Título: | INFLUENCE OF CAPILLARY CONDENSATION IN NANOSCALE FRICTION | ||||||||||||||||||||||||||||||||||||||||
Autor: |
ROBERT RONALD MAGUINA ZAMORA |
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Colaborador(es): |
RODRIGO PRIOLI MENEZES - Orientador |
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Catalogação: | 27/JUN/2005 | Língua(s): | PORTUGUESE - BRAZIL |
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Tipo: | TEXT | Subtipo: | THESIS | ||||||||||||||||||||||||||||||||||||||
Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=6648&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=6648&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.6648 | ||||||||||||||||||||||||||||||||||||||||
Resumo: | |||||||||||||||||||||||||||||||||||||||||
In this work, the procedures developed to the calibration
of the AFM
photodetector and cantilevers for lateral force
measurements in our AFM is
presented. A Matlab code that controls the microscope
allows the study of the
influence of the normal force on the lateral one. A second
Matlab code was
developed in order to study the adhesion forces in an
automated way. We present
and discuss the influence of the surface free energy on the
friction and adhesion
forces. In this work, the lateral forces were measured at
hydrophilic and
hydrophobic surfaces. It was observed that the nano
asperities may form single
asperity contacts described by the Hertz model as well as
multi-asperity type of
contacts described by the Greenwood model. The nanoasperity
contact may be
controlled by the wettability and ambient relative
humidity. It is seen that the
capillar formed between the tip and the surface influences
the tip-surface normal
force and the friction forces due to the dissipation of
energy caused by the drag or
brake of the capillar meniscous. The effect of capillary
condensation kinetics was
studied as well. It is shown that the surface wettability
is determinant to the
energy dissipation mechanism in nanoscale. The influence of
the surface
wettability on the friction coefficient is presented. The
observed correlation
between the friction coefficient and contact angle enhances
the influence of the
surface wettability and its kinetics in the friction forces
at nanoscale.
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