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E u r o S c i C o n C o n f e r e n c e o n

Chemistry

2018

Chemistry 2018

Journal of Organic & Inorganic Chemistry

ISSN 2472-1123

F e b r u a r y 1 9 - 2 0 , 2 0 1 8

P a r i s , F r a n c e

Page 23

W

e classify macroscopic amounts of matter according to various

concepts, as metals, semiconductors, insulators, atoms, molecules,

complexes, polymers, and so on. Each of these terms triggers a specific

image that has a consistent meaning throughout the scientific community. But

which of these describe adequately an isolated nanocluster like Pt13? We use

Newtonian mechanics to describe the frictionless, periodic motion of a system

consisting of a few particles, and we can give trajectories and the momentum

of every particle at each instant of time. In contrast, systems consisting of

large numbers of particles are treated thermodynamically as ensembles

in which the information of individual particles is lost and available only as

a statistical average. Spontaneous processes occur under heat dissipation,

are not normally periodic and approach an equilibrium characterized by a

minimum in free energy. Is Newtonian mechanics or thermodynamics more

appropriate for treating nanoclusters? Many of the concepts that we use to

describe macroscopic amounts of matter break down for nanomaterials.

Metals turn into semiconductors and insulators; phase transition temperatures

shift dramatically, and the transitions broaden and disappear completely so

that the Gibbs phase rule loses its meaning. Heat and temperature that are

normally understood to represent kinetic energy are no longer well defined.

According to traditional definition we may find that a small system cools down

instead of heating up when we deposit more energy on it, pretending a negative

heat capacity. Small systems are getting increasingly relevant in chemistry and

physics, e.g. in catalysis, molecular electronics or energy devices. It is here

where one starts to find amazing and perhaps disturbing phenomena, and

these are becoming a hot field of research. Even in an expected thermodynamic

system one may find quantum phenomena. The question comes up how we

manage the transition between unexpectedly incompatible descriptions.

Biography

Emil Roduner studied Chemistry at the University of Zürich and

at the Rensselaer Polytechnic Institute in Troy, NY. In 1988, he

was awarded the Werner Prize by the Swiss Chemical Society

for developing muon spin resonance to a universal method

for studying structure and reaction behaviour of free radicals.

During 1995-2012 he held a Chair of Physical Chemistry at the

University of Stuttgart. After retirement he accepted a part-time

Professorship at the University of Pretoria in South Africa. He

wrote an advanced textbook,

“Nanoscopic Materials: Size-De-

pendent Phenomena and Growth Principles”

(RSC, 2014). His

research interests include studies on structure, size-effects and

magnetism of platinum nano-clusters and dynamics of mole-

cules in the pores of zeolites, mechanisms of elementary steps

in catalysis, kinetic isotope effects, degradation and proton

conductivity of fuel cell polymer membranes. In South Africa, he

is working on the electrochemical conversion of CO2 to liquid

fuels using solar energy.

e.Roduner@ipc.uni-stuttgart.de

Nanomaterials: in between traditional concepts of understanding

matter

Emil Roduner

University of Stuttgart, Germany

Emil Roduner, J Org Inorg Chem 2018, Volume: 4

DOI: 10.21767/2472-1123-C1-002