Dear Arpan,

Int. J. Electrochem. Sci., 7 (2012) 3577 - 3590

International Journal of

ELECTROCHEMICAL

SCIENCE

www.electrochemsci.org

Zeta Potential of Modified Multi-walled Carbon Nanotubes in Presence of poly (vinyl alcohol) Hydrogel

Enedina Francisco de la Cruz1 , Yudong Zheng1,* , Erika Torres1 , Wei Li1

, Wenhui Song2 , Krishna Burugapalli3

Zeta Potential Measurement and Electrophoretic Deposition

To Determine the Zeta Potential and mobility measurements of MWCNT modified with CTAB and SDS as well as MWCNT-PVA solution were using a Delsa Nano-Particle Analyzer model A54412AA. The instrument employs Smoluchowski’s Equation 1 to determine the electrophoretic mobility of the particle and subsequently convert it in the Zeta Potential.

(1) For the equation, please use the link at the bottom of this message.

The Smoluchowski’s Equation employs four known parameters: viscosity (µ), conductivity (σ), permittivity (εε0), and linear fits to the pressure-voltage curve.

The Zeta Potential of the MWCNT, was measured as function of the concentration of the surfactant and PVA concentration. In order to analyzed the behavior of the MWCNT-PVA solution in relation of the pH changing, solution of HCl (0.5%) and NaOH (0.5%) was used for adjusting the value pH in the range of 3-11. The solution of CNT-PVA with the highest zeta potential is used for EPD.

EPD was carried out under room temperature and certain parameter conditions (ZP,

MWCNT concentration, field strength, time deposition and distance between the substrate electrode), in order to establish the optimal conditions. The Electrodes in EPD were made of 304 Stainless Steel (10mm·20mm·1mm). The electrodes were sonicated 15 minutes with ethanol and distilled water to clean them. The two electrodes were fixed parallel at 1cm distance in the suspension. The signal used were rectangular pulses with 70% duty cycle, the frequency value was:

1Hz and the instrument used was a Function Generator model GFG-8016D. The time of exposure was 3, 5, 10 and 15 minutes. The samples were exposed at cross-linking by thawing-freezing method, 3 cycles were used, each cycle consist in 8-hours freezing and 8-hours thawing, then the samples were kept in ambient conditions until the analysis test was made.

For more details, please use the following link:

http://www.electrochemsci.org/papers/vol7/7043577.pdf

Hoping this will be helpful,

Rafik

Dear Arpan,

I now too master an electrophoresis on the NanoBrook Omni device (Brookhaven) in the option PALS. Also I want to note still very important point. These methods based on light scattering are very sensitive to dust. Problems arise even at determination of potential of standard samples. Therefore I recommend to remove dust from dispersions and an electrophoretic cell filtering (5-10 times) through 0.2 microns  filter. The result is much better and sensitivity increases almost much (I work with organic solvents). Besides, you have to consider existence of ionic micelles of CTAB, DDSNa (if you take Rafik  advice) and to make in addition background experiments.

Progress

Thank you all for your answers.