124
Bacterial Cellulose
molecular.orientation.axis.of.the.NOC..Moreover,.the.obtained.films.were.
all.transparent,.as.the.photographs.in.Figure 6.6.indicate..Thus.the.orientation.of.molecular.chains.and.the.transparency.of.NOC.was.maintained,.even.
after.crystallization.took.place..This.indicates.that.the.domain.sizes.of.the.
crystallites.were.quite.small.even.though.they.were.well.oriented.along.the.
same.molecular.orientation.direction.of.the.initial.NOC.film.
The. equatorial. WAXD. patterns. of. the. profiles. in. Figures 6.6b–6.6d. were.
easily.identified.as.cellulose.II,.III,.and.IV,.respectively..The.results.suggest.
that.transformation.into.each.allomorph.was.completed..It.should.be.noted.
that.all.of.the.transformations.were.accomplished.under.milder.conditions.
than. the. conventional. methods. reported. for. the. preparation. of. each. allomorphs. (Chidambareswaran. et. al.. 1978;. Fengel. et. al.,. 1995).. For. example,.
16.5%.NaOH.aqueous.solution.has.thus.far.been.required.for.transformation.
from. .
cellulose. I. to. cellulose. II. when. cotton. fibers. are. used. as. the. starting.
cellulose.(Fengel.et.al..1995)..Using.NOC.as.the.starting.cellulose.assembled.
state,. 7%. NaOH. was. enough. for. the. transformation.. In. particular,. NOC.
yielded.. cellulose.IV.directly.by.a.hydrothermal.treatment.at.more.than.100°C.
without.the.formation.of.cellulose.III.as.an.intermediate..In.a.similar.manner,.
we.employed.cotton.cellulose.and.a.commercially.available.cellophane.film.
as.a.reference.of.the.starting.cellulose.to.transform.into.polymorphs.under.
the. same. conditions. used. for. NOC.. However,. both. cotton. and. cellophane.
could.never.be.transformed.into.each.allomorph..The.facile.transformations.
are.attributed.only.to.the.supramolecular.structure.of.NOC,.which.is.well.
ordered.but.composed.mainly.of.noncrystalline.regions..In.fact,.the.degrees.
of.crystallinity.of.the.three.crystallized.films.from.NOC.were.around.45%..
Moreover,.our.results.have.demonstrated.that.such.NOC.structure.in.a.film.
material. provides,. under. milder. treatments,. a. facile. direct. transformation.
into.the.oriented.films.having.highly.aligned.domains.of.cellulose.II,.III,.and.
IV.allomorphs.along.the.initial.orientation.in.the.NOC.
Various Nematic Ordered Templates and Modified NOC
Nematic Ordered Chitin and Chitin/Cellulose Blends
Figure 6.7. shows. an. image. of. the. chitin. template. prepared. in. the. same.
manner. as. the. NOC. template. and. observed. with. high-resolution. TEM. as.
well. as. atomic. force. microscopy. (AFM). (Kondo. et. al.. 2004,. 2012).. The. two.
images.exhibited.the.orientation.of.molecular.chains,.but.they.were.not.clear.
enough.to.be.estimated..To.obtain.the.distance.between.individual.molecular.chains,.selected.oriented.areas.(shown.in.the.rectangles.of.Figure 6.7).of.
both.high-resolution.images.were.at.first.Fourier.transformed.to.obtain.the.
diffraction.images..Then.the.manipulated.diffraction.images,.as.seen.in.the.
Bacterial Cellulose
molecular.orientation.axis.of.the.NOC..Moreover,.the.obtained.films.were.
all.transparent,.as.the.photographs.in.Figure 6.6.indicate..Thus.the.orientation.of.molecular.chains.and.the.transparency.of.NOC.was.maintained,.even.
after.crystallization.took.place..This.indicates.that.the.domain.sizes.of.the.
crystallites.were.quite.small.even.though.they.were.well.oriented.along.the.
same.molecular.orientation.direction.of.the.initial.NOC.film.
The. equatorial. WAXD. patterns. of. the. profiles. in. Figures 6.6b–6.6d. were.
easily.identified.as.cellulose.II,.III,.and.IV,.respectively..The.results.suggest.
that.transformation.into.each.allomorph.was.completed..It.should.be.noted.
that.all.of.the.transformations.were.accomplished.under.milder.conditions.
than. the. conventional. methods. reported. for. the. preparation. of. each. allomorphs. (Chidambareswaran. et. al.. 1978;. Fengel. et. al.,. 1995).. For. example,.
16.5%.NaOH.aqueous.solution.has.thus.far.been.required.for.transformation.
from. .
cellulose. I. to. cellulose. II. when. cotton. fibers. are. used. as. the. starting.
cellulose.(Fengel.et.al..1995)..Using.NOC.as.the.starting.cellulose.assembled.
state,. 7%. NaOH. was. enough. for. the. transformation.. In. particular,. NOC.
yielded.. cellulose.IV.directly.by.a.hydrothermal.treatment.at.more.than.100°C.
without.the.formation.of.cellulose.III.as.an.intermediate..In.a.similar.manner,.
we.employed.cotton.cellulose.and.a.commercially.available.cellophane.film.
as.a.reference.of.the.starting.cellulose.to.transform.into.polymorphs.under.
the. same. conditions. used. for. NOC.. However,. both. cotton. and. cellophane.
could.never.be.transformed.into.each.allomorph..The.facile.transformations.
are.attributed.only.to.the.supramolecular.structure.of.NOC,.which.is.well.
ordered.but.composed.mainly.of.noncrystalline.regions..In.fact,.the.degrees.
of.crystallinity.of.the.three.crystallized.films.from.NOC.were.around.45%..
Moreover,.our.results.have.demonstrated.that.such.NOC.structure.in.a.film.
material. provides,. under. milder. treatments,. a. facile. direct. transformation.
into.the.oriented.films.having.highly.aligned.domains.of.cellulose.II,.III,.and.
IV.allomorphs.along.the.initial.orientation.in.the.NOC.
Various Nematic Ordered Templates and Modified NOC
Nematic Ordered Chitin and Chitin/Cellulose Blends
Figure 6.7. shows. an. image. of. the. chitin. template. prepared. in. the. same.
manner. as. the. NOC. template. and. observed. with. high-resolution. TEM. as.
well. as. atomic. force. microscopy. (AFM). (Kondo. et. al.. 2004,. 2012).. The. two.
images.exhibited.the.orientation.of.molecular.chains,.but.they.were.not.clear.
enough.to.be.estimated..To.obtain.the.distance.between.individual.molecular.chains,.selected.oriented.areas.(shown.in.the.rectangles.of.Figure 6.7).of.
both.high-resolution.images.were.at.first.Fourier.transformed.to.obtain.the.
diffraction.images..Then.the.manipulated.diffraction.images,.as.seen.in.the.