Agriculture Reference
In-Depth Information
2.2 Current Use of Nanotechnology in Fertilizers
and Supplements
In this section, published papers, patents, and commercial products will be divided
into one of three categories related to nanotechnology in agricultural inputs. Box
1
defines some key terminology in nanotechnology as it relates to fertilizers. It is
important to note that the definitions for nano-object, nanoparticles, and
nanomaterials appear to be somewhat relaxed when applied to fertilizer inputs.
Several patents in particular describe materials with dimensions of less than
1,000 nm as “nano” providing they exhibit unique properties not recognized in
micron- or larger-sized particles. It is debatable whether this is an accurate use of
the term “nano”; however, these studies have been included nevertheless in this
analysis. Nanomaterials can be realized using two different approaches: “bottom-
up” or “top-down.” Top-down approaches use physical or chemical processing to
convert bulk materials into nanoscale ones. Examples of these processes include
grinding, etching, and milling. Bottom-up nanotechnology relies on self-assembly
and self-organization of smaller building blocks to create functional nanoscale
materials. One example in this category could be the self-assembly of nanoscale
liposomes from lipid molecules.
Box 1: Definitions in Nanotechnology
Nano-object: Materials with one, two, or three dimensions in the size range
from 0.1 to 100 nm. In fertilizer applications, a looser definition appears to be
in use. Materials with one, two, or three dimensions less than 1,000 nm that
exhibit unique properties unseen in the bulk material have been termed
“nano” in many fertilizer patents and publications.
Nanomaterial: Encompasses both “nano-objects” and “nano-structured
materials” which are bulk materials that have important features on the
nanometer length scale.
Nanoparticle: A material with all three dimensions in the nanoscale regime.
Granulation: The process of forming or crystallizing a material into small
grains.
Shearing: The process of grinding or cutting of a material substance in which
parallel internal surfaces slide past one another at high speeds.
Ball-milling: The process of grinding a material into a very fine powder using
a cylindrical device filled with both the material to be processed and a
grinding medium.
Emulsification: The process of forming a mixture of two immiscible
(unblendable) liquids, yielding micro- or nano-sized droplets.
