C hapter 10 nanomaterial product Forms and Functions
446
used electron-beam lithography to create an array of holes in a thin
film (PMMA) supported on a substrate. Nanopillars were about
600 nm high and 400 nm in diameter. Experiments in air and water
demonstrated increased and repeatable sticking power. Adhesive
qualities in wet environments were especially enhanced. Considerable work needs to be done with these bio-inspired adhesives, but it is
clear that they are opening up a very positive area of investigation.
All these remarkable new adhesives have great potential in many
applications, ranging from the commonplace to the exotic. Product
manufacturers are always on the lookout for new adhesives to
replace invariably troublesome mechanical connections. In the
electronics industry, nanoadhesives have great appeal in systems
that do automatic positioning and connecting of components; with
adhesives this can be a completely clean manipulation.
nanoporous materials
Porous materials are commonplace and are found as constituent
elements in a wide variety of products. A porous material has a
network of voids (pores) that are distributed through the whole
of the primary material. Generally the presence of voids results in
materials with relatively low densities. Many porous materials have
interconnected voids that allow the material to have a greater or
lesser degree of permeability to fluids or gases. Polymers, ceramics,
and even metals can come in porous forms. Applications include
many kinds of membranes, filters, adsorbents, insulators, ion
exchangers, catalyst supports, and others. With polymers alone,
many kinds have been developed for various purposes, including
thermal insulation material for buildings, common dust filters,
and a host of everyday consumer products such as common cups.
Porous ceramics also find use in both products and many industrial
applications. They can also play a pivotal role in various kinds of
environmental applications having to do with air and water environments, including remediation of water and air pollution (see
Chapter 11).
Critical characteristics of porous materials include their pore size
and shape, pore volume, surface area, and various pore surface
properties (e.g., hydrophobic, hydrophilic, other). Porosity is commonly measured in terms of volume percentage. Figure 10.39 illustrates the general relationship between porosity and pore size for
several kinds of porous materials and for various typical applications. Note that certain materials, such as activated carbons, have
quite small pore sizes, as does xerogel (aerogels have larger pore
446
used electron-beam lithography to create an array of holes in a thin
film (PMMA) supported on a substrate. Nanopillars were about
600 nm high and 400 nm in diameter. Experiments in air and water
demonstrated increased and repeatable sticking power. Adhesive
qualities in wet environments were especially enhanced. Considerable work needs to be done with these bio-inspired adhesives, but it is
clear that they are opening up a very positive area of investigation.
All these remarkable new adhesives have great potential in many
applications, ranging from the commonplace to the exotic. Product
manufacturers are always on the lookout for new adhesives to
replace invariably troublesome mechanical connections. In the
electronics industry, nanoadhesives have great appeal in systems
that do automatic positioning and connecting of components; with
adhesives this can be a completely clean manipulation.
nanoporous materials
Porous materials are commonplace and are found as constituent
elements in a wide variety of products. A porous material has a
network of voids (pores) that are distributed through the whole
of the primary material. Generally the presence of voids results in
materials with relatively low densities. Many porous materials have
interconnected voids that allow the material to have a greater or
lesser degree of permeability to fluids or gases. Polymers, ceramics,
and even metals can come in porous forms. Applications include
many kinds of membranes, filters, adsorbents, insulators, ion
exchangers, catalyst supports, and others. With polymers alone,
many kinds have been developed for various purposes, including
thermal insulation material for buildings, common dust filters,
and a host of everyday consumer products such as common cups.
Porous ceramics also find use in both products and many industrial
applications. They can also play a pivotal role in various kinds of
environmental applications having to do with air and water environments, including remediation of water and air pollution (see
Chapter 11).
Critical characteristics of porous materials include their pore size
and shape, pore volume, surface area, and various pore surface
properties (e.g., hydrophobic, hydrophilic, other). Porosity is commonly measured in terms of volume percentage. Figure 10.39 illustrates the general relationship between porosity and pore size for
several kinds of porous materials and for various typical applications. Note that certain materials, such as activated carbons, have
quite small pore sizes, as does xerogel (aerogels have larger pore