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L. M. Haverhals et al.
viscose process produces significant waste, and both processes require relatively pure
cellulose pulp inputs. These types of processes fully denature and dissolve the starting
cellulosic materials. In addition to causing confusion over the source of cellulose
[29] and traceability (e.g., “sustainable” bamboo versus “sustainable” beechwood or
eucalyptus), full dissolution often results in deleterious materials properties [30] that
have limited the breadth of adoption. Lastly, the ability to functionalize manufactured
cellulose and to create complex (multi-material) composites is limited.
Life processes produce remarkably diverse composite materials that cannot be
easily produced by any other means at a relevant scale. For example, similar to the
annular growth rings of trees, cotton fibers exhibit daily growth rings. These ring
structures reveal exquisitely controlled orientation of cellulose microstructures that
enables cotton to exhibit wet strength that is important for durability during laundering of fabrics. Full dissolution of these structures destroys native order and structure.
Upon regeneration, entropy dictates that complex microstructures are not remade.
Loss of structure often yields suboptimal consequences and includes lack of wet
strength for rayon (viscose) [30]. Cotton is the primary plant-based fiber produced
for textiles today, but it is just one of many fibers that can be produced in overwhelming abundance by sustainable agriculture. Flax (linen), jute, kapok (Ceiba pentandra),
bamboo, ramie, kenaf, industrial hemp, etc. are all examples of plant-based fibers that
can grow in different climates and exhibit diverse microstructures and useful macromorphologies. Likewise, various differentiated types of animal-based materials, such
as leather, wool, silk, and chitin (e.g., purified from shrimp and crab shells), have
important utility within higher price sectors of the textile industry. In particular, the
abundance of cellulosic fibers is practically inexhaustible with estimates approaching 100 gigatons of global annual production of cellulose biopolymers alone [31,
32]. The 100 billion pounds of staple and filament polyester fiber produced and utilized annually represents just ~0.045 gigatons, and thus, a tiny ~0.00045 fraction
compared to the estimated annual cellulose production by life processes [33]. Of
course, plants harness sunlight to produce these wondrously diverse materials while
sequestering carbon dioxide. Natural systems are well balanced and have evolved to
thrive with 100s of gigatons of cellulose and lignocellulose fibers in various stages
of growth and decomposition (in all forms of biodegradable macro and “microfiber“
formats) within global ecosystems. This global system essentially constitutes the
original cradle-to-cradle materials manufacturing technology on earth. So long as
natural fibers, such as cotton, are not treated with toxic chemistries (e.g., fluorinated
water repellants), it is clear that sustainably grown, biodegradable, biopolymer-based
fibers are sufficiently abundant and circular to drive the global materials economy
for textiles and beyond, as shown in Fig. 9.1.
L. M. Haverhals et al.
viscose process produces significant waste, and both processes require relatively pure
cellulose pulp inputs. These types of processes fully denature and dissolve the starting
cellulosic materials. In addition to causing confusion over the source of cellulose
[29] and traceability (e.g., “sustainable” bamboo versus “sustainable” beechwood or
eucalyptus), full dissolution often results in deleterious materials properties [30] that
have limited the breadth of adoption. Lastly, the ability to functionalize manufactured
cellulose and to create complex (multi-material) composites is limited.
Life processes produce remarkably diverse composite materials that cannot be
easily produced by any other means at a relevant scale. For example, similar to the
annular growth rings of trees, cotton fibers exhibit daily growth rings. These ring
structures reveal exquisitely controlled orientation of cellulose microstructures that
enables cotton to exhibit wet strength that is important for durability during laundering of fabrics. Full dissolution of these structures destroys native order and structure.
Upon regeneration, entropy dictates that complex microstructures are not remade.
Loss of structure often yields suboptimal consequences and includes lack of wet
strength for rayon (viscose) [30]. Cotton is the primary plant-based fiber produced
for textiles today, but it is just one of many fibers that can be produced in overwhelming abundance by sustainable agriculture. Flax (linen), jute, kapok (Ceiba pentandra),
bamboo, ramie, kenaf, industrial hemp, etc. are all examples of plant-based fibers that
can grow in different climates and exhibit diverse microstructures and useful macromorphologies. Likewise, various differentiated types of animal-based materials, such
as leather, wool, silk, and chitin (e.g., purified from shrimp and crab shells), have
important utility within higher price sectors of the textile industry. In particular, the
abundance of cellulosic fibers is practically inexhaustible with estimates approaching 100 gigatons of global annual production of cellulose biopolymers alone [31,
32]. The 100 billion pounds of staple and filament polyester fiber produced and utilized annually represents just ~0.045 gigatons, and thus, a tiny ~0.00045 fraction
compared to the estimated annual cellulose production by life processes [33]. Of
course, plants harness sunlight to produce these wondrously diverse materials while
sequestering carbon dioxide. Natural systems are well balanced and have evolved to
thrive with 100s of gigatons of cellulose and lignocellulose fibers in various stages
of growth and decomposition (in all forms of biodegradable macro and “microfiber“
formats) within global ecosystems. This global system essentially constitutes the
original cradle-to-cradle materials manufacturing technology on earth. So long as
natural fibers, such as cotton, are not treated with toxic chemistries (e.g., fluorinated
water repellants), it is clear that sustainably grown, biodegradable, biopolymer-based
fibers are sufficiently abundant and circular to drive the global materials economy
for textiles and beyond, as shown in Fig. 9.1.