trunk/tengDissertation/LiquidCrystal.tex

\chapter{\label{chapt:liquidcrystal}LIQUID CRYSTAL}

\section{\label{liquidCrystalSection:introduction}Introduction}
% liquid crystal

Long range orientational order is one of the most fundamental
properties of liquid crystal mesophases. This orientational
anisotropy of the macroscopic phases originates in the shape
anisotropy of the constituent molecules. Among these anisotropy
mesogens, rod-like (calamitic) and disk-like molecules have been
exploited in great detail in the last two decades. Typically, these
mesogens consist of a rigid aromatic core and one or more attached
aliphatic chains. For short chain molecules, only nematic phases, in
which positional order is limited or absent, can be observed,
because the entropy of mixing different parts of the mesogens is
paramount to the dispersion interaction. In contrast, formation of
the one dimension lamellar sematic phase in rod-like molecules with
sufficiently long aliphatic chains has been reported, as well as the
segregation phenomena in disk-like molecules.

% banana shaped
Recently, the banana-shaped or bent-core liquid crystal have became
one of the most active research areas in mesogenic materials and
supramolecular chemistry. Unlike rods and disks, the polarity and
biaxiality of the banana-shaped molecules allow the molecules
organize into a variety of novel liquid crystalline phases which
show interesting material properties. Of particular interest is the
spontaneous formation of macroscopic chiral layers from achiral
banana-shaped molecules, where polar molecule orientational ordering
is shown within the layer plane as well as the tilted arrangement of
the molecules relative to the polar axis. As a consequence of
supramolecular chirality, the spontaneous polarization arises in
ferroelectric (FE) and antiferroelectic (AF) switching of smectic
liquid crystal phases, demonstrating some promising applications in
second-order nonlinear optical devices.

The most widely investigated mesophase formed by banana-shaped
moleculed is the $\text{B}_2$ phase, which is also known as
$\text{SmCP}$.

%Previous Theoretical Studies

\section{\label{liquidCrystalSection:model}Model}

\section{\label{liquidCrystalSection:methods}Methods}

\section{\label{liquidCrystalSection:resultDiscussion}Results and Discussion}
Revision:	2781
Committed:	Wed May 31 04:29:44 2006 UTC (18 years, 1 month ago) by tim
Content type:	application/x-tex
File size:	2297 byte(s)
Log Message:	begin Liquid Crystal Chapter
#	User	Rev	Content
1	tim	2685	\chapter{\label{chapt:liquidcrystal}LIQUID CRYSTAL}
2
3			\section{\label{liquidCrystalSection:introduction}Introduction}
4	tim	2781	% liquid crystal
5	tim	2685
6	tim	2781	Long range orientational order is one of the most fundamental
7			properties of liquid crystal mesophases. This orientational
8			anisotropy of the macroscopic phases originates in the shape
9			anisotropy of the constituent molecules. Among these anisotropy
10			mesogens, rod-like (calamitic) and disk-like molecules have been
11			exploited in great detail in the last two decades. Typically, these
12			mesogens consist of a rigid aromatic core and one or more attached
13			aliphatic chains. For short chain molecules, only nematic phases, in
14			which positional order is limited or absent, can be observed,
15			because the entropy of mixing different parts of the mesogens is
16			paramount to the dispersion interaction. In contrast, formation of
17			the one dimension lamellar sematic phase in rod-like molecules with
18			sufficiently long aliphatic chains has been reported, as well as the
19			segregation phenomena in disk-like molecules.
20
21			% banana shaped
22			Recently, the banana-shaped or bent-core liquid crystal have became
23			one of the most active research areas in mesogenic materials and
24			supramolecular chemistry. Unlike rods and disks, the polarity and
25			biaxiality of the banana-shaped molecules allow the molecules
26			organize into a variety of novel liquid crystalline phases which
27			show interesting material properties. Of particular interest is the
28			spontaneous formation of macroscopic chiral layers from achiral
29			banana-shaped molecules, where polar molecule orientational ordering
30			is shown within the layer plane as well as the tilted arrangement of
31			the molecules relative to the polar axis. As a consequence of
32			supramolecular chirality, the spontaneous polarization arises in
33			ferroelectric (FE) and antiferroelectic (AF) switching of smectic
34			liquid crystal phases, demonstrating some promising applications in
35			second-order nonlinear optical devices.
36
37			The most widely investigated mesophase formed by banana-shaped
38			moleculed is the $\text{B}_2$ phase, which is also known as
39			$\text{SmCP}$.
40
41			%Previous Theoretical Studies
42
43	tim	2685	\section{\label{liquidCrystalSection:model}Model}
44
45			\section{\label{liquidCrystalSection:methods}Methods}
46
47			\section{\label{liquidCrystalSection:resultDiscussion}Results and Discussion}