C hapter 10 nanomaterial product Forms and Functions
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multifunctional materials. Many tents, for example, are now embedding various types of flexible photovoltaic materials directly into
the basic tent material, to serve an energy supply function. Clearly,
the list of needed characteristics is extensive and highly dependent
on product type. Interesting applications based on nanomaterials
include improved textiles for use as filters and as devices for administering medicines.
In architecture, textiles are widely used in a number of applications.
In primary structures, many pneumatic, membrane, and net structures make extensive use of textiles for surface shapes. Pneumatic
structures, for example, are widely used in sports applications to
cover large arenas. The interior is pressurized and the skin simply
inflates to the desired shape. Membrane structures consist of doubly
curved surfaces that are stretched via externally applied jacking
forces. Net structures use cables to form the shape but have a skin
stretched over them. These flexible surface-forming structures carry
loads primarily through the development of tension stresses. Surface
shapes are invariably pretensioned via either internal inflation
pressures in pneumatic structures or external jacking forces in membrane structures, necessary to maintain their shape and stability under
fluctuating wind and other forces that act on the surface. Both the
pretensioning stresses and the stresses that result from the applied
loadings can be quite high. Hence, when textiles are used directly
as the skin, they must be able to directly carry significant stresses or
have special higher-strength strands embedded in them. Stresses are
invariably biaxial and vary considerably throughout a skin.
In architectural structures that use traditional woven textiles, considerable attention is paid to the various relative strengths of the
material in the warp and weft direction and in orienting the material so that these strengths best correspond to actual stress levels
found in the materials (which can be found by various structural
analysis techniques). Additionally, the materials used must be
resistant to tearing and abrasion. These same surfaces must typically also be waterproof and not degrade over time due to exposure to UV sun rays. For occupant safety, surfaces must have low
flame-spread characteristics and not give off toxic gases during
fire situations. Resistance to discoloration is highly desirable. For
enclosed structures, some level of thermal insulation capability is
always desirable. As with textiles used in products, current design
trends pay special attention to multifunctional materials. The idea
of using flexible photovoltaic elements in the skin is an obvious
one for structures of this type, as a way of generating energy. Skins
incorporating phase-change materials are being explored to help
452
multifunctional materials. Many tents, for example, are now embedding various types of flexible photovoltaic materials directly into
the basic tent material, to serve an energy supply function. Clearly,
the list of needed characteristics is extensive and highly dependent
on product type. Interesting applications based on nanomaterials
include improved textiles for use as filters and as devices for administering medicines.
In architecture, textiles are widely used in a number of applications.
In primary structures, many pneumatic, membrane, and net structures make extensive use of textiles for surface shapes. Pneumatic
structures, for example, are widely used in sports applications to
cover large arenas. The interior is pressurized and the skin simply
inflates to the desired shape. Membrane structures consist of doubly
curved surfaces that are stretched via externally applied jacking
forces. Net structures use cables to form the shape but have a skin
stretched over them. These flexible surface-forming structures carry
loads primarily through the development of tension stresses. Surface
shapes are invariably pretensioned via either internal inflation
pressures in pneumatic structures or external jacking forces in membrane structures, necessary to maintain their shape and stability under
fluctuating wind and other forces that act on the surface. Both the
pretensioning stresses and the stresses that result from the applied
loadings can be quite high. Hence, when textiles are used directly
as the skin, they must be able to directly carry significant stresses or
have special higher-strength strands embedded in them. Stresses are
invariably biaxial and vary considerably throughout a skin.
In architectural structures that use traditional woven textiles, considerable attention is paid to the various relative strengths of the
material in the warp and weft direction and in orienting the material so that these strengths best correspond to actual stress levels
found in the materials (which can be found by various structural
analysis techniques). Additionally, the materials used must be
resistant to tearing and abrasion. These same surfaces must typically also be waterproof and not degrade over time due to exposure to UV sun rays. For occupant safety, surfaces must have low
flame-spread characteristics and not give off toxic gases during
fire situations. Resistance to discoloration is highly desirable. For
enclosed structures, some level of thermal insulation capability is
always desirable. As with textiles used in products, current design
trends pay special attention to multifunctional materials. The idea
of using flexible photovoltaic elements in the skin is an obvious
one for structures of this type, as a way of generating energy. Skins
incorporating phase-change materials are being explored to help