**5.2. Ceramic Matrix Nanocomposites**

Ceramic matrix composites (CMCs) can extensively overcome the intrinsic brittleness and lack or mechanical reliability of monolithic ceramics, which are otherwise attractive for their high stiffness and strength. In addition to mechanical effects, the reinforcing phase can improve electrical conductivity, thermal expansion coefficient, hardness and thermal shock resistance. The combination of these characteristics with intrinsic advantages of ceramic materials such as high-temperature stability, high corrosion resistance, light weight and electrical insulation, makes CMCs very attractive functional and structural materials for a variety of applications. A wide range of reinforcing fibers have been investigated, including those based on SiC, carbon, alumina, and mullite. However, carbon fibers are among the highest performance toughening elements investigated [73, 74].

Electrodeposition of ceramic films employing electrochemical methods is a fast evolving field. The methods for electrodeposition may be divided into two: electrophoretic and electrolytic deposition. Electrolytic deposition can be driven using cathodic currents by either reducing the metal ions, which causes their deposition, e.g., Cu2O, or by driving a proton dependent reducing process, leading to an increase of the pH on the electrode surface and the subsequent metal hydroxide deposition. The deposition of ceramic nanocomposite materials is of utmost importance in different fields spanning from supercapacitors to anticorrosion films and from coatings of medical implants to advanced lubricant materials [75].

### **5.3. Polymeric matrix nanocomposites PNCs**

Cathodic electrodeposition of polymer-metal and polymer-ceramic materials is an area of intense interest. Such materials exhibit interesting mechanical, thermal, electrical, optical and magnetic properties whose applications have motivated the development of electrochemical techniques [76, 77]. PNCs are among the most promising class of new materials because they are light weight, flexible, low cost, anti-corrosive, and have good process ability and mechan‐ ical properties. Most polymers are electrical insulators and are used for a variety of insulating applications in industry. However, the inherent electrical insulation means polymers tend to hold the electrostatic charges, and allow the electromagnetic frequency interference (EMI) to travel through without loss [78]. electrochemical techniques [76, 77]. PNCs are among the most promising class of new materials because they are light weight, flexible, low cost, anti-corrosive, and have good process ability and mechanical properties. Most polymers are electrical insulators and are used for a variety of insulating applications in industry. However, the inherent electrical

the metallic matrix formed by staked hexagonal plates oriented in different direction. These unique characteristics are essential for the thermal conversion of Zn to ZnO. The photoelectrochemical degradation of organic molecules was achieved with this type of Ti/ZnO-

**Figure 4.** FEG-SEM images for (a) as-deposited and (b) annealed Zn-TiO2 nanocomposite films [72].

Ceramic matrix composites (CMCs) can extensively overcome the intrinsic brittleness and lack or mechanical reliability of monolithic ceramics, which are otherwise attractive for their high stiffness and strength. In addition to mechanical effects, the reinforcing phase can improve electrical conductivity, thermal expansion coefficient, hardness and thermal shock resistance. The combination of these characteristics with intrinsic advantages of ceramic materials such as high-temperature stability, high corrosion resistance, light weight and electrical insulation, makes CMCs very attractive functional and structural materials for a variety of applications. A wide range of reinforcing fibers have been investigated, including those based on SiC, carbon, alumina, and mullite. However, carbon fibers are among the highest performance

Electrodeposition of ceramic films employing electrochemical methods is a fast evolving field. The methods for electrodeposition may be divided into two: electrophoretic and electrolytic deposition. Electrolytic deposition can be driven using cathodic currents by either reducing the metal ions, which causes their deposition, e.g., Cu2O, or by driving a proton dependent reducing process, leading to an increase of the pH on the electrode surface and the subsequent metal hydroxide deposition. The deposition of ceramic nanocomposite materials is of utmost importance in different fields spanning from supercapacitors to anticorrosion films and from

Cathodic electrodeposition of polymer-metal and polymer-ceramic materials is an area of intense interest. Such materials exhibit interesting mechanical, thermal, electrical, optical and magnetic properties whose applications have motivated the development of electrochemical

TiO2 photoanodes (Figure 4).

16 Electrodeposition of Composite Materials

**5.2. Ceramic Matrix Nanocomposites**

toughening elements investigated [73, 74].

**5.3. Polymeric matrix nanocomposites PNCs**

coatings of medical implants to advanced lubricant materials [75].

Some polymer/nanoparticle (NP) composites have already been reported in the literatures, such as polyaniline/metal oxide NP composites, PPy/TiO2, PPy/Ti, PPy/Au, PPy/Ag, PPy/Pt, and PPy/Pd, prepared by electrodeposition [79]. The incorporation of metal nanoparticles into the conducting polymer offers improved performance for both the host and the guest. They can be applied in application in electronics because incorporation of metal clusters is known to increase the conductivity of the polymer. The applications of these composites have also been extended to various fields such as, sensors, photovoltaic cells, memory devices, protective coatings against corrosion, and supercapacitors. The application of these composites in catalysis is of particular interest. The polymer allows the control of the environment around the metal center, thus influencing selectivity of the chemical reactions [80]. insulation means polymers tend to hold the electrostatic charges, and allow the electromagnetic frequency interference (EMI) to travel through without loss [78]. Some polymer/nanoparticle (NP) composites have already been reported in the literatures, such as polyaniline/metal oxide NP composites, PPy/TiO2, PPy/Ti, PPy/Au, PPy/Ag, PPy/Pt, and PPy/Pd, prepared by electrodeposition [79]. The incorporation of metal nanoparticles into the conducting polymer offers improved performance for both the host and the guest. They can be applied in application in electronics because incorporation of metal clusters is known to increase the conductivity of the polymer. The applications of these composites have also been extended to various fields such as, sensors, photovoltaic cells, memory devices, protective coatings against corrosion, and supercapacitors. The application of these composites in catalysis is of particular interest. The polymer allows the control of the

Conducting polymer/inorganic oxide nanocomposites have recently attracted great attention due to their unique microstructure, physiochemical and electro-optical properties, and a wide range of their potential usage in battery cathodes and in the construction of nanoscopic assemblies in sensors and microelectronics. Conductive polymer/ZnO nanocomposites coating were prepared on type-304 austenitic stainless steel (SS) using H2SO4 acid as electrolyte by potentiostatic methods. It was found that ZnO nanoparticles improve the barrier and electrochemical anticorrosive properties of polymer [81]. [80]. Conducting polymer/inorganic oxide nanocomposites have recently attracted great attention due to their unique microstructure, physiochemical and electro-optical properties, and a wide range of their potential usage in battery cathodes and in the construction of nanoscopic assemblies in sensors and microelectronics. Conductive polymer/ZnO nanocomposites coating were prepared on type-304 austenitic stainless steel (SS) using H2SO4 acid as electrolyte by potentiostatic methods. It was found that ZnO nanoparticles improve the barrier and electrochemical anticorrosive properties of polymer [81].

environment around the metal center, thus influencing selectivity of the chemical reactions

Figure 5. SEM micrographs of the deposits; a) ZnO NPs, b) ZnO NPs [81]. Electrically conducting polypyrrole (PPy)–iron group (Ni, Co, Fe and their alloys) composite **Figure 5.** SEM micrographs of the deposits; (a) ZnO NPs, (b) ZnO NPs [81].

17 films have been electrodeposited at cathodic process to give ''tailored'' soft and hard Electrically conducting polypyrrole (PPy)–iron group (Ni, Co, Fe and their alloys) composite films have been electrodeposited at cathodic process to give ''tailored'' soft and hard magnet‐ ism. The composites of the PPy doped with dodecylsulfate (DS) (PPy–DS) with NiFe alloy showed soft magnetism with coercivity HC, k <9 Oe, while the PPy–DS with CoMnP alloy showed hard magnetism with HC, k>1085 Oe. These results indicated the possibility conduct‐ ing polymer–magnetic metals composites fabrication by electrodeposition [82].

The incorporation of metal nanoparticles into the conducting polymer offers enhanced performance for both the host and the guest. They have diverse application potentials in electronics because incorporation of metal clusters is known to increase the conductivity of the polymer. The applications of these composites have also been extended to various fields such as, sensors, photovoltaic cells, memory devices, protective coatings against corrosion, and supercapacitors. Of particular interest is the application of these composites in catalysis. The polymer allows the control of the environment around the metal center, thus influencing selectivity of the chemical reactions [83]. magnetism. The composites of the PPy doped with dodecylsulfate (DS) (PPy–DS) with NiFe alloy showed soft magnetism with coercivity HC, k <9 Oe, while the PPy–DS with CoMnP alloy showed hard magnetism with HC, k>1085 Oe. These results indicated the possibility conducting polymer–magnetic metals composites fabrication by electrodeposition [82]. The incorporation of metal nanoparticles into the conducting polymer offers enhanced performance for both the host and the guest. They have diverse application potentials in electronics because incorporation of metal clusters is known to increase the conductivity of the polymer. The applications of these composites have also been extended to various fields such as, sensors, photovoltaic cells, memory devices, protective coatings against corrosion, and supercapacitors. Of particular interest is the application of these composites in catalysis.

Y. Lattach et al. [84] stated that nanocomposite anode materials for water oxidation have been readily synthesized by electrodeposition of iridium oxide nanoparticles into poly (pyrrolealkylammonium) films. Electroanalytical investigations have shown that the electrocatalytic activity of iridium oxide nanoparticles is fully maintained when they are incorporated in the polymer matrix. The polymer allows the control of the environment around the metal center, thus influencing selectivity of the chemical reactions [83]. Y. Lattach et al. [84] stated that nanocomposite anode materials for water oxidation have been readily synthesized by electrodeposition of iridium oxide nanoparticles into poly (pyrrole-alkylammonium) films. Electroanalytical investigations have shown that the electrocatalytic activity of iridium oxide nanoparticles is fully maintained when they are

Electrodeposition process was carried out by dispersing UHMWPE powders in an electrolytic solution of cobalt sulphate/cobalt chloride solution to obtain Co/UHMWPE composite coating on stainless steel substrate (304L). UHMWPE was selected as surface modifier element, due to its high biocompatibility and low coefficient of friction. This material can be used in many biomedical applications [85]. incorporated in the polymer matrix. Electrodeposition process was carried out by dispersing UHMWPE powders in an electrolytic solution of cobalt sulphate/cobalt chloride solution to obtain Co/UHMWPE composite coating on stainless steel substrate (304L). UHMWPE was selected as surface modifier element, due to its high biocompatibility and low coefficient of friction. This material can be used in many biomedical applications [85].

Figure 6 SEM surface morphology of coatings obtained at current density of 48 mA/cm2 and **Figure 6.** SEM surface morphology of coatings obtained at current density of 48 mA/cm deposition time of 30 min: (a) Pure Co; Co/UHMWPE Composite Coatings with 30g/L [85]. <sup>2</sup> and deposition time of 30 min: (a) Pure Co; (b) Co/UHMWPE Composite Coatings with 30g/L [85].
