Characterization of poly(ethylene imine) layers on mica by the streaming potential and particle deposition methods

Adamczyk, Zbǐgniew; Michna, Aneta; Szaraniec, Magdalena; Bratek, Anna; Barbasz, Jakub

doi:10.1016/j.jcis.2007.04.005

Cited by 56 publications

(80 citation statements)

References 43 publications

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“…This indicates that adsorption sites consisting of one Fb molecule were not effective to immobilize the latex particle of much larger dimensions. Analogous phenomenon was observed previously in the case poly(allylamine) hydrochloride and poly(ethylene imine) polyelectrolytes (Adamczyk et al , 2007, where latex particle deposition occurred at adsorption centers composed of two or more closely spaced polyelectrolyte chains. It was shown, assuming the Poisson statistics that the coverage of adsorption sites composed of n s or more particles is given by the expression (Adamczyk et al , 2007 Θ s (n s …”

Section: Resultssupporting

confidence: 85%

“…7 theoretically since such colloid enhancement experiments have not been done before in the literature. We applied the random site method, used previously to interpret particle deposition on surfaces covered by polyelectrolyte molecules (Adamczyk et al , 2007. The basic parame- Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Streaming potential measurements were carried out using a home-made apparatus described in details previously (Adamczyk et al , 2007Zembala and Adamczyk 2000). The main part of the cell was the parallel plate channel of dimensions 2b c × 2c c × L equal to 0.027 × 0.29 × 6.2 cm formed by mica sheets separated by a perfluoroethylene spacer.…”

Section: The Experimental Methodsmentioning

confidence: 99%

“…Latex article deposition proceeded over a desired time (typically 24 hours). The true coverage of particles was determined by a direct optical microscope counting under wet conditions, as described in our previous works (Adamczyk et al , 2007Zembala and Adamczyk 2000;Zembala et al 2003). Particles were counted over 10-20 equal sized areas chosen randomly over the mica sheet.…”

Section: The Experimental Methodsmentioning

confidence: 99%

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Irreversible adsorption of latex particles on fibrinogen covered mica

2010

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Physicochemical properties of bovine plasma fibrinogen (Fb) in electrolyte solutions were characterized. These comprised the diffusion coefficient (hydrodynamic radius), determined by the DLS method, electrophoretic mobility and the isoelectric point. The hydrodynamic radius of Fb was 12 nm for pH < 5. The number of uncompensated (electrokinetic) charges on the protein N c was calculated from the electrophoretic mobility data. It was found that for pH < 5.8 the electrokinetic charge was positive, independently of the ionic strength and negative for pH > 5.8. For pH = 3.5 the value of N c , was 26 for 10 −3 M. Similar electrokinetic measurements were performed for the mica substrate using the streaming potential cell. It was shown that for pH = 3.5 and 10 −3 M, the zeta potential of mica remained negative (−50 mV). This promoted an irreversible, electrostatically driven adsorption of Fb, which was confirmed in experiments carried out under diffusion-controlled transport. The surface concentration of Fb on mica was determined directly by AFM counting. By adjusting the time of adsorption, Fb monolayers of desired coverage were produced. Independently, the presence of Fb on mica was determined quantitatively by the colloid enhancement method, in which negatively charged latex particles were used, having the diameter of 800 nm. It was found that for Fb coverage below 0.05 the method was more sensitive than other indirect methods. The experimental data obtained in latex deposition experiments were adequately interpreted in terms of the random site model used previously for polyelectrolytes. It was shown that adsorption sites consisted of a cluster of Z. Adamczyk ( ) · M. Nattich · M. Wasilewska

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Section: Resultssupporting

confidence: 85%

Section: Resultsmentioning

confidence: 99%

Section: The Experimental Methodsmentioning

confidence: 99%

Section: The Experimental Methodsmentioning

confidence: 99%

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Irreversible adsorption of latex particles on fibrinogen covered mica

2010

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“…From a practical point of view, however, especially interesting seems the problem of particle deposition at heterogeneous surfaces, covered by adsorption sites such as polyelectrolytes and polymers [35][36][37][38][39][40][41], proteins [42,43] or colloid nanoparticles [44][45][46][47].…”

Section: Introductionmentioning

confidence: 99%