Polyelectrolyte brushes: Water Content, Zeta Potential and Mechanical Properties

2015 ◽  
Vol 1754 ◽  
pp. 53-58
Author(s):  
Joseba Irigoyen ◽  
Jagoba Iturri ◽  
José Luis Camacho ◽  
Edwin Donath ◽  
Sergio Moya
Keyword(s):  
Ionic Strength ◽  
Zeta Potential ◽  
Water Content ◽  
Polymer Brushes ◽  
Polymer Brush ◽  
Trimethylammonium Chloride ◽  
Surface Approach ◽  
Force Microscopy ◽  
Polyelectrolyte Brushes ◽  
Atomic Force

ABSTRACTPolymer brushes of poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride (PMETAC) and poly(sulfo propyl methacrylate) (PSPM) were synthesized by Atomic Transfer Radical Polymerization from planar and colloidal surfaces. Polymer brush growth was followed by QCMD and the water content determined by combined QCMD and elipsometry. From the water content the percentage of water lost during the brush collapse with the ionic strength could be obtained.Highly charged PSPM brushes were indented by Atomic Force Microscopy at different ionic strengths. The force response was fitted to a phenomenological equation analogous to the equation of state of a compressible fluid. Internal energy and brush compressibility were obtained as a function of ionic strength.Spherical brushes of PMETAC and PSPM display an invariance of the zeta potential with ionic strength in the range from 20 mM to 200 mM NaCl, the zeta potential remains almost constant. This invariance can be explained applying a hairy surface approach.

scholarly journals Study the Effect of Water Content on the Structure of Electrochemically Prepared TiO2 Nanotubes

2022 ◽  
Author(s):  
Sara Al-Waisawy ◽  
Ahmed Kareem Abdullah ◽  
Hadi A. Hamed ◽  
Ali A. Al-bakri
Keyword(s):  
Water Content ◽  
Pure Titanium ◽  
Electrochemical Anodization ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Titania Nanotube Arrays ◽  
Anodization Process ◽  
Titania Films ◽  
Average Size

In this research, the pure titanium foil was treated in glycerol base electrolyte with 0.7 wt.% NH4F and a small amount of H2O at 17 V for 2 hours by electrochemical anodization process in order to prepare Titania nanotube arrays at room temperature (~25 ºC), different water content was added to the electrolyte as a tube enhancing agent. The high density uniform arrays are prepared by using organized and well aligned these tubes. The average size of tube diameter, ranging from 57 to 92 nm which found it increases with increasing water content, and the length of the tube ranging from 2.76 to 4.12 µm, also found to increase with increasing water content and ranging in size of wall thickness from 23 to 35 nm. A possible growth mechanism is presented. The X-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM) were utilized to study the structure and morphology of the Titania films.

A novel approach for measuring the intrinsic nanoscale thickness of polymer brushes by means of atomic force microscopy: application of a compressible fluid model

Nanoscale ◽  
2013 ◽  
Vol 5 (23) ◽  
pp. 11679 ◽  
Author(s):  
José Luis Cuellar ◽  
Irantzu Llarena ◽  
Jagoba J. Iturri ◽  
Edwin Donath ◽  
Sergio Enrique Moya
Keyword(s):  
Atomic Force Microscopy ◽  
Compressible Fluid ◽  
Polymer Brushes ◽  
Fluid Model ◽  
Force Microscopy ◽  
Atomic Force ◽  
Novel Approach

Direct Force Measurements at Polymer Brush Surfaces by Atomic Force Microscopy

1998 ◽  
Vol 31 (13) ◽  
pp. 4297-4300 ◽  
Author(s):  
Tommie W. Kelley ◽  
Phillip A. Schorr ◽  
Kristin D. Johnson ◽  
Matthew Tirrell ◽  
C. Daniel Frisbie
Keyword(s):  
Atomic Force Microscopy ◽  
Polymer Brush ◽  
Force Measurements ◽  
Force Microscopy ◽  
Atomic Force

Comparison of atomic force microscopy and zeta potential derived surface charge density

2020 ◽  
Vol 130 (3) ◽  
pp. 36001
Author(s):  
M. Herzberg ◽  
S. Dobberschütz ◽  
D. Okhrimenko ◽  
N. E. Bovet ◽  
M. P. Andersson ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Zeta Potential ◽  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Investigation of Moisture Dissipation of Water-Foamed Asphalt and Its Influence on the Viscosity

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5325
Author(s):  
Ning Li ◽  
Wei Tang ◽  
Xin Yu ◽  
He Zhan ◽  
Hui Ma ◽  
...  
Keyword(s):  
Water Content ◽  
Asphalt Mixture ◽  
Viscosity Reduction ◽  
Residual Water ◽  
Rotational Viscometer ◽  
Force Microscopy ◽  
Foamed Asphalt ◽  
Foaming Process ◽  
Atomic Force ◽  
Afm Analysis

Water-foamed asphalt is capable of improving the workability of asphalt mixture. It has been extensively used for its energy-saving and emission-reducing features. Water plays an essential part in improving the workability of water-foamed asphalt mixture. However, there is still lack in profound studies of moisture dissipation of the water-foamed asphalt over time and its influence on workability. In this study, the evolutions of residual water content and rotational viscosity of the water-foamed asphalt with time were respectively measured by the analytical balance and modified rotational viscometer (RV). The atomic force microscopy (AFM) analysis was conducted to discuss the mechanism of viscosity reduction of water-foamed asphalt. The results showed that moisture evaporation is significantly influenced by the foaming water content and ambient temperature, which results in the different stabilizing time of water-foamed asphalt. When water-foamed asphalt was stabilized, the residual water inside the asphalt was less than 0.01% relative to the asphalt mass. The AFM analysis showed that the foaming process changed the distribution of wax in the water-foamed asphalt resulting in reduction of viscosity. The viscosity reduction of asphalt is highly related to the initial foaming water content. After the foaming process, the viscosity keeps stable and is independent of moisture dissipation.

scholarly journals Interaction Mechanism between Molybdenite and Kaolinite in Gypsum Solution Using Kerosene as the Flotation Collector

Minerals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 304 ◽  
Author(s):  
Liqing Sun ◽  
Yijun Cao ◽  
Yinfei Liao ◽  
Zilong Ma
Keyword(s):  
Zeta Potential ◽  
Calcium Ion ◽  
Potential Distribution ◽  
Detrimental Effect ◽  
Adhesion Force ◽  
Interaction Mechanism ◽  
Solution Concentration ◽  
Force Microscopy ◽  
Atomic Force ◽  
Flotation Collector

This paper aims to understand the fundamental interaction mechanism between molybdenite and kaolinite in gypsum solution using kerosene as collector. Micro-flotation tests were conducted to study the effect of gypsum solution on the flotation performance of mixed −74 μm molybdenite and −10 μm kaolinite mineral. The results showed that the recovery of molybdenite decreased from 86% to 74% while the gypsum solution concentration increased from 0 to 800 mg/L, indicating the detrimental effect of kaolinite on molybdenite flotation could be enhanced by gypsum solution. This is mainly caused by the slime coating of kaolinite on molybdenite through dissolved calcium ion of gypsum solution. In order to confirm the slime coating phenomenon, zeta potential distribution, scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements were used to investigate interaction characteristics and mechanisms. The zeta potential distribution results revealed that mixed samples had the value between signal molybdenite and kaolinite samples in gypsum solution, which proved the coating phenomenon of kaolinite on molybdenite. Moreover, the coating phenomenon was becoming more and more obvious with the gypsum solution concentration. The coating phenomenon of kaolinite on molybdenite surface was also directly observed from SEM results. The AFM results provided further evidence for the possibility of slime coating, as the adhesion force increased with the gypsum solution concentration, which means the aggregates of molybdenite and kaolinite were becoming more stable.

Probing biofouling resistant polymer brush surfaces by atomic force microscopy based force spectroscopy

2013 ◽  
Vol 102 ◽  
pp. 923-930 ◽  
Author(s):  
Peter Schön ◽  
Edit Kutnyanszky ◽  
Bas ten Donkelaar ◽  
M. Gabriella Santonicola ◽  
Tugba Tecim ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Polymer Brush ◽  
Force Spectroscopy ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Self-Assembly of Rice Bran Globulin Fibrils in Electrostatic Screening: Nanostructure and Gels

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Lihua Huang ◽  
Yehui Zhang ◽  
Haibin Li
Keyword(s):  
Ionic Strength ◽  
Rice Bran ◽  
Self Assembly ◽  
Gel Properties ◽  
Sem Images ◽  
Force Microscopy ◽  
Atomic Force ◽  
Repulsive Forces ◽  
Low Ionic Strength ◽  
Kinetics Of

The effects of various ionic strengths and protein concentrations on the fibrils structure and gel properties of rice bran globulin (RBG) at pH 2.0 were investigated using atomic force microscopy (AFM), rheometer, and scanning electron microscope (SEM). AFM images showed the morphology of assembling RBG fibrils from strand beads to becoming branch clustered, when electrostatic repulsive forces attenuated gradually with increasing ionic strength. NaCl seems to accelerate the kinetics of fibrils formation, resulting in a significant increase in Th T fluorescence intensity. The increased ionic strengths promote particle size increasing and zeta potential decreasing synchronously. The percolation modelG'~C-Cpnbe used to calculate theoretical RBG gels concentration at various ionic strengths (0–500 mM), which decreased from 15.17 ± 0.63 to 2.26 ± 0.27 wt%. SEM images exhibited a granular mesh-like gel structure. A more homogenous structure occurred in low ionic strength. This study elucidates properties of RBG fibrils and gels as a bioactive material.

Atomic Force Microscopy of Humic Substances:  Effects of pH and Ionic Strength

1999 ◽  
Vol 33 (21) ◽  
pp. 3911-3917 ◽  
Author(s):  
Eric Balnois ◽  
Kevin J. Wilkinson ◽  
Jamie R. Lead ◽  
Jacques Buffle
Keyword(s):  
Atomic Force Microscopy ◽  
Ionic Strength ◽  
Humic Substances ◽  
Force Microscopy ◽  
Atomic Force ◽  
Effects Of Ph
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