**2.1. Metallographic preparation of titanium substrates**

Titanium sheets were used as a substrate for their high mechanical resistance and corrosion, sectioned in square pieces with dimensions 1 × 1 cm and 0.1 cm thick for the cathode and 3 × 3 cm and 0.1 cm for the anode.

#### **2.2. Profiles of ζ =** *f* **(pH) of TiO2 and different stabilizing agents**

The surface charge density, isoelectric point, and stabilizing agents-dosing strategy for the formulation of TiO2 dispersion were determined with the profiles ζ = *f* (pH). The zeta potential measurement was performed using the SZ-100 of Horiba Scientific equipment based on studies by López-Maldonado et al. [23, 24].

#### **2.3. Colloidal titration of TiO2 dispersions**

The profiles of ζ = *f* (stabilizing agent dose) were performed to determine the dose of the stabilizing agent and improve the stability of the TiO2 dispersion. The TiO2 dispersions were prepared with water and water/ethanol mixtures (90:10 and 50:50) using surfactants of different chemical nature such as CTAB, SDS, Betaine, and Triton X-100 and a cationic biopolyelectrolyte chitosan (Ch), see **Figure 1**. The nominal concentration of TiO2 was kept fixed at a value of 0.1% wt, while the concentration of the dispersing agents was varied.

The zeta potential measurements were approximated with the equipment called Stabino Particle Charge Mapping.

The stabilizing agents used in the colloidal titration of the TiO2 dispersion are shown in **Table 1**.

#### **2.4. EPD process of TiO2 with stabilizing agents**

To assign the function of each electrode in the EPD cell (anode or cathode), it was necessary to measure the zeta potential of the dispersed particles of each formulation, before the experiment (see **Figure 2**). All experiments were performed in a conventional 2-electrode electrophoresis cell, with a capacity of 50 mL. All TiO<sup>2</sup> dispersions were prepared from 40 mL of a TiO2 0.1 wt. % (water) dispersion and then 4 mL of each stabilizing agent 1 wt. % was added, achieving a weight ratio of stabilizing agent to TiO2 of 1:1. For the EPD process, a potential difference of 10 V and an electrodeposition time of 1 h were used. Working electrodes and

titanium counter electrodes were used with an area of 1 and 9 cm2

**Dispersion Stabilizing agent Type of stabilizer**

CTAB Cationic Triton X-100 No ionic Betaine Amphoteric Ch Biopolyelectrolyte

TiO2 SDS Anionic

**Table 1.** Stabilizing agents used in the colloidal titration of the TiO2

**2.5. Physicochemical characterization of TiO<sup>2</sup>**

**Figure 2.** Experimental strategy for making TiO2

Electrodeposits of TiO2

**3. Results and discussion**

**3.1. Profiles of ζ =** *f* **(pH) of TiO2**

trodeposits were carried out under pressure and at room temperature.

sive spectroscopy) BRUKER detector microscope to observe the composition.

 **coatings**

red spectroscopy (FTIR), Raman spectroscopy, and scanning electron microscopy (SEM). FTIR spectra of samples were recorded using a Nicolet FT-IR spectrometer. The SEM-EDS analysis was performed on SEM (ZEISS EVO-MA15), equipped with an EDS (energy disper-

coatings by EPD.

 **and different stabilizing agents**

The zeta potential is a parameter by electrochemical nature that allows to study and predict

different stabilizing agents, also it indicates the degree of stability of dispersion in an aqueous medium from the point electrically. The aim is to employ ζ measurements to know and understand the behavior of the type of stabilizing agents in the EPD process performance.

the interactions occurring at the molecular level between the colloidal particles TiO2

obtained on Ti sheets, were characterized by Fourier transform infra-

dispersion.

Innovation in the Electrophoretic Deposition of TiO2 Using Different Stabilizing Agents and Zeta…

, respectively. All TiO2

http://dx.doi.org/10.5772/intechopen.73210

181

elec-

and the

**Figure 1.** Chemical structure of stabilizing agents.


biopolyelectrolyte chitosan (Ch), see **Figure 1**. The nominal concentration of TiO2

The stabilizing agents used in the colloidal titration of the TiO2

phoresis cell, with a capacity of 50 mL. All TiO<sup>2</sup>

**Figure 1.** Chemical structure of stabilizing agents.

achieving a weight ratio of stabilizing agent to TiO2

 **with stabilizing agents**

Particle Charge Mapping.

180 Titanium Dioxide - Material for a Sustainable Environment

**2.4. EPD process of TiO2**

TiO2

fixed at a value of 0.1% wt, while the concentration of the dispersing agents was varied.

The zeta potential measurements were approximated with the equipment called Stabino

To assign the function of each electrode in the EPD cell (anode or cathode), it was necessary to measure the zeta potential of the dispersed particles of each formulation, before the experiment (see **Figure 2**). All experiments were performed in a conventional 2-electrode electro-

0.1 wt. % (water) dispersion and then 4 mL of each stabilizing agent 1 wt. % was added,

difference of 10 V and an electrodeposition time of 1 h were used. Working electrodes and

was kept

dispersion are shown in **Table 1**.

dispersions were prepared from 40 mL of a

of 1:1. For the EPD process, a potential

**Figure 2.** Experimental strategy for making TiO2 coatings by EPD.

titanium counter electrodes were used with an area of 1 and 9 cm2 , respectively. All TiO2 electrodeposits were carried out under pressure and at room temperature.

#### **2.5. Physicochemical characterization of TiO<sup>2</sup> coatings**

Electrodeposits of TiO2 obtained on Ti sheets, were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and scanning electron microscopy (SEM). FTIR spectra of samples were recorded using a Nicolet FT-IR spectrometer. The SEM-EDS analysis was performed on SEM (ZEISS EVO-MA15), equipped with an EDS (energy dispersive spectroscopy) BRUKER detector microscope to observe the composition.
