What is Materials Chemistry - Springer

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MATERIAL MATTERS

Wha t is MaterialsChemistry

Xiaoyu

e Xiao

Examinin

g the Question I n

the past 10 years, materials chemistryhas attracted worldwide interest as a newand important interdiscipline resultingfrom the confluence of two streams:chemistry, and materials science and engi-neering. Materials chemistry is clearly anemerging subdiscipline, related to bothchemistry and materials

science; however,the exact definition of materials chemistryremains a question.

L.V. Interrante in 1992referred to materials chemistry as "chem-istry directed at the preparation, process-ing, and analysis of materials.

1

This was acommon viewpoint at that time whichshould be developed further as researchin this area flourishes.

I am fortunate to be involved inresearch and teaching of materials chem-istry, but at th e same time I am somewhat perplexed . In 1994 I was asked to start a cours e called "Materials Chemistry" for senio r students in the Department of

Material

s Science and Engineering at

Tsinghu

a University. When I entered the classroo m the first question I was asked wa s "What is the definition of materials chemistry? " Since no textbook was avail-able, I faced difficulty preparing lectures an d my students had difficulty learning th e subject. The only choice I had was to reorganiz e part of the contents of New

Directions

in Solid State Chemistry 2 and suppl y

some review articles.With littlesatisfaction after one semester, I realizedthe urgent need for a real textbook onmaterials chemistry and for a satisfactorydefinition of that term.

T o understand the concept of materialschemistry, we can review the definitions ofchemistry and of materials. Chemistry is define d as "the science that deals with the compositio n of properties of substances,"3 an d focuses traditionally on atomic and molecula r interactions, that is, study at the microscopi c level. On the other hand, material s are "the substance or substances ju t of which a thing is constructed," 3 that s , study at the macroscopic level, traditionally , several well-established sub- irea s of chemistry are involved in materi- il s study, for example solid state chem- stry , surface chemistry, and polymerchemistry. Each has its own direction and specifi c emphasis. Among these subareas, th e definition of solid state chemistry seem s to be closest to that for materials chemistry . In 1986 C.N.R. Rao and J.

Gopalakrishna

n defined the latter as fol- lows : "Solid state chemistry deals with a variet y of solids, inorganic as well as organic ; the solids can be crystalline or non-crystalline....I t is mainly concerned wit h the development of new methods of synthesis , new ways of identifying and characterizin g materials and of describing thei r structure, and above all, with new strategie s for tailor-making materials with desire d and controllable properties...."2 Here , synthesis, characterization, and pro- cessin g for controllable properties of mate- rial s are emphasized. This definition is simila r to that of Interrante's. Th e Traditional Role of Chemistry in

Material

s Science A s

a new subdiscipline, materials chem-istry must have its own characteristics,and must differ from those of other subar-eas of chemistry, especially from solidstate chemistry. Actually, the origin ofmaterials chemistry results from the evo-lution of chemistry in materials science ascatalyzed b

y the development of modern hig h technologies. Th e earliest studies in materials science wer e concerned with earth materials,4 that is , minerals and stones. In fact, civilization starte d with the utilization of stone as tools . With the development of science an d technology, the stone age progressed t o the bronze age, the iron age, the porce- lai n age, the polymer age, and so on. Durin g this evolution, chemistry played a n important role. 5 Generally, the role of chemistr y in materials science can be briefl y described as follows: New materi- al s are synthesized and characterized, thei r properties are identified by the disci- I

Materia

l

Matters is a forum forexpressing personal points ofview on issues of interest to thematerials community.

plin e of physics, and new products aremade throug h engineering design and processin g (Figure 1). Th e importance of chemistry (including synthesi s and characterization) in materi- al s science can be seen in this figure. J.L. Warre n and T.H. Geballe pointed out in 198
0 that the level of sophistication of material s science in a country is reflected i n its level of synthesis and characteriza- tion , which in turn can be measured by th e number of articles published in theJournal of Solid State Chemistry. 6

Material

s Chemistry: An Interdiscipline

Chemistr

y

became more and moreimportant in materials research and devel-opment as the world entered into thehigh-technology era, which is based onadvanced materials. Competition in hightechnology

relies greatly on developmentsin materials science and engineering.Therefore progress in the twenty-first cen-tury cannot be separated from develop-ment

and utilization of new materials in suc h areas as bioengineering, information, energy , space, and oceanography. Th e important position of materials sci- enc e in this high-tech era requires the mergin g of chemistry with materials sci-ence. As a result new chemistry subareas an d methods have been developed for material s study, for example, sol-gel, chemica l vapor deposition, sonochem- istry , shock-wave chemistry, microwave chemistry , magnetic-field chemistry, microgravit y chemistry, and soft chem- istr y such as intercalation, redox insertion, dr y extraction, grafting and pillaring, exfoliatio n reactions, and ion exchange.

Severa

l important events in the last 10 year s have encouraged chemists to becom e involved in materials research. • In 1986, at the Spring Meeting of the

Material

s Research Society, the contribu- tion s of chemistry to materials research wer e clearly evident. In fact, someone said , "Physics has had its crack at ceram-ics, now let chemistry have its turn." As a result , MRS published a proceedings enti- tle d Better Ceramics Through Chemistry. A serie s of proceedings with the same titlehas been published in the following years. • At almost the same time, J.G. Bednorzand K.A. Miiller at IBM Laboratory report-ed the discovery of perovskite Ba-La-Bu-Osuperconductor. 7

In 1987, the AmericanChemical Society (ACS) held its 194thmeeting where chemists focused on suchtopics as "Chemistry of High-TemperatureSuperconductors."

8

Chemists made sub-stantial and even unique contributions toall aspects of oxide superconductors,including surfaces and interfaces, process-ing and fabrication, and applications.

/IR S BULLETIN/DECEMBER 1996

MATERIAL MATTERS

Chemistr

yEngineering ^ "^^

Product

s ) - i

Material

s Science Figure 1. A view of materials science as built on chemistry, physics, and engineering.

Material

s

Chemistr

y

Evaluatio

n &

Feedbac

k

Material

s

Scienc

e Figure 2. The functions of materials chemistry in materials science. • The collaboration of chemists H.W. Krot o (University of Sussex) and R.E.

Smalle

y (Rice University) led to the dis- cover y of carbon-60 Buckminsterfullerene i n 1985." [Editor's note: Kroto, Smalley,
an d R.F. Curl Jr. (Rice University) just receive d the Nobel Prize for their work on fullerenes. ] In 1990 solid carbon-60 crys- tallite s were obtained in the laboratory by W . Kratschmer et al.; 1 0 this discovery resulte d in a global research wave.

Subsequently

, new materials such as graphit e and WS 2 buckminster micro- tubes , and met-car Ti g C 1 2 have also been reported. 11 " 1 3 I n response to the emerging subdiscipline o f materials chemistry, ACS began publish- in g the journal Chemistry of Materials in 1989
, and the Royal Society of Chemistry introduce d the journal of Materials Chemistry i n 1991. ACS has also established a Materials

Chemistry

Secretariat to coordinate academic activitie s in materials chemistry. In 1992 asymposium on materials chemistry was ini-tiated by

ACS in which various topics relat-ed to materials chemistry are discussed. In1993 a special meeting named "Interna-tional Meeting on Chimie Douce: SoftChemistry Routes to New Solids" was heldin Nantes, France. Meanwhile, the Interna-tional Union of Pure and Applied Chem-istry (IUPAC) published a book entitled

Chemistry

of Advanced Materials as part of th e

IUPAC monograph series on Chemistryfor the 21st Century. After its Meeting onAdvanced Materials for Innovations inEnergy, Transportation, and Communica-tions held in

Tokyo in 1987, IUPAC is goingto focus its CHEMRAWN IX Meeting inSeoul in 1996 on The Role of AdvancedMaterials in Sustainable Development.

Th e

inevitable outcome of the impact ofchemistry on materials science is theemergence of "materials chemistry" as aninterdiscipline that differs from the tradi-tional role of chemistry in materials sci-ence (Figure 1). Materials chemistry hasbecome involved in every corner of mate-rials science with important and evenunique contributions (Figure 2), and hasbecome one of the most active and excit-ing areas in materials science.

A

merging of chemistry and materialsscience clearly leads to the generation ofmaterials chemistry, which bridges thegap between microscopic and macroscop-ic studies of substances. When we cite"materials chemistry," we refer to thestudy of materials (the goal) at macro-scopic levels through chemistry routes(the way) at microscopic levels, thusincluding all chemical aspects of materialsstudy. Thus the definition of materialschemistry can be given as follows:

Materials

chemistry extends from atoms and molecules to useful substances that are achieved with design, synthesis, processing, modification, characterization, property pre- diction, and control of materials through chemistry routes.

Reference

s 1 . L.V. Interrante, MRS Bulletin XVII (1) (1992) p. 4. 2 . C.N.R. Rao and J. Gopalakrishnan, Eds., New

Directions

in Solid State Chemistry (Cambridge

Universit

y Press, London, 1986). 3 . G.D. Pimentel, Ed., Opportunities in Chemistry (Nationa l Academy Press, Washington, 1985). 4 . R.C. Ewing and A. Navrotsky, MRS Bulletin XVI I (5) (1992) p. 19. 5 . L.V. Interrante, L.A. Caspar, and A.B. Ellis, Eds. , Materials Chemistry, An Emerging Discipline (America n Chemical Society, Washington, 1995). 6 . J.L. Warren and T.H. Geballe, Mater. Sci. Eng. 5 0 (1981) p. 149. 7 . J.G. Bednorz and K.A. Muller, Z. Phys. B 64 (1986 ) p. 189. 8 . D.L. Nelson, M.S. Whittingham, and T.F.

George

, Eds., Chemistry of High-Temperature

Superconductors

(American Chemical Society,

Washington

, 1987).
9 . H.W. Kroto, J.R. Health, S.C. O'Brien et al.,

Nature

318 (6042) (1985) p. 162.
10 . W. Kratschmer, L.D. Lamb, and K.

Fortiropoulo

s et al., Nature 347 (6291) (1990) p. 354. U.S . Iijima,Nature354 (6348) (1991)p.56. 12 . R. Tenne, L. Margulis, and M. Genut, et al.,

Nature

360 (6403) (1992) p. 444.
13 . Z.Y. Chen, G.J. Walder, and A.W. Castleman, Jr. , /. Phys. Chem. 96 (23) (1992) p. 9581.

Xiaoyue

Xiao is an Associate Professor at the Department of Materials Science and

Engineering,

and the Deputy Director of the State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University. He received his PhD degree in inorganic chem- istry at Purdue University in 1992. His research interest lies in functional ceramics and materials chemistry. E-mai l Letters to the Editor to bulletin@mrs.org. MR S BULLETIN/DECEMBER 1996