Table Of ContentSoap, science, and fl at-screen TVs
This page intentionally left blank
Soap, science, and
fl at-screen TVs
(cid:1)
A history of liquid crystals
David Dunmur
Tim Sluckin
1
3
Great Clarendon Street, Oxford ox2 6dp
Oxford University Press is a department of the University of Oxford.
It furthers the University’s objective of excellence in research, scholarship,
and education by publishing worldwide in
Oxford New York
Auckland Cape Town Dar es Salaam Hong Kong Karachi
Kuala Lumpur Madrid Melbourne Mexico City Nairobi
New Delhi Shanghai Taipei Toronto
With offi ces in
Argentina Austria Brazil Chile Czech Republic France Greece
Guatemala Hungary Italy Japan Poland Portugal Singapore
South Korea Switzerland Thailand Turkey Ukraine Vietnam
Oxford is a registered trade mark of Oxford University Press
in the UK and in certain other countries
Published in the United States
by Oxford University Press Inc., New York
© David Dunmur and Tim Sluckin 2011
The moral rights of the authors have been asserted
Database right Oxford University Press (maker)
First published 2011
All rights reserved. No part of this publication may be reproduced,
stored in a retrieval system, or transmitted, in any form or by any means,
without the prior permission in writing of Oxford University Press,
or as expressly permitted by law, or under terms agreed with the appropriate
reprographics rights organization. Enquiries concerning reproduction
outside the scope of the above should be sent to the Rights Department,
Oxford University Press, at the address above
You must not circulate this book in any other binding or cover
and you must impose the same condition on any acquirer
British Library Cataloguing in Publication Data
Data available
Library of Congress Cataloging in Publication Data
Data available
Typeset by SPI Publishing Services, Pondicherry, India
Printed in Great Britain
on acid-free paper by
CPI Antony Rowe, Chippenham, Wiltshire
ISBN 978–0–19–954940–5
1 3 5 7 9 10 8 6 4 2
(cid:1)
Contents
Preface vii
Science and history: the two cultures – A note to readers xiii
1 It’s all Greek to me: an introduction 1
2 Crystals that fl ow: fact or fi ction 17
3 Liquid crystals, where do they come from? 41
4 La Gloire Française 63
5 The meeting that wasn’t and the meeting that was 91
6 The threads of life 119
7 The winds of war 143
8 Renaissance 167
9 An unlikely story 193
10 The light dawns in the West 209
11 The sun rises in the East 235
12 The new world of liquid crystal materials 251
Glossary 2 85
Timeline of events in the history of liquid crystals 2 93
Chapter notes 297
Bibliography 3 07
Acknowledgements for fi gures and photographs 3 23
Index 3 25
This page intentionally left blank
(cid:1)
Preface
LCD TV is a short-hand description that will be recognized by many,
but understood by few. Modern methods of communication demand
shorthand txts and acronyms, and these come close to constituting a
new form of language. It is for others to decide whether such develop-
ments enhance or diminish the effi cacy of communication. But, what-
ever the message, the medium through which this new language is
transmitted and received is, more often than not, an LCD: a liquid crys-
tal display.
This is the entry point for the general public to liquid crystal science,
but for the authors it represents just one outcome of more than a century
of scientifi c investigation into a remarkable form of matter. Our title of
Soap, science, and fl at-screen TVs is a whimsical description of the
breadth of liquid crystal science, which indeed embraces soaps and
LCDs, but also includes living cells and new materials.
Our inspiration, like that of many others, derives from the Greeks. It
was Aristotle who divided up the natural world into earth, water, air, and
fi re. The fi rst three of his elements survive as exemplars of our more
rigorous description of states of matter as solid, liquid, and gas. This
aspect of Aristotelian science has survived until the present day, while
it was only a couple of hundred years ago that Aristotle’s fourth element
of fi re as a separate substance was fi nally abandoned.
This categorization of the material world into gases, liquids, and
solids lasted as an adequate representation of the universe until the
beginning of the twentieth century. Then an age of enlightenment began
to dawn, and it become clear that things were not quite so simple or
clear cut. The three classical states of matter no longer suffi ced.
Now, if you search the internet, you will fi nd the fourth state of mat-
ter described as a plasma—a gas of positively charged atoms in a sea of
electrons. Do not be deceived. This is simply the gaseous equivalent of
a metal, and it is not very common. On earth, plasmas can be found in
the glass envelopes of fl uorescent lights and in the picture elements of
some large-area television sets. Only in the heavens will plasma be
commonly encountered, in the form of the northern (or southern) lights,
or in stars, galactic trails, and other astronomical phenomena, but on
our planet, there are no free-standing plasmas.
viii Preface
Liquid crystals, on the other hand, are indeed a terrestrial fourth
state of matter. We shall present the scientifi c story of liquid crystals in
this spirit. They take their place naturally in the scale of things, being
something like solids and something like liquids, but different in essence
from both. As such, liquid crystals contribute to many aspects of our
world, but for the present generation of consumers, liquid crystals will
be recognized as the materials of displays. Mobile phones, cameras,
iPods, laptops, TVs, cars, as well as all manner of domestic and scien-
tifi c equipment all employ a liquid crystal screen to display information
or images. The ultimate manifestation of the liquid crystal display, or
LCD as it has become known, is the large-area fl at screen colour televi-
sion. Today the LCD is ubiquitous and has had a similar impact on
human life as the discovery of the wheel. Small wonder that we think
liquid crystal displays are important.
Liquid crystals were missed by the Greeks because they do not read-
ily proclaim their existence. They can be identifi ed only by those with
skill and experience, but they are abundant in nature. In particular, liq-
uid crystals are to be found in living things. Animals and plants consist
of cells, and cells function because they are surrounded by a liquid crys-
tal membrane. It might not always have been so, but the formation of
liquid crystal membranes was a crucial step in the evolution of cellular
life. Our liquid crystal scientists made the connection between liquid
crystals and life at a very early stage. Indeed some of them thought they
had discovered the secret of life. It was not to be, but, as we will show,
liquid crystals are nevertheless an important component of living
organisms.
The science of liquid crystals began more than a century ago with a
baffl ing observation of two melting points in a single pure substance by
a German botanist (Friedrich Reinitzer). The botanist passed his results
to a physicist (Otto Lehmann), who realized that he was studying
something interesting, but misidentifi ed the physical phenomenon as
crystalline in origin. Despite his misidentifi cation, Lehmann gave us a
name that stuck, l iquid crystals , and our subject was born. Later, a
combative French crystallographer (Georges Friedel) realized that the
materials were not crystals at all, but special liquids, albeit exhibiting
some properties akin to those of crystals, and put the subject on a fi rmer
footing.
The early story of liquid crystals involves botanists, chemists, physi-
cists, mineralogists, and mathematicians, mainly from Europe, who pur-
sued their interests through a turbulent period of history involving wars
(the Great War and World War II) and revolutions (the birth of commu-
nism and the rise of fascism). The events of history took their toll on our
scientists (Vsevolod Konstantinovich Frederiks published and perished
in one of Stalin’s gulags), but did nothing to stem their fervour or deter-
mination to promote their ideas.
Preface ix
In common with many other physical sciences, liquid crystals ben-
efi ted from a post-war burgeoning in both fundamental science and
applications. The former resulted in a Nobel Prize for one of the scien-
tists involved (Pierre-Gilles de Gennes), while the latter led to the birth
of the multi-billion dollar display industry, and fame and fortune for
other players in the story of liquid crystals.
The origin of our interest in the history of liquid crystals goes back
to an inaugural lecture given by one of the authors (TJS) in March 2000,
celebrating his election to the Chair of Applied Mathematical Physics at
the University of Southampton. The title of this lecture (‘Fluids with
attitude—the story of liquid crystals from oddity to technology’) was an
attempt to review the origins of the science of liquid crystals for a gen-
eral university audience. A specifi c goal was to show how a multibillion
dollar industry developed from Reinitzer’s esoteric observations on
compounds ostensibly extracted from carrots, but a secondary objective
was to explore the personalities of the scientists involved.
A transcript of the original lecture has been published (with addi-
tions by DAD) in Portuguese, under the title F luidos fora da lei ( Fluids
outside the law ). We are grateful to the translator of that work, Dr Paulo
Teixeira, for advice and encouragement in the preparation of this book.
In 2005 the present authors, together with the German liquid crystal
expert and science historian Professor Horst Stegemeyer, published a
source book of the scientifi c history of liquid crystals entitled C rystals
that Flow . That book was a collection of 46 classic papers on liquid
crystal science spanning the period 1888 to 1980, a number of which
had been translated into English by the authors for the fi rst time.
Accompanying the reprinted papers were fi ve chapters of commentary
by the authors to explain the background to the science and scientists,
and set the work in context.
The present volume represents a natural evolution of our desire to
communicate the excitement of liquid crystals to a wider audience.
A volume such as this has required input from many sources. A princi-
pal source has been our earlier book. The many colleagues who
provided advice and guidance concerning material for that volume
have been recorded and acknowledged in the preface to that publica-
tion. We should also record our thanks to academic colleagues with
whom we have interacted over the years, and who have helped to shape
our understanding of liquid crystals.
In this book, the authors have cast the net wider, and it is a pleasure
to thank additional colleagues who have helped us to access and
understand more esoteric material. First and foremost amongst these
must be our co-author of C rystals that Flow , Horst Stegemeyer. Indeed
it was Horst’s enthusiasm and knowledge that caused us to embark on
this historical quest in the fi rst place. Professor Stegemeyer and col-
leagues have established a permanent exhibition on liquid crystals at
