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2006 International 2006 International Conference on Conference on
Nanotechnology, Nanotechnology, April 26April 26--28, 200628, 2006
Atlanta, GAAtlanta, GA
Synthesis of Hollow TiOSynthesis of Hollow TiO22Towards a Fundamental Understanding of Towards a Fundamental Understanding of
the Relationship between Filler the Relationship between Filler Morphology and PerformanceMorphology and Performance
Presented by: Kim NelsonPresented by: Kim NelsonPhD CandidatePhD Candidate
CoCo--Author: Author: YulinYulin Deng Deng AdvisorAdvisorGeorgia Institute of TechnologyGeorgia Institute of Technology
OutlineOutline
i.i. Conventional TiOConventional TiO22 in papermakingin papermakingii.ii. Current market conditionsCurrent market conditionsiii.iii. Hollow TiOHollow TiO22 nanoparticlesnanoparticlesiv.iv. Shape control using cellulose Shape control using cellulose
nanowhiskersnanowhiskersv.v. Morphological control of hollow TiOMorphological control of hollow TiO22
spheresspheresvi.vi. Cost effective hollow TiOCost effective hollow TiO22
TiOTiO22: Papermaking Pigment: Papermaking Pigment
•• AdvantagesAdvantages–– Whiteness/brightnessWhiteness/brightness–– OpacityOpacity–– Minimal impact on strengthMinimal impact on strength
•• DisadvantagesDisadvantages–– COST!COST!
•• $3,000/ton (PCC $150/ton)$3,000/ton (PCC $150/ton)•• ApplicationsApplications
wood fiber
fiber
TiO2clay
PCC
Reflection Refraction Diffraction
TiOTiO22: Papermaking Pigment: Papermaking Pigment
Market ConditionsMarket Conditions
•• Increasing demandIncreasing demand60% from China60% from China
•• Decreasing Titanium ReservesDecreasing Titanium ReservesChina, India, AfricaChina, India, Africa
•• Papermaking TrendsPapermaking TrendsPulpPulpBasis WeightBasis Weight
Hollow Titania Nano StructuresHollow Titania Nano Structures•• SpheresSpheres
–– PolydispersePolydisperse
–– No size controlNo size control
–– ExpensiveExpensive
•• TubesTubes–– Batch processingBatch processing
–– ExpensiveExpensive
LayerLayer--byby--Layer Self AssemblyLayer Self Assembly
Colloid TemplateColloid Template
Calcination at 525 Calcination at 525 °°CC
for 4 hoursfor 4 hours
++PDADMACPDADMAC
TALH TALH
++++ ++
++ ++
Reflux at 100 Reflux at 100 °°CC
for 24 hours for 24 hours
SolSol--Gel SynthesisGel Synthesis
MMO
O
O
OMO
O
O
O
MO
O
O
OMO
O
O
O
ROH
ROH R
OH
ROH
H
H
H
H
MO
O
O
O
R
R
R
RMO
O
O
O+
+
+
H
H
H
H
MO
O
O
OH
H
H
H
MO
O
O
OH
H
H
H
MO
O
O
OH
H
H
H
MO
O
O
O +++
HO H
HO H H O
H
HO H
A) HydrolysisA) Hydrolysis
B) CondensationB) Condensation200 nm
HO H
HO H H O
H
HO H
Cellulose Nano WhiskersCellulose Nano Whiskers
380 nm
Preparation of Cellulose WhiskersPreparation of Cellulose Whiskers
(5) Sonication(5) Sonication (6) Mixed Bed Resin(6) Mixed Bed Resin(4) Dialysis(4) Dialysis
(1) Cotton Pulp(1) Cotton Pulp (2) Ground Pulp(2) Ground Pulp (3) Hydrolysis (3) Hydrolysis
Tunable Aspect RatioTunable Aspect Ratio
120 nm120 nm
120 nm 120 nm
SolSol--GelGel
LBLLBL
Tunable Aspect RatioTunable Aspect Ratio
500 nm 500 nm
Tunable Aspect RatioTunable Aspect Ratio
00
11
22
33
44
55
66
00 55 1010 1515 2020 2525 3030 3535 4040 4545
Aspect ratio of cellulose templateAspect ratio of cellulose template
Asp
ect r
atio
of c
oate
d pa
rticl
eA
spec
t rat
io o
f coa
ted
parti
cle SolSol--Gel CoatingGel Coating
LBL CoatingLBL Coating
Tunable Aspect RatioTunable Aspect Ratio
hnDhnrhnD
D
Dhn
Dhnr
hnDhnL
WW
LL
WWWW
LL
WW
LLr2
222
1
2
2
20
0
0
0
0
00
0
0
++⎟
⎟⎠
⎞⎜⎜⎝
⎛+
=+
+
=+
+=
LBLLBLnnwwhhw w = 39.4 nm= 39.4 nmnnLLhhL L = 9.3 nm= 9.3 nm
SolSol--GelGelnnwwhhw w = 28.9 nm= 28.9 nmnnLLhhL L = 18.5 nm= 18.5 nm
nnLLhhLLnnwwhhww
n = Number of Layersn = Number of Layersh = Layer Thicknessh = Layer Thickness
Tunable CavityTunable Cavity
RemoveRemovetemplatetemplateCoatingCoating CoatingCoating
Hollow TiOHollow TiO22 NanoparticlesNanoparticles
40 nm 10 nm
100 nm
100 nm 10 nm
Hollow Nanoparticle CharacterizationHollow Nanoparticle Characterization
1010 2020 3030 4040 5050 6060 7070 80802 2 θθ, degrees, degrees
(a) Calcined at 600 (a) Calcined at 600 ººCC
(b) Calcined at 525 (b) Calcined at 525 °°CC
(c) Cellulose template(c) Cellulose template
EDSEDS XRDXRD
Hollow Titania SpheresHollow Titania Spheres
Cavity sizeCavity sizeCrystallite sizeCrystallite sizeCrystal phaseCrystal phasePorosityPorosityShell thicknessShell thickness
TBTTBTMicrogelMicrogelAOTAOT
CalcinationCalcination
SolSol--gel Method for Preparing gel Method for Preparing Hollow TiOHollow TiO22
200 nm 200 nm
ConclusionConclusion
•• Particle shape of hollow TiOParticle shape of hollow TiO22 can be can be tunedtuned
•• Cavity shape can be tunedCavity shape can be tuned•• Tools available to control morphology of Tools available to control morphology of
hollow TiOhollow TiO22 spheresspheres•• Effect of morphology on opacifying Effect of morphology on opacifying
power will be studiedpower will be studied
AcknowledgementsAcknowledgements
•• Drs. Q. Sun, Z. Yan, Y. ZhouDrs. Q. Sun, Z. Yan, Y. Zhou•• N. Sanders from Specialty MineralsN. Sanders from Specialty Minerals•• R. Johnson & F. Vanhecke from DupontR. Johnson & F. Vanhecke from Dupont•• IPST at Georgia TechIPST at Georgia Tech
Center for Nanoscience Center for Nanoscience and Nanotechnology and Nanotechnology
