Kinetics of Adsorption of Water-Soluble Associative Polymer on a Planar Titanium Dioxide Surface

Filippov, Leonid K.; Silebi, C. A.; El‐Aasser, M. S.

doi:10.1021/la00003a032

Cited by 8 publications

(18 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With ellipsometry, the determination of thicknesses and refractive indices of thin adsorbed layers (<10 nm) can be performed and further be used for calculating the surface excess. In previous articles, ellipsometry has been shown to provide valuable information for understanding adsorption mechanisms, adsorption/desorption kinetics, and transient as well as equilibrium structures of adsorbed layers. , …”

Section: Introductionmentioning

confidence: 99%

Ellipsometric Study of the Adsorption of Hydrophobically Modified Polyacrylates at Hydrophobic Surfaces

1998

View full text Add to dashboard Cite

The adsorption of hydrophobically modified polyelectrolytes (HMPEs) at hydrophobic surfaces was studied by ellipsometry. Both the adsorbed amount of polymer Γ and the layer thickness d were measured as a function of time. The HMPEs are polyacrylates carrying various fractions of grafted dodecyl chains. Hydrophobic interactions are responsible for the adsorption (unmodified polyacrylate does not adsorb at the surface). The surface anchoring of grafted dodecyl groups is coupled with the repulsion of charged acrylate groups. This results in the formation of large loops at the interface, separated by very short trains, since the probability to have two or more successive alkyl groups grafted at the polymer chain is small. As in the case of ordinary polyelectrolytes, the mean thickness of the adsorbed layer decreases with increasing solution ionic strength. Changes of the HMPE chemical composition (molar ratio, X, of alkyl units attached on the polyacrylate backbone) affect the adsorbed layer structure in a complex fashion. HMPEs with relatively few grafted chains form thick dilute adsorbed layers. Increasing the ratio of grafted chains to the number of polyelectrolyte monomers results in a monotonic decrease of the thickness and an increase of the HMPE density. However, the adsorbed amount exhibits a maximum at a relatively small ratio between 5% and 7%, above which the effect of the decrease of Γ caused by the decrease of the average loop size becomes larger than the opposing effect of the increasing surface density of anchors. We also discuss the shape of the adsorption isotherms, experimental evidence for the existence of a depletion layer located outside the adsorbed layer, and the time evolution of adsorption and desorption.

show abstract

Section: Introductionmentioning

confidence: 99%

Ellipsometric Study of the Adsorption of Hydrophobically Modified Polyacrylates at Hydrophobic Surfaces

1998

View full text Add to dashboard Cite

show abstract

“…The principle of using plane polarized light to calculate average values for the refractive index and the thickness of the adsorbed layer is shown in Figure . The method of analysis of the ellipsometric data is detailed in the Appendix and another publication …”

Section: Experimental Methods and Instrumentationmentioning

confidence: 99%

“…The difference between the averaged values, Γ av ( t ), for two or three independent runs was no more than 10%. The average adsorbed layer thickness, d ad layer , and the average refractive index, n ad layer , of the adsorbed layer were found simultaneously by using the following equations. , where Re(δ) and Im(δ) are the real and imaginary parts of the phase shift, respectively, λ is the wavelength of light (λ = 632.8 nm), θ sol is the angle of incidence of the He−Ne laser beam, and n ad layer and n sol are the refractive indices (average values) of the adsorbed layer and the polymer solutions, respectively. First, the values of d ad layer and n ad layer from eq 1 are calculated by using ellipsometric data (Δ and ψ) for the model shown in Figure .…”

Section: Experimental Methods and Instrumentationmentioning

confidence: 99%

“…Ellipsometry was selected for this study because this technique allows measurements of the time-dependent adsorbed polymer concentration during adsorption. From these ellipsometric measurements one can calculate (a) the polymer adsorption rate constant, (b) the diffusion coefficient, and (c) the activation energy for diffusion in the adsorbed layer . A recently developed model to study the adsorption kinetics 31 was used for analyzing the ellipsometry results and the determination of average values for the adsorbed layer thickness, the amount adsorbed at the surface, the area occupied by each polymer chain, the conformation of the polymer chains, and the mechanism of adsorption.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Adsorption Kinetics of Amphipathic Polystyrene-block-polybutadiene onto Silicon Wafer and Polystyrene Planar Surfaces

et al. 1997

View full text Add to dashboard Cite

Adsorption kinetics of amphipathic diblock AB copolymers of polystyrene-block-polybutadiene from selective solvent onto planar silicon wafer and polystyrene surfaces have been studied by ellipsometry. A theoretical analysis of the adsorption kinetics was applied to investigate the adsorbed layer thickness, the total amount adsorbed at each concentration, and the area occupied by each copolymer chain. Some insight into the architecture of the buoy in the solution is presented. In these studies we found a strong dependence of adsorption rate on the chemical nature of the substrates and on the bulk concentration of the adsorbent. Further, the kinetics of adsorption at different concentrations and temperatures suggest that both single polymer molecules and micelles are responsible for adsorption.

show abstract

“…The behaviour of DMetEtBAmAc could be explained by great affinity between adsorbate and adsorbent molecules, particularly in some special zones in the adsorbent surface known as Henry's Zones [55]. This process can consist of three stages [56]: (1) a kinetic process (0 B h B 0.5) in the Henry's Zones, (2) a kinetic-diffusive process and (3) a diffusive process at the same time as concentration of CI was higher.…”

Section: Adsorption Isothermmentioning

confidence: 99%

Adsorption and corrosion inhibition of amphiphilic compounds on steel pipeline grade API 5L X52 in sulphuric acid 1 M

2010

View full text Add to dashboard Cite

The effect of seven amphiphilic compounds, on steel API 5L X52 corrosion in sulphuric acid 1 M solution was studied by potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS). Potentiodynamic polarization curves indicated that these compounds acted mainly as cathodic type inhibitors. The EIS spectrums showed that the mechanism of corrosion inhibition is mainly a faradic process, the spectra were fitted with one electrical equivalent circuit (EEC) using a constant phase element (CPE). Double layer capacitance associated with CPE was also obtained. Langmuir, Temkin, and Henry adsorption isotherm described the experimental findings. This information suggested that organic molecules were adsorbed on active sites on metal surface avoiding contact of corrosive media with steel surface, having adsorbate molecules low molecular interaction between them even with the presence of more amphiphilic molecules on the steel surface as concentration got higher values.

show abstract

Kinetics of Adsorption of Water-Soluble Associative Polymer on a Planar Titanium Dioxide Surface

Cited by 8 publications

References 0 publications

Ellipsometric Study of the Adsorption of Hydrophobically Modified Polyacrylates at Hydrophobic Surfaces

Ellipsometric Study of the Adsorption of Hydrophobically Modified Polyacrylates at Hydrophobic Surfaces

Adsorption Kinetics of Amphipathic Polystyrene-block-polybutadiene onto Silicon Wafer and Polystyrene Planar Surfaces

Adsorption and corrosion inhibition of amphiphilic compounds on steel pipeline grade API 5L X52 in sulphuric acid 1 M

Contact Info

Product

Resources

About