132
S. A. Pauline
against other hard objects. However, in the nanoscale, their properties are unique,
differ widely from that of macroscale ceramics and are of greater use in various fields.
Ceramic nanoparticles have properties lying in between metals and non-metals. The
improved properties include dielectricity, ferroelectricity, piezoelectricity, pyroelectricity, ferromagnetism, magnetoresistance and superconductivity [1]. Nanoceramics
also have excellent mechanical, processing and surface properties such as biocompatibility, superplasticity, mechanical resistance, chemical resistance, strength and
hardness at normal as well as high temperatures [2]. The properties of nanoceramics
depend and vary based on the type of nanoceramic, its size and shape. The bonding
between their constituent atoms defines their properties which are a combination of
ionic and covalent bonds [3].
Nanoceramic materials were first discovered in the early 1980s using sol-gel
method, a form of chemical solution deposition. Larger scale materials have flaws
that make them brittle, but due to their small size, nanoceramics are flawless. Interest
and research in nanoceramics are blooming since then owing to its varied properties and extensive applications. In the 2000s, synthesis methods evolved using heat
and pressure in sintering process. The method of synthesis of nanoceramics plays a
great role in determining the shape and size of the particles and hence its properties.
During the past 20 years, research in nanoceramics has resulted in positive outcomes
and the advanced materials prepared are being used in several industries such as
sensors, batteries, capacitors, corrosion-resistant coatings, thermal barrier coatings,
solid electrolytes, catalysts, cosmetics, automotive, optoelectronics, computers, electronics, biomaterials, etc. [4]. They have special applications in the field of medicine
owing to their biocompatibility, bioactivity and hydrophilicity and hence are used as
bioimplants, as drug delivery devices and also in cancer treatment as chemotherapy
delivery vehicles [5].
Nanoceramics are characterized by large surface area due to their small particle
size. This is especially useful in cases, where their surface properties play a role
in its effective functioning. For example, when nanoceramics are used as catalysts,
their small particle size increases the rate of reaction [6]. When they are used as
bioimplants, nanoceramics facilitate faster bone-implant interface establishment and
aids in faster healing. When used as drug delivery systems, the drug reaches the target
site faster, does not get released in non-target sites, react with the target effectively
and carry out the intended purpose.
The design and development of nanoceramics of different sizes and shapes by new
techniques have garnered much attention as each of them come with unique properties. Till now, nanoceramics in different sizes and shapes such as nanoparticles,
nanorods, nanoribbons, nanotubes, nanosheets and nanofluids have been synthesized [4]. Modification in various physical, chemical and biological properties can
be bought about by modifying the nanoceramics size, shape, by doping different
elements in their crystallographic sites as impurity or by creating defects using ion
implantation method [7]. Advanced nanoceramics are of 3 major types: (i) oxides
S. A. Pauline
against other hard objects. However, in the nanoscale, their properties are unique,
differ widely from that of macroscale ceramics and are of greater use in various fields.
Ceramic nanoparticles have properties lying in between metals and non-metals. The
improved properties include dielectricity, ferroelectricity, piezoelectricity, pyroelectricity, ferromagnetism, magnetoresistance and superconductivity [1]. Nanoceramics
also have excellent mechanical, processing and surface properties such as biocompatibility, superplasticity, mechanical resistance, chemical resistance, strength and
hardness at normal as well as high temperatures [2]. The properties of nanoceramics
depend and vary based on the type of nanoceramic, its size and shape. The bonding
between their constituent atoms defines their properties which are a combination of
ionic and covalent bonds [3].
Nanoceramic materials were first discovered in the early 1980s using sol-gel
method, a form of chemical solution deposition. Larger scale materials have flaws
that make them brittle, but due to their small size, nanoceramics are flawless. Interest
and research in nanoceramics are blooming since then owing to its varied properties and extensive applications. In the 2000s, synthesis methods evolved using heat
and pressure in sintering process. The method of synthesis of nanoceramics plays a
great role in determining the shape and size of the particles and hence its properties.
During the past 20 years, research in nanoceramics has resulted in positive outcomes
and the advanced materials prepared are being used in several industries such as
sensors, batteries, capacitors, corrosion-resistant coatings, thermal barrier coatings,
solid electrolytes, catalysts, cosmetics, automotive, optoelectronics, computers, electronics, biomaterials, etc. [4]. They have special applications in the field of medicine
owing to their biocompatibility, bioactivity and hydrophilicity and hence are used as
bioimplants, as drug delivery devices and also in cancer treatment as chemotherapy
delivery vehicles [5].
Nanoceramics are characterized by large surface area due to their small particle
size. This is especially useful in cases, where their surface properties play a role
in its effective functioning. For example, when nanoceramics are used as catalysts,
their small particle size increases the rate of reaction [6]. When they are used as
bioimplants, nanoceramics facilitate faster bone-implant interface establishment and
aids in faster healing. When used as drug delivery systems, the drug reaches the target
site faster, does not get released in non-target sites, react with the target effectively
and carry out the intended purpose.
The design and development of nanoceramics of different sizes and shapes by new
techniques have garnered much attention as each of them come with unique properties. Till now, nanoceramics in different sizes and shapes such as nanoparticles,
nanorods, nanoribbons, nanotubes, nanosheets and nanofluids have been synthesized [4]. Modification in various physical, chemical and biological properties can
be bought about by modifying the nanoceramics size, shape, by doping different
elements in their crystallographic sites as impurity or by creating defects using ion
implantation method [7]. Advanced nanoceramics are of 3 major types: (i) oxides