Page 29 - Book Hosokawa Nanoparticle Technology Handbook

FUNDAMENTALS CH. 1 BASIC PROPERTIES AND MEASURING METHODS OF NANOPARTICLES

0.01nm 0.1nm (1A) 1 nm 10nm 100nm 1 m 10 m

Wave length X-ray Ultraviolet Visible light Infrared
Pore Micropore Mesopore Macropore
Atomic radius Hydrogen Lead

Gold, silver colloid Ferrite Atomized iron powder
Metal
Magnetic bacteria Blue powder
Inorganic Colloidal silica
(catalyst) TiO (pigment)
TiO 2 2
FCM nanocomposite oxide particles
Fine ground CaCO
Colloidal CaCO 3 3
Fullerene Nanodiamond Carbon black Graphite

Carbon nanotube (diameter)
Organic PMMA nanoparticles
PLGA nanospheres Toner
Liposome Starch

Bio, pharmaceutical DNA dia Red blood cell
Virus Mitochondria Biologic cell
Dry Powder Inhalation

Aerosol Cigarette smoke

FCM : Flash Creation Method
PLGA : Poly-lactic-glycolic acid (Spherical crystallization method)
PMMA : Polymethylmethacrylate

Figure 1.1.1
Examples of nanoparticles and related phenomena.

Then the BET (Brunauer-Emmett-Teller) specific 1.1.4 Properties of nanoparticle and size effect
surface measurement based on the gas adsorption is
often applied as a simple method to evaluate the size As mentioned above, with the decreasing particle
of nanosized primary particles. size, the solid particles generally tend to show differ-
By this method, it is possible to estimate the ent properties from the bulk material and even the
particle size from the specific surface area under physical properties like melting point and dielectric
the assumption of spherical particle shape. This constant themselves which have been considered as
equivalent particle size based on the specific sur- specific properties may change, when the particles
face area is useful for the evaluation of nanoparticle become in several nanometer size. These changes in
size, though it may differ from the particle size the fundamental properties with the particle size is
observed by the electron microscope depending called “size effect” in a narrower sense.
upon the surface state and the inner structure of the On the contrary, in a broader sense, it could also
particles. include the change in the various characteristics and

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