 and 9 the effect of polyacrylic acid is significant. At pH = 3 it creates destabilization of the suspension while at pH = 9 PAA it improves significantly the stability of Al 2 O 3 .It was shown that the increase in solution pH affects conformation of adsorbed macromolecules which causes the decrease in PAA adsorbed amount and thickness of polymer adsorption layer.By comparing the values of diffusion layer and surface charges, main effects responsible for the decrease in surface charge and ζ potential of the solid in the presence of the polymer as well as suspension stability were determined.

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Structure of polyelectrolyte layers on colloidal particles at different ionic strengths

Cited by 15 publications

References 20 publications

Early steps in layer-by-layer construction of polyelectrolyte films: The transition from surface/polymer to polymer/polymer determining interactions

Early steps in layer-by-layer construction of polyelectrolyte films: The transition from surface/polymer to polymer/polymer determining interactions

Optically Active Spherical Polyelectrolyte Brushes with a Nanocrystalline Magnetic Core

Influence of solution pH on stability of aluminum oxide suspension in presence of polyacrylic acid

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