This document summarizes various methods for synthesizing liquid crystalline nanoparticles and arranging them into organized structures. It discusses techniques like the Brust-Schiffrin method for producing gold nanoparticles, seed-mediated growth for rods and branches, and templating methods using liquid crystals. Reverse templating and self-assembly are described for controlling nanoparticle shape and arrangement. Decorating nanoparticles with liquid crystalline ligands can induce mesophase formation and one-dimensional ordering. The document concludes that tailoring nanoparticle properties through shape, size, composition and self-assembly has applications in areas like sensing, catalysis and drug delivery.

1. Nitya Singh
1
O master!
Thou art the real goal of human lif
We are yet but slaves of wishes,
Putting bar to our advancement ,
Thou art the only God & power
To bring us upto that stage.
-Amen

2. SYNTHESIS USING LC’S
• Lyotropic LC’s as surfactants and phase transfer
agents :
 The Brust-Schiffrin method:
1. Synthesis of monolayer-protected clusters.
2. Mainly production of stable functionalized spherical
nanoparticals .
3. Size: 1-5nm.
4. It’s includes continuous nucleation, growth &
capping of particles.
5. Shape can be controlled by changing reducing agent,
stabilizer concentration, structure of surfactants.
2

3. • Phase transfer
H+ AuCl4- (aq)+ (R 8)4N+ Br- (org) (R8 )4N+ AuX4- (org) + HX (aq)
• Seperation of two phases and reduction of Au(III) to Au(I)
(R8)4N+AuX4 - + 3RSH -(AuSR)n- + RSSR + (R8)4N+ +4X
- + 3H+
• Reduction with NaBH4 :
-(AuSR)n- + BH4-+ RSH + RSSR Aux (SR)y
(R8 )4N+ AuX4- + BH4- + RSH + RSSR Aux(SR)y
3
Langmuir 2013, 29, 9863-9873

4. 4
www.researchgate.net/figure/51652237_fig21_Figure-1-Scheme-1-The-one-and-two-phase-Brust-Schiffrin-method-for-the-synthesis-
Langmuir 2013, 29, 9863-9873

5.  Seed mediated growth method:
1. Heterogeneous Nucleation Process
2. Nanoporous membrane based techniques.
3. Shape specific nanoparticles are formed depending on
shape directing agents (LLC’s).
4. Synthesis:
• Spherical nanoparticals of 3.5nm diameter are produced
using hydride reduction. (As Seeds)
• Transfered in solution containing CTAB along with the
seed source.
• Addition of Sodium hydroxide along with Ascorbic acid
and CTAB gives longer nanorods.
5

6. 6
Inorganic Chemistry, Vol. 45, No. 19, 2006

7. 7
http://pubs.rsc.org/en/content/articlehtml/2013/cs/c2cs35367a
CTAB- Cetyltrimethylammonium
bromideExamples: gold, silver, tellurium ,selenium nanorods.

8. http://www.ece.rochester.edu/courses/ECE580/docs/metal_nano_Gao.pdf
TEM image ,From A-D:
Increasing concentration of CTAB and Silver
nitrate.
TEM images of branched Au
Nanoparticles, varing dimension and
number of branches:
(dependent on shape of the seeds
formed).
A-tetrapods.
B-star shaped
C-larger terta-pods
D-multipods
E-multipods
8

9. 9
Dodecyltrimethylammonium bromide-
DTAB
nanophotonics.spiedigitallibrary.org

10. TRUE LIQUID CRYSTAL TEMPLATING:
1. Synthesis of mesoporous nanostructures.
2. We get porous inorganic replicates of the parent LLC
upon calicination (hardcopy of original phase).
3. The liquid continuous phase can be composed of
siliceous material or an aqueous metal salt.
10

11. http://pubs.rsc.org/en/content/articlehtml/2012/sm/c1sm06526b
11

12.  Production of materials with uniform pore size,
morphology, 3D distribution.
 Additional advantage is the pore size can be increased
through addition of a hydrophobic component due to
expansion of the interiors of the micelles.
 Examples: CdS & CdSe composites, Pt/Ru alloys, Ni/Co
alloys.
12
Phil. Trans. R. Soc. A (2006)

13. 13

14. REVERSE TEMPLATING:
• LLC’s acts as a nanosupport or “nanoreactors”.
• Controlling type of liquid crystalline phase one may
control the size and shape of nanoparticles grown within.
• Preparation of these nanoreactors is easily reproducible &
can be generated in large volume.
• Synthesis of metallic NPs, nanostructured conducting
polymers.
• Synthesis-
a) Metal salt mixed with an appropriate amount of liquid
crystalline host such that desired LLC phase is formed.
b) Precipitation is induced with aggregation of clusters
c) Forms single nanostructures. 14

15. http://iopscience.iop.org/article/10.1088/0957-4484/17/13/007/pdf
. Formation of ZnSe quantum dots in the spherical nanodomains of PEO–
PPO–PEO/water/p-xylene reverse liquid crystals. (a) Mechanism of
formation
. Growth of ZnSe nanolaminates. (a) Mechanism of formation. (b) TEM image of ZnSe
nanoplates synthesized in a lamellar liquid crystal 15

16. • Columnar phase forms rod-like nanostructurs.
• Cubic and lamellar form spherical or disc-like
nanostructures.
• Lamellar LLC-roughly spherical 5.0nm particle.
• Hexagonal LLC- arrow shaped rods -100nm wide &
250 nm long.
16
Examples: nanowires of: Ag, ZnS, CaSO4,Cu, BaSO3.
Spherical NPs of :Bi, Pd, PbS,KMnF3, CoFe2O4.

17. SELF ASSEMBLY OF LIQUID CRYSTALLINE
NANOPARTICLES
• Arrangement of metallic, magnetic or semi conducting
NPs to self assemble to larger structures preferred due
to low cost and high yield.
• Properties of NPs depend on their arrangement and
response to external stimuli.
• Manipulation of the self assembled arrays required
using molecular recognition and supramolecular
techniques.
• For a NP to exhibit thermotropic LC phase, they need to

18. LIQUID CRYSTALLINE DISC SHAPED
NANOPARTICLES
• Disc shaped CuS
nanoparticles
arrange to
columnar hcp
packed structures
Nano Lett.,6,2959 (2006)

19. LIQUID CRYSTALLINE NANORODS
• Thermotropic nematic and cubic phases by coating
needle-shaped
α-Fe2O3 and SiO2-coated Fe3O4 nanorods or -platelets
JACS, 127, 11578 (2008)

20. LIQUID CRYSTALLINE NANORODS
• Rod shaped nanoparticles in concentrated dispersions
and in evaporated films show liquid crystal ordering.
Nano Lett., 2, 557 (2002)

21. LC DECORATED NANOPARTICLES
• Decorating small, spherical nanoclusters with thermotropic
mesogenic or pro-mesogenic molecules is required to assemble
spherical NPs.
• For gold nanoparticles, alkyl thiolated liquid crystals can modify the
surface. • Mesophase confirmed by DSC and
Polarising Optical Microscope.
• 1D arrangement of functionalised
Au nanoparticles observed by
TEM and XRD.

22. • It was observed by grazing small angle X ray diffraction that
GNPs arrange to rhombohedral or hexagonal columnar phase.
Adv. Mater., 2009, 21, 1746–
1750.

23. MIXED MODIFICATION OF AU NPS:
SYNTHESIZED BY LIGAND EXCHANGE REACTION WITH
FUNCTIONALISED THIO ALKYL CHAINS .
EXHIBITS BOTH SMECTIC AND COLUMNAR LIQUID CRYSTAL
PHASES
Chem. Soc. Rev., 2011, 40, 306–
319

24. TRIPHENYLENE COVERED GOLD IN A
COLUMNAR MATRIX
• Triphenylene covered GNP showed random arrangement while
dispersing through a media of columnar discotic liquid crystals.
• Increase in electric conductivity is seen in this system.
Soft Matter, 2007, 3, 896–
900

25. • Arrangement of Au NPs functionalised with triphenyl derivatives.
• The self assembly of the particles depends on size of AuNP, length
of alkyl chains, extent of π-π interactions and solvent hydrophillicity
J. Am. Chem. Soc., 2007,129, 14271–
14280

26. CONCLUSION
• Tailoring properties of NPs by tuning shape,size and composition.
• Self assembly promoted by coating NPs with mesogenic ligands.
• Mesophase formation is not guaranteed by functionalisation by a
ligand.
• Future prospects: 'nanoreactors', single electron microelectronics,
sensing, catalysis, drug delivery.
26

27. REFERNCES:
• Beilstein J. Org. Chem. 2012, 8, 349–370.
• Journal of Inorganic and Organometallic
Polymers and Materials,2007, Vol. 17.
• Chem. Soc. Rev., 2011, 40, 306–319
• Langmuir 2013, 29, 9863−9873
27

28. 28