126
Bacterial Cellulose
of.a.chitin-cellulose.blend.with.a.composition.of.75-25,.which.was.prepared.
in.the.same.manner.as.NOC,.also.exhibit.orientation.of.molecular.aggregation,.but.are.not.resolved.at.the.individual.molecular.chain.scale.(Kondo.et.
al..2004)..The.white.dots.or.lines.in.the.chitin-cellulose.blend.of.Figure 6.7.
indicate.molecular.chains.or.molecular.aggregates..Some.parts.are.well.oriented.parallel.to.the.stretching.direction.and.the.molecular.aggregates.are.
entirely.ordered.along.the.stretching.axis.
By. image. analyses. of. the. TEM. image. in. this. figure,. the. average. width.
and. distance. between. two. parallel. lines. were. obtained. as. 1.38. ±. 0.18. nm.
and.1.65.±.0.27.nm,.respectively..The.average.line.width.is.narrower.than.
that.from.the.TEM.image.(1.51.±.0.27.nm).of.nematic.ordered.pure.chitin,.
indicating.that.the.intermolecular.interaction.between.cellulose.and.chitin.
may.be.engaged..Possibly.each.molecular.chain.is.facing.each.other.against.
the.surface.by.a.hydrophobic.interaction.such.as.van.der.Waals.forces..On.
the. other. hand,. the. average. distance. between. two. parallel. lines. was. not.
significantly. different. between. the. two. stretched. films. from. pure. chitin.
(1.62.±.0.21.nm).and.the.cellulose-chitin.blend.(1.65.±.0.27.nm)..Therefore.
it.is.thought.that.the.cellulose-chitin.molecular.aggregates.in.the.stretched.
film.are.aligned.similarly.to.nematic.ordered.pure.chitin..In.addition,.these.
results.indicate.the.presence.of.another.nematic.ordered.state.with.a.different.scale.(e.g.,.nano/micro.hierarchical.structures).in.chitin.and.the.blends.
with. cellulose.. (See. the. more. detailed. study. using. WAXD. on. . nematic.
ordered.pure.chitin.and.the.blends.with.cellulose.in.Kondo.et.al..[2004].and.
Kondo.[2007].)
Modified NOC
The.author.proposes.in.the.following.sections.a.novel.type.of.biomineralization. process. by. developing. a. bifunctional. cellulose. template. (Higashi. and.
Kondo. 2012).. Namely,. the. NOC. template. has. been. modified. into. a. bifunctional. template. having. a. pair. of. the. functions. required. for. biomineralization,.resulting.in.oriented.deposition.of.the.biominerals.as.well.as.supplying.
anions.in.the.synthesis..In.this.case,.the.new.NOC.template.that.is.prepared.
to.contain.phosphate.anions.(termed.p-NOC).is.expected.to.mediate.a.unique.
order.patterned.deposition.of.calcium.phosphates.on.the.surface.by.reaction.
with.calcium.cations.during.immersion.in.a.buffer.solution.
The. modification. of. NOC. is. performed. as. follows:. A. transparent. waterswollen. . fixed. gel. of. cellulose. (WSC). is. followed. by. a. procedure. using. a.
DMAc/LiCl. solvent. system,. as. previously. described. (Kondo. et. al.. 2001;.
Togawa.and.Kondo.1999)..The.WSC.is.immersed.in.phosphate.buffered.saline.
(PBS;.Sigma-Aldrich).for.1.week.to.prepare.a.WSC.gel.containing.phosphate.
anions..Starting.with.the.gel-like.films.containing.phosphate.anions,.p-NOC.is.
perature..In.the.drawing.process,.the.specimen.is.kept.in.a.wet.state.by.pouring.the.PBS.on.the.surface.of.the.film..The.specimen.is.then.air.dried.for.24.h.
Bacterial Cellulose
of.a.chitin-cellulose.blend.with.a.composition.of.75-25,.which.was.prepared.
in.the.same.manner.as.NOC,.also.exhibit.orientation.of.molecular.aggregation,.but.are.not.resolved.at.the.individual.molecular.chain.scale.(Kondo.et.
al..2004)..The.white.dots.or.lines.in.the.chitin-cellulose.blend.of.Figure 6.7.
indicate.molecular.chains.or.molecular.aggregates..Some.parts.are.well.oriented.parallel.to.the.stretching.direction.and.the.molecular.aggregates.are.
entirely.ordered.along.the.stretching.axis.
By. image. analyses. of. the. TEM. image. in. this. figure,. the. average. width.
and. distance. between. two. parallel. lines. were. obtained. as. 1.38. ±. 0.18. nm.
and.1.65.±.0.27.nm,.respectively..The.average.line.width.is.narrower.than.
that.from.the.TEM.image.(1.51.±.0.27.nm).of.nematic.ordered.pure.chitin,.
indicating.that.the.intermolecular.interaction.between.cellulose.and.chitin.
may.be.engaged..Possibly.each.molecular.chain.is.facing.each.other.against.
the.surface.by.a.hydrophobic.interaction.such.as.van.der.Waals.forces..On.
the. other. hand,. the. average. distance. between. two. parallel. lines. was. not.
significantly. different. between. the. two. stretched. films. from. pure. chitin.
(1.62.±.0.21.nm).and.the.cellulose-chitin.blend.(1.65.±.0.27.nm)..Therefore.
it.is.thought.that.the.cellulose-chitin.molecular.aggregates.in.the.stretched.
film.are.aligned.similarly.to.nematic.ordered.pure.chitin..In.addition,.these.
results.indicate.the.presence.of.another.nematic.ordered.state.with.a.different.scale.(e.g.,.nano/micro.hierarchical.structures).in.chitin.and.the.blends.
with. cellulose.. (See. the. more. detailed. study. using. WAXD. on. . nematic.
ordered.pure.chitin.and.the.blends.with.cellulose.in.Kondo.et.al..[2004].and.
Kondo.[2007].)
Modified NOC
The.author.proposes.in.the.following.sections.a.novel.type.of.biomineralization. process. by. developing. a. bifunctional. cellulose. template. (Higashi. and.
Kondo. 2012).. Namely,. the. NOC. template. has. been. modified. into. a. bifunctional. template. having. a. pair. of. the. functions. required. for. biomineralization,.resulting.in.oriented.deposition.of.the.biominerals.as.well.as.supplying.
anions.in.the.synthesis..In.this.case,.the.new.NOC.template.that.is.prepared.
to.contain.phosphate.anions.(termed.p-NOC).is.expected.to.mediate.a.unique.
order.patterned.deposition.of.calcium.phosphates.on.the.surface.by.reaction.
with.calcium.cations.during.immersion.in.a.buffer.solution.
The. modification. of. NOC. is. performed. as. follows:. A. transparent. waterswollen. . fixed. gel. of. cellulose. (WSC). is. followed. by. a. procedure. using. a.
DMAc/LiCl. solvent. system,. as. previously. described. (Kondo. et. al.. 2001;.
Togawa.and.Kondo.1999)..The.WSC.is.immersed.in.phosphate.buffered.saline.
(PBS;.Sigma-Aldrich).for.1.week.to.prepare.a.WSC.gel.containing.phosphate.
anions..Starting.with.the.gel-like.films.containing.phosphate.anions,.p-NOC.is.
perature..In.the.drawing.process,.the.specimen.is.kept.in.a.wet.state.by.pouring.the.PBS.on.the.surface.of.the.film..The.specimen.is.then.air.dried.for.24.h.